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Background: Le Fort III distraction for syndromic craniosynostosis is performed using internal or external devices. The authors compared the results of both devices., Methods: The authors retrospectively evaluated 60 patients with syndromic craniosynostosis treated with Le Fort III distraction (internal or external device) between 2001 and 2021. The authors verified demographic data, surgery-related data, and complications using medical records. For each of the 2 devices, they compared the various factors associated with the device to each other., Results: For the external device, 32 patients with syndromic craniosynostosis were included. The mean age at surgery was 11.7 years, and the mean elongation length was 20.0 mm. Class III occlusion reoccurred in 11 patients and was significantly associated with age at surgery. Seven complications (device problems and others) were noted. Cranial pin slippage was significantly related to the elongation length. For the internal device, 28 patients with syndromic craniosynostosis were included. The mean age at surgery was 10.4 years, and the mean elongation length was 18.7 mm. There were 15 complications, including device problems, zygomaticomaxillary fractures, and infections. Elongation length was significantly related to these complications. Class III occlusion reoccurred in 9 patients and was significantly related to age at surgery., Conclusions: This study found that complications are significantly more likely to occur in internal devices than in external devices, especially device infection. The authors' findings identified several factors that may assist surgeons in selecting between external and internal devices. The relationship between the amount of extension and device-related problems found in this study will be beneficial for solving these problems., Clinical Question/level of Evidence: Therapeutic, III., (Copyright © 2023 by the American Society of Plastic Surgeons.)

Background: Femoral fracture after femoral lengthening in patients with achondroplasia and hypochondroplasia is a frequent complication, occurring in up to 30%. The purpose of this study is to demonstrate the effectiveness of prophylactic intramedullary rodding in preventing this complication., Methods: Multicenter retrospective study involving 86 femoral lengthening procedures in 43 patients with achondroplasia or hypochondroplasia. Forty-two femora (21 patients) were prophylactically managed with intramedullary Rush rodding after external fixation removal (11 females and 10 males, mean age 14.6 years) compared with 44 femora (22 patients) without prophylactic intramedullary rodding (13 females and 9 males, mean age 15.2 years). The mean amount of lengthening in the rodding group was 13.3 cm (52.6%) with an External Fixation Index of 25.8 days/cm; in patients without rodding was 14.3 cm (61.5%) and 24.5 days/cm, respectively., Results: Seven cases (15.9%) without rodding developed fractures. Four of them required surgical correction due to displacement or shortening. Only 1 patient (2.4%) had fracture of the femur after prophylactic rodding, and surgery was not required. The incidence of femur fracture was significantly lower in the prophylactic rodding group compared with the nonrodding group (2.4% vs. 15.9%, respectively; P =0.034). There were no cases of infection or avascular necrosis., Conclusions: Prophylactic intramedullary rodding is a safe and effective method for preventing femoral fractures after femoral lengthening in patients with achondroplasia or hypochondroplasia., Level of Evidence: Level III-a retrospective comparative study., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Open reduction internal fixation (ORIF) and intramedullary nail fixation (IMN) are the predominant repair methods for operative treatment of humeral diaphyseal fractures; however, the optimal method is not fully elucidated. The purpose of this study was to analyze whether IMN or ORIF humeral diaphyseal surgeries result in a significantly higher prevalence of adverse outcomes and whether these outcomes were age dependent. We hypothesize there is no difference in reoperation rates and complications between IMN and ORIF for humeral diaphyseal fractures., Methods: Data collected from 2015 to 2017 from the Nationwide Readmissions Database were evaluated to compare the prevalence of six adverse outcomes: radial nerve palsy, infections, nonunion, malunion, delayed healing, and revisions. Patients treated for a primary humeral diaphyseal fracture with either IMN or ORIF were matched and compared (n = 2,804 pairs). Patients with metastatic cancer were excluded., Results: Following an ORIF procedure, there was a greater odds of undergoing revision surgery (p = 0.03) or developing at least one of the complications of interest (p = 0.03). In the age-stratified analysis, no significant differences were identified in the prevalence of adverse outcomes between the IMN and ORIF cohorts in the 0-19, 20-39, and 40-59 age groups. Patients who were 60 + had 1.89 times the odds of experiencing at least one complication and 2.04 times the odds of undergoing a revision after an ORIF procedure versus an IMN procedure (p = 0.03 for both)., Discussion: IMN and ORIF for humeral diaphyseal fractures are comparable in regard to complications revision rates in patients under the age of 60. Meanwhile, patients 60 + years show a statistically significant increase in the odds of undergoing revision surgery or experiencing complications following an ORIF. Since IMN appears to be more beneficial to older patients, being 60 + years old should be considered when determining fracture repair techniques for patients presenting with primary humeral diaphyseal fractures., (© 2023. The Author(s).)

Introduction: Periprosthetic distal femur fractures (PPDFFs) are a common complication after total knee arthroplasty (TKA). In the setting of well-fixed TKA components, treatment options include retrograde intramedullary nailing (rIMN) or lateral locked plating. Treatment with rIMN has historically been associated with potential for extension deformity when using conventional nails. We hypothesized that the PPDFFs treated with an intramedullary nail with a specifically designed 10-degree distal bend for periprosthetic fractures would result in improved post-operative sagittal alignment compared to conventional intramedullary nails., Materials and Methods: The study was conducted at a level-1 trauma center over a 12-year period (2010 - 2022). Patients over the age of 18 who sustained a PPDFF treated with rIMN were identified. The primary outcomes of the study were post-operative coronal and sagittal alignment determined by reviewing post-operative radiographs., Results: A total of 50 patients were included. Twenty-three patients were treated with a rIMN with a 10° distal bend. Twenty-seven patients were treated with a rIMN with distal bend of 5° The mean aPDFA for the 10° distal bend group was 81.7° compared to 92.8° in the 5° distal bend group (p<0.001). There were 3/23 (13%) significant sagittal plane deformities the 10° distal bend group compared to 11/27 (41%) in the 5° distal bend group (p = 0.03). There was one patient with a post-operative extension deformity in the 10° distal bend group compared to 11 patients in the 5° distal bend group (p = 0.02)., Conclusion: Retrograde intramedullary nailing of PPDFF with a 10° distal bend results in significantly better alignment in the sagittal plane when compared to a conventional 5° nail. The use of a 5° nail resulted in an extension deformity significantly more frequently. We therefore recommend the utilization of a rIMN with a 10° distal bend when treating PPDFFs., Summary: Periprosthetic distal femur fractures are a common complication following total knee arthroplasty. While several studies report on the use of retrograde intramedullary nails in the treatment of periprosthetic distal femur fractures, there are limited reports of the use of a novel retrograde intramedullary nail with a 10° distal bend in the treatment of these injuries. Herein we present a radiographic study comparing coronal and sagittal postoperative alignment following treatment with retrograde intramedullary nails with a 10° distal bend versus conventional retrograde nails with a 5° distal bend., Competing Interests: Declaration of Competing Interest GH receives royalties from Depuy Synthes on the implant used in this study. No funding was received in support of the study., (Copyright © 2022. Published by Elsevier Ltd.)

Background: As overall cancer survival continues to improve, the incidence of metastatic lesions to the bone continues to increase. The subsequent skeletal related events that can occur with osseous metastasis can be debilitating. Complete and impending pathologic femur fractures are common with patients often requiring operative fixation. However, the efficacy of an intramedullary nail construct, on providing stability, continue to be debated. Therefore, the purpose of this study was to utilize a synthetic femur model to determine 1) how proximal femur defect size and cortical breach impact femur load to failure (strength) and stiffness, and 2) and how the utilization of an IMN, in a prophylactic fashion, subsequently alters the overall strength and stiffness of the proximal femur., Methods: A total of 21 synthetic femur models were divided into four groups: 1) intact (no defect), 2) 2 cm defect, 3) 2.5 cm defect, and 4) 4 cm defect. An IMN was inserted in half of the femur specimens that had a defect present. This procedure was performed using standard antegrade technique. Specimens were mechanically tested in offset torsion. Force-displacement curves were utilized to determine each constructs load to failure and overall torsional stiffness. The ultimate load to failure and construct stiffness of the synthetic femurs with defects were compared to the intact synthetic femur, while the femurs with the placement of the IMN were directly compared to the synthetic femurs with matching defect size., Results: The size of the defect invertedly correlated with the load the failure and overall stiffness. There was no difference in load to failure or overall stiffness when comparing intact models with no defect and the 2 cm defect group (p=0.98, p=0.43). The 2.5 cm, and 4.5 cm defect groups demonstrated significant difference in both load to failure and overall stiffness when compared to intact models with results demonstrating 1313 N (95% CI: 874-1752 N; p<0.001) and 104 N/mm (95% CI: 98-110 N/mm; p=0.03) in the 2.5 cm defect models, and 512 N (95% CI: 390-634 N, p<0.001) and 21 N/mm (95% CI: 9-33 N/mm, p<0.001) in the models with a 4 cm defect. Compared to the groups with defects, the placement an IMN increased overall stiffness in the 2.5 cm defect group (125 N/mm; 95% CI:114-136 N/mm; p=0.003), but not load to failure (p=0.91). In the 4 cm defect group, there was a significant increase in load to failure (1067 N; 95% CI: 835-1300 N; p=0.002) and overall stiffness (57 N/mm; 95% CI:46-69 N/mm; p=0.001)., Conclusion: Prophylactic IMN fixation significantly improved failure load and overall stiffness in the group with the largest cortical defects, but still demonstrated a failure loads less than 50% of the intact model. This investigation suggests that a cortical breach causes a loss of strength that is not completely restored by intramedullary fixation. Level of Evidence: II ., (Copyright © The Iowa Orthopaedic Journal 2022.)

