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This article discusses the use of pharmacological interventions to prevent bleeding in people undergoing fracture fixation or joint replacement surgeries. The authors focus on the use of tranexamic acid (TXA), an antifibrinolytic drug, which has been shown to reduce blood loss and the need for blood transfusions during and after surgery. The Cochrane review included in the article found low-certainty evidence that intravenous TXA reduces the risk of blood transfusion and all-cause mortality. However, the review was limited by the small number of included studies and participants. The article also mentions other studies that support the efficacy and relative safety of TXA, although more research is needed to evaluate its cost-effectiveness. Based on the available evidence, the authors recommend the use of TXA for all patients undergoing fracture fixation surgery, with the exception of those with a known allergy. [Extracted from the article]

Background: Patients with traumatic pelvic ring injury may present with hypotension secondary to hemorrhage. Preperitoneal pelvic packing (PPP) and angioembolization (AE) are alternative interventions for management of hypotension associated with pelvic ring injury refractory to resuscitation and circumferential compression. We hypothesized that PPP may be independently associated with increased risk of venous thromboembolism (VTE) compared with AE in patients with hypotension and pelvic ring injury.Methods: Adult patients with pelvic ring injury and hypotension managed with PPP or AE were retrospectively identified in the Trauma Quality Improvement Program (TQIP) database from 2015 to 2019. Patients were matched on a propensity score for receiving PPP based on patient, injury, and treatment factors. The primary outcome was the risk of VTE after matching on the propensity score for treatment. The secondary outcomes included inpatient clinically important deep vein thrombosis, pulmonary embolism, respiratory failure, mortality, unplanned reoperation, sepsis, surgical site infection, hospital length of stay, and intensive care unit (ICU) length of stay.Results: In this study, 502 patients treated with PPP and 2,439 patients treated with AE met inclusion criteria. After propensity score matching on age, smoking status, Injury Severity Score, Tile B or C pelvic ring injury, bilateral femoral fracture, serious head injury, units of plasma and platelets given within 4 hours of admission, laparotomy, and level-I trauma center facility designation, 183 patients treated with PPP and 183 patients treated with AE remained. PPP, compared with AE, was associated with a 9.8% greater absolute risk of VTE, 6.5% greater risk of clinically important deep vein thrombosis, and 4.9% greater risk of respiratory failure after propensity score matching.Conclusions: PPP for the management of hypotension associated with pelvic ring injury is associated with higher rates of inpatient VTE events and sequelae compared with AE.Level Of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Objective: To evaluate whether delay in the diagnosis of pelvic avulsion fractures in young athletes leads to prolonged treatment and prolonged return toward sport activities, whether fractures at certain locations are associated with a greater risk of diagnostic delay, and what reasons may exist for delay in diagnosis. Design: Retrospective chart review of young patients who presented with pelvic region avulsion fracture to a community-based sports medicine clinic over a 19-year period. Setting: Private practice, primary care sports medicine clinic. Patients: Patients younger than 20 years diagnosed with pelvic region avulsion fracture. Interventions: None, this was a retrospective study. Main Outcome Measures: Clearance for return toward sport activities. Results: Two hundred twenty-five cases were reviewed for reasons for delay in diagnosis; 208 cases met criteria for the duration of treatment and return to play activities portions of the study. The mean time from date of injury diagnosis was 19.59 days, and the mean duration from date of injury to clearance for return to play advancement was 67.20 days. Duration of treatment varied slightly depending on timing of diagnosis, whereas duration from date of injury to clearance for return to play advancement varied greatly depending on diagnostic delay. Those who did not sense a "pop" at the time of injury were more likely to experience diagnostic delay, as were athletes with ischial tuberosity fractures. The most common cause of diagnostic delay was patient/family decision on when to seek care; misdiagnosis as a muscle strain was also common. Conclusions: Diagnostic delay of adolescent pelvic avulsion fractures may unnecessarily prevent athletes from returning to play within an optimal time frame. Our observations highlight a need for educating athletes and their families on when to seek initial or follow-up medical care as well as educating medical providers regarding the diagnosis of pelvic avulsion fractures. [ABSTRACT FROM AUTHOR]

Background: Understanding pelvic anatomy is an important part of education during obstetrics and gynecology residency. Traditional teaching methods to learn pelvic anatomy have obstacles and are often costly.Method: We provide a self-constructed clay pelvic model to aid in the mastery of pelvic anatomy for obstetrics and gynecology residents and to estimate whether building a clay pelvic model would increase residents' confidence and knowledge in pelvic anatomy.Experience: Each resident constructed a clay pelvic model on a bony pelvis, along with the traditional didactic on pelvic anatomy. Demographics of the participants were obtained, followed by a knowledge test and confidence level and satisfaction surveys. Descriptive analysis and Wilcoxon signed-rank test were used for data analysis. Nine residents (three postgraduate year [PGY]-1, one PGY-2, two PGY-3, three PGY-4) completed the knowledge and confidence questions before and after the simulation, along with the satisfaction survey. The median score from the 10 multiple-choice knowledge questions was 50% (30-70%) on the pretest and 70% (40-100%) on the posttest (P=not significant). Although most residents scored higher on the posttest, two residents scored 10% lower. Overall, 66.7% of residents improved their knowledge scores up to 30% after the simulation session. Self-assessed confidence level scores improved from 2-3 to 4 (1, lowest; 5, highest) for all questions asked (P=.010 to approximately .019). A majority of residents responded with 4 or 5 to the satisfaction statements.Conclusion: A low-budget clay pelvic model is easy to build and did increase residents' confidence in pelvic anatomy knowledge and satisfaction. Self-constructing a clay pelvic model would provide an excellent way of reviewing the major landmarks of pelvic anatomy. [ABSTRACT FROM AUTHOR]

Background: Occult instability of lateral compression type-1 (LC1) pelvic ring injuries may be determined with a fluoroscopic stress examination under anesthesia (EUA) performed in the operating room. We hypothesized that LC1 injuries, similar to some fractures of the extremities, could be radiographically stressed for stability in the emergency department (ED). Our primary objective was to determine if stress examination of LC1 fractures could be safely and accurately performed in the ED and could be tolerated by patients.Methods: A prospective, consecutive series of 70 patients with minimally displaced LC1 pelvic injuries (<10-mm displacement on presentation) underwent stress examinations performed by the on-call orthopaedic resident in the ED radiology suite. The stress examination series included static 40° inlet, internal rotation stress inlet, and external rotation stress inlet views. Pelvic fractures that had positive stress results (≥10 mm of overlap of the rami) were indicated for a surgical procedure. These fractures also underwent EUA in order for the 2 techniques to be compared.Results: All patients tolerated the ED stress examination without general anesthetic or hemodynamic instability. Fifty-seven patients (81%) had negative stress results and were allowed to bear weight. All patients with negative stress results who had 3-month follow-up went on to radiographic union without substantial displacement. For the patients with a positive stress result in the ED, the mean displacement was 15.15 mm (95% confidence interval [CI], 10.8 to 19.4 mm) for the ED stress test and 15.60 mm (95% CI, 11.7 to 19.4 mm) for the EUA (p = 0.86). Two patients with a negative ED stress test did not mobilize during their hospitalization and underwent EUA and conversion to a surgical procedure. Thus, a total of 11 patients underwent both stress testing in the ED and EUA; no patient had a positive result on one test but a negative result on the other.Conclusions: ED stress examination of LC1 injuries is a safe and reliable method to determine pelvic ring stability. The displacement measured in the ED stress examination is similar to the displacement measured under general anesthesia. Furthermore, a negative ED stress examination predicts successful nonoperative treatment. Given the results of this study, we encourage the use of stress examination in the ED for LC1-type injuries involving complete sacral fractures only. Widescale adoption of this streamlined protocol may substantially diminish cost, anesthetic risk, and potential operations for patients.Level Of Evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Objective: The objective of this descriptive study was to evaluate pelvic region avulsion fractures in adolescents, including age of injury, location of injury, activity and mechanism at time of injury, treatments used, duration of treatment, and outcomes. Design: This was a retrospective chart review of patients who presented with pelvic region avulsion fracture over a 19-year period. Setting: Private practice, primary care sports medicine clinic. Patients: All patients younger than 20 years of age diagnosed with an acute pelvic region avulsion fracture. Interventions: There was no set intervention protocol. A variety of interventions and combination of interventions were used and determined by the treating physician on a case-by-case basis. Main Outcome Measures: Clearance for return toward sport activities. Results: Of the 242 cases, 162 were male. Soccer was the most common sport at the time of injury, and running/sprinting was the most common mechanism. Males were generally older at presentation and were more likely than females to have anterior inferior iliac spine injuries, whereas females were more likely to have iliac crest avulsions. Conservative treatment was effective in all cases. Males were treated for a shorter duration than females, but this difference was not statistically significant. Conclusions: Pelvic avulsion fractures are a rare injury in adolescent athletes. Males are twice as likely to experience these injuries and are older at presentation compared to females. Conservative management leads to successful outcomes in most cases. [ABSTRACT FROM AUTHOR]

Footnotes 1 I This i CORR Insights® I is a commentary on the article i "Does the SORG Orthopaedic Research Group Hip Fracture Delirium Algorithm Perform Well on an Independent Intercontinental Cohort of Patients With Hip Fractures Who Are 60 Years or Older?" They demonstrated a very good ability to distinguish between those with and without delirium, but the algorithm overestimated who was at a high risk for delirium; the Brier score was only marginally better than assuming everyone had delirium. CORR Insights®: Does the SORG Orthopaedic Research Group Hip Fracture Delirium Algorithm Perform Well on an Independent Intercontinental Cohort of Patients With Hip Fractures Who Are 60 Years or Older? Does the SORG orthopaedic research group hip fracture delirium algorithm perform well on an independent intercontinental cohort of patients with hip fractures who are 60 years or older?. [Extracted from the article]

➤: The proper diagnosis and treatment of patients with concurrent hip and spine pathological processes can be challenging because of the substantial overlap in symptomatology.➤: There is no consensus on which pathological condition should be addressed first.➤: Factors such as advanced spinal degeneration, deformity, and prior fusion alter the biomechanics of the spinopelvic unit. Attention should be paid to recognizing these issues during the work-up for a total hip arthroplasty as they can result in an increased risk of dislocation.➤: In patients with concurrent spine and hip degeneration, the surgeon must pay close attention to appropriate implant positioning and have consideration for implants with enhanced stability to minimize the risk of dislocation.➤: A proper understanding of sagittal balance and restoration of this balance is integral to improving patient outcomes following spinal surgery.➤: The advent of new imaging modalities, increased awareness of spinopelvic mobility, as well as a better understanding of sagittal alignment will hopefully improve our treatment of patients with hip-spine syndrome. [ABSTRACT FROM AUTHOR]

