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Background: Automated broaching has recently been introduced for total hip arthroplasty (THA), with the goal of improving surgical efficiency and reducing surgeon workload. While studies have suggested that this technique may improve femoral sizing and alignment, little has been published regarding its safety, particularly with regard to calcar fractures. The purpose of our study was to evaluate the risk of calcar fracture during automated broaching, and to determine if this risk can be mitigated., Methods: We queried our prospective institutional database and identified 1596 unilateral THAs performed by the senior author using automated impaction between 2019 and 2023. We identified the incidence of calcar fracture with automated impaction, and whether the fracture occurred during broaching or stem insertion. We additionally determined calcar fracture incidence within two consecutive subgroups of patients using different stem insertion techniques; subgroup (1): automated broaching with automated stem insertion for all patients; versus subgroup (2): automated broaching with automated stem insertion ONLY if a cushion of cancellous bone separated the broach from the calcar, otherwise the stem was placed manually. Continuous and categorical variables were analyzed with Student's t-test and Fisher's exact test, respectively., Results: Seventeen calcar fractures occurred intraoperatively (1.1 %). Only two fractures occurred during automated broaching (0.1 %), while fifteen occurred during final stem impaction (0.9 %) (p = 0.007). Four calcar fractures (1.4 %) occurred in subgroup 1, compared to two in subgroup 2 (0.6 %) (p = 0.28)., Conclusions: Our study found a calcar fracture incidence of 1.1 % using automated impaction, consistent with historically reported rates of 0.4-3.7 %. We found that calcar fractures are more likely to occur during stem insertion than during femoral broaching. We recommend that if any part of the final broach is in direct contact with the calcar, the final stem should be impacted manually to minimize fracture risk., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Impaction in total hip arthroplasty has typically been conducted using a mallet. A surgical automated impactor has been developed with the goal of reducing surgeon variability, fatigue, and injury. There is also potential to reduce the variability of each impaction step in which automated impaction is used, through reproducible and consistent application of force., Methods: Patients were randomized into either the mallet control group, or the automated impaction study group (1:1 randomization). The primary endpoint analysis was conducted to demonstrate that femoral broaching time (in minutes) with an automated impactor is noninferior to femoral broaching time with manual instruments (mallet) under a noninferiority (NI) margin of 1.25 minutes, with a subsequent test of superiority. A total of 218 patients were randomized and treated (109 in each group)., Results: Mean femoral broaching time was 5.8 minutes in the automated impaction study group (automated), and 8.1 minutes in the mallet control group (mallet), a 28.4% reduction ( P  = .0005). However, there was not a difference in surgery duration between the groups. Three fractures were reported in the mallet group and 1 in the automated group., Conclusions: In this randomized multicenter study, an automated impactor was shown to reduce femoral broaching time in primary total hip arthroplasty, with no increase in fractures, but no decrease in operating room time was noted., (© 2024 The Authors.)

Background: Recently, fluoroscopy-assisted computer navigation has been developed to assess intraoperative cup inclination/anteversion and leg-length discrepancy (LLD) in the operating room. However, there is a relative dearth of studies investigating the accuracy of this software compared with postoperative radiographs., Materials and Methods: We prospectively enrolled 211 navigated anterior total hip arthroplasties using fluoroscopy-assisted computer navigation software. Intraoperative navigated measurements were compared with postoperative anteroposterior radiographs to assess accuracy of cup inclination/anteversion and LLD. Continuous variables were analyzed using the Student's t test, and categorical variables were analyzed using Fisher's exact test., Results: On postoperative radiographs, 94.3% of cups (199 of 211) were positioned within the Lewinnek "safe zone," compared with 99.1% navigated intraoperatively ( P =.01). Eighty-two percent of hips (174 of 211) were navigated intraoperatively to LLDs within ±2 mm; on postoperative radiographs, 65% of hips (138 of 211) had LLDs within ±2 mm ( P =.0001). Intraoperatively, 100% of hips (211 of 211) were navigated to LLDs within ±5 mm; similarly, on postoperative radiographs, 98% of hips (207 of 211) had LLDs within ±5 mm ( P =.12)., Conclusion: A novel fluoroscopy-assisted computer navigation platform accurately assessed intraoperative cup position and LLD during anterior total hip arthroplasty. Careful attention to fluoroscopic technique, positioning of radiographic landmarks, and knowledge of the limitations of fluoroscopy, including parallax effect, are important concepts that surgeons should incorporate into their decision algorithm. [ Orthopedics . 2024;47(4):e174-e180.].