Background: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is one of several approaches to lumbar interbody fusion that has proven to be a safe and effective treatment for symptomatic lumbar degenerative disease The clinical outcomes of MIS-TLIF are generally favorable, but there is still controversy regarding its ability to restore sagittal alignment. For this reason, expandable transforaminal lumbar interbody fusion cages have been developed and designed to improve ability to restore disc height and segmental lordosis. The use of expandable cages in transforaminal lumbar interbody fusion has increased drastically; however, it is not clear how effective cage expansion is in regard to disc space lordosis, distraction, and long-term outcome., Methods: We reviewed a cohort of patients with symptomatic lumbar degenerative disc pathology who underwent MIS-TLIF at our institution. We compared clinical and radiographic outcomes of expandable versus nonexpandable cage use in MIS-TLIF focusing on mean changes in segmental lordosis, disc height, and postoperative complications. The results were compared with other studies reported in the international literature., Results: Mean change in segmental lordosis was not significantly different between the 2 groups. A significantly higher rate of postoperative subsidence was demonstrated in the expandable cage group., Conclusion: This study established that expandable cage use in single-level transforaminal lumbar interbody fusion did not reduce the rate of postoperative complications, but rather significantly increased a patient's risk of postoperative subsidence. Expandable cages do not presently demonstrate improved clinical outcomes or improved sagittal alignment compared with static cages., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Interbody fusion at the caudal levels of long constructs for adult spinal deformity (ASD) surgery is used to promote fusion and secure a solid foundation for maintenance of deformity correction. We sought to evaluate long-term pseudarthrosis, rod fracture, and revision rates for TLIF performed at the base of a long construct for ASD., Methods: We reviewed 316 patients who underwent TLIF as a component of ASD surgery for medical comorbidities, surgical characteristics, and rate of unplanned reoperation for pseudarthrosis or instrumentation failure at the TLIF level. Fusion grading was assessed after revision surgery for pseudarthrosis at the TLIF level., Results: Rate of pseudarthrosis at the TLIF level was 9.8% (31/316), and rate of rod fractures was 7.9% (25/316). The rate of revision surgery at the TLIF level was 8.9% (28/316), and surgery was performed at a mean of 20.4 ± 16 months from the index procedure. Current smoking status (odds ratio 3.34, P = 0.037) was predictive of pseudarthrosis at the TLIF site. At a mean follow-up of 43 ± 12 months after revision surgery, all patients had achieved bony union at the TLIF site., Conclusions: At 3-year follow-up, the rate of pseudarthrosis after TLIF performed at the base of a long fusion for ASD was 9.8%, and the rate of revision surgery to address pseudarthrosis and/or rod fracture was 8.9%. All patients were successfully treated with revision interbody fusion or posterior augmentation of the fusion mass, without need for further revision procedures at the TLIF level., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Pectus excavatum is the most common congenital anomaly of the chest wall. Surgical management of this problem has evolved to encompass many modifications of Dr Ravitch's initial groundbreaking repair to include the insertion of mesh, metal struts, and bars to bolster the repair through open and minimally invasive approaches. This report presents a case of right ventricular outflow tract obstruction from a dislodged pectus bar after a modified Ravitch procedure. The presentation, diagnosis, and management of this exceedingly rare complication are described, and the discussion also provides clinical pearls and inspiration for future research directions that are based on this experience., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate risk factors of cage retropulsion after posterior lumbar interbody fusion (PLIF) in China and to establish a scoring system of cage retropulsion., Methods: The retrospective analysis was based on two hospital databases. The medical data records of posterior lumbar interbody fusion with cage retropulsion were selected from August 2009 to August 2019. Inclusion and exclusion criteria were set in advance. Risk factors including patients' baseline demographics (age, gender, operation diagnosis time difference), preoperative neurological symptoms, whether the fusion involves single or double segments, screw type, intraoperative compression, preoperative bone mineral density, whether there are neurological symptoms before surgery, whether there is urine dysfunction before surgery, disease type, complete removal of the endplate, and patient's education level. The research endpoint was the retropulsion of fusion cages. The Kaplan-Meier (K-M) method was used to analyze potential risk factors, and multivariate Cox regression was used to identify independent risk factors (P < 0.05). The Statistical Package for the Social Sciences (version 22.0; SPSS, IBM, Chicago, IL, USA) software was used for statistical analysis, and univariate analysis was used to screen out the factors related to cage retropulsion. All independent risk factors were included to predict the survival time of the retropulsion of cage., Results: This study included a total of 32 patients with PLIF between 2009 to 2019. All patients were residents of China. Univariate analysis showed that there were 13 patients over 60 years old and 19 patients under 60 years old. There were 20 male patients and 12 female patients. The surgical diagnosis time was seven patients within 1 month, 17 patients within 1 to 3 months, and eight patients over 3 months. The disease type was 18 cases of lumbar disc herniation, 10 cases of lumbar spinal stenosis, four cases of lumbar spondylolisthesis. The fusion segment was 18 cases of single segment, 14 cases of double segment. The intraoperative compression was seven cases of compression, 25 cases of no compression. The preoperative bone mineral density was 10 cases of low density, 18 cases of normal, four cases of osteoporosis. The screw type was 27 cases of universal screw, five cases of one-way screw. Preoperative neurological symptoms were found in 25 cases and not in seven cases. Preoperative urination dysfunction occurred in 8 cases, whereas 24 cases did not have this dysfunction. The endplate was completely removed in 10 cases and not in 22 cases. Education level was nine cases of primary school education, 10 cases of secondary school, 13 cases of university level. Cox regression analysis showed that intraoperative pressure (hazard ratio [HR] = 4.604, P = 0.015) and complete removal of the endplate (HR = 0.205, P = 0.027) are associated with the time of cage retropulsion. According to the HR of each factor, the scoring rules were formulated, and the patients were divided into the low-risk group, moderate-risk group, and high-risk group according to the final score. The three median survival times of the three groups were 66 days in the low-risk group, 55 days in the moderate-risk group, and 45 days in the high-risk group, with statistical significance (P < 0.05)., Conclusion: Intraoperative pressure and complete removal of the intraoperative endplate can be helpful to evaluating the expected time of cage retropulsion in patients with PLIF, and this clinical model guided the selection of postoperative prevention and follow-up treatment., (© 2021 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

To investigate the factors associated with proximal junctional kyphosis (PJK). A systematic search was performed. The weighted mean difference (WMD) was pooled for continuous variables, and the odds ratio (OR) was calculated for dichotomous variables. The PJK group had higher values for age (WMD = 2.53, 95%CI = 1.38 ~ 3.68, P < 0.001), female gender (OR = 1.56, 95%CI = 1.29 ~ 1.87, P < 0.001), and diagnosed osteoporosis (OR = 1.58, 95%CI = 1.11 ~ 2.26, P = 0.01). Preoperatively, significant differences were detected in sagittal vertical axis (SVA) (WMD = 19.29, 95%CI = 16.60 ~ 21.98, P < 0.001), pelvic incidence minus lumbar lordosis (PI-LL) (WMD = 2.71, 95%CI = 0.25 ~ 5.18, P = 0.03), pelvic tilt (PT) (WMD = 2.64, 95%CI = 1.38 ~ 3.90, P < 0.001), lumbar lordosis (LL) (WMD = - 1.76, 95%CI = - 2.73 ~ -0.79, P < 0.001), and sacral slope (SS) (WMD = - 2.80, 95%CI = - 5.57 ~ -0.04, P = 0.001). At follow-up, the following were higher in the PJK group: thoracic kyphosis (TK) (WMD = 5.51, 95%CI = 2.23 ~ 8.80, P < 0.001), proximal junctional angle (PJA) (WMD = 9.07, 95%CI = 4.21 ~ 13.92, P < 0.001), and PT (WMD = 1.51, 95%CI = 0.31 ~ 2.72, P = 0.01). However, there was no significant difference in SS (P = 0.49), and SVA (P = 0.11) between groups. Fusion to S1 or pelvis significantly increased the risk of PJK (OR = 2.08, P < 0.001). Ligament augmentation reduced the risk of PJK (OR = 0.34, 95%CI = 0.21 ~ 0.53, P < 0.001) better than the use of laminar hook (OR = 0.46, P < 0.001). Although no difference was detected for preoperative SRS-22 score (P = 0.056), a lower score (WMD = - 0.24, 95%CI = - 0.35 ~ -0.14, P < 0.001) was detected in PJK group at follow-up. The elderly female ASD patients were more susceptible to PJK, especially for those with osteoporosis, high preoperative SVA, low LL, large PT, and LIV extended to pelvis. The use of laminar hook and ligament reinforcement at the proximal end might prevent PJK.