Background: Few investigations of venous tumor thrombus (VTT) in primary pelvic bone sarcomas are available. We aimed to identify the prevalence, associated factors, and prognosis of VTT across different types of pelvic sarcomas and to propose an algorithm for management.Methods: We included 451 consecutive cases of primary, bone-derived, treatment-naive, pelvic sarcomas in this study. Demographic data and the results of initial laboratory tests, imaging examinations, and oncological evaluations were extracted and analyzed. Forty-four cases of VTT were diagnosed with radiographic examinations, and 18 of them were verified histologically.Results: The cohort consisted of chondrosarcomas (41.2%), osteosarcomas (30.4%), Ewing sarcomas (15.5%), bone-derived undifferentiated pleomorphic sarcomas (5.8%), and other bone sarcomas (7.1%). The prevalence of VTT was 9.8% in the whole group, and associated factors included a lactate dehydrogenase (LDH) level of ≥230.5 U/L and invasion of the L5-S1 intervertebral foramen. Patients with pelvic osteosarcoma had a high prevalence of VTT (22.6%), and the associated factors in this group included a chondroblastic subtype, an LDH level of ≥187 U/L, and invasion of the obturator foramen and the L5-S1 intervertebral foramen. Patients with VTT had a poor prognosis with a median overall survival time of 14 months. Subgroup analyses of localized pelvic osteosarcoma indicated that the presence of VTT decreased the median overall survival time (21.5 versus 54.0 months for those without VTT, p = 0.003), median recurrence-free survival time (18.6 versus 32.4 months, p = 0.020), and median metastasis-free survival time (11.2 versus 41.0 months, p < 0.001).Conclusions: VTT is most common in patients with pelvic osteosarcoma as compared with patients with other primary bone sarcomas, and it is associated with several factors. It is a negative prognostic factor. An algorithm for management of pelvic sarcomas with VTT stratified by the classification of the VTT might be beneficial, but further validation is necessary.Level Of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Study Design. Cross-sectional study conducted between December 2017 and October 2019. Objective. To determine the prevalence and risk factors associated with pregnancy-related pelvic girdle pain (PPGP) in Australia. Summary of Background Data. PPGP is a common condition worldwide yet the prevalence and associated risk factors are not known in Australia. Methods. A random sample of pregnant women (N=780) of (mean [SD]) 31 (5) years of age between 14 and 38 weeks gestation attending ante-natal care in a tertiary referral hospital in Sydney, Australia was conducted. The main outcome measure was point-prevalence of PPGP as classified by recommended guidelines including a physical examination. A number of potential risk factors, including socio-demographic characteristics, country of birth, ethnicity, history of low back pain (LBP) and PPGP, family history of PPGP, occupational factors, and physical activity were investigated with logistic regression. Results. The point-prevalence of PPGP in a random sample of 780 Australian women was 44% with the odds of having PPGP increasing with each additional week of gestation (odds ratio [OR]) (OR 1.02). Increasing parity (P=0.03, OR 1.15), country of birth (P=0.03), and greater duration of time spent standing (P=0.009, OR 1.06) were associated with PPGP. The strongest predictors of PPGP were previous LBP and/or PPGP both pregnancy (P<0.001, OR 4.35) and not pregnancy related (P<0.001, OR 2.24), and a family history of PPGP (P<0.001, OR 3.76). Conclusion. The prevalence of PPGP in Australian women was high with almost half the sample classified with PPGP, matching data reported worldwide. The identified risk factors associated with PPGP can be included in routine ante-natal care to screen women and identify those at risk of this common and disabling condition. [ABSTRACT FROM AUTHOR]

Background: Reconstruction after pelvic tumor resection of the acetabulum is challenging. Previous methods of hip transposition after acetabular resection have the advantages of reducing wound complications and infections of the allograft or metal endoprosthesis but were associated with substantial limb length discrepancy. We therefore developed a modification of this procedure, rotation hip transposition after femur lengthening, to address limb length, and we wished to evaluate its effectiveness in terms of complications and functional outcomes.Questions/purposes: In this study, we asked: (1) What were the Musculoskeletal Tumor Society scores after this reconstruction method was used? (2) What complications occurred after this reconstruction method was used? (3) What proportion of patients achieved solid arthrodesis (as opposed to pseudarthrosis) with the sacrum and solid union of the femur? (4) What were the results with respect to limb length after a minimum follow-up of 2 years?Methods: From 2011 to 2017, 83 patients with an aggressive benign or primary malignant tumor involving the acetabulum were treated in our institution. Of those, 23% (19 of 83) were treated with rotation hip transposition after femur lengthening and were considered for this retrospective study; 15 were available at a minimum follow-up of 2 years (median [range], 49 months [24 to 97 months]), and four died of lung metastases before 2 years. No patients were lost to follow-up before 2 years. During the period in question, the general indications for this approach were primary nonmetastatic malignant bone tumor or a locally aggressive benign bone tumor that could not be treated adequately with curettage. There were seven men and 12 women with a median age of 43 years. Nine patients underwent Zones I + II resection, eight patients had Zones I + II + III resection, and two received Zones II + III resection. After tumor resection, rotation hip transposition after femur lengthening reconstruction was performed, which included two steps. The first step was to lengthen the femur with the insertion of an allograft. Two methods were used to achieve limb lengthening: a "Z" osteotomy and a transverse osteotomy. The second step was to take the hip transposition and rotate the femoral head posteriorly 10° to 20°. The median (range) operative time was 510 minutes (330 to 925 minutes). The median intraoperative blood loss was 4000 mL (1800 to 7000 mL). We performed a chart review on the 15 available patients for clinical and radiographic assessment of functional outcomes and complications. Arthrodesis and leg length discrepancy were evaluated radiographically.Results: The median (range) Musculoskeletal Tumor Society score was 21 points (17 to 30). Eleven of 19 patients developed procedure-related complications, including six patients with allograft nonunion, two with deep infection, two with delayed skin healing, and one with a hematoma. Two patients had minor additional surgical interventions without the removal of any implants. Local recurrences developed in four patients, and all four died of disease. All seven patients treated with a Z osteotomy had bone union. Among the eight patients with transverse osteotomy, bone union did not occur in six patients. After hip transposition, stable iliofemoral arthrodesis was achieved in seven patients. Pseudarthrosis developed in the remaining eight patients. The median (range) lower limb length discrepancy at the last follow-up visit or death was 8 mm (1 to 42 mm).Conclusion: Although complex and challenging, rotation hip transposition after femur lengthening reconstruction with a Z osteotomy provides acceptable functional outcomes with complications that are within expectations for resection of pelvic tumors involving the acetabulum. Because of the magnitude and complexity of this technique, we believe it should be used primarily for patients with a favorable prognosis, both locally and systemically. This innovative procedure may be useful to other surgeons if larger numbers of patients and longer-term follow-up confirm our results.Level Of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: In patients undergoing iliosacral resections, pelvic ring reconstruction can maintain stability of the pelvis and spinal column, which is expected to achieve good functional outcomes. However, no optimal reconstruction method has been established. We aimed to analyze the outcome of pelvic ring reconstruction using double-barreled free vascularized fibular graft (FVFG) and internal fixation after iliosacral resections in children.Methods: We retrospectively reviewed 16 children with pelvic Ewing sarcoma who underwent pelvic ring reconstruction using double-barreled FVFG after iliosacral resection. The fibular graft was placed between the supraacetabular region distally and the remaining ilium or sacrum proximally. The stability of the remaining pelvis and spinal column was provided by minimal spinal instrumentation.Results: Eleven Type-I and 5 Type-I+IV resections were performed for 10 boys and 6 girls, who had a mean age of 13.4 years (range, 10 to 18 years). The mean follow-up was 49.8 months (range, 28 to 96 months). At the time of the final follow-up, 14 patients were alive and 2 patients had died of disease. The mean time for bone union was 9 months (range, 6 to 12 months). Graft hypertrophy was evident in all patients at 12 months. The median Musculoskeletal Tumor Society (MSTS) score at the time of the final follow-up was 80% (range, 60% to 96.6%). Seven patients had complications. Three complications required reoperation: 1 deep infection, 1 hematoma, and 1 wound dehiscence. Three patients had disease relapse in terms of lung metastases.Conclusions: This reconstruction method can achieve a high rate of bone union and can provide good functional outcomes following resection of pediatric pelvic Ewing sarcomas with iliosacral involvement. Complications are usually manageable without a need for revision surgical procedures.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Study Design: Finite element analysis.Objective: The aim of this study was to determine the role of biological fusion and anterior column support in a long lumbopelvic spinal fixation.Summary Of Background Data: Retrospective studies have shown that adding anterior column support is not sensitive to construct failure, highlighting that posterior fusion quality may be a more important factor.Methods: Finite element models were created to match the average spinal-pelvic parameters of two patient cohorts reported in the literature: major failure and nonfailure. A moment load was applied at the T10 superior endplate to simulate gravimetric loading in a standing position. Effects of three factors on the biomechanical behavior of a fused spine were evaluated: sagittal alignment; posterior fusion versus no fusion; and anterior support at L4-S1 versus no anterior support.Results: Sagittal balance of the major failure group was positively correlated with 15% higher translation, 14% higher rotation, and 16% higher stress than in the nonfailure group. Simulated posterior fusion-only decreased motion by 32% and 29%, and alleviated rod stress by 15% and 5% and S1 screw stress by 26% and 35%, respectively, in major failure and non-failure groups. The addition of anterior fusion without posterior fusion did not help with rod stress alleviation but dramatically decreased S1 screw stress (by 57% and 41%), respectively. With both posterior fusion and anterior support, screw stress at the S1 was decreased by additional 30% and 6%, respectively.Conclusion: The spinopelvic parameters of the major failure group produced increased gravity load, resulting in increased stresses in comparison to the nonfailure group. Simulated posterior "solid" fusion in the lumbar region helped reduce stresses in both major failure and nonfailure patients. Anterior column support was an important factor in reducing S1 screw stress, with or without posterior fusion, and should be considered for patients with poor alignment.Level of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Background: Osteoporosis is often undiagnosed until patients experience fragility fractures. Pelvic fractures are common but underappreciated sentinel fractures. Screening patients with a pelvic fracture for osteoporosis may provide an opportunity to initiate appropriate treatments such as anti-osteoporosis therapy to prevent additional fractures.Methods: This retrospective cohort review examined the management of osteoporosis after pelvic fractures at a large tertiary care center without an established secondary fracture prevention program. Data were extracted from electronic medical records of all new patients with a pelvic fracture who were ≥50 years of age from this center and its affiliated community hospitals from 2008 to 2014. Outcome measures included the initiation of anti-osteoporosis therapy before the fracture, within the year following the fracture, >1 year following the fracture, or never and new osteoporotic fractures within 2 years after a pelvic fracture.Results: From 2008 to 2014, 947 patients presented with pelvic fractures. Of these patients, 27.1% (257 patients) were taking anti-osteoporosis medications before the fracture. Four percent of treatment-naïve patients began anti-osteoporosis therapy within 1 year of fracture, with 1.2% (11 patients) starting after 1 year. Of the treatment-naïve patients, 92.3% (637 patients) were never prescribed anti-osteoporosis therapy. Treatment rates were consistent over time. Within 2 years, 41.0% (388 patients) developed fragility fractures at secondary sites: 12.0% (114 patients) experienced a hip fracture, and 16.4% (155 patients) experienced a vertebral fracture.Conclusions: Osteoporosis screening and initiation of secondary fracture prevention after a pelvic fracture were inadequate in the study population. Of the patients in this study, 909 (96.0%) never underwent a dual x-ray absorptiometry (DXA) scan during the study period. Of the 690 treatment-naïve patients, 637 (92.3%) were never administered anti-osteoporosis medications. Within 2 years, 41.0% of all patients developed additional osteoporotic fractures. This study demonstrates an opportunity to improve bone health by screening for and treating osteoporosis in patients with a pelvic fragility fracture.Level Of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Case: This is a challenging case of infected native pelvic discontinuity with massive acetabular bone loss. The infection was persistent despite repeated debridement. A new technique of articulated antibiotic spacer plus Mexican hat antibiotic spacer has been used. A triflanged custom-made implant was used in the second-stage surgery. The 2-year follow-up showed no recurrence of infection and no loosening. Conclusion: Using a Mexican hat spacer is a good option when there is a massive bone loss medially. Custom-made triflanged cup showed to be a viable treatment modality for infected pelvic discontinuity despite the cost of the implant. [ABSTRACT FROM AUTHOR]