Background: Successful total hip arthroplasty (THA) relies on the correct implant position. THA accuracy can be improved with the use of intraoperative fluoroscopic-assisted computer navigation. Artificial intelligence (AI) software may enhance fluoroscopic navigation; however, the accuracy of the AI compared to human-controlled software in assessing acetabular component position and leg length discrepancy (LLD) has not been studied., Methods: We analyzed 420 consecutive primary THAs performed by a single surgeon using fluoroscopic-assisted computer navigation software. The first cohort of 211 patients required inputs from a human technician (manual), while the second cohort of 209 patients used an automated version of the software controlled by AI. The intraoperative acetabular component placement (inclination and anteversion) and LLD were recorded and compared to the 2-week postoperative standing anterior-posterior pelvis radiograph., Results: Ninety-four percent (199/211) of cups in the manual cohort and 95% (198/209) of cups in the AI cohort were within the Lewinnek "safe-zone" ( P  = 1.0). In the manual cohort, 69% (146/211) of THAs had a final LLD within ±2 mm of the intraoperatively navigated LLD (ie, ΔLLD ≤2 mm). In the AI cohort, 66% (137/209) of THAs had a final LLD within ±2 mm of the intraoperatively navigated LLD ( P  = .47). Ninety-nine percent (209/211) of hips in the manual cohort and 98% (205/209) of hips in the AI cohort had a final LLD within ±5 mm of the intraoperatively navigated LLD ( P  = .45)., Conclusions: Both AI and human-controlled versions of the same navigation platform were similarly accurate for navigating cup position within the Lewinnek "safe zone" and LLD accuracy., (© 2024 The Authors.)

Instability remains a challenge after total hip arthroplasty (THA). We have previously utilized a monofilament polypropylene mesh to reconstruct the posterior capsule for unstable THA. This study identified 24 hips that underwent mesh reconstruction of the posterior capsule for instability. Survivorship was 70.8% at mean 6.5 years (range 6 weeks-20.1 years). Six patients underwent re-operation, and one patient had the mesh removed. Of eight hips, five (62.5%) with a history of prior revision re-dislocated, while only 2/16 hips (12.5%) with no previous revision history re-dislocated (p = 0.02). Posterior capsule reconstruction with polypropylene mesh has reasonable mid-term survivorship in this challenging population. (Journal of Surgical Orthopaedic Advances 32(2):092-096, 2023).

Background: This study sought to determine the accuracy in placing the acetabular component, estimation of leg length, offset, radiation time and dose, and operative time using a handheld navigation device compared to conventional anterior total hip arthroplasty (THA). It also examined the learning curve of the handheld navigation device., Methods: Data were prospectively collected for a consecutive series of 159 THAs; 99 THAs with handheld navigation and 60 conventional THAs. Thresholds of <5°, ≥5° to <10°, and ≥10° for acetabular inclination and version and thresholds of <5 mm, ≥5 mm to <10 mm, and ≥10 mm for leg-length and combined offset discrepancy were used to assess accuracy. Fluoroscopy time and exposure, operative time, and complications were compared. Learning curve was determined using operative time. Statistical analysis was performed for the different accuracy thresholds with P values set a <0.05 for significance., Results: The handheld navigation device demonstrated a mean accuracy of 3.2° and 1.8° for version and inclination, respectively. The handheld navigation group had significantly fewer outliers in version ( P < .001), inclination ( P < .001), leg-length discrepancy ( P < .001), and offset discrepancy ( P < .001). Fluoroscopic dose and time ( P < .001) were lower in the handheld navigation cohort. The learning curve for handheld navigation was 31-35 cases. The mean operative time after the learning curve was similar to that in the conventional fluoroscopy group ( P  = .113)., Conclusions: Handheld navigation technology provided more accurate results while mitigating radiation exposure to the surgeon and patient. There were fewer outliers in the handheld navigation group. After the learning curve, all metrics improved in accuracy, and operative time was similar to that of the conventional technique., (© 2022 Published by Elsevier Inc. on behalf of The American Association of Hip and Knee Surgeons.)