Background: Although Fassier-Duval (FD) rods have been used for almost 2 decades, knowledge of factors predisposing to their failure is limited. Thus, the purpose of this study was to: (1) present the most common complications of FD rodding, (2) present tips on how to avoid or overcome them, and (3) identify factors predisposing to treatment failure., Methods: Fifty-eight rod segments in 19 patients with osteogenesis imperfecta (mainly type III) underwent analysis with a median follow-up (FU) time of 4.4 years. We assessed the total number of complications clinically and radiographically. Next, the possible predisposing factors leading to failure were assessed using the Mann-Whitney U test. In addition, we evaluated the cutoff age for the increased rate of complications using the Youden index. A P<0.05 was considered significant., Results: The total number of complications reached 44.8%. The most common complications included: migration of the male or female implant (45.7% and 25.7% out of the total number of complications, respectively), bone fracture with bending of the rod (8.6%), and rotational deformities (8.6%). Significant differences in patients' ages at the time of surgery were found between the group with and without complications (P=0.04), while sex, segment treated, preceding surgeries, length of FU, FD rod diameter, and length of bisphosphonate treatment were not significant. The Youden index showed that the risk of complications rose significantly in patients treated when younger than 5.5 years of age (P<0.05)., Conclusions: This series displays the effectiveness and utility of FD rods at a median FU of over 4 years. Complication rates were comparable with the existing literature, with a notable increase in the number of side effects observed in younger patients (below the age of 5)., Level of Evidence: Level IV-therapeutic study., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: The high prevalence of intraoral wound dehiscence (IOWD) following open reduction internal fixation of mandibular fractures has not been well studied., Objective: A retrospective cohort study was conducted to investigate and assess possible risk factors for IOWD related to patients and surgical technique., Methods: All patients who did not have diabetes, were not medically compromised such as patients with nutritional deficiencies or endocrine disorders, did not smoke, did not consume alcohol, and had mandibular fractures managed through open reduction internal fixation and via intraoral vestibular incision from January 2007 to December 2019, at Al-Azhar University Hospitals, in Cairo, Egypt were included in the study. Study data were collected and grouped according to the demographic characteristics of patient age and sex and fracture-related factors of cause, side, site, displacement severity, fixation device, infection, and history of dehiscence. Follow-up of all patients was conducted daily during the first week and weekly during the first month after surgery. Data were analyzed using cross-tabulation with Pearson chi-squared test to calculate the significance of associations between various independent variables and occurrence of IOWD; P less than or equal to .05 was viewed as statistically significant., Results: The study included 69 mandibular fracture patients (age range, 13-55 years [mean, 28.13 ± 11.5 years]) treated using different osteosynthesis fixation devices, including miniplates, lag screws, and heavy locking plates. No statistically significant differences were noted between groups in terms of age, sex, and surgical attributes of fracture site, displacement severity, or fixation type with regard to IOWD (P > .05). None of the included patients were medically compromised, smoked, or used alcohol. Intraoral wound dehiscence occurred in 7 patients (10.1%) and was managed conservatively through copious irrigation with warm saline and chlorhexidine mouthwash in intermittent cycles of 5 times a day for 2 weeks; when infection was present, antibiotic prescription and drainage were provided. Complete wound closure was achieved after a maximum period of 2 weeks., Conclusions: A small proportion of mandibular fracture patients are expected to have IOWD complication even if a meticulous and appropriate surgical technique is implemented. Intraoral wound dehiscence has a good prognosis and it may require a maximum of 2 weeks to obtain healing with secondary epithelization of the bared bony sites.

Abstract: Although transforaminal lumbar interbody fusion (TLIF) is a widely accepted procedure, major complications such as cage retropulsion (CR) can cause poor clinical outcomes. Endplate injury (EI) was recently identified as a risk factor for CR, present in most levels developing CR. However, most EIs occurred in non-CR levels, and the features of EIs in CR levels remain unknown.The aim of this study was to identify risk factors for CR following TLIF; in particular, to investigate the relationship between EIs and CR, and to explore the features of EIs in CR.Between October 2010 and December 2016, 1052 patients with various degenerative lumbar spinal diseases underwent bilateral instrumented TLIF. Their medical records, radiological factors, and surgical factors were reviewed and factors affecting the incidence of CR were analyzed.Twenty-one patients developed CR. Nine had back pain or leg pain, of which six required revision surgery. A pear-shaped disc, posterior cage positioning and EI were significantly correlated with CR (P < .001, P = .001, and P < .001, respectively). Computed tomography (CT) scans revealed the characteristics of EIs in levels with and without CR. The majority of CR levels with EIs exhibited apparent compression damage in the posterior part of cranial endplate on the decompressed side (17/18), accompanied by caudal EIs isolated in the central portion. However, in the control group, the cranial EIs involving the posterior part was only found in four of the total 148 levels (P < .001). Most of the injuries were confined to the central portion of the cranial or caudal endplate or both endplates (35 in 148 levels, 23.6%). Additionally, beyond cage breaching into the cortical endplate on lateral radiographs, a characteristic appearance of coronal cage misalignment was found on AP radiographs in CR levels with EIs.A pear-shaped disc, posterior cage positioning and EI were identified as risk factors for CR. EI involving the posterior epiphyseal rim had influence on the development of CR. Targeted protection of the posterior margin of adjacent endplates, careful evaluation of intraoperative radiographs, and timely remedial measures may help to reduce the risks of CR., Competing Interests: The authors have no conflict of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

The current study is aimed at developing and validating a nomogram of the risk of failure of internal fixation devices in Chinese patients undergoing spinal internal fixation. We collected data from a total of 1139 patients admitted for spinal internal fixation surgery at the First Affiliated Hospital of Guangxi Medical University from May 2012 to February 2019. Of these, 1050 patients were included in the spinal internal fixation group and 89 patients in the spinal internal fixation device failure group. Patients were divided into training and validation tests. The risk assessment of the failure of the spinal internal fixation device used 14 characteristics. In the training test, the feature selection of the failure model of the spinal internal fixation device was optimized using the least absolute shrinkage and selection operator (LASSO) regression model. Based on the characteristics selected in the LASSO regression model, multivariate logistic regression analysis was used for constructing the model. Identification, calibration, and clinical usefulness of predictive models were assessed using C-index, calibration curve, and decision curve analysis. A validation test was used to validate the constructed model. In the training test, the risk prediction nomogram included gender, age, presence or absence of scoliosis, and unilateral or bilateral fixation. The model demonstrated moderate predictive power with a C-index of 0.722 (95% confidence interval: 0.644-0.800) and the area under the curve (AUC) of 0.722. Decision curve analysis depicted that the failure risk nomogram was clinically useful when the probability threshold for internal fixation device failure was 3%. The C-index of the validation test was 0.761. This novel nomogram of failure risk for spinal instrumentation includes gender, age, presence or absence of scoliosis, and unilateral or bilateral fixation. It can be used for evaluating the risk of instrumentation failure in patients undergoing spinal instrumentation surgery., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2021 Chong Liu et al.)

Summary: Negative-pressure wound therapy with instillation and dwell (NPWTi-d) is an option for management of wounds with exposed orthopedic fixation hardware. The mechanical effect of the negative-pressure therapy works to contract the wound edges, and the instillation of solution and its subsequent removal help remove infectious material. NPWTi-d also promotes robust granulation tissue formation. In this article, we discuss the science behind NPWTi-d and its role in the treatment of wounds with indwelling orthopedic fixation hardware., (Copyright © 2020 by the American Society of Plastic Surgeons.)

Study Design: A retrospective cohort study., Objective: To determine the risk factors of cage subsidence in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and its correlation with patient-reported outcomes., Summary of Background Data: Cage subsidence is among the cage-related complications after TLIF and may lead to poor outcomes. Few studies have addressed the incidence of cage subsidence in MI-TLIF., Methods: This retrospective study of a prospectively collected database was conducted from October 2015 to October 2017. All patients received MI-TLIF with a minimum of 2-year follow-up. All levels were separated into the cage subsidence (CS group) and no cage subsidence (non-CS group) groups. Cage subsidence was evaluated using lateral radiographs and defined as more than 2 mm migration of the cage into the endplate of adjacent vertebral body. Patient demographics, perioperative details, and radiographic parameters were recorded. Cage-related parameters were cage height, cage insertion level, and cage position. Cage position was recorded using central point ration (CPR). Patient-reported outcome was analyzed using the Oswestry Disability Index (ODI) questionnaire and Visual Analog Scale (VAS) preoperatively and at 2 years postoperatively., Results: Ninety-three patients (126 levels) were included. Mean age was 66.5 years with an average follow-up of 36.9 months. Overall incidence of cage subsidence was 34.1%. The CS group had significantly higher body mass index, less bone mineral density (BMD), shorter disc height, and higher CPR than the non-CS group. BMD, disc height, and CPR were significantly negatively correlated with depth of cage subsidence. ODI improvement was significantly lesser in the CS group than in the non-CS group. Fusion rate and complications were unrelated to cage subsidence., Conclusion: The BMD, disc height, and cage position were the most significant risk factors that were negatively correlated with depth of cage subsidence. Placing a TLIF cage anteriorly if possible may reduce the risk of cage subsidence., Level of Evidence: 3.

Study Design: Multicenter retrospective., Objective: To determine the long-term complication rate associated with surgical treatment of spondylolisthesis in adolescents. There is limited information on the complication rate associated with posterior spinal fusion (PSF) of spondylolisthesis in the pediatric and adolescent population., Methods: Patients who underwent PSF for spondylolisthesis between 2004 and 2015 at four spine centers, < 21 years of age, were included. Exclusion criteria were < 2 years of follow-up or anterior approach. Charts and radiographs were reviewed., Results: 50 patients had PSF for spondylolisthesis, 26 had PSF alone, while 24 had PSF with trans-foraminal lumbar interbody fusion (TLIF). Mean age was 13.9 years (range 9.6-18.4). Mean follow-up was 5.5 years (range 2-15). Mean preoperative slip was 61.2%. 20/50 patients (40%) experienced 23 complications requiring reoperation at a mean of 2.1 years (range 0-9.3) for the following: implant failure (12), persistent radiculopathy (3), infection (3), persistent back pain (2), extension of fusion (2), and hematoma (1). In addition, there were 22 cases of radiculopathy (44%) that were transient. Rate of implant failure was related to preoperative slip angle (p = 0.02). Reoperation rate and rates of implant failure were not associated with preoperative % slip (reoperation: p = 0.42, implant failure: p = 0.15), postoperative % slip (reoperation: p = 0.42, implant failure: p = 0.99), postoperative kyphosis of the lumbosacral angle (reoperation: p = 0.81, implant failure: p = 0.48), change in % slip (reoperation: p = 0.30, implant failure: p = 0.12), change in slip angle (reoperation: p = 0.42, implant failure: p = 0.40), graft used (reoperation: p = 0.22, implant failure: p = 0.81), or addition of a TLIF (reoperation: p = 0.55, implant failure: p = 0.76)., Conclusion: PSF of spondylolisthesis in the adolescent population was associated with a 40% reoperation rate and high rate of post-operative radiculopathy. Addition of a TLIF did not impact reoperation rate or rate of radiculopathy.