Background: An understanding of pelvic and acetabular morphology and orientation is required for accurate surgical reconstruction of the hip and spine, as well for component placement in a total hip arthroplasty. Our objectives were to develop an automated system for measuring pelvic and sacral orientations utilizing computed tomographic (CT) scans and to characterize these measures across 200 asymptomatic subjects.Methods: An automated feature recognition algorithm was created to identify acetabular and pelvic orientation across 200 scans generated for non-musculoskeletal conditions. Three-dimensional models were generated from CT data to serve as inputs to the algorithm. Acetabular orientation was defined by comparing a plane fit to the acetabular rim with the anterior pelvic plane. Pelvic inclination, pelvic tilt, and sacral slope were defined as the angles between landmarks identified across the pelvis: pubic tubercles, acetabular center, left and right anterior superior iliac spines, and sacral plate.Results: The mean sacral slope was 36.49°, the mean pelvic tilt was 15.60°, and the mean pelvic incidence was 52.05°. The mean sacropubic angle was 32.48° and the mean pelvic-Lewinnek angle was 8.93°. Significant differences between male and female subjects were observed in the sacral slope (mean difference, 4.72°; p < 0.05), pelvic tilt α (mean difference, 4.17°; p < 0.05), pelvic tilt γ (mean difference, 3.06°; p < 0.05), and the pelvic-Lewinnek angle (mean difference, 1.76°; p < 0.05). The comparison of acetabular orientation measures with those in a prior study of the same cohort yielded intraclass correlation coefficients (ICCs) all above 0.97. The validation of sacral orientation via manual measurement also yielded ICC values all at or above 0.97.Conclusions: Our algorithm showed a high degree of consistency in acetabular orientation measures with respect to a prior study of the same cohort. The measures of pelvic orientation were found to be accurate and reliable when compared with manual measurements of the same data set. All measurements of pelvic orientation were consistent with the means reported in the literature.Clinical Relevance: An accurate and reproducible, automated technique for determining pelvic and acetabular orientation provides a way to characterize these measures as an aid in clinical diagnosis and preoperative planning. [ABSTRACT FROM AUTHOR]

Background: Sacral tumor resections require a multidisciplinary approach to achieve a cure and a functional outcome. Currently, there is no accepted classification system that provides a means to communicate among the multidisciplinary teams in terms of approach, osseous resection, reconstruction, and acceptable functional outcome. The purpose of this study was to report the outcome of sacral tumor resection based on our classification system.Methods: In this study, 196 patients (71 female and 125 male) undergoing an oncologic en bloc sacrectomy were reviewed. The mean age (and standard deviation) was 49 ± 16 years, and the mean body mass index was 27.2 ± 6.4 kg/m. The resections included 130 sarcomas (66%). The mean follow-up was 7 ± 5 years.Results: Resections included total sacrectomy (Type 1A: 20 patients [10%]) requiring reconstruction, subtotal sacrectomy (Type 1B: 5 patients [3%]) requiring reconstruction, subtotal sacrectomy (Type 1C: 104 patients [53%]) not requiring reconstruction, hemisacrectomy (Type 2: 29 patients [15%]), external hemipelvectomy and hemisacrectomy (Type 3: 32 patients [16%]), total sacrectomy and external hemipelvectomy (Type 4: 5 patients [3%]), and hemicorporectomy (Type 5: 1 patient [1%]). The disease-specific survival was 66% at 5 years and 52% at 10 years. Based on the classification, the 5-year disease-specific survival was 34% for Type 1A, 100% for Type 1B, 71% for Type 1C, 65% for Type 2, 57% for Type 3, 100% for Type 4, and 100% for Type 5 (p < 0.001). Tumor recurrence occurred in 67 patients, including isolated local recurrence (14 patients), isolated metastatic disease (31 patients), and combined local and metastatic disease (22 patients). At 5 years, the local recurrence-free survival was 77% and the metastasis-free survival was 68%. Complications occurred in 153 patients (78%), most commonly wound complications (95 patients [48%]). Following the procedure, 154 patients (79%) were ambulatory, and the mean Musculoskeletal Tumor Society (MSTS93) score was 60% ± 23%.Conclusions: Although resections of sacral malignancies are associated with complications, they can be curative in a majority of patients, with a majority of patients ambulatory with an acceptable functional outcome considering the extent of the resection. At our institution, this classification allows for communication between surgical teams and implies a surgical approach, staging, reconstruction, and potential functional outcomes.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective study.Objective: To identify on early postoperative radiographs the risk factors for late distal decompensation in adolescent idiopathic scoliosis (AIS) patients undergoing posterior fusion surgery to L3.Summary Of Background Data: Sparing distal fusion levels in AIS surgery is considered beneficial for postoperative mobility and outcomes; nonetheless, late distal decompensation is of concern. L3 is often advocated as lower instrumented vertebra in posterior fusion, but progressive angulation of the L3/4 disc is commonly observed.Methods: A retrospective analysis was conducted on 78 AIS patients who underwent posterior fusion to L3 from 2007 to 2014. Patients' demographic data, early and 2-year postoperative standing radiographs by biplanar imaging system were investigated. Late decompensation was defined as progressive increase of L3-4 disc wedging angle at 2-year follow-up. Coronal, sagittal, and rotational radiographic parameters were compared between those with and without decompensation. SRS-30 scores were reviewed.Results: Mean age was 14.5-year, and fusion levels averaged 12.0 (range: 6-15); 43 out of 78 patients (55%) experienced progressive L3-4 disc wedging, with 6 showing wedging >5°. L3 translation from the central sacral vertical line (13.9 vs. 11.1 mm, P = 0.13) and increased pelvic tilt (13.3° vs. 8.6°, P = 0.06) on the early postoperative radiograph were associated with increased L3-4 disc wedging. Multivariate analysis revealed that larger pelvic tilt was a significant risk factor for decompensation (odds ratio = 1.1 per 1°, 95% confidence interval: 1.0-1.1, P = 0.04). SRS-30 scores did not differ significantly between the two groups (4.0 vs. 4.1, P = 0.44).Conclusions: Pelvic retroversion and increased translation of L3 from the central sacral line on the early postoperative radiograph were associated with late L3-4 disc wedging in AIS fusions to L3. Careful surgical planning and correction of sagittal alignment are imperative to ensure the long-term outcomes.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Background: Functional reconstruction after resection of pelvic malignancies involving the acetabulum remains challenging. Numerous reconstruction methods have been proposed, but they are generally associated with mechanical and nonmechanical complications. To improve the function of patients with primary malignancies of the acetabulum after internal hemipelvectomy and reduce the complication rate after this procedure, we designed a series of three-dimensionally (3D) printed, custom-made, integrative hemipelvic endoprostheses with a porous structure and wanted to present the early results of using this construct to determine whether it could be considered a reasonable reconstruction option.Questions/purposes: We performed this study to (1) evaluate, in a small group of patients, whether the new endoprosthesis restores short-term lower-limb function; (2) identify short-term complications associated with the use of this endoprosthesis; and (3) assess osseointegration between the host bone and the 3D-printed integrative hemipelvic endoprosthesis with a porous structure.Methods: Between October 2016 and May 2017, our center treated 26 patients with malignancies involving the acetabulum. Thirteen of these patients received hemipelvic replacement with a 3D-printed, custom-made, integrative endoprosthesis, six received hemipelvic replacement with a modular endoprosthesis, four received radiotherapy, and three received external hemipelvectomy. Resection and reconstruction with a 3D-printed, custom-made, integrative endoprosthesis were indicated if the resection margin was the same as that achieved in hemipelvectomy, if reconstruction would preserve reasonable function after resection, if the patient had a good physical status and life expectancy longer than 6 months, and if the patient was willing to accept the potential risk of a 3D-printed, custom-made, endoprosthesis. The exclusion criteria were an inability to achieve a satisfactory surgical margin with limb salvage, inability to preserve the function of the limb because of tumor involvement of the sacral nerve or sciatic nerve, and unresectable and/or widely metastatic disease on presentation. Pain and function were evaluated with the 10-cm VAS score (range 0 to 10; a lower score is desirable), the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score (range 0 to 30; a higher score is desirable), and the Harris hip score ([HHS]; range 0 to 100; a higher score is desirable) were evaluated preoperatively and at a median of 27 months after reconstruction (range 24 to 31 months). The functional scores and complications were recorded after reviewing the patients' records. Osseointegration was assessed with digital tomosynthesis by two senior surgeons. We observed the trabecular structures connected to the implant surface to assess whether there was good osseointegration.Results: The median preoperative VAS score, MSTS-93 score, and HHS were 5 (range 2 to 8), 14 (range 3 to 18), and 64 (range 20 to 76) points, respectively. At the latest follow-up interval, the median VAS score, MSTS-93 score, and HHS were 2 (range 0 to 6), 23 (range 15 to 27), and 82 (range 44 to 93) points, respectively. No deep infection, dislocation, endoprosthetic breakage, aseptic loosening, or local recurrence occurred. Two patients experienced delayed wound healing; the wounds healed after débridement. Using digital tomography, we found that all implants were well-osseointegrated at the final follow-up examination.Conclusions: A 3D-printed, custom-made, integrative hemipelvic endoprosthesis provides acceptable early outcomes in patients undergoing pelvic reconstruction. Osseointegration is possible, and we anticipate this will lead to biologic stability with a longer follow-up interval. The custom-made integrative design ensured precise implantation. Although a few patients in this study had only a short follow-up duration, the functional results were reasonable. We have observed no major complications so far, but this was a very small series and we caution that these are large reconstructions that will certainly result in complications for some patients. Our method uses a precise preoperative simulation and endoprosthesis design to aid the surgeon in performing challenging operations. If our early results are confirmed with more patients and longer follow-up and are replicated at other centers, this may be a reconstruction option for patients with periacetabular malignancies.Level Of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