Background: Total hip arthroplasty (THA) in patients with severe chronic pubic diastasis from either congenital or acquired causes presents an exceptionally difficult challenge that has rarely been addressed in the arthroplasty literature. The purpose of this paper is to present a series of THAs in patients with severe chronic pubic diastasis, asking the following research questions: (1) What is the survivorship and clinical outcomes after THA in patients with severe chronic pubic diastasis? And (2) What is the rate of complications after THA surgery in this challenging patient population? We additionally describe our algorithm for preoperative planning and rationale for surgical technique and implant position., Material and Methods: We retrospectively queried the prospective arthroplasty database of 2 high-volume referral centers, yielding 6 THA in 4 patients with severe chronic pubic diastasis (minimum 8 cm) with a mean follow-up of 2.7 years. We recorded baseline demographic and intraoperative variables, as well as survivorship, patient-reported outcomes (Hip disability and Osteoarthritis Outcome Score for Joint Replacement score), and incidence of complications., Results: There were no failures reported (100% survivorship) at a mean follow-up of 2.7 years. Mean Hip disability and Osteoarthritis Outcome Score for Joint Replacement scores improved from 36.0 preoperatively to 82.8 postoperatively. There were no infections, dislocations, fractures, or any major complications in the postoperative period., Conclusion: THA for patients with severe chronic pubic diastasis remains a rare but challenging reconstructive procedure. Excellent outcomes can be achieved with adequate preparation, particularly regarding the acetabular component position. Understanding the nature of the hemipelvis deformity and meticulous templating using "normalized" views of the hip are important components to a successful preoperative plan., (© 2022 The Authors.)

Background: Pelvic tilt affects acetabular anteversion, and thus total hip arthroplasty (THA) dislocation risk. The pubic symphysis-sacrococcygeal distance (PSCD) is an indicator of pelvic tilt, and a PSCD < 0 mm (ie, excessive posterior pelvic tilt) is associated with a 3.7-fold increase in postoperative dislocation rate. However, it is not known if the direct anterior (DA) approach might reduce this dislocation rate, specifically in high-risk populations such as negative PSCD., Methods: Standing anteroposterior radiographs were reviewed for 510 consecutive DA THAs to determine PSCD. Patients were separated into 2 groups: (1) PSCD > 0 mm (PSCD[+]) and (2) PSCD < 0 mm (PSCD[-]). Incidence of dislocation was determined. We recorded if patients had spinal deformity or lumbar fusion. Continuous variables were analyzed using Student's t-test, categorical variables were analyzed using Fisher's exact test, and a sample size calculation was performed., Results: Three hundred fifty-eight hips (70.2%) were PSCD[+], while 152 hips (29.8%) were PSCD[-]. Three dislocations (3/510 hips, 0.6%) occurred. Two dislocators were in the PSCD[-] group (2/152 hips, 1.3%) and 1 dislocator was in the PSCD[+] group (1/358 hips, 0.3%) (P = .21). Twenty-four patients had degenerative scoliosis (24/510, 4.7%), of which 1 had a dislocation (1/24, 4.2%); 2 dislocations occurred in nonscoliosis patients (2/486, 0.4%) (P = .134). Twenty-seven patients had lumbar spinal fusion (27/510, 5.3%), of which there were no dislocations (0/27, 0.0%); all dislocations were in nonfusion patients (3/483, 0.6%) (P = 1.0)., Conclusion: We demonstrate no increased risk for THA dislocation in patients with a PSCD < 0 mm who have undergone a DA approach. These data would suggest a protective effect of the DA approach against dislocation, even in historically high-risk populations., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Comparing total joint arthroplasty (TJA) costs and patient-reported outcomes between a physician-owned hospital (POH) and a non-POH., Methods: Costs for each 90-day TJA episode at both facilities were determined, and patients were asked to complete a patient satisfaction questionnaire., Results: Average TJA episode cost was $19,039 at the POH, compared to $21,302 at the non-POH, a difference of $2,263 ( p  = 0.03), largely driven by decreased skilled nursing facility utilization in the POH group. There were no differences between groups for patient satisfaction., Conclusion: TJA can be performed at reduced cost with comparable patient satisfaction at POHs, compared to non-POH facilities., Competing Interests: The authors have declared no conflict of interest., (© 2021 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Acetabular exposure for direct anterior (DA) total hip arthroplasty (THA) can be performed using hands-free, self-retaining retractors. No current study quantitatively compares this self-retaining technique with the traditional manual technique. In 65 consecutive DA THA hips, two "best-view" digital photographs were taken of the exposure-one using Charnley/self-retaining retractors and one using a traditional three-retractor manual technique. Percent exposure of the polyethylene liner was calculated. Percent acetabular exposure averaged 80.0% using the Charnley/self-retaining technique, compared with 73.1% using the manual technique ( P =.0002). A hands-free technique provides superior acetabular exposure compared with the manual technique. Increasing body mass index predicts decreasing exposure with both techniques. [ Orthopedics . 2021;44(2):e309-e313.].