Study Design: Single-center, retrospective., Objectives: To assess the restoration of ideal sagittal spine shape in accordance to the Roussouly classification and the effect on postoperative mechanical complications. Surgical correction of Adult Spinal Deformity is both challenging and complex. The risk of postoperative complications is considerable, especially mechanical complications requiring revision surgery. Attention has been directed toward defining alignment targets in attempts to minimize these risks, and the Roussouly classification has been proposed as a potential surgical aim., Methods: All patients undergoing ASD surgery from 2013-2016 were included at a single, quaternary institute. Successful restoration of Roussouly spine shape was retrospectively assessed, and patients were classified as either "restored" or "non-restored". Cumulative incidence of revision surgery due to mechanical failure was estimated using the Aalen-Johansen estimator, with death as the competing risk. A multivariable proportional odds model was used to estimate the effect of the Roussouly algorithm on revision surgery due to mechanical failure., Results: We identified a complete and consecutive cohort of 233 patients who were followed for a mean period of 36 (± 14) months. The 2-year cumulative incidence of revision surgery was 28%. Comparing the "restored" to the "non-restored" group, the overall revision rates were high in both groups. However, when adjusting for known cofounders in a multivariable proportional odds analysis, there was an almost fivefold increased odds of revision due to mechanical failure in the "non-restored" group (p = 0.036)., Conclusion: Surgical correction of ASD in accordance to the ideal Roussouly spine shape was correlated to a marked and significant decrease in risk of revision surgery due to mechanical failure. Nonetheless, the overall revision risk was elevated in both groups., Level of Evidence: Therapeutic III.

Background: Cannulated pedicle screw (CPS) augmented by polymethylmethacrylate (PMMA) can achieve satisfactory clinical efficacy in the treatment of lumbar spondylolisthesis with osteoporosis. However, accurate application of CPSs will help to avoid the difficulty of screw revision and reduce the incidence of PMMA-related complications. This study aimed to investigate the mid-term efficacy of CPS compared to unilateral and bilateral applications in this common lumbar degenerative disease., Methods: May 2011 and May 2018, 50 patients with lumbar spondylolisthesis with osteoporosis who underwent posterior fixation and fusion using traditional pedicle screws or CPSs were included in the study. Patients were divided into two groups based on the application: the unilateral PMMA-augmented CPS group (UC, n = 29) and the bilateral PMMA-augmented CPS group (BC, n = 21). Operation time, blood loss, average hospitalization time, PMMA leakage, and other complications were recorded. The visual analog scale (VAS) and Oswestry disability index (ODI) scores were used to evaluate symptom recovery. Radiographic results were compared for intervertebral fusion and screw loosening., Results: There were no significant differences in the baseline data of the two groups. The VAS and ODI scores improved significantly after surgery (P < 0.05), with no significant differences between the groups (P > 0.05). The operation time and blood loss in the UC group were significantly lower than those in the BC group (P < 0.05). However, the loss of intervertebral disk height and Taillard index did not differ significantly between the groups. The rates of PMMA leakage in the UC and BC groups were 7.0% and 11.9%, respectively (P < 0.05). Bony fusion was achieved in all groups without screw loosening at the last follow-up. Only one patient experienced superficial infection in both groups, while cerebrospinal fluid leakage was observed in two patients in the BC group., Conclusions: Unilateral application of PMMA-augmented CPS may provide adequate clinical safety and effectiveness in the surgical treatment of lumbar spondylolisthesis with osteoporosis.

Background: This study was aimed at investigating the causes of lower extremity weaknesses after posterior lumbar spine fusion surgery and looking at subsequent treatment strategies., Methods: Patients who underwent posterior lumbar spine fusion surgery in the Peking University First Hospital between January 2009 and December 2018 were counted. Those who needed secondary surgery because of subsequent lower extremity weaknesses were selected. CT scans and MRIs were used to evaluate the reasons for weaknesses before secondary surgery. Muscle strength was evaluated after surgery., Results: Thirty patients (30/4078, 0.74%) required a secondary surgery because of lower extremity weaknesses after posterior lumbar spine fusion surgery. The main causes of weakness were (1) internal fixation malposition and loosening (11 patients, 36%), (2) epidural hematomas (9 patients, 30%), (3) insufficient decompression (5 patients, 17%), and (4) nerve root edemas (5 patients, 17%). Weakness occurred on average 2.9 days after surgery (1-9 days). Twenty-seven patients (90%) got improved muscle strength after their secondary surgery., Conclusions: Iatrogenic neurologic deficits and lower extremity weaknesses were rare complications after posterior lumbar spine fusion surgeries, but important to recognize and manage. The main causes of weakness were internal fixation malposition and loosening, epidural hematomas, insufficient decompression, or root edemas. There may be positive, therapeutic effects to subsequent, active surgical exploration.

Background: The application of nano-hydroxyapatite/polyamide 66(n-HA/PA66) struts has become reliable in anterior cervical corpectomy and fusion (ACCF) as a source of sufficient segmental stability. This was a retrospective and long-term imaging evaluation of the n-HA/PA66 strut in 1-level ACCF., Methods: The patients between June 2006 and December 2014, who underwent 1-level ACCF using an n-HA/PA66 strut, were reviewed. The neurological status was assessed using the Japanese Orthopedic Association (JOA) score and axial pain was evaluated using a Visual Analogue Scale (VAS) score and the radiographic parameters were determined by X-ray and 3-D CT examinations when necessary for the evaluation of bone fusion using the Brantigan scale and imaging characteristics., Results: A total of 520 patients underwent one-level ACCF, with a mean follow-up (FU) duration of 72.38 ± 24.56 months. The level of surgery was C4 in 58 cases, C5 in 173 cases, C6 in 208 cases, and C7 in 81 cases. According to the Brantigan scale, on X-ray examination, the bony fusion rate was observed to be 40%, 70%, 93%, and 98% at 3 months, 6 months, 1 year and the final FU. An interesting radiographic appearance of the bone graft growth pattern was classified into three types. 95% of the patients accounted for types a and b. No significant differences were observed in age, hospitalization duration, surgical haemorrhage volume, or fusion rate among the types except in the percentage and sex of the patients among the types. Type a had better cervical lordosis, and less subsidence than types b and c (P < 0.05). No significant difference was found in segment angle between type a and type b. Type c was more often observed with subsidence rate, segmental angle loss and cervical alignment loss than types a and b (P < 0.05). Type a also had a slightly higher fusion rate, than types b and c, but there were no significant differences. The overall mean JOA score at the final follow-up among the groups were significantly improved comparing that preoperatively and no significant differences were found among the groups, no matter pre-operation or final follow-up. The overall mean VAS score at the final follow-up among the groups were significantly improved comparing that preoperatively and no significant differences in preoperative VAS score were found among the groups. However, the VAS score at the final follow-up of type a or type b was better than type c. No patients received revision surgery., Conclusions: The type a bone graft growth pattern could allow a lower incidence of subsidence and better maintenance of local and global alignment to be achieved and is thus proposed for surgeons.

Objective: The aims of this study were, first, to assess the loss of reduction after fixation of Rockwood type V acromioclavicular joint dislocation (ACJD) with the TightRope device (Arthrex, Naples, FL, USA) and, second, to present the functional and radiological outcomes of this treatment., Methods: We retrospectively reviewed the medical records of 15 patients (12 males; mean age=39.2 years; age range=23-61) with Rockwood type V ACJD who were treated by the TightRope fixation device. The mean follow-up period was 19.3 (range=12-30) months. Functional status was assessed using the Constant-Murley score (CMS) at the final follow-up examination. To determine the reduction loss of ACJ, we measured and compared the coracoclavicular (CC) distance using radiographs with Zanca view in the early postoperative period and at the final follow-up examination. The fixation procedures were performed with an open technique using the TightRope fixation device., Results: The mean CMS at the final follow-up was 93.2 (range=82-100) points. All the patients experienced full recovery of the shoulder's range of motion, were able to return to the activities of daily living, and were satisfied with the treatment. ACJ reduction was successfully achieved in all the patients using the TightRope technique. Postoperative radiographs revealed no reduction loss in the ACJ, and the CC distance was well maintained. The mean CC distance was 19.95 (range=13.1-28.3) mm before surgery. The mean CC distance was 7.47 (range=4.2-11.5) mm in the early postoperative radiographic measurements. This difference was statistically significant (p=0.001). The mean CC distance at the final follow-up examination was 7.70 (range=4.5-11.7) mm. At the final follow-up visit, the shoulders of all the patients were still completely reduced, with a mean difference in the CC of 0.23 (range=0-1.3) mm compared with that in the early postoperative period. The difference in the CC between the early postoperative and final follow-up intervals was not statistically significant (p=0.055). No patient experienced recurrence or required an operation for hardware removal., Conclusion: It seems that the TightRope device can provide anatomical restoration in patients with acute type V ACJD without subluxation at the final follow-up examination., Level of Evidence: Level IV, Therapeutic study.