Supplemental digital content is available in the text. Stress fractures are common among elite ballet dancers whereby musculoskeletal health may be affected by energy balance and overtraining. Purpose: This study aimed to characterize bone health in relation to stress fracture history, body composition, eating disorder risk, and blood biomarkers in professional male and female ballet dancers. Methods: A single cohort of 112 dancers (male: 55, 25 ± 6 yr; female: 57, 24 ± 6 yr) was recruited. All participants underwent bone and body composition measures using dual-energy x-ray absorptiometry. In a subset of our cohort (male: 30, 24 ± 6 yr; female, 29, 23 ± 5 yr), a blood panel, disordered eating screen, menstrual history, and stress fracture history were also collected. Age-matched Z scores and young-adult T scores were calculated for bone mineral density (BMD) and body composition. Independent-samples t -tests and Fisher's exact tests were used to compare BMD, Z -scores, T scores, and those with and without history of stress fractures. A 1 × 3 ANOVA was used to compare BMD for those scoring 0–1, 2–6, and 7+ using the EAT26 questionnaire for eating disorder risk. Regression was used to predict BMD from demographic and body composition measures. Results: Female dancers demonstrated reduced spinal (42nd percentile, 10% T < −1) and pelvic (16th percentile, 76% T < −1) BMD. Several anthropometric measures were predictive of BMD (P < 0.05, r 2 = 0.65–0.81, standard error of estimate = 0.08–0.10 g·cm−2, percent error = 6.3–8.5). Those scoring >1 on EAT26 had lower BMD than did those with a score of 0–1 (P < 0.05). Conclusions: Professional female ballet dancers exhibit reduced BMD, fat mass, and lean mass compared with the general population whereby low BMD and stress fractures tend to be more prevalent in those with a higher risk of disordered eating. Anthropometric and demographic measures are predictive of BMD in this population. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective analysis.Objective: Our goal was to provide a predictive model and a risk classification system that predicts cancer-specific survival (CSS) from spinal and pelvic tumors.Summary Of Background Data: Primary bone tumors of the spinal and pelvic are rare, thus limiting the understanding of the manifestations and survival from these tumors. Nomograms are the graphical representation of mathematical relationships or laws that accurately predict individual survival.Methods: A total of 1033 patients with spinal and pelvic bone tumors between 2004 and 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate Cox analysis was used on the training set to select significant predictors to build a nomogram that predicted 3- and 5-year CSS. We validate the precision of the nomogram by discrimination and calibration, and the clinical value of nomogram was assessed by making use of a decision curve analyses (DCA).Results: Data from 1033 patients with initially-diagnosed spinal and pelvic tumors were extracted from the SEER database. Multivariate analysis of the training cohort, predictors included in the nomogram were age, pathological type, tumor stage, and surgery. The value of C-index was 0.711 and 0.743 for the internal and external validation sets, respectively, indicating good agreement with actual CSS. The internal and external calibration curves revealed good correlation of CSS between the actual observation and the nomogram. Then, the DCA showed greater net benefits than that of treat-all or treat-none at all time points. A novel risk grouping system was established for CSS that can readily divide all patients into three distinct risk groups.Conclusion: The proposed nomogram obtained more precision prognostic prediction for patients with initially-diagnosed primary spinal and pelvic tumors.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Background: The spine-pelvis-hip interaction during postural change should be considered in the functional anatomy of the hip. The component parts of this anatomy and how they influence hip function are important to know. Pelvic incidence (PI) is one of these components. We studied if PI was preoperatively predictive of impingement risk and if it postoperatively influences hip position, which could cause outliers from the functional safe zone of hip replacement.Methods: This was a prospective radiographic study of 187 consecutive patients (200 hips) who had lateral spinopelvis-hip radiographs before and after primary total hip arthroplasty with measurements of the component factors that influence mobility and position of the functional anatomy. The predictive value of PI for risk of impingement of the hip and its postoperative relationship to functional safe-zone outliers were assessed. Forty-one dislocations from our clinical practice were also reviewed.Results: Of 200 hips, the PI was normal in 145 hips (73%), low in 18 hips (9%), and high in 37 hips (19%). Eighty-two hips had spinopelvic imbalance: 12 (67%) of the 18 hips with low PI, 56 (39%) of the 145 hips with normal PI, and 14 (38%) of the 37 hips with high PI. Low-PI hips was the most predictive of the risk of impingement and postoperatively these hips had the most outliers from the functional safe zone.Conclusions: PI is an anatomical component that is predictive of both impingement risk and functional safe-zone outliers. Preoperative risk, based on factors such as the Lewinnek zones and combined anteversion, is an established guide in determining cup position in hip replacement. Low-PI hips that have the "terrible triad" of a posteriorly tilted pelvis, stiff pelvic mobility, and increased femoral flexion therefore have no functional safe zone.Level Of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective case series.Objective: To evaluate the short- and long-term treatment effect (TE) of spinopelvic parameters after surgical correction of adult spine deformity (ASD) utilizing preoperative planning and patient-specific spine rods (PSSRs), and to assess the correspondence between planned and real outcomes.Summary Of Background Data: PSSR have been used in ASD correction for the last decade. However, a TE and predictability of spinopelvic alignment at long-term follow-up has not been studied.Methods: Inclusion criteria: male or female; age more than 20 years; correction of ASD with PSSR; 24-month follow-up (or revision surgery). Studied parameters: sagittal vertical axis; lumbar lordosis (LL); pelvic tilt (PT); sacral slope; pelvic incidence (PI); and PI-LL. The measurement error, TE (the differences between postoperative and preoperative values), standardized TE, and predictability of the studied parameters assessed. The variables included categorical (optimal/nonoptimal) and continuous obtained by direct measurements and weighted by individual optimal values. Statistical significance was set at P ≤ 0.05.Results: Thirty-four patients were included: 56% women; the mean age, 63.4 (standard deviation, 12.7); at each follow-up: 32 at 1 to 3 months, 34 at 11 to 13, and 14 at 23 to 25 with 9 followed to the revision surgery. Strong or moderate TE was shown for sagittal vertical axis, LL, and PI-LL. The TE of PT and sacral slope was less significant and lower than planned. PI was not stable in 18%. The changes of continuous variables were more prominent and statistically significant then categorical. The mean values did not show significant differences between planned and postoperative outcomes except for PT. However, the individual deviations were substantial for all parameters. Significant predictability was shown only for LL and PI.Conclusion: Use of PSSR showed strong and relatively stable TE in ASD during 2 postoperative years. However, improvement of the planning accuracy may contribute to further enhancement of the method's efficacy.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective radioanatomic single-center cohort study.Objective: To investigate sex-specific differences in transsacral corridor dimensions, determine feasibility rates of transsacral screw placement without extended safety zones around planned screw positions, and develop an index defining sacral dysmorphism (SD) irrespective of transsacral corridor diameters.Summary Of Background Data: Previously reported SD definitions used radiologically identifiable pelvic characteristics or predefined minimum diameter thresholds of transsacral corridors in the upper sacral segment including safety zones for screw placement. Technical progress of surgical 3D image guidance improved sacral screw insertion accuracy questioning established minimum diameter threshold-based SD definitions.Methods: Datasets from cross-sectional pelvic imaging of 100 women and 100 men presenting to a general hospital from July 2018 through August 2018 were included in a database to evaluate transsacral trajectory rates, and dimensions of transsacral corridor lengths, widths (TSCWs), and heights (TSCHs) in sacral segments I to III (S1-3). SD was assumed, if no transsacral trajectory was found in S1 with a corridor diameter of at least 7.5 mm.Results: Women presented significantly higher rates of transsacral trajectories in the inferior sector of S1 (P = 0.03), and larger transsacral corridor lengths in S2 (superior sector, P = 0.045), and S3 (central position, P = 0.02). In men, significantly higher feasibility rates were found for the placement of two transsacral screws in S2 (P = 0.0002), and singular screws in S3 (P = 0.006), with larger S1- (P = 0.0002), and central S2-TSCWs (P = 0.006). SD was prevalent in 17% of women, and 16% of men (P = 0.85). Calculating TSCW ratios of S1 and S2 was significantly indicative for SD at values below a threshold of 0.8 in women (P < 0.00001), and men (P = 0.0004).Conclusion: SD is independent of sex despite significant differences in sacral morphology. An index defining SD irrespective of absolute transsacral corridor dimensions is presented to reliably differentiate dysmorphic from nondysmorphic sacra in women and men.Level Of Evidence: 2. [ABSTRACT FROM AUTHOR]

Study Design: Single-center retrospective study.Objective: Investigate how differing degrees of pelvic incidence (PI) modulate the recruitment of pelvic tilt (PT) in response to similar amounts of sagittal malalignment as measured by T1-Pelvic Angle (TPA).Summary Of Background Data: Past research has shown that some patients do not recruit PT in response to sagittal malalignment. Given the anatomic relationship between PI and PT, we sought to determine whether differing PI is associated with variable recruitment of PT.Methods: Single-center retrospective study of 2077 patients undergoing full body radiographs and TPA>10°. Five groups of patients (Very Low, Low, Average, High, and Very High PI) were defined utilizing PI ranges on a Gaussian distribution. Linear regression (LR) evaluated correlation of TPA to PT within each PI group. Multivariate LR evaluated whether correlation between TPA and PT differed between each PI group.Results: Mean PT increased with increasing levels of PI (P < 0.05). Within the full cohort, PT correlated with TPA (r = 0.80, P < 0.001). Multivariate LR revealed significant differences between slopes and intercepts of the linear relationship between PT and TPA within the PI groups. Compared with patients with an average PI, patients with Very Low PI had 3.4° lower PT while holding TPA constant (P < 0.001). Further, patients with Very High PI displayed a PT of 1.9° higher than patients with an Average PI while holding TPA constant (P = 0.01). A similar difference of -1.8°, and 1.2° with respect to the Average PI group was observed in the Low and High PI groups, respectively (P < 0.001). Means and standard deviations of PT at varying levels of TPA were defined for PI groups.Conclusion: This is the first study which demonstrated that PI is associated with varied recruitment of PT while maintaining constant sagittal malalignment. The results reported herein are intended to allow surgeons to assess a patient's magnitude of compensatory PT for an individual patient's PI.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective analysis.Objective: Determine whether deformity corrections should vary by pelvic incidence (PI).Summary Of Background Data: Alignment targets for deformity correction have been reported for various radiographic parameters. The T1 pelvic-angle (TPA) has gained in applications for adult spinal deformity (ASD) surgical-planning since it directly measures spinal alignment separate from pelvic- and lower-extremity compensation. Recent studies have demonstrated that ASD corrections should be age specific.Methods: A prospective database of consecutive ASD patients was analyzed in conjunction with a normative spine database. Clinical measures of disability included the Oswestry Disability Index (ODI) and Short Form 36 Survey (SF-36) Physical Component Score (PCS). Baseline relationships between TPA, age, PI, and ODI/SF-36 PCS scores were analyzed in the ASD and asymptomatic patients. Linear regression modeling was used to determine alignment targets based on PI and age-specific normative SF-36-PCS values.Results: Nine hundred three ASD patients (mean 53.7 yr) and 111 normative subjects (mean 50.7 yr) were included. Patients were subanalyzed by PI: low, medium, high (<40, 40-75, >75); and age: elderly (>65 yr, n = 375), middle age (45-65 yr, n = 387), and young (18-45 yr, n = 141). TPA and SRS-Schwab parameters correlated with age and PI in ASD and normative subjects (r = 0.42, P < 0.0001). ODI correlated with PCS (r = 0.71, P < 0.0001). Linear regression analysis using age-normative SF-36-PCS values demonstrated that ideal spinopelvic alignment is less strict with increasing PI and age.Conclusion: Targets for ASD correction should vary by age and PI. This is demonstrated in both asymptomatic and ASD subjects. Using age-normative SF-36 PCS values, alignment targets are described for different age and PI categories. High-PI patients do not require as rigorous realignments to attain age-specific normative levels of health status. As such, sagittal spinal alignment targets increase with increasing age as well as PI.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