Objective: To investigate the effect of accelerometry-based navigation (ABN) on early clinical outcomes after TKA., Methods: 71 TKAs were performed via ABN and 37 TKAs via standard instrumentation (STD). Patients were assessed at the second post-operative visit to determine early KOOS, JR scores., Results: At average 2.7 months, mean KOOS, JR in the ABN group was 68.5 (range 34.2-100) compared to 62.5 (range 20.9-84.6) in the STD group ( p  = 0.045). Tourniquet time averaged 65.2min (range 51-79min) in STD group, compared with 70.7min (range 53-108min) in ABN group ( p  = 0.029)., Conclusion: Early KOOS, JR scores are improved with ABN for TKA., Competing Interests: The authors have declared no conflict of interest., (© 2020 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Purpose of Review: The purpose of this review was to evaluate the available literature to determine what may be considered urgent indications for total hip arthroplasty, in the unprecedented setting of the worldwide COVID-19 pandemic., Recent Findings: SARS-CoV-2 is a novel coronavirus currently presenting in the form of a global pandemic, referred to as COVID-19. In this setting, multiple states have issued executive orders prohibiting "elective" surgery, including arthroplasty, in order to preserve healthcare resources. However, during this unprecedented reduction in elective surgery, there is likely to be some controversy as to what constitutes a purely "elective" procedure, versus an "urgent" procedure, particularly regarding hip arthroplasty. We reviewed the available literature for articles discussing the most commonly encountered indications for primary, conversion, and revision hip arthroplasty. Based upon the indications discussed in these articles, we further stratified these indications into "elective" versus "urgent" categories. In patients presenting with hip arthroplasty indications, the decision to proceed urgently with surgery should be based upon (a) the potential harm incurred by the patient if the surgery was delayed and (b) the potential risk incurred by the patient in the context of COVID-19 if surgery was performed. The authors present a decision-making algorithm for determining surgical urgency in three patients who underwent surgery in this context. Urgent total hip arthroplasty in the setting of the COVID-19 pandemic is a complex decision-making process, involving clinical and epidemiological factors. These decisions are best made in coordination with a multidisciplinary committee of one's peers. Region-specific issues such as hospital resources and availability of PPE may also inform the decision-making process.

Objective: Investigate the efficiency/accuracy of surgical automation versus manual component implantation in DA THA., Methods: Retrospective review of 111 hips: 51 hips via automation and 60 hips via manual technique for DA THA., Results: OR time averaged 8 min faster in the Automated group, compared to Manual group ( p  = 0.0009). Average femoral size was one size larger in the Automated group compared to Manual group ( p  = 0.007). No clinically significant differences were found between Manual and Automated groups for cup position or limb-length discrepancy. One calcar fracture occurred in the Automated group., Conclusion: Surgical automation is efficient and accurate for DA THA., (© 2020 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Objective: Assessing financial effects of removal of TKA from CMS inpatient-only list on physician-owned bundles., Methods: We determined whether Medicare TKAs remained inpatient, versus changed to observational. We used CMS data to determine savings. Direct costs associated with BPCI were calculated., Results: 7/28 TKAs (25.0%) had inpatient status changed to observational, excluding them from BPCI. Estimated savings losses were $24,332. Direct costs for administrating BPCI were $51,250. Had the rate of patients changed to observational been 50%, bundle savings from remaining patients would be less than direct costs., Conclusion: Removing TKA from CMS inpatient-only list may have negative financial implications., (© 2020 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Objective: To determine what factors increase the risk of early wound complications in patients undergoing direct anterior total hip arthroplasty whose wounds were closed with 2-octyl cyanoacrylate with mesh., Methods: This study was a retrospective review of 75 consecutive patients who underwent direct anterior total hip arthroplasty closed with 2-octyl cyanoacrylate with mesh., Main Results: Of 29 patients who were smokers, five patients (17.2%) developed a wound complication, whereas out of 46 nonsmokers, only one patient (2.2%) developed a wound complication (P = .029)., Conclusions: The authors recommend a closure technique that sufficiently protects the wound during healing, as well as preoperative patient optimization and smoking cessation.