Objective: The lateral lumbar interbody fusion (LLIF) technique is used to treat many common spinal degenerative pathologies including kyphoscoliosis. The use of spinal navigation for LLIF has not been broadly adopted, especially in adult spinal deformity. The purpose of this study was to evaluate the feasibility as well as the intraoperative and navigation-related complications of computer-assisted 3D navigation (CaN) during multiple-level LLIF for spinal deformity., Methods: Retrospective analysis of clinical and operative characteristics was performed for all patients > 18 years of age who underwent multiple-level CaN LLIF combined with posterior instrumentation for adult spinal deformity at the University of Michigan between 2014 and 2020. Intraoperative CaN-related complications, LLIF approach-related postoperative complications, and medical postoperative complications were assessed., Results: Fifty-nine patients were identified. The mean age was 66.3 years (range 42-83 years) and body mass index was 27.6 kg/m2 (range 18-43 kg/m2). The average coronal Cobb angle was 26.8° (range 3.6°-67.0°) and sagittal vertical axis was 6.3 cm (range -2.3 to 14.7 cm). The average number of LLIF and posterior instrumentation levels were 2.97 cages (range 2-5 cages) and 5.78 levels (range 3-14 levels), respectively. A total of 6 intraoperative complications related to the LLIF stage occurred in 5 patients. Three of these were CaN-related and occurred in 2 patients (3.4%), including 1 misplaced lateral interbody cage (0.6% of 175 total lateral cages placed) requiring intraoperative revision. No patient required a return to the operating room for a misplaced interbody cage. A total of 12 intraoperative complications related to the posterior stage occurred in 11 patients, with 5 being CaN-related and occurring in 4 patients (6.8%). Univariate and multivariate analyses revealed no statistically significant risk factors for intraoperative and CaN-related complications. Transient hip weakness and numbness were found to be in 20.3% and 22.0% of patients, respectively. At the 1-month follow-up, weakness was observed in 3.4% and numbness in 11.9% of patients., Conclusions: Use of CaN in multiple-level LLIF in the treatment of adult spinal deformity appears to be a safe and effective technique. The incidence of approach-related complications with CaN was 3.4% and cage placement accuracy was high.

Study Design: Descriptive case series., Objective: The aim of the study is to investigate the pain associated with magnetically controlled growing rod (MCGR) lengthening procedures. MCGRs have gained popularity because they offer non-surgical lengthening procedures in early-onset scoliosis (EOS) instead of semi-annual open surgery elongations with traditional growing rods. Many aspects of MCGR treatment have been investigated, but pain in conjunction with distraction is only sparsely described in the literature., Methods: Pain intensity was assessed in 25 EOS patients before, during and after MCGR lengthening procedures in an outpatient setup. They underwent at least two (range 2-16) lengthening procedures prior to this study. The pain intensity was estimated using patient-reported Faces Pain Scale (FPS-R), caregiver-reported pain numeric rating scale (NRS), and NRS and revised Face, Legs, Activity, Cry, Consolability scale (r-FLACC) by two medically trained observers. The inter-rater reliability and correlation between instruments were analyzed., Results: 23 of 25 EOS patients (8- to 16-year old) with mixed etiology were able to self-report pain. The average pain intensity was mild: median 1 (range 0-6) on all four instruments on a 0-to-10 scale. Afterward, 22/25 patients (88%) were completely pain free and the remaining 3 patients had a pain score of 1. MCGR stalling (i.e. clunking) was encountered in 14/25 (56%) of the patients without impact on the pain intensity., Conclusions: The average maximum pain intensities during the lengthening procedures were mild and pain ceased within few minutes. The inter-rater reliability was good to excellent for NRS and r-FLACC, and there were high correlations between all the four pain instruments, indicating high criterion validity., Level of Evidence: Level IV, case series.

Background: The use of modern rigid instrumentation in pediatric cervical fusions decreases the risk of implant-related complications, both acute and long term. However, previous studies have indicated that acute implant-related issues still occur in the adult population. Reports of pediatric acute implant complications, occurring within 3 months of surgery, are under-represented in the literature. The purpose of this study is to document the prevalence of acute implant-related complications in a pediatric cervical fusion population., Methods: A retrospective review of instrumented cervical fusions from August 2002 to December 2018 was conducted. Acute implant-related complications were defined as malposition, fracture, or disengagement of cervical instrumentation, including screws, rods, and plates, within 90 days of surgery., Results: A total of 166 cases were included (55% male individuals) with an average age at surgery of 12.5 years (SD, ±5.28). Acute implant-related complications occurred in 5 patients (3%). All 5 patients had a syndromic diagnosis: Loeys-Dietz (n=1), osteopetrosis (n=1), neurofibromatosis (n=1), trisomy 20 (n=1), and achondroplasia (n=1). One case involved asymptomatic screw protrusion, 1 case lateral mass screw pull-out, 2 more had screw-rod disengagement, and the last experienced dislodgement of the anterior plate. The median time until the presentation was 25 days (range, 1 to 79 d). All patients (n=5) required surgical revision., Conclusions: This case series suggests that the overall incidence of acute cervical implant failure is low. However, failure is more likely to occur in patients with underlying syndromes compared with patients with different etiologies. Intraoperative use of 3-dimensional computed tomography imaging is recommended to evaluate the screw position and potentially avoid later surgery.

Study Design: Multicenter, retrospective cohort study., Objectives: Analyze the impact of MCGR proximal anchor location and density on radiographic outcomes and complications. Magnetically controlled growing rods (MCGRs) reduce the need for repeat operations for lengthening when treating spinal deformity in children. The evidence behind choosing the location and density of proximal anchors comes from the traditional growing rod and rib-based distraction technique literature. Thus, there is much debate regarding the optimal quantity and location of proximal anchors., Methods: This study included early-onset scoliosis patients treated with MCGR with a minimum 2-year follow-up. Comparisons of 2-year correction in the coronal and sagittal planes, complication rates, and patient-reported outcomes were made based on proximal fixation type, proximal anchor density, and type of case (primary, conversion)., Results: This study included 155 MCGR patients. Spinal deformity correction at 2 years was significantly higher in spine-based than rib-based constructs, in terms of both the major (23.9° vs. 17.1°, p = 0.05) and minor curves (10.0° vs. 4.5°, p = 0.03). Greater proximal anchor density, regardless of location, was also associated with better major curve correction at 2 years (25.0° vs. 18.2°, p < 0.05). There was a trend towards higher risk of device migration with rib-based fixation (13.8% vs. 4.1%, p = 0.06) and rod breakage with spine-based fixation (10.3% vs. 3.4%, p = 0.21). Having 5+ proximal anchors did not significantly decrease the risk of complication, including device migration (8.4% vs. 7.7%)., Conclusions: When using the MCGR, proximal spine anchors and greater anchor density impart superior deformity correction but do not significantly impact the risk of device complications. Although rib-based constructs afford less rigidity than spine-based constructs, there is a similar risk of rod breakage and device migration. This study suggests that having 5+ MCGR proximal anchors does not protect against proximal anchor complication., Level of Evidence: Level III-therapeutic.

Study Design: This was a systematic review., Objective: The objective of this study was to review radiographic, clinical, and surgical outcomes of expandable interbody device implantation following lumbar fusion., Summary of Background Data: Few studies have evaluated postsurgical outcomes of expandable implants following lumbar interbody fusion., Methods: A systematic review was performed to identify studies investigating expandable intervertebral body devices in lumbar fusion. Radiographic parameters, fusion assessments, patient-reported outcomes (PROs), complications, and revision data were recorded. A comparison of expandable and static devices was performed using a meta-analysis., Results: Eleven articles were included. Postoperative improvements for each radiographic parameters for expandable versus static device implantation ranged from: lumbar lordosis, +2.0 to +5.0 degrees (expandable) versus +1.0 to +4.4 degrees (static); segmental lordosis, +1.0 to +5.2 degrees (expandable) versus+1.1 to +2.3 degrees (static); disk height, +0.82 to +4.8 mm (expandable) versus +0.26 to +6.9 mm (static); foraminal height, +0.13 to +2.8 mm (expandable) versus and +0.05 to +3.0 mm (static). Fusion rates ranged from 72.1% at 6 months to 100% at terminal follow-up. Preoperative to final follow-up improvement for the various PROs assessed were: Oswestry Disability Index, -15.4 to -56.3 (expandable) versus -13.6 to -26.3 (static); Visual Analog Scale (VAS) Back, -3.2 to -6.0 (expandable) versus -3.1 to -4.1 (static); and VAS Leg, -2.9 to -7.1 (expandable) -3.0 versus -4.8 (static). Static cages had a reported complication rate ranging from 6.0% to 16.1% and a subsidence rate of 6.0%. Expandable cages had a reported complication rate that ranged from 0.0.% to 10.0% and a subsidence rate of 5.5%-10.0%. A meta-analysis demonstrated a statistically significant difference in the PRO Oswestry Disability Index, but not VAS Back, VAS Leg, or radiographic outcomes (disk height or foraminal height)., Conclusion: There is no clear evidence for the use of expandable interbody devices over static devices.

Introduction: Based on global knowledge regarding sagittal alignment, preoperative planning is a crucial point in the management of adult spinal deformity (ASD). Patient-specific rods (PSR) have been recently developed in order to change preoperative planning into a postoperative reality. The aim of this study was therefore to analyze the 1-year radiographic results of prospective ASD cohorts managed using PSR., Methods: In this prospective study, all patients managed for an ASD using PSR since 2014 and with a minimal follow-up of 1-year were included. Radiographic parameters were evaluated pre and postoperatively and patients were stratified according to their final sagittal alignment status (A: aligned vs. MA: malaligned) according to the age-related Schwab classification. Statistical analyses were performed using the Student's-t-test in order to compare groups., Results: Eighty-six patients were included in the study, with a mean age of 57.2 years. At one-year follow-up, mean sagittal vertical axis and pelvic incidence-lumbar lordosis mismatch were significantly improved. Twenty-two patients were aligned on both sagittal and coronal planes, 52 patients were still considered as malaligned in the sagittal plane, 3 were still malaligned in the coronal plane and 9 patients were malaligned in both planes (vs. 42 patients preoperatively). At final follow-up, the rate of mechanical complications was 18%., Conclusion: Based on our results, patient-specific rods can represent a useful supplementary tool in the management of ASD and transform preoperative planning into a postoperative reality. Corrections rates are comparable to other series in the literature with conventional rods, and fewer complications have been reported. However, further studies will be required in order to confirm these results., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Introduction: There is no data regarding the incidence and treatment of deep infection affecting the surgical implants after rib fixation. The aim of this study is to share our experience in the management of infected material after surgical rib fixation., Methods: The medical records of operated patients from January 2012 to December 2018 were retrospectively analyzed., Results: Three patients out of 87 (3.44%) developed an infection. One patient was treated conservatively and two patients were operated for hardware removal., Conclusions: The lack of evidence prompts for the design of surgical databases to share experience and enhance available data., Competing Interests: None declared., (Georg Thieme Verlag KG Stuttgart · New York.)