For example, a plan to decrease VTE risk by aggressive anticoagulation and mobilization in a hypercoagulable patient with hip fracture would certainly be limited preoperatively since the patient cannot be over-anticoagulated for the operating room and certainly cannot mobilize well because of the hip fracture. CORR Insights®: Rotational Thromboelastometry Findings Are Associated with Symptomatic Venous Thromboembolic Complications after Hip Fracture Surgery Certainly, any patients symptomatic for PE would also be screened with CT angiography, and it may also seem reasonable to do CT angiography on any patients with abnormal ROTEM results. [Extracted from the article]

Case: We describe the case of a 75-year-old patient diagnosed with high-grade epithelioid hemangioendothelioma in the left hemipelvis. She underwent an internal hemipelvectomy, followed by reconstruction with a tumor prosthesis with iliac anchorage using 3D-printed cutting and placement guides. Eighteen months postoperatively, she is pain-free and walks without appliances. Conclusions: Using 3D-printed guides could be an appropriate alternative for patients with aggressive bone tumors in the pelvic area that require hemipelvectomy and reconstruction using a prosthesis with iliac anchorage. 3D-printed cutting guides allow precise resection with appropriate margins, could reduce the risk of injuring critical structures, and facilitate proper prosthetic component positioning. [ABSTRACT FROM AUTHOR]

Background: Anatomic and surgical complexity make pelvic and sacral bone sarcoma resections challenging. Positive surgical margins are more likely to occur in patients with pelvic and sacral bone sarcomas than in those with extremity sarcomas and are associated with an increased likelihood of local recurrence. Intraoperative navigation techniques have been proposed to improve surgical accuracy in achieving negative margins, but available evidence is limited to experimental (laboratory) studies and small patient series. Only one small historically controlled study is available. Because we have experience with both approaches, we wanted to assess whether navigation improves our ability to achieve negative resection margins.Questions/purposes: Are navigated resections for pelvic and sacral primary bone sarcomas better able to achieve adequate surgical margins than nonnavigated resections?Methods: Thirty-six patients with pelvic or sacral sarcomas treated with intraoperative navigation were retrospectively compared with 34 patients undergoing resections without navigation. All patients underwent resections between 2000 and 2017 with the intention to achieve a wide margin. Patients in the navigation group underwent surgery between 2008 and 2017; during this period, all resections of pelvic and sacral primary bone sarcomas with the intention to achieve a wide margin were navigation-assisted by either CT fluoroscopy or intraoperative CT. Patients in the control group underwent surgery before 2008 (when navigation was unavailable at our institution), to avoid selection bias. We did not attempt to match patients to controls. Nonnavigated resections were performed by two senior orthopaedic surgeons (with 10 years and > 25 years of experience). Navigated resections were performed by a senior orthopaedic surgeon with much experience in surgical navigation. The primary outcome was the bone and soft-tissue surgical margin achieved, classified by a modified Enneking system. Wide margins (≥ 2 mm) and wide-contaminated margins, in which the tumor or its pseudocapsule was exposed intraoperatively but further tissue was removed to achieve wide margins, were considered adequate; marginal (0-2 mm) and intralesional margins were considered inadequate.Results: Adequate bone margins were achieved in more patients in the navigated group than in the nonnavigation group (29 of 36 patients [81%] versus 17 of 34 [50%]; odds ratio, 4.14 [95% CI, 1.43-12.01]; p = 0.007). With the numbers available, we found no difference in our ability to achieve adequate soft-tissue margins between the navigation and nonnavigation group (18 of 36 patients [50%] versus 18 of 34 [54%]; odds ratio, 0.89 [95% CI, 0.35-2.27]; p = 0.995).Conclusions: Intraoperative guidance techniques improved our ability to achieve negative bony margins when performing surgical resections in patients with pelvic and sacral primary bone sarcomas. Achieving adequate soft-tissue margins remains a challenge, and these margins do not appear to be influenced by navigation. Larger studies are needed to confirm our results, and longer followup of these patients is needed to determine if the use of navigation will improve survival or the risk of local recurrence.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: The etiology of hip pain in pediatric and adolescent patients can be unclear. Osteoid osteoma (OO) about the hip in children has only been described in case reports or small studies. The present study assessed the clinical presentation and diagnostic course, imaging, and treatment approaches in a large cohort of pediatric cases of OO about the hip.Methods: Medical record and imaging results were reviewed for all cases of OO identified within or around the hip joint in patients <20 years old between January 1, 2003, and December 31, 2015, at a tertiary-care pediatric center. Demographic, clinical, and radiographic data were analyzed.Results: Fifty children and adolescents (52% female; mean age, 12.4 years; age range, 3 to 19 years) were identified. Night pain (90%) and symptom relief with nonsteroidal anti-inflammatory drugs (NSAIDs) (88%) were common clinical findings. Sclerosis/cortical thickening was visible in 58% of radiographs, although a radiolucent nidus was visible in only 42%. Diagnostic imaging findings included perilesional edema and a radiolucent nidus on 100% of available magnetic resonance imaging (MRI) and computed tomography (CT) scans, respectively. Initial alternative diagnoses were given in 23 cases (46%), the most common of which was femoroacetabular impingement (FAI). Delay in diagnosis of >6 months occurred in 43% of patients. Three patients underwent operative procedures for other hip diagnoses, but all had persistent postoperative pain until the OO was treated. Of the 41 patients (82%) who ultimately underwent radiofrequency ablation (RFA), 38 (93%) achieved complete post-RFA symptom resolution.Conclusions: Initial misdiagnosis, the most common of which was FAI, and delayed correct diagnosis are common in pediatric OO about the hip. Presenting complaints were variable and nonspecific MRI findings were frequent. Night pain and relief with NSAIDs were present in the vast majority of cases. CT scans provided definitive diagnosis in all patients who received them. As increasing numbers of young, active patients are being evaluated for various causes of hip pain, such as FAI, OO should not be overlooked in the differential diagnosis.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Study Design: Systematic review and meta-analysis.Objective: This study aims to determine the differences in sagittal spinopelvic parameters between adolescent idiopathic scoliosis (AIS) Lenke types and non-scoliotic controls through a systematic review and meta-analysis of the available literature.Summary Of Background Data: AIS classification mainly focuses on frontal curve differences; however, the variations in the sagittal spinopelvic alignment in the current classification system is not fully established.Methods: Following preferred reporting items for systematic reviews and meta-analyses guidelines, searches were performed for sagittal spinal and pelvic parameters of Lenke types and non-scoliotic controls in PubMed, Scopus, EMBASE, and Cochrane databases. Selection criteria were: (1) age range 10 to 21 years; (2) Lenke types 1-6 (for AIS group) or non-scoliotic adolescents (for the control group); (3) preoperative data for T5-T12 thoracic kyphosis (TK), L1-S1 lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and sagittal vertical axis (SVA). (4) Written in English language. PI-LL mismatch was calculated from the weighted average of PI and LL. Publication bias between studies and within studies quality were assessed. A meta-regression compared each measured variable between groups. Thoracic (Lenke1 and 2) and thoracolumbar/lumbar (Lenke 5 and 6) scoliosis were combined and statistically compared with the control group.Results: Meta-analysis, including 81 AIS and 18 control studies, showed no significant differences in sagittal parameters between Lenke types and controls for LL, PI, PI-LL mismatch, SS, and SVA (P > 0.05). Publication bias was significant in Lenke 1 TK, Control LL, and Lenke 1, and 5 SVA. Stratification based on deformity region (thoracic vs. thoracolumbar/lumbar) showed no significant differences in sagittal spinopelvic parameters (P > 0.05).Conclusion: No definitive difference was found between non-scoliotic adolescents and Lenke types in sagittal spinal and pelvic parameters. Future studies on developing a sagittal classification specific to AIS patients with a goal to improve surgical planning and outcome prediction are highly encouraged.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional study using radiological measurements and longitudinal data analysis.Objective: We aim to explore hip/pelvic geometry on anteroposterior radiographs and examine if such parameters are associated with clinical symptoms.Summary Of Background Data: Pregnancy-related sacroiliac joint pain is a common disease and is responsible to the disability of daily activities. The etiology is likely to be correlated with the biomechanical factors which are determined by trunk load and hip/pelvic geometry. Previous studies have already found the association between symptoms and weight increase during pregnancy. However, the relationship between bony anatomy and pregnancy-related sacroiliac joint pain remains unknown.Methods: In total, 72 women were included in the final analysis. In pregnant women with self-reported sacroiliac joint pain, pain scores at 12, 24, 30, and 36 weeks of pregnancy were recorded and included in a mixed-effect linear regression model as dependent variables. The radiological measurements were included as independent variables. Furthermore, to investigate the relationship between hip/pelvic geometry and the activity-specific nociceptive phenomenon, the radiological measurements between patients with and without activity-induced pain were compared using a binominal logistic regression model.Results: The relative bilateral is chial tuberosity distance (betta coefficient: 0.078; P = 0.015) and the relative bilateral femoral head length (betta coefficient: 0.011; P = 0.028) showed significant interactions with the slope of pain scores. Moreover, women whose pain exacerbate during prolonged walking had a higher odds in hip/pelvic geometry of the bilateral ischial tuberosity distance (odds ratio [OR]: 1.12; P = 0.050) and the bilateral femoral head length (OR: 1.16; P = 0.076) with approximately significant P-value.Conclusion: These data indicate hip/pelvic anatomical variations are associated with the degree of pain increasing and the activity-specific pain during pregnancy, which may help to have further understanding on the biomechanical factor in developing pregnancy-related sacroiliac joint pain.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Study Design: A systematic review and meta-analysis.Objective: The aim of this study was to determine the differences in the sagittal spinopelvic parameters between the nonscoliotic controls, preoperative, and different time points postoperative in Lenke 1 and 5 adolescent idiopathic scoliosis (AIS).Summary Of Background Data: The postoperative changes in the sagittal profile of Lenke 1 and 5 AIS at varying time points after posterior spinal fusion (PSF) has not been rigorously demonstrated; studies performed have had conflicting results.Methods: Sagittal spinal and pelvic parameters, T5-T12 thoracic kyphosis (TK), L1-S1 lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and sagittal vertical axis (SVA), for Lenke 1 and 5 preoperatively, at immediate, less than 2-year, and more than 2-year postoperatively, and for nonscoliotic adolescents were searched. Differences in the sagittal spinopelvic parameters between preoperative and the follow-ups and between the nonscoliotic and pre- and postoperative AIS subtypes were calculated through meta-analysis.Results: A total of 22 studies on Lenke1 (1229 patients), 13 studies on Lenke5 (437 patients), and 18 studies on controls (1636 patients) were reviewed. Among all the measured variables, only PI in Lenke1 was significantly different between the final follow-up and controls, P < 0.05. In Lenke 1, SVA was significantly more anterior at the immediate postoperative than preoperative, but continued moving posteriorly up to 2-year postoperative resulting in no significant difference in the SVA position between the final follow-up and preoperative, P > 0.05. In Lenke 5, SVA was significantly more posterior at the immediate postoperative and more anterior at the final follow-up than the preoperative measurements, p < 0.05.Conclusions: Continuous changes in the sagittal spinal parameters should be expected after PSF. Normalization of the sagittal spinal parameters appears to be the rule after PSF, and watchful waiting appears to be appropriate in this population when viewing the lateral X-ray postoperatively.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design: This is a retrospective radiographic study of a consecutive case series of dropped head syndrome (DHS) at a single tertiary referral center.Objective: The aim was to clarify the spinal sagittal alignment of DHS.Summary Of Background Data: DHS is characterized by chin-on-chest deformity and devastatingly impedes activities of daily living in affected individuals. Among various forms of DHS, isolated neck extensor myopathy (INEM) is considered to cause the chin-on-chest symptom in the absence of specific abnormality. There is a paucity of literature about spinal sagittal alignment, of this condition however.Methods: Thirty-seven patients diagnosed with INEM DHS were enrolled. Radiographic measurements were made, including the following parameters: C2 slope (C2S), C2-C7 A, C2-C7 sagittal vertical axis (SVA), T1 slope (T1S), C7-S1 SVA, T1-T4 thoracic kyphosis (TK), T4-T12 TK, lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). Sixty-one patients with cervical spondylosis were enrolled as a control group.Results: C2-C7 SVA was greater in INEM DHS (52.0 ± 2.9 vs. 18.6 ± 1.9 mm). C2S and T1S were larger to the control (C2S: 52.6° ± 2.0° vs. 13.0° ± 1.4°, T1S: 37.3° ± 2.2° vs. 22.7° ± 1.4°). C2-C7 A was smaller in INEM DHS (-7.8° ± 2.6° vs. 15.2° ± 2.7°). Among sagittal parameters, C2S, T1S, and T1-T4 TK positively correlated with C2-C7 SVA (r = 0.63, r = 0.54, and r = 0.58). For these correlations with C2-C7 SVA, both logistic and linear regression models predicted threshold of 40° for C2S, 40° for T1S, and 15° for T1-T4 TK responsible for C2-C7 SVA > 40 mm, respectively.Conclusion: Increased offset of the gravity axis of the head represented by C2-C7 SVA was observed in INEM DHS. Magnified offset of the gravity axis of the head was affected by enlarged C2S, T1S, and T1-T4 TK for the strong correlation with C2-C7 SVA, respectively. Cervical kyphosis was considered as some of the anthropometric characteristics due to regressive changes in affected individuals; a correlation between C2-C7 A and C2-C7 SVA was exhibited.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design: Reliability analysis.Objective: To assess intra- and interobserver agreement of the T1 pelvic angle (T1PA), a novel radiographic measure of spinal sagittal alignment. Orthopedic surgeons of various levels of experience measured the T1PA in a series of healthy adult volunteers. The relationship of the TIPA to pelvic position was also assessed.Summary Of Background Data: Recent literature suggests that the T1PA is a more reliable measure of global sagittal alignment than traditional measurements (i.e., sagittal vertical axis). Previous research focuses on postoperative patients with known spinal deformity. No published research exists evaluating the use of T1PA on healthy subjects without spinal deformity. The purpose of this study is: (1) to assess the reliability of measurements of the T1PA, (2) to examine its relationship to pelvic position.Methods: Seven evaluators of varying orthopedic experience measured the T1PA in 50 healthy adult volunteers. Subjects were radiographed in each of three pelvic positions: resting, maximal anterior pelvic rotation, and maximal posterior pelvic rotation. After a washout period, the measurement was repeated. Using intraclass correlation coefficients, the intra- and inter-rater agreement for the T1PA was measured. The collected data was also used to determine the accuracy of this measurement and its relationship to pelvic position.Results: A very high level of agreement was found in measurements of the T1PA (intraclass correlation coefficients r = 0.98). At each pelvic position, all examiners had excellent intrarater reliability, > 0.85. The inter-rater reliability, compared with a gold standard, consistently measured the T1PA within ± 2°. The data also shows that the T1PA changes with pelvic rotation.Conclusion: T1PA is a reproducible and reliable measure of global sagittal alignment regardless of the level of training. The T1PA varies based on pelvic rotation; this variation must be taken into account when assigning an absolute target for correction.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective analysis.Objective: To define thoracic compensation and investigate its association with postoperative reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) SUMMARY OF BACKGROUND DATA.: Adult spinal deformity (ASD) patients recruit compensatory mechanisms like pelvic retroversion and knee flexion. However, thoracic hypokyphosis is a less recognized compensatory mechanism.Methods: Patients enrolled in a multicenter ASD registry undergoing fusions to the pelvis with upper instrumented vertebra (UIV) between T9 and L1 were included. Patients were divided into those with postoperative reciprocal thoracic kyphosis (reciprocal kyphosis [RK]: change in unfused thoracic kyphosis [TK] ≥15°) with and without PJK and those who maintained thoracic alignment (MT). Thoracic compensation was defined as expected thoracic kyphosis (eTK) minus preoperative TK.Results: For RK (n = 117), the mean change in unfused TK was 21.7° versus 6.1° for MT (n = 102) and the mean PJK angle change was 17.6° versus 5.7° for MT (all P < 0.001). RK and MT were similar in age, body mass index (BMI), sex, and comorbidities. RK had larger preoperative PI-LL mismatch (30.7 vs. 23.6, P = 0.008) and less preoperative TK (22.3 vs. 30.6, P < 0.001), otherwise sagittal vertical axis (SVA), pelvic tilt (PT), and T1 pelvic angle (TPA) were similar. RK patients had more preoperative thoracic compensation (29.9 vs. 20.0, P < 0.001), more PI-LL correction (29.8 vs. 17.3, P < 0.001), and higher rates of PJK (66% vs. 19%, P < 0.001). There were no differences in preoperative health-related quality of life (HRQOL) except reciprocal kyphosis (RK) had worse Scoliosis Research Society questionnaire (SRS) appearance (2.2 vs. 2.5, P = 0.005). Using a logistic regression model, the only predictor for postoperative reciprocal thoracic kyphosis was more preoperative thoracic compensation. Postoperatively the RK and MT groups were well aligned. Both younger and older (>65 yr) RK patients had greater thoracic compensation than MT counterparts. The eTK was not significantly different from the postoperative TK for the RK group without PJK (P = 0.566).Conclusion: The presence of thoracic compensation in adult spinal deformity is the primary determinant of postoperative reciprocal thoracic kyphosis and these patients have higher rates of proximal junctional kyphosis.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