Objective: Investigating patients' perceptions regarding need for antibiotic prophylaxis during dental procedures after undergoing joint arthroplasty., Methods: Questionnaire was administered to patients presenting at: 1)an orthopaedic office; 2)a dental office; regarding perceptions of antibiotic prophylaxis., Results: 36 orthopaedic patients responded "Yes" to always taking prophylaxis; 36 patients responded "No" (36/72, 50.0% compliance). Five dental patients responded "Yes" to always taking prophylaxis; 19 patients responded "No" (5/24, 20.8% compliance) ( p  = 0.017). 67/135 orthopaedic patients (49.6%) endorsed some form of dental prophylaxis, versus 34/58 dental patients (58.6%) ( p  = 0.27)., Conclusion: Patient perceptions of the need for dental prophylaxis vary within orthopaedic and dental practices., (© 2019 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Templating for total hip arthroplasty requires proper radiographic calibration. One option for radiograph calibration is using a cobalt-chrome femoral head ball. The authors reviewed radiographs and clinical data for patients undergoing primary total hip arthroplasty. Radiographs were calibrated using a 28-mm cobalt-chrome femoral head ball. Agreements between templated and actual implant size were calculated. The templated acetabulum matched within one size of the actual acetabulum in 76.7% to 80.0% of cases. The templated femur matched within one size of the actual femur in 83.3% to 93.3% of cases. This technique is an attractive option when a standardized calibration marker is unavailable. [Orthopedics. 2019; 42(3):e346-e349.]., (Copyright 2019, SLACK Incorporated.)

Objective: To investigate patient factors influencing length-of-stay (LOS) after revision metal-on-metal (MoM) total hip arthroplasty (THA)., Methods: We reviewed 23 hips undergoing revision of a MoM THA with minimum 2-year follow-up. A multiple linear regression was calculated to predict LOS using multiple variables., Results: Average length of stay (LOS) was 2.1 days. Multiple linear regression analysis identified a significant correlation between presence of an abductor injury (beta = 0.8886; p  < 0.0001), patient age (beta = -0.4452, p  = 0.0083), and pre-revision head size (beta = 0.4082; p  = 0.0172) with LOS (R 2  = 0.6351, p  = 0.0002)., Conclusion: Patients with abductor injury, larger femoral heads, and younger age are at risk for longer LOS.

Release of the conjoined tendon has been reported to facilitate femoral exposure during a direct anterior hip approach. However, the authors are not familiar with any description of an anterior approach repair technique for this important structure. Conjoined tendon repair is commonly performed in the posterior approach to help preserve hip biomechanics and restore anatomic tissue planes. The authors describe their algorithm for sequential soft tissue releases to facilitate femoral exposure and a technique for repairing the insertion of the conjoined tendon after it has been released for exposure during the direct anterior approach. [Orthopedics. 2018; 41(4):e583-e586.]., (Copyright 2018, SLACK Incorporated.)