Study Design: A retrospective analysis of a prospectively collected consecutive case series of patients with adult spinal deformity who underwent 3-column osteotomy (3-CO) with pelvic fixation., Objectives: The objectives were to verify the effect of additional rods and determine the optimal type of additional rod for preventing rod fracture (RF). RF is a frequent complication following 3-CO surgery in patients with adult spinal deformity. Two types of additional rod constructs were utilized to prevent RF., Methods: We evaluated data retrieved from a prospectively collected single-center database. Patients were classified into two groups depending on rod constructs: conventional 2-rod and 2-rod constructs with additional rods. The additional rod constructs were also stratified into two groups according to the location that they covered: only osteotomy site (short additional rod) or osteotomy site and lumbosacral junction (long additional rod)., Results: A total of 48 patients (average age 67.6 years; follow-up rate: 90.6%; 2-rod: 25 cases and additional rod: 23 cases) were included. No significant difference was observed in age, fusion level, operation time, blood loss, and rod composition. The incidence of RF in the additional rods (36%) was significantly lower than that in the 2-rod constructs (68%). Comparing the additional rod constructs, RF occurred in 7 cases (64%) in short additional rod and 2 cases (17%) in long additional rod. RF occurred at the level below the additional rod construct in 6 of 7 RF cases with short additional rod., Conclusions: Additional rods covering the osteotomy site and lumbosacral junction reduced the incidence of RF following 3-CO surgery with pelvic fixation in short term., Level of Evidence: 3.

Background: The zero-profile anchored cage (ZP) has been widely used for its lower occurrence of dysphagia. However, it is still controversial whether it has the same stability as the cage-plate construct (CP) and increases the incidence of postoperative subsidence. We compared the rate of subsidence after anterior cervical discectomy and fusion (ACDF) with ZP and CP to determine whether the zero-profile device had a higher subsidence rate., Methods: We performed a meta-analysis of studies that compared the subsidence rates of ZP and CP. An extensive and systematic search covered the PubMed and Embase databases according to the PRISMA guidelines and identified ten articles that satisfied our inclusion criteria. Relevant clinical and radiological data were extracted and analyzed by the RevMan 5.3 software., Results: Ten trials involving 626 patients were included in this meta-analysis. The incidence of postoperative subsidence in the ZP group was significantly higher than that in the CP group [15.1% (89/588) versus 8.8% (51/581), OR = 1.97 (1.34, 2.89), P = 0.0005]. In the subgroup analysis, we found that the definition of subsidence did not affect the higher subsidence rate in the ZP group. Considering the quantity of operative segments, there was no significant difference in the incidence of subsidence between the two groups after single-level fusion (OR 1.43, 95% CI 0.61-3.37, P = 0.41). However, the subsidence rate of the ZP group was significantly higher than that of the CP group (OR 2.61, 95% CI 1.55-4.40, P = 0.0003) after multilevel (≥ 2-level) procedures. There were no significant differences in intraoperative blood loss, JOA score, NDI score, fusion rate, or cervical alignment in the final follow-up between the two groups. In addition, the CP group had a longer operation time and a higher incidence of dysphagia than the ZP group at each follow-up time., Conclusion: Based on the limited evidence, we suggest that ZP has a higher risk of postoperative subsidence than CP, although with elevated swallowing discomfort. A high-quality, multicenter randomized controlled trial is required to validate our results in the future.

Objective: The most common cause of contralateral symptoms after unilateral transforaminal lumbar interbody fusion (TLIF) is contralateral foraminal stenosis (FS). This retrospective cohort study aimed to investigate the cause of and risk factors for contralateral FS after unilateral TLIF with a single cage., Methods: Patients with degenerative lumbar spinal disorders who underwent unilateral TLIF at L4-5 were divided into 2 groups: those without contralateral radicular symptoms after surgery (group A; n = 340) and those with contralateral radicular symptoms after surgery (group B; n = 16). We investigated the influence of various radiological and cage-related factors on postoperative contralateral FS with radicular symptoms. The cage location indicates whether the cage's anterior tip crosses the disc midline-exceeding 50%-and in such a case, how far., Results: Group B showed significantly increased postoperative coronal angle and sagittal angle and decreased contralateral foraminal height and foraminal area. Statistically significant (P < 0.01) factors according to the multivariate logistic regression analysis were the preoperative sagittal range of motion (odds ratio [OR]: 1.562, P = 0.004) and cage location (OR: 2.047, P = 0.015). The cutoff values for the sagittal range of motion and the cage location were 9.0° and 50.5%, respectively. The preoperative and postoperative 6-month visual analog scale scores and Oswestry disability index values were not significantly different between the groups., Conclusions: The 2 most meaningful risk factors were the preoperative sagittal range of motion and cage location. Inserting the cage beyond the disc midline, especially in patients with a high preoperative sagittal range of motion (≥9.0°), would help reduce postoperative complications., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Case: We report the case of an 82-year-old woman with diabetes, arteriosclerosis, chronic heart failure, and hypertension treated with an anatomical locking plate and multiple cables for a spiral-wedged periprosthetic fracture of the distal femur which was complicated by direct occlusion of the femoral artery and crush of the sciatic nerve, resulting in leg necrosis and, ultimately, through-knee disarticulation despite early recognition and arterial repair., Conclusions: Neurovascular injury is a potential complication of cerclage cables placement around the femoral shaft during complex fracture fixation. Devastating complications cannot always be corrected despite early vascular intervention.

Background Context: Over the last two decades, there has been a rapid increase in the use of cervical spine interbody fusion cages. Reoperation rate remains an important determinant of procedural efficacy and safety., Purpose: To evaluate the rate and reasons for reoperations in cervical spondylosis patients undergoing anterior decompression and fusion using stand-alone cervical interbody fusion cages., Study Design: A retrospective study of 2,078 consecutive cases of degenerative cervical spine disease undergoing fusion using stand-alone cages., Patient Sample: Between January 2005 and December 2014, 2,078 patients underwent anterior cervical decompression and fusion using stand-alone cages in our institution., Outcome Measures: The reoperations were analyzed and classified into early (during the first 90 days postoperatively) and late (after 90 days) reoperations. The rate and the causes of reoperation in both groups were reported and the results were compared., Methods: In 1,558 patients, a short segment fusion (≤2 levels) was performed, while the remaining 520 patients underwent a long segment fusion (≥3 levels)., Results: The overall incidence of reoperation was 5.63%. The rate of early reoperations was 2.07%, mostly due to postoperative hematoma, and the rate of late reoperations was 3.56%, mostly due to adjacent segment disease. Revision due to pseudarthrosis was performed in 0.58% of cases. The early reoperation rate was significantly higher in the group with a long segment fusion, while the late reoperation rate was significantly higher in patients undergoing a short segment fusion., Conclusion: Following anterior cervical decompression and fusion with a stand-alone cage, the overall incidence of symptomatic pseudarthrosis is low. Patients undergoing long segment fusion should be closely observed in the early postoperative period as they have a higher early complication rate. On the other hand, long segment fusions have a lower incidence of adjacent segment disease over the years., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The surgical approaches to thoracolumbar junction (T12-L1) tuberculosis were controversial. We aimed to compare the safety and efficacy of three different procedures through a multicentre retrospective study., Methods: The medical records of thoracolumbar junction tuberculosis patients (n = 177) from January 2005 to January 2015 were collected and reviewed. Forty-five patients underwent anterior debridement and instrumented fusion (Group A), 52 underwent anterior combined with posterior debridement and instrumented fusion (Group B) and 80 underwent posterior-only debridement and instrumented fusion (Group C). Patients with neurological deficit were 10 in Group A, 23 in Group B, 36 in Group C. All patients had a standard preoperative and postoperative anti - tuberculous therapy regimen. Clinical outcomes, laboratory indexes and radiological evaluation of the three groups were compared. Operations at each centre were performed by the respective senior medical teams of the six different hospitals., Results: All three surgical approaches achieved bone fusion and pain relief. Cases with neurological deficits had different degrees of improvement after surgery. The operative time was 330.2 ± 45.4 min, 408.0 ± 54.3 min, 227.9 ± 58.5 min, and the blood loss was 744.0 ± 193.8 ml, 1134.6 ± 328.2 ml, 349.8 ± 289.4 ml in groups A, B and C respectively. The average loss of correction was 5.5 ± 3.7° in group A, 1.6 ± 1.9° in group B, 1.7 ± 2.2° in group C, and the difference between groups except B vs C were of statistically significant (P < 0.05)., Conclusions: For patients with thoracolumbar junction (T12-L1) tuberculosis, the posterior-only procedure is the better than the anterior-only procedure in the correction of kyphosis and maintenance of spinal stability. The posterior-only procedure is recommended because it achieves the same efficacy as combined procedure with shorter operation time, less blood loss and trauma.