The article discusses the association of spine, pelvis and hip in the functioning of a total hip replacement. Topics including normal motion from standing to sitting that involves hip flexion, hip stiffness that reduce pelvic mobility, and decreased tilt of the pelvis during movement which occurs with stiffness of the spine are also discussed.

Background: Pelvic ring reconstruction after resection of pelvic malignancies or aggressive benign tumors remains challenging, especially when the tumor invades periacetabular bone, resulting in a Type II resection as classified by Enneking and Dunham (removal of part or all of the acetabulum). Although numerous treatment approaches are in use, none is clearly superior to the others. An alternative involving use of the ipsilateral proximal femur as an autograft has not been well characterized, so we present our preliminary experience with this approach.Questions/purposes: (1) What were the oncologic outcomes after using an ipsilateral proximal femur autograft for reconstruction after Type II pelvic resection in a small series of patients who underwent this reconstructive approach? (2) What were the Musculoskeletal Tumor Society (MSTS) scores after this reconstruction? (3) What complications were observed?Methods: Between October 2006 and May 2016, we treated 67 patients with Type II malignant or aggressive benign tumors of the ilium. Of those, we used an ipsilateral proximal femur and a prosthesis as a reconstruction method for 11 patients with pelvic tumors. In general, we performed this approach in young or middle-aged patients with primary malignant or aggressive benign tumors involving pelvic area II and in whom the tumor did not invade the hip. The method used for resection of pelvic tumors included osteotomy of the femoral shaft, harvesting the proximal femur as a graft. The length of the femoral graft was determined by the extent of the pelvic defect. The proper placement was selected after a comparison of the proximal femur and the pelvic defect. A curved reconstruction plate and cancellous bone screws were used for pelvic fixation. The operative duration and total blood loss were recorded. Of the 11 patients who underwent this approach, all but one had at least 2 years of followup unless death occurred earlier, and all but one have been seen within the last year for evaluation. Functional outcomes were assessed using the MSTS scoring system. Local recurrence, metastases, and deaths were recorded as were complications including infection, bone nonunion, mechanical failure and sciatic nerve palsy.Results: The followup was a mean of 37 months (range, 13-96 months). One patient was lost to followup. Three patients died of disease owing to local recurrence or lung metastasis. The other seven patients lived without evidence of tumor. The main complications included mechanical failure in two patients, nonunion in one patient, infection in two patients, and sciatic nerve palsy in one patient. The median MSTS function score was 70% (21 of 30 points; range, 11-25 points).Conclusions: Our preliminary results show that this technique of using the ipsilateral proximal femur may be an alternative method for reconstruction of pelvic bone defects after tumor resection. Even with this short followup, complications were common, but short-term function appears to be comparable to studies of other options. Longer term followup with more patients is necessary to confirm our results.Level Of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Application of surgical navigation for pelvic bone cancer surgery may prove useful, but in addition to the fact that research supporting its adoption remains relatively preliminary, the actual navigation devices are physically large, occupying considerable space in already crowded operating rooms. To address this issue, we developed and tested a navigation system for pelvic bone cancer surgery assimilating augmented reality (AR) technology to simplify the system by embedding the navigation software into a tablet personal computer (PC).Questions/purposes: Using simulated tumors and resections in a pig pelvic model, we asked: Can AR-assisted resection reduce errors in terms of planned bone cuts and improve ability to achieve the planned margin around a tumor in pelvic bone cancer surgery?Methods: We developed an AR-based navigation system for pelvic bone tumor surgery, which could be operated on a tablet PC. We created 36 bone tumor models for simulation of tumor resection in pig pelves and assigned 18 each to the AR-assisted resection group and conventional resection group. To simulate a bone tumor, bone cement was inserted into the acetabular dome of the pig pelvis. Tumor resection was simulated in two scenarios. The first was AR-assisted resection by an orthopaedic resident and the second was resection using conventional methods by an orthopaedic oncologist. For both groups, resection was planned with a 1-cm safety margin around the bone cement. Resection margins were evaluated by an independent orthopaedic surgeon who was blinded as to the type of resection. All specimens were sectioned twice: first through a plane parallel to the medial wall of the acetabulum and second through a plane perpendicular to the first. The distance from the resection margin to the bone cement was measured at four different locations for each plane. The largest of the four errors on a plane was adopted for evaluation. Therefore, each specimen had two values of error, which were collected from two perpendicular planes. The resection errors were classified into four grades: ≤ 3 mm; 3 to 6 mm; 6 to 9 mm; and > 9 mm or any tumor violation. Student's t-test was used for statistical comparison of the mean resection errors of the two groups.Results: The mean of 36 resection errors of 18 pelves in the AR-assisted resection group was 1.59 mm (SD, 4.13 mm; 95% confidence interval [CI], 0.24-2.94 mm) and the mean error of the conventional resection group was 4.55 mm (SD, 9.7 mm; 95% CI, 1.38-7.72 mm; p < 0.001). All specimens in the AR-assisted resection group had errors < 6 mm, whereas 78% (28 of 36) of errors in the conventional group were < 6 mm.Conclusions: In this in vitro simulated tumor model, we demonstrated that AR assistance could help to achieve the planned margin. Our model was designed as a proof of concept; although our findings do not justify a clinical trial in humans, they do support continued investigation of this system in a live animal model, which will be our next experiment.Clinical Relevance: The AR-based navigation system provides additional information of the tumor extent and may help surgeons during pelvic bone cancer surgery without the need for more complex and cumbersome conventional navigation systems. [ABSTRACT FROM AUTHOR]