Background: Factor-Xa inhibitors have been introduced for prevention of venous thromboembolism (VTE) after joint arthroplasty. However, these agents could also be associated with bleeding or wound complications after surgery., Methods: We retrospectively reviewed a consecutive series of 59 patients (31 knees, 28 hips) undergoing joint arthroplasty at a high-volume joint arthroplasty referral center, both before and after implementation of a new VTE risk-stratification tool at our institution. Patients with a history of VTE, bilateral procedures, or medical conditions already requiring VTE chemoprophylaxis were excluded. We reviewed the medical records to determine (1) type of VTE prophylaxis used, (2) incidence of bleeding/wound complications in the postoperative period, (3) incidence of VTE in the postoperative period, and (4) change in serum hemoglobin., Results: Twenty-seven patients (46%) were given aspirin for VTE prophylaxis, while 32 patients (54%) received a factor-Xa inhibitor. There were no new VTE complications in either group. And 6 of 32 patients (18.7%) in the Xa inhibitor group had a postoperative bleeding/wound complication (4 delayed healing/blistering, 1 hematoma/excessive ecchymosis, and 1 readmission for cellulitis). There were no (0%) bleeding/wound complications in the aspirin group (P = .03). The change in hemoglobin level was -2.76 g/dL in patients receiving aspirin vs -2.84 g/dL in patients receiving a Xa inhibitor (P = .73)., Conclusion: In our study of total joint patients, factor-Xa inhibitors were associated with a higher incidence of bleeding/wound complications. The choice of VTE prophylaxis should be based on the perceived risks of bleeding and wound complications compared to the risks of VTE in each patient., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Custom triflange acetabular components are being increasingly used for the reconstruction of Paprosky type IIIB acetabular defects. However, midterm survivorship data are lacking., Methods: We queried the prospective registries at 2 high-volume revision centers for patients who had undergone revision total hip arthroplasty using a custom triflange component between 2000 and 2011. We identified 73 patients with minimum 5-year follow-up. These patients' records were reviewed to determine incidence of revision or reoperation, clinical performance, and radiographic stability. The mean follow-up was 7.5 years (range 5-12 years)., Results: Fifteen of 73 triflange components (20.5%) were indicated for revision during the follow-up period, including 6 for instability (8%) and 8 for infection (11%). Twelve of 73 patients (16%) underwent reoperation for reasons other than failure of the triflange component. The median hip disability and osteoarthritis outcome score for joint replacement score at midterm follow-up was 85 (interquartile range 73-100). Only 1 of 73 implants was determined to be radiographically loose at midterm follow-up., Conclusion: Custom triflange reconstruction for severe acetabular deficiency is a viable option; however, complications are common and significant challenges remain for those that fail., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Study Design: A prospective study of a new technique., Objective: The aims of this study were to report a manual technique for measuring vertebral curves on digital spine radiographs, and to assess the agreement of this technique with that of digital software for measuring vertebral curves., Summary of Background Data: Modern picture archiving and communication systems (PACS) typically include software for evaluating radiographic measurements. However, in the outpatient spine setting, patients may present with radiographs stored on a physical disc, which may not include software for measuring vertebral curves. Certain smartphone applications may be used to determine curve magnitude; however, the need exists for an accurate manual technique to measure vertebral curves on digital radiographs in the absence of available analytic software or smartphone technology., Methods: We prospectively reviewed anteroposterior and lateral spine radiographs of 24 spinal deformity patients. Two independent observers measured Cobb angles for: (1) the major coronal curve; (2) the thoracic kyphosis (T2-T12); and (3) the lumbar lordosis (T12-S1). Measurements were made: (1) digitally using our institution's PACS; and (2) by a manual technique, which involves placement of an adhesive Post-It note directly on the computer screen, transcribing the angle onto the Post-It note with a pencil, and measuring the angle with a handheld goniometer. Intraclass correlation coefficients (ICCs) were calculated to determine the agreement between the 2 methods., Results: For both observers, the agreement between the digital PACS and manual Post-It techniques was graded as excellent for both coronal and sagittal plane curves (all ICCs>0.9). Interobserver reliability between the 2 observers was also graded as excellent for both the PACS and Post-It techniques (all ICCs>0.9)., Conclusions: The Post-It technique for measuring Cobb angles demonstrated excellent agreement with the PACS system in our series of spinal deformity patients. Curves on digital radiographs can be accurately measured using a convenient manual technique.

Differentiating septic arthritis of the pediatric hip from other causes of hip pain and effusion continues to present a diagnostic challenge for the clinician. Although septic arthritis traditionally has been reported to have a synovial white blood cell count of 75,000 cells/mm3 or greater, lower counts can be seen in this condition. In cases where a synovial sample has been obtained and the cell count falls in the intermediate range between 25,000 and 75,000 cells/mm(3), it is unclear what proportion of these cases may be truly septic hips. In this evidence-based review, we examine Heyworth et al's study focusing on the predictive value of this intermediate white cell count range in a Lyme-endemic region.