Design: Multicenter retrospective review., Objective: To evaluate radiographic outcomes and complication rates of patients treated with distraction based implants and pelvic fixation with either screws (sacral-alar-iliac [SAI] screws or iliac screws) or hooks (S hook iliac fixation)., Summary of Background Data: Multiple options exist for pelvic fixation in distraction-based growing rod systems; however, limited comparative data are available., Methods: Early-onset scoliosis (EOS) patients of all diagnoses with distraction-based implants that had pelvic fixation from 2000 to 2013 were reviewed from two EOS multicenter databases. Patients were divided into two groups by type of pelvic fixation: (1) screw group (SAI screws or iliac screws) or (2) S hooks. Exclusion criteria were as follows: index instrumentation ≥10 years old and follow up <2 years. A total of 153 patients met the inclusion criteria. Mean age at index surgery was 6.1 years (range 1.0-9.9 years) and mean follow-up was 4.9 years., Results: Pelvic fixation in the 153 patients was as follows: screw group = 42 and S hook group = 111. When comparing patients with >20° of initial pelvic obliquity, the screw group had significantly more correction; mean 26° ± 13° for the screw group versus mean 17° ± 7° in the S hook group (p = .039). There was no significant difference in change in T1-S1 length (40 vs. 39 mm, p = .89) or correction of Cobb angle (30° vs. 24°, p = .24). The total complication rate for the screw group was 14% (6/42) versus 25% (28/111) in the S hook group, though this did not achieve significance (p = .25). The most common complications were device migration (13), implant failure (8), and implant prominence (4) for S hooks and implant failure (3), implant prominence (2), and device migration (1) for the screw group., Conclusion: In distraction-based growth-friendly constructs, pelvic fixation with screws achieved better correction of pelvic obliquity than S hooks. Complications were almost twice as common with S hooks than screws, though this did not reach statistical significance., (Copyright © 2019 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Background: Surgical stabilization of rib fractures (SSRF) can be used to improve pulmonary mechanics; however, hardware infection is a morbid complication. Antibiotic impregnated beads have been used to suppress infection in orthopedic practices. We aimed to determine the efficacy of antibiotic beads for infected and at-risk SSRF hardware., Methods: This is a single institution retrospective review of adults (18 years or older) that received SSRF between 2009 and 2017. Infected and at-risk hardware were managed with antibiotic beads. The primary outcome was bony union of rib fractures., Results: There were 285 SSRF patients. Infection rate was 3.5%. Antibiotic beads were placed in 17 patients - 9 for infected hardware and 8 for prophylaxis. Increased body mass index (p = 0.04) and hemorrhagic shock at admission (p = 0.03) were risk factors for infection. There was 100% bony union post-operatively., Conclusion: SSRF hardware infection is morbid. Antibiotic beads can salvage SSRF hardware until bony union., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: In the treatment of lumbar spinal stenosis, interspinous spacers can be used in a tissue and time sparing technique. Relief of low back pain might be achieved by stress reduction of facet joints and limitation of segmental mobility., Aim: Presentation of dynamic stabilization by means of an interspinous spacer with and without decompression and to compare it with the outcome of decompression and fusion., Material and Methods: As part of a PubMed search, randomized controlled trials (RCTs) and non-RCTs from high-quality controlled clinical trials were selected and contrasted with our own experience., Results: The current literature was evaluated, which assesses interspinous spacers with and without decompression in comparison with the "gold standard", the microsurgical interlaminar decompression., Conclusion: Published data indicate that the use of interspinous spacers with or without decompression for the treatment of lumbar spinal stenosis is not less effective than stand-alone decompression. The reoperation rate can only be proven for implants without decompression on the basis of Level I studies. However, as a link between decompression alone and fusion, it cannot yet provide a scientifically clear solution.

Objective: To determine longitudinal effects of changes in endplate cystic lesions on oblique lumbar interbody fusion (OLIF), the relationship between bone healing and endplate cystic lesion changes, and clinical significance of cyst formation., Patients and Methods: A total of 107 segments in 67 patients who underwent OLIF between January 2013 and July 2016 were examined in this retrospective study. Using computed tomography, radiographic examinations of endplate cystic lesion, positive or negative cyst formation, cage subsidence, and fusion status were performed. Clinical outcomes were measured using visual analogue scale (VAS) pain scores, Oswestry disability index (ODI), and modified Macnab criteria. Outcomes were compared with preoperatively and postoperatively. A logistic regression analysis was performed to evaluate the relationship between measurements for endplate cysts., Results: The fusion rate after OLIF was 94.4% at 2-year follow-up, with 86% of cases reporting satisfactory outcome (based on modified Macnab criteria). A significantly higher (P <  0.01) VAS score for back pain was observed in the cystic lesion group than non-cystic lesion group at 6-month follow-up. Cage subsidence significantly increased the risk of non-union (odds ratio [OR]: 17.24; 95% confidence interval [CI]: 1.67-178.09). Positive cyst sign was a significant risk factor for cage subsidence (OR: 8.52; 95% CI: 2.73-26.62) while cage subsidence was also a significant risk factor for positive cyst formation (OR: 8.37; 95% CI: 2.71-25.89)., Conclusions: Cystic lesion may increase back pain in the early postoperative period. However, the preoperative cystic lesion does not aggravate a positive cyst formation or affect the final clinical result. Positive cyst formation was a significant risk factor for cage subsidence. In addition, cage subsidence was a significant predictor of non-union. Thus, the authors can speculate that positive cyst sign was potentially an indirect predictor of non-union., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Hip screw cutout is among the most common causes of intertrochanteric fracture fixation failure using dynamic hip screws (DHS). This study aimed to evaluate the effect of using an additional anti-rotation screw on hip screw migration or cutout in intertrochanteric fracture fixation., Materials and Methods: We screened 488 patients with unilateral fragile intertrochanteric fractures treated with DHS between January 2001 and March 2016. The inclusion criteria were as follows: (1) age ≥ 50 years; (2) low-energy injury; (3) follow-up of at least 6 months; and (4) short barrel plate used in the operation. The exclusion criteria were as follows: (1) combination with other fracture; or (2) pathological fracture. Subsequently, 166 patients were enrolled; of them, 128 underwent surgery using DHS with an additional screw (Group 1) and 38 patients underwent surgery without an additional screw (Group 2). We compared the postoperative results and clinical outcomes while focusing on screw migration and cutout. Furthermore, we investigated the risk factors for lag screw migration., Results: Bone union was achieved in 160 patients (96.4%) without secondary intervention. Two patients (1.6%) in Group 1 and 1 (2.6%) in Group 2 developed screw cutout, while 18 (14.1%) in Group 1 and 12 (31.6%) in Group 2 developed screw migration. Thus, Group 2 demonstrated a higher screw migration rate. Multiple logistic regression analysis revealed that the additional anti-rotation screw was the most important factor in preventing screw migration (P = 0.019)., Conclusion: The additional anti-rotation screw reduced the lag screw migration rate following DHS surgery for intertrochanteric fractures., Level of Evidence: Level IV, retrospective series.

Background: Yellow nail syndrome is a rare condition associated with a triad of symptoms: yellow nails, lung lesions, and lymphedema. We report a case of yellow nail syndrome caused by titanium exposure from multiple artificial joint replacements., Case Presentation: A 78-year-old Asian woman presented to our outpatient department with chief complaints of cough, fever, and nausea. The patient was hospitalized for observation because of the presence of hypoxemia and bilateral pleural effusion. Her medical history included knee joint replacement and two spinal fusion surgeries. Her physical examination conducted following hospitalization revealed yellow nails on both hands and feet. This finding, combined with the observation of bilateral pleural effusion, raised suspicion for yellow nail syndrome. Blood analysis yielded negative results, as did the tests for sputum culture, interferon liberation, pleural effusion culture, and pleural effusion cytology. Pleural histopathological analysis and imaging yielded negative results. Considering the possibility of titanium exposure from artificial joints based on the patient's medical history, we examined a chest radiograph obtained before the second spinal fusion surgery; however, no pleural effusion was observed. Pleural effusion was observed, however, following the surgery. On the basis of these findings, the patient was diagnosed with yellow nail syndrome due to titanium exposure., Conclusions: Clinicians should examine the nails of patients with unexplained pleural effusion. Moreover, they should inquire about titanium exposure when obtaining the patient's medical history.

Purpose: Post-operative instrumented spine infection (PISI) is an infrequent complication. Diagnosis of spinal implant infection can be difficult, especially in case of chronic infection., Methods: This retrospective study attempts to evaluate the diagnostic performance of [ 18 F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in PISI. Imagings were performed between April 2010 and June 2018 among patients referred for suspected chronic spinal implant infection. PET/CT were performed more than 12 weeks after surgery. PET/CT images were re-interpreted independently by two nuclear medicine physicians without knowledge of the patient's conditions. PET/CT data were analyzed both visually and semi-quantitatively (SUV max ). MRI results were collected from medical records. The final diagnosis of infection was based on bacteriological cultures or a twelve-month follow-up., Results: Forty-nine PET/CT were performed in 44 patients (22 women, median age 65.0 years). Twenty-two patients had a diagnosis of infection during follow-up. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PET/CT were 86.4%, 81.5%, 79.2%, and 88.0%. Sensitivity, specificity, PPV and NPV were 66.7%, 75.0%, 66.0%, 75.0% respectively for MRI and 50.0%, 92.6%, 84.6% and 69.4% for serum C-reactive protein (CRP). Although these values were higher for PET/CT than for MRI or CRP, the differences were not statistically significant. In this setting, false positives with PET/CT can be observed in case of previous spine infection or adjacent segments disc disease. False negatives can result of extensive instrumented arthrodesis or infection with low virulence bacteria., Conclusion: PET/CT is useful for the diagnosis of PISI. These results should be evaluated in further prospective study., (Copyright © 2019 Société française de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.)