Background: Sagittal spinopelvic balance and proper sagittal alignment are important when planning corrective or reconstructive spinal surgery. Prior research suggests that people from different races and countries have moderate divergence; to the best of our knowledge, the population of Taiwan has not been studied with respect to this parameter.Questions/purposes: To investigate normal age- and sex-related differences in whole-spine sagittal alignment and balance of asymptomatic adults without spinal disorders.Methods: In this prospective study, we used convenience sampling to recruit asymptomatic volunteers who accompanied patients in the outpatient orthopaedic department. One hundred forty males with a mean age of 48 ± 19 years and 252 females with a mean age of 53 ± 17 years underwent standing lateral radiographs of the whole spine. For analysis, participants were divided in three groups by age (20 to 40 years, 41 to 60 years, and 61 to 80 years) and analyzed by sex (male and female). The following eight radiologic parameters were measured: sacral slope, pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis, cervical lordosis, C2-C7 sagittal vertical axis, and C7-S1 sagittal vertical axis. Three observers performed estimations of the sagittal parameters twice, and the intraclass correlation coefficients for inter- and intraobserver variability were 0.81 and 0.83.Results: The mean pelvic incidence was 49° ± 12°; lumbar lordosis was smaller in the group that was 61 to 80 years old than in the groups that were 20 to 40 years and 41 to 60 years (95% CI of the difference, 4.50-13.64 and 1.00- 9.60; p < 0.001), while cervical lordosis was greater in the 61 to 80 years age group than the other two groups (95% CI of the difference, -14.64 to -6.57 and -11.57 to -3.45; p < 0.001). The mean C7-S1 sagittal vertical axis was 30 ± 29 mm, and there was no difference among the three groups and between males and females. Pelvic tilt was greater in the group 61 to 80 years old than the 20 to 40 years and 41 to 60 years age groups (95% CI of the difference, -10.81 to -5.42 and -7.15 to -2.08; p < 0.001), while sacral slope was larger in 61 to 80 years age group than in the 41 to 60 years group (95% CI of the difference, 0.79-6.25; p = 0.006). C7 slope was greater in 61 to 80 years age group than in the 20 to 40 years group (95% CI of the difference, -7.49 to -1.26; p = 0.002) and larger in 41 to 60 years age group than in 20 to 40 years group (95% CI of the difference, -6.31 to -0.05; p = 0.045). C2-C7 sagittal vertical axis was greater in males than in females (95% CI of the difference, 2.84-7.74; p < 0.001). C7 slope was negatively correlated with thoracic kyphosis (95% CI of the difference, -0.619 to 0.468; p < 0.001) and lumbar lordosis (95% CI of the difference, -0.356 to -0.223; p < 0.001), and positively correlated with pelvic incidence (95% CI of the difference, 0.058- 0.215; p < 0.001) and cervical lordosis (95% CI of the difference, 0.228 - 0.334; p < 0.001).Conclusions: Normal values of the spinopelvic sagittal parameters vary by age and sex in Taiwanese individuals.Clinical Relevance: Pelvic incidence and sacral slope observed in this population seemed smaller than those reported in other studies of white populations; this seems important when considering spine surgery in Taiwanese patients. Future studies should include collection of whole body sagittal parameters of larger and more-diverse populations, and assessments of patients with symptomatic spinal disorders. [ABSTRACT FROM AUTHOR]

Background: Several methods are commonly used to predict lower-limb-length discrepancy (LLD) on pelvic radiographs. It is not clear how the lower-limb length of patients with unilateral developmental dislocation of the hip (DDH) changes and whether a pelvic radiograph is reliable to predict LLD. In this study, we analyzed the characteristics of LLD in patients with unilateral DDH by measuring full-length standing anteroposterior radiographs.Methods: The radiographic data of all patients with unilateral DDH who met the inclusion criteria from March 2011 to May 2016 were retrospectively reviewed. These data included femoral length, tibial length, skeletal limb length, and distance from the lesser trochanter to the tibial plafond. We also compared LLD between patients with Hartofilakidis type-II DDH and those with type III.Results: Sixty-seven patients (12 male and 55 female) were included. The tibial length, skeletal limb length, and lesser trochanter-tibial plafond distance were significantly greater (p < 0.001, p = 0.040, and p < 0.001, respectively) on the ipsilateral (DDH) side, compared with the contralateral side, in 51 patients (76%), 43 patients (64%), and 52 patients (78%), respectively, with the values on the ipsilateral side exceeding those on the contralateral side by an average of 4.6 mm (range, 0.4 to 17.5 mm), 7.0 mm (range, 0.3 to 21.1 mm), and 10.0 mm (range, 1.1 to 28.8 mm), respectively. The femoral length did not differ significantly between the 2 sides (p = 0.562). There was also no significant difference in LLD, femoral length, tibial length, skeletal limb length, or lesser trochanter-tibial plafond distance between patients with Hartofilakidis type II and those with type III (p > 0.05).Conclusions: Patients with unilateral DDH, regardless of whether the hip dislocation is low or high, may present with LLD derived from both the femur and the tibia. This LLD includes a greater ipsilateral tibial length, skeletal limb length, and lesser trochanter-tibial plafond distance in most patients and an unpredictable femoral length. Using the lesser trochanter on pelvic radiographs to predict LLD is not reliable. The use of full-length standing anteroposterior radiographs for preoperative templating is advisable for this special group of patients.Level Of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Studies focusing on the oncological outcome after treatment of conventional primary central chondrosarcoma of pelvic bone are lacking. We conducted this retrospective study at 5 referral centers to gain insight in the outcome of treatment for this tumor type and to identify risk factors for impaired oncological outcome.Methods: One hundred and sixty-two consecutive patients (118 male patients [73%]) who underwent resection of a conventional primary central chondrosarcoma of pelvic bone from 1985 to 2013 were evaluated. The median age was 51 years (range, 15 to 78 years). The median follow-up was 12.6 years (95% confidence interval [CI], 8.4 to 16.9 years). There were 30 grade-I lesions (19%), 93 grade-II lesions (57%), and 39 grade-III lesions (24%).Results: Sixty-two patients (38%) experienced local recurrence: 9 grade-I lesions (30%), 31 grade-II lesions (33%), and 22 grade-III lesions (56%). Forty-eight patients (30%) developed metastases. The risk of disease-related death was 3% for grade-I tumors (1 of 30; this patient had a grade-II recurrence and died of metastases), 33% (31 of 93) for grade-II tumors, and 54% (21 of 39) for grade-III tumors. Identified risk factors for impaired disease-specific survival were tumor grade (grade II: hazard ratio [HR], 20.18; p = 0.003; and grade III: HR, 58.94; p < 0.001), resection margins (marginal: HR, 3.21; p = 0.001; and intralesional: HR, 3.56; p < 0.001), and maximal tumor size (HR, 1.08 per cm; p = 0.026). Deep infection (19% [n = 31]) was the predominant complication.Conclusions: This study offers a standard for survival rates for conventional primary central chondrosarcoma of the pelvis. The survival for grade-I tumors was excellent. Wide resection margins were associated with a significant survival advantage for higher-grade tumors. Because of the inability to reliably distinguish low-grade and high-grade tumors preoperatively, we conclude that any central pelvic chondrosarcoma should be treated with aggressive primary resection with the aim of obtaining wide resection margins. There may be aggressive biologic features in some tumors for which a surgical procedure alone may not be adequate to improve outcomes.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: The correct amount of external rotation of the femoral component during TKA is controversial because the resulting changes in biomechanical knee function associated with varying degrees of femoral component rotation are not well understood. We addressed this question using a computational model, which allowed us to isolate the biomechanical impact of geometric factors including bony shapes, location of ligament insertions, and implant size across three different knees after posterior-stabilized (PS) TKA.Questions/purposes: Using a computational model of the tibiofemoral joint, we asked: (1) Does external rotation unload the medial collateral ligament (MCL) and what is the effect on lateral collateral ligament tension? (2) How does external rotation alter tibiofemoral contact loads and kinematics? (3) Does 3° external rotation relative to the posterior condylar axis align the component to the surgical transepicondylar axis (sTEA) and what anatomic factors of the femoral condyle explain variations in maximum MCL tension among knees?Methods: We incorporated a PS TKA into a previously developed computational knee model applied to three neutrally aligned, nonarthritic, male cadaveric knees. The computational knee model was previously shown to corroborate coupled motions and ligament loading patterns of the native knee through a range of flexion. Implant geometries were virtually installed using hip-to-ankle CT scans through measured resection and anterior referencing surgical techniques. Collateral ligament properties were standardized across each knee model by defining stiffness and slack lengths based on the healthy population. The femoral component was externally rotated from 0° to 9° relative to the posterior condylar axis in 3° increments. At each increment, the knee was flexed under 500 N compression from 0° to 90° simulating an intraoperative examination. The computational model predicted collateral ligament forces, compartmental contact forces, and tibiofemoral internal/external and varus-valgus rotation through the flexion range.Results: The computational model predicted that femoral component external rotation relative to the posterior condylar axis unloads the MCL and the medial compartment; however, these effects were inconsistent from knee to knee. When the femoral component was externally rotated by 9° rather than 0° in knees one, two, and three, the maximum force carried by the MCL decreased a respective 55, 88, and 297 N; the medial contact forces decreased at most a respective 90, 190, and 570 N; external tibial rotation in early flexion increased by a respective 4.6°, 1.1°, and 3.3°; and varus angulation of the tibia relative to the femur in late flexion increased by 8.4°, 8.0°, and 7.9°, respectively. With 3° of femoral component external rotation relative to the posterior condylar axis, the femoral component was still externally rotated by up to 2.7° relative to the sTEA in these three neutrally aligned knees. Variations in MCL force from knee to knee with 3° of femoral component external rotation were related to the ratio of the distances from the femoral insertion of the MCL to the posterior and distal cuts of the implant; the closer this ratio was to 1, the more uniform were the MCL tensions from 0° to 90° flexion.Conclusions: A larger ratio of distances from the femoral insertion of the MCL to the posterior and distal cuts may cause clinically relevant increases in both MCL tension and compartmental contact forces.Clinical Relevance: To obtain more consistent ligament tensions through flexion, it may be important to locate the posterior and distal aspects of the femoral component with respect to the proximal insertion of the MCL such that a ratio of 1 is achieved. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to investigate the 3-dimensional (3D) morphological features of the true acetabulum in patients with developmental dysplasia of the hip (DDH).Methods: Seventy-nine hips-53 in patients with developmental dysplasia of the hip (DDH) and 36 normal hips-were included in the present study. According to the Crowe classification, 26 hips were graded as Class I, 31 were Class II or III, and 22 were Class IV. The anterior pelvic plane was defined to standardize the measurements in the study. A selected virtual cup component was implanted into the true acetabulum of a 3D pelvic model of each hip. The acetabular anteversion angle, effective center-edge (CE) angle, effective Sharp angle, and thickness of the medial wall were measured to provide morphological indices of the true acetabulum. Acetabular sector angles and the component coverage ratio were measured to provide coverage indices.Results: The acetabular anteversion angle increased with the severity of the DDH. Crowe-II/III hips had the smallest effective CE angle and the largest effective Sharp angle. The mean medial wall thickness was greatest in the Crowe-II/III hips (8.72 mm; 95% confidence interval [CI] = 7.52 to 9.92 mm), intermediate in the Crowe-I hips (7.17 mm; 95% CI = 6.24 to 8.11 mm), and smallest in the Crowe-IV hips (6.05 mm; 95% CI = 4.78 to 7.32 mm). The integrated coverage ratio of the Crowe-II/III hips was significantly less than that of the Crowe-I and IV hips.Conclusions: The morphological features of the true acetabulum in patients with DDH can be evaluated comprehensively by using 3D implantation simulation. Segmental bone deficiency was prevalent in the dysplastic hips, especially those in the Crowe-II/III group. Both the severity and the individual morphology of the acetabular dysplasia should be carefully considered in preoperative planning. [ABSTRACT FROM AUTHOR]

Background: Following resection of malignant tumors of the spine and pelvis, reconstructive surgeons often face large structural defects. Unlike reconstruction in the extremities, wherein a free vascularized fibular graft (FVFG) is a highly utilized option for segmental osseous reconstruction, there are limited data on the use of an FVFG in the spine and pelvis. The aim of this study was to review our institution's experience with reconstruction with use of an FVFG following oncological resection in the spine and pelvis.Methods: We reviewed 24 cases involving the use of an FVFG in reconstruction of segmental osseous defects of the spine and pelvis following oncological resection from 2000 to 2015. The cohort consisted of 12 male and 12 female patients with a mean age of 37 years and a mean follow-up of 5 years. Fifty-four percent of the reconstructions were spinopelvic or sacropelvic.Results: The overall 2, 5, and 10-year rate of survival was 76%, 55%, and 37%, respectively. With regard to disease-free survival, the overall 2, 5, and 10-year rate was 81%, 72%, and 48%. The overall rate of union was 86%, with a mean time to union of 7 months. Complications were common, with 83% of the patients sustaining at least 1 postoperative complication. Following the procedure, the mean Musculoskeletal Tumor Society rating was 53%.Conclusions: An FVFG provides a durable means of reconstruction of osseous defects in the spine and pelvis. Although patient function was acceptable following these large reconstructions, the rate of postoperative complications was high.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Pelvic discontinuity is uncommon and presents the surgeon with complex reconstructive challenges. The objective of this study is to report the results of current strategies used in the treatment of pelvic discontinuity.Methods: We retrospectively analyzed prospectively collected data on 113 consecutive revision total hip arthroplasties performed for the treatment of unilateral pelvic discontinuity at a single institution. The study included 18 male and 95 female patients with a mean age of 63 years at the time of revision surgery. Preoperative, immediate postoperative, and latest follow-up radiographs were reviewed to assess healing of the discontinuity as well as acetabular component stability. Treatment modalities included an uncemented cup with a posterior column plate (50 hips; 44%), a cup-cage construct (27 hips; 24%), an antiprotrusio cage with or without a posterior column plate (26 hips; 23%), and an uncemented cup alone (10 hips; 9%). The average duration of follow-up for each of these types of surgical reconstruction was similar (range, 3.9 to 7.2 years).Results: Five-year revision-free survivorship of the implant was best with a cup-cage construct (100%) and worst with an uncemented cup with a posterior column plate (80%) and a cup alone (80%). Healing of the discontinuity was achieved in 50% of the hips with an uncemented cup alone, 74% of the hips with an uncemented cup and a posterior column plate, 74% of the hips with a cup-cage construct, and 88% of the hips with an antiprotrusio cage construct (91% of these hips when structural allograft was used). The overall complication rate was 26.5%. The average Harris hip score improved from 54 preoperatively to 69 postoperatively (95% confidence interval: 50 to 57 preoperatively and 65 to 72 postoperatively; p = 0.017).Conclusions: Improved survivorship and healing rates were seen in this series when a reconstruction cage was used as an adjunct to an uncemented cup (cup-cage) or in combination with structural allograft bone that bridged the discontinuity.Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Resection of pelvic and sacral tumors can cause severe blood loss, complications, and even postoperative death. Hypotensive epidural anesthesia has been used to mitigate blood loss after elective arthroplasty, but to our knowledge, it has not been studied as an approach that might make resection of pelvic and sacral tumors safer.Questions/purposes: The purposes of this study were (1) to compare the blood loss and blood product use for patients undergoing pelvic and sacral tumor surgery under standard anesthesia or hypotensive epidural anesthesia; (2) to assess the frequency of end-organ damage with the two techniques; and (3) to compare 90-day mortality between the two techniques.Methods: Between 2000 and 2014, 285 major pelvic and sacral resections were performed at one center. A total of 174 (61%) had complete data sets for analysis of blood loss, transfusion use, complications, and mortality at 90 days. Of those, 102 (59%) underwent hypotensive epidural anesthesia, whereas the remainder received standard anesthetic care. The anesthetic approach was determined by the anesthetists in charge of the case with hypotensive epidural anesthesia exclusively performed by one of two subspecialty trained anesthetists as their routine for major pelvic or sacral surgery. The groups were comparable in terms of potential confounding variables such as age, gender, tumor volume, and operation performed. Hypotensive epidural anesthesia was defined as a technique using an extensive epidural block up to T2-3 dermatome, peripherally administered low-concentration intravenous adrenaline infusion, and using unimpeded spontaneous respiration to achieve controlled hypotension, precise rate control of the heart, and enhanced velocity of venous return, all aggregated thus to minimize blood loss during pelvic surgery while preserving vital perfusion. The groups were assessed for perioperative blood loss calculated from pre- and postsurgery hemoglobin and transfusion use as well as postoperative complications, morbidity, and mortality at 90 days.Results: There was less mean blood loss in the hypotensive epidural anesthesia group (1457 mL, SD 1721, 95% confidence interval [CI], 1114-1801 versus 2421 mL, SD 2297, 95% CI, 1877-2965; p = 0.003). Patients in the hypotensive epidural anesthesia group on average received fewer packed red cell transfusions (2.7 units, SD 2.9, 95% CI, 2.1-3.2 versus 3.9 units, SD 4.4, 95% CI, 2.9-5.0; p = 0.03). There were no differences in the proportions of patients experiencing end-organ injury (7%, n = seven of 102 versus 6%, n = four of 72; p = 0.72). With the numbers available, there was no difference in 90-day mortality rate between groups (1.9%, n = two of 102 versus 1.3%, n = one of 72; p = 0.77).Conclusions: We found that hypotensive epidural anesthesia resulted in less blood loss, fewer transfusions, and no apparent increase in serious complications in pelvic and sacral tumor surgery performed in the setting of a high-volume tertiary sarcoma referral hospital. We recommend that further collaborative studies be undertaken to confirm our results with hypotensive epidural anesthesia in surgery for pelvic tumors.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the outcome at skeletal maturity of combined pelvic and femoral varus osteotomies in children with Legg-Calvé-Perthes (LCP) disease.Methods: From January 1998 to December 2009, 69 patients with LCP disease underwent combined osteotomies at our institution. Fifty-two children (19 girls and 33 boys) met the inclusion criteria and were enrolled in the study. The LCP disease was classified and the cases of all patients were reviewed at skeletal maturity. The mean age (and standard deviation) at the time of diagnosis was 6.9 ± 2.4 years, and the mean age at the time of surgery was 7.9 ± 2.3 years. The mean time to follow-up was 10.8 ± 3.5 years. The final follow-up radiographs were assessed according to the Stulberg classification and the sphericity deviation score.Results: The mean Harris hip score at the time of follow-up was 90 ± 13.2. According to the Harris hip score grading system, 37 patients (71%) had an excellent outcome; 8 patients (15%), a good result; 3 patients (6%), a fair result; and 4 patients (8%), a poor result. Seven patients (13%) were classified as having a Stulberg class-I hip; 20 (38%), a class-II hip; 15 (29%), a class-III hip; 6 (12%), a class-IV hip; and 4 (8%), a class-V hip. The mean sphericity deviation score was 24.4 ± 14.4 at skeletal maturity. There was a strong relationship between a younger age at diagnosis and better functional and radiographic outcomes.Conclusions: In the absence of a randomized study design, conclusions have to be drawn with caution. Combined pelvic and femoral osteotomies in these children with LCP disease did not result in better functional or radiographic outcomes compared with the historic results of Salter osteotomy or proximal femoral osteotomy alone.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Previous studies have noted a correlation between bony pelvic measurements and the diagnosis of prolapse via musculofascial insertion points on magnetic resonance imaging. We investigated the importance of bony measurements of the lumbar spine and pelvis as risk factors in the development of prolapse via routine computed tomography (CT) imaging. METHODS: We sampled 171 UBMD obstetrics and gynecology clinic patients who were at least 40 years of age and had an abdominal/pelvic CT scan. Demographic and medical history was reviewed and collected. Participants were then divided into those with and without prolapse. CT images were uploaded to 3D Slicer 5.10. Each study was analyzed by a trained annotator blinded to prolapse status. The area of the anterior pelvis, interspinous diameter, pelvic outlet, ischial spine to pubic symphysis, sacrococcygeal junction to ischial spine, and lumbar and sacrococcygeal curvature were annotated. Demographic characteristics and measured annotations were compared using χ2 test. RESULTS: Women with prolapse were more likely to be older (P <.05) and of lower weight (mean 71.6 kg, P <.05) than controls. Patients with prolapse had a significantly larger area of their anterior pelvis (P <.05) and a significantly longer interspinous diameter (P <.05). Distance from ischial spine to pubic symphysis was significantly longer (P <.05), and pelvic outlet in women with prolapse was significantly longer than in controls (P <.05). CONCLUSION: In addition to known risk factors, bony measurements of the pelvis are significantly different in those with and without pelvic organ prolapse, which may be observed on routine CT imaging. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective review.Objective: To evaluate preoperative variability in radiographic sagittal parameters in adult spinal deformity (ASD).Summary Of Background Data: In ASD surgical planning, deformity magnitude is determined from preoperative radiographs. There are no studies evaluating the clinical relevance and timing to repeat radiographs during interval clinic visits and timing to repeat radiograph for preoperative planning.Methods: A total of 139 patients with ASD with minimum two preoperative full-body spine x-rays were included. Cervical, thoracic, lumbar, pelvic, and hip/knee sagittal alignment parameters were analyzed using dedicated spine measurement software. Patients were grouped by time intervals between x-rays: A: 8 weeks or lesser, B: 10 to 20 weeks, and C: 21 weeks or more. Changes in sagittal parameters were correlated to age and deformity magnitude (T1 pelvic angle or pelvic tilt [PT] >20°).Results: The cohort had mean age 59 years, mean body mass index 27, 30% men, 95 patients with no prior spine surgery, and 44 patients at minimum 9 months since prior spine surgery. There were 25 patients in group A, 38 in B, and 71 in C. All radiographic measures showed good time-based consistency at intervals less than 21 weeks (groups A and B). Group C had significant increases in PT (1.5°) and hip extension (2.1°) (P < 0.05). These changes were greater in group C patients with previous surgery (PT 3.7°; P < 0.006, hip extension 3.2°; P < 0.025). Greater interval changes in parameters were also associated with higher magnitudes of deformity and younger patient ages.Conclusion: All sagittal radiographic parameters were statistically consistent at intervals of less than 21 weeks. In patients with more than 21 weeks between interval x-rays, change in PT was greater than the standard error of measurement for patients with prior surgery or severe deformity. Consideration should be made to obtain new x-rays for patients with ASD when the interval between clinical visits exceeds 5 months.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]