Objective: We aimed to compare the clinical efficacy of titanium mesh cage with that of allogeneic bone graft to reconstruct the anterior column through posterior approach for the surgical management of patients with thoracolumbar spinal tuberculosis with kyphosis., Methods: From January 2011 to March 2013, 57 patients with single-segment or two-segments thoracolumbar spinal tuberculosis with kyphosis were treated by debridement, interbody graft, posterior instrumentation, and fusion via a posterior-only procedure. Twenty-four patients in group A were treated with allogeneic bone graft to reconstruct the anterior column, whereas 33 patients in group B were treated with titanium mesh cage. The clinical efficacy was evaluated by visual analog scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), neurologic function recovery, kyphotic Cobb angle, and postoperative complications., Results: The mean follow-up was 72.4 months. Neurologic function was significantly improved after surgery in all cases. There were significant differences of VAS, ESR, and CRP between preoperation and postoperation at the final follow-up, with no significant difference between the two groups. The kyphotic Cobb correction was significantly improved when compared with those in preoperation, but there was no significant difference between the two groups. One patient in group A with two segments involved experienced graft fracture. He had anterior bone graft with titanium mesh cage., Conclusions: Minimum 5-year follow-up outcomes showed that one-stage posterior focus debridement, interbody graft using titanium mesh cages, posterior instrumentation, and fusion is an effective treatment for patients with thoracolumbar spinal tuberculosis accompanied by kyphosis. It may obtain better clinical efficacy than allogeneic bone graft for treating two-segments thoracolumbar spinal tuberculosis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: Presently, unstable intertrochanteric femur fractures are treated commonly with intramedullary nailing devices. Various designs of intramedullary nail are introduced. The conventional Proximal Femoral Nail has given diverse outcome. Complications have also been noted with this implant. Newer designs like Proximal Femoral Nail Antirotation-2 have been introduced for Asian population. The aim of our study was to compare the radiological and functional outcome of unstable intertrochanteric femur fracture treated with conventional Proximal Femoral Nail and Proximal Femoral Nail Antirotation-2 in osteoporotic patients., Materials and Methods: Patients presenting with unstable intertrochanteric femur fracture (AO classification) and Singh's index ≤ 3 were included. Patients were assigned to the groups based on the implant used for treatment (PFN and PFNA2 group). Post-operative radiographs were used to assess the quality of reduction, by calculating neck shaft angle. The quality of fixation was assessed, by calculating tip apex distance and Cleveland index. The duration of surgery, blood loss, number of fluoroscopic images taken and length of hospital stay were noted. Patients were followed up for 6 months, and complications were noted. The functional outcome was compared using modified Harris hip score. The data analysis was done using Student's unpaired t test/Mann-Whitney U test and Chi-square test/Fisher's exact test. A p value less than 0.05 was considered significant., Results: Seventy-eight patients with unstable intertrochanteric fractures and Singh's index < 3 were included. Thirty-seven were treated with PFNA2 and 41 with PFN. The average age in PFNA2 group was 69.51, and PFN group was 70.804. Nine patients in PFNA2 group and 10 patients in PFN group had tip apex distance more than 25 mm. Twelve patients in PFNA2 group and 14 Patients in PFN group had sub-optimal implant position as per Cleveland index. The difference in neck shaft angle between uninjured and operated side was more than 10° in four patients of PFNA2 group and seven patients of PFN group. The average Harris hip score was 74.55 for PFNA2 group and 69.88 for PFN group. Four complications were seen in PFNA2 group and 5 in PFN group., Conclusion: The functional outcome (p = 0.102) achieved with both the implants was similar. Good functional outcome can be achieved, when the radiological parameters are restored, i.e. TAD < 25 mm, Cleveland index in centre-centre position and neck shaft angle difference < 5°. The overall complications, in the set-up of osteoporosis, seen with both the implants were similar (p = 0.44). PFNA2 group showed better results in terms of perioperative morbidity.

Background: The risk of posterior cage migration (PCM) exists when a fusion cage is used for transforaminal lumbar interbody fusion (TLIF). This complication is influenced by contact pressure between the endplate and the cage. Previous reports demonstrated that anteriorly located cages bore more load and had greater strain than posteriorly located cages. However, there have been no detailed reports on the correlation between cage positioning and PCM., Methods: From March 2014 to October 2015, we reviewed 953 patients receiving open transforaminal lumbar interbody fusion (TLIF) and bilateral pedicle screw instrumentation. One hundred patients without PCM were randomly sampled as the control group. Postoperative sagittal and coronal cage positions in the disc space were evaluated with the 'depth ratio' and the 'coronal ratio'. The demographic data of patients with and without PCM were compared to detect patient-related factors. Radiographic and cage related parameters, including cage position, preoperative disc height, preoperative spine stability, cage geometry, cage size, and height variance (= cage height - preoperative disc height) were compared between the PCM group and the control group. Univariate analyses and a multivariate logistic model were used to identify risk factors of PCM., Results: Posterior cage migration occurred in 24 (2.52%) of 953 patients. The univariate and multivariate analyses revealed that those with a decreased depth ratio (OR, 9.78E-4; 95% CI, 9.69E-4 - 9.87E-4; p < 0.001) and height variance (OR, 0.757, 95% CI, 0.575-0997, p = 0.048) had a significantly higher risk of developing PCM., Conclusions: Our results verified that posteriorly located cages and undersized cages are more prone to developing PCM, which may aid surgeons in making optimal decisions during TLIF procedures.

Background: Growing rod constructs are an important contribution in the treatment of children with early onset scoliosis even though these devices experience high rates of rod fracture. The mechanical performance of traditional, distraction-based dual growing rod constructs is not well understood, and mechanical models for predicting device performance are limited., Purpose: Two mechanical models were developed and used to determine the mechanical performance of various growing rod configurations by increasing construct complexity., Study Design/setting: Mechanical bench testing and finite element (FE) analysis., Methods: Static and dynamic compression bending tests were based on an ASTM F1717 method modified to accommodate dual growing rod constructs. Six construct configurations were tested, mechanical properties were recorded, and statistical analyses were performed to determine significant differences between groups: (1) no connectors (rods only), (2) side-by-side connectors, (3) side-by-side connectors plus 4 crosslinks, (4) (40-mm long tandem connectors, (5) 80-mm long tandem connectors, and (6) 80-mm long tandem connectors plus 4 crosslinks. FE analysis was used to predict the stress distribution within the constructs., Results: The static results indicated greater stiffness, yield load, and peak load as the axial connector length increased (side-by-side to 40 mm tandem to 80 mm tandem). The dynamic results showed similar cycles to failure for side-by-side and tandem connector (40 and 80 mm) construct configurations without crosslinks. Crosslinks shifted the location of rod fracture observed experimentally and significantly reduced the fatigue life of the construct. The flexibility of the construct decreased significantly as the axial connector length increased. FE predictions were highly consistent with the experimentally measured values and provided information on stress distribution within the rod for comparison to experimental fracture locations., Conclusions: This is the first study to evaluate mechanical performance of various configurations of pediatric growing rod constructs using preclinical models. The current study is consistent with a previous retrieval study in that rigid constructs lacking flexibility (ie, higher stiffness and lower displacement), such as those with 80-mm tandem connectors and multiple crosslinks, demonstrated decreased mechanical performance as shown through both experimental and computational models. Additionally, the experimental and computational findings suggest that surgeons should strategically consider the number of interconnecting components and subsequent stress concentrations along the posterior side of the rod. For example, changing the placement of crosslinks to low stress regions of the construct or not using crosslinks in the construct are options., (Published by Elsevier Inc.)

Background: Postoperative dysphagia is one major concern in the treatment for patients with cervical spine spondylosis by using anterior cervical discectomy and fusion (ACDF) with plating and cage system., Purpose: To evaluate the influence of two types of surgery for multilevel cervical spondylotic myelopathy (CSM) on postoperative dysphagia, namely ACDF with cage alone (ACDF-CA) using Fidji cervical cages and ACDF with cage and plate fixation (ACDF-CP)., Methods: A retrospective study was performed in 62 consecutive patients with multilevel CSM, including 32 underwent ACDF-CA (group A) and 30 underwent ACDF-CP (group B). All enrolled patients were followed up at 48 h, 2 months and 6 months postoperatively, when the dysphagia rate, Swallowing-Quality of Life (SWAL-QOL) score and the thickness of prevertebral soft tissue were recorded., Results: At 48 h and 2 months, the dysphagia rate and thickness of prevertebral soft tissue were both significantly lower in group A than in group B, while the SWAL-QOL score of group A was significantly higher than that of group B. No significant difference was observed at 6 months., Conclusion: Fidji cervical cages could relieve postoperative dysphagia in the treatment of multilevel CSM with ACDF, especially at the first several months postoperatively., (Copyright © 2019. Published by Elsevier Ltd.)

Study Design: A retrospective database review., Objective: The purpose of this study was to analyze the rate of nonunion in patients treated with structural allograft and intervertebral cages in anterior cervical discectomy and fusion (ACDF)., Summary of Background Data: Existing literature consists primarily of single-center studies with inconsistent findings., Methods: We performed a retrospective analysis of 6130 patients registered in the PearlDiver national database through Humana Insurance from 2007 to 2016. All ACDF patients with anterior plating who were active in the database for at least 1 year were included in the study. Patients with a fracture history within 1 year of intervention, past arthrodesis of hand, foot, or ankle, or a planned posterior approach were excluded from the study. Patients were stratified by number of levels treated, tobacco use, and diabetic condition. Nonunion rates of structural allograft and intervertebral cage groups after 1 year were compared using Chi-squared analyses., Results: Four thousand sixty-three patients were included in the allograft group, while 2067 were included in the cage group. Overall nonunion rates were significantly higher in the cage group (5.32%) than in allograft group (1.97%) (P < 0.01). When controlling for confounders, increased rates of nonunion were consistently observed in the cage group, achieving statistical significance in 25 of the 26 analyses., Conclusion: The increased rate of nonunion associated with intervertebral cages may suggest the superiority of allograft over cages in ACDF., Level of Evidence: 3.