Background: Knowledge of the complex kinematics of the native knee is a prerequisite for a successful reconstructive procedure. The aim of this study is to describe the primary and coupled motions of the native knee throughout the range of knee flexion, in response to applied varus and valgus loads., Methods: Twenty fresh-frozen cadaver knees were affixed to a six degree of freedom robotic arm with a universal force-moment sensor, and loaded with a 4Nm moment in varus and valgus at 0, 15, 30, 45, and 90° of knee flexion. The resulting tibiofemoral angulation, displacement, and rotation were recorded., Results: For each parameter investigated, the knee joint demonstrated more laxity at higher flexion angles. Varus angulation increased progressively from zero (2.0° varus) to 90 (5.2° varus) degrees of knee flexion (p<0.001). Valgus angulation also increased progressively, from zero (1.5° valgus) to 90 (3.9° valgus) degrees of knee flexion (p<0.001). At all flexion angles, the magnitude of tibiofemoral angle deviation was larger with varus than with valgus loading (p<0.05)., Conclusions: We conclude that the native knee exhibits small increases in coronal plane laxity as the flexion angle increases, and that the knee has generally more laxity under varus load than with valgus load throughout the Range of Motion (ROM). Larger differences in laxity of more than 2 to 3°, or peak laxity specifically during the range of mid-flexion, were not found in our cadaver model and are not likely to represent normal coronal plane kinematics., Level of Evidence: Level V, biomechanical cadaveric study., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective: To analyze knees in varying stages of osteoarthritis (OA) for the presence of coronal tibiofemoral (CTF) subluxation and to determine if CTF subluxation severity is related to knee OA worsening., Methods: We retrospectively evaluated CTF subluxation and limb alignment in 113 patients with different stages of knee OA who were being considered for an arthroplasty procedure. Knee OA was classified as "mild" or "severe" according to Kellgren-Lawrence scale. CTF subluxation was measured in the study groups and in 40 knees of healthy controls using software developed specifically on the basis of Iterative Closest Point mathematical algorithm., Results: Mean CTF subluxation in "mild OA" and "severe OA" groups was 3.5% (±2) and 3.5 % (±5) of the tibial plateau, respectively. For both the mild and severe OA groups, CTF subluxation was significantly increased compared to the 1.4% (±1) CTF subluxation in the control group, (p < 0.0001) and (p = 0.012), respectively. However, there was no significant difference in CTF subluxation between the mild OA and severe OA groups (p = 0.75). Limb varus malalignment in mild OA and severe OA groups was 3.6° (±2.2) and 5.3° (±2.6), respectively. Both significantly increased comparing to the 1° (±0.7) control group alignment (p < 0.0001). Varus malalignment in the severe OA group was significantly increased comparing to the mild OA group (p = 0.0003)., Conclusions: CTF subluxation is a radiographic finding related to knee OA which occurs mainly in the early stages of the osteoarthritic process and stagnates as OA progresses.

Introduction: Limb alignment after unicondylar knee arthroplasty (UKA) has a significant impact on outcomes. The literature lacks lateral UKA alignment studies, making our understanding of this issue based on medial UKA., Methods: We evaluated limb alignment in 241 patients who underwent medial (229 knees) or lateral (37 knees) UKA. Alignment was measured pre and postoperatively in radiographs and intra-operatively using a navigation system. We compared the percentage of over-correction and the difference between post-operative alignment and navigation measurement., Results: Percentage of overcorrection was significantly higher in the lateral UKAs (11%) compared to the medial UKAs (4%). In medial UKAs, the mean difference between the intraoperative alignment and the post-operative was 1.33°. This was significantly lower than the mean 1.86° difference in the lateral UKAs., Conclusions: Our data demonstrated an increased risk of "overcorrection," and greater difficulty in predicting postoperative alignment using computer navigation, when performing lateral UKAs compared to medial UKAs., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Unicompartmental knee arthroplasty (UKA) is an increasingly popular option for the treatment of single-compartment knee osteoarthritis (OA) in adults. Two options for tibial resurfacing during UKA are (1) all-polyethylene inlays and (2) metal-backed onlays., Questions/purposes: The aim of this study was to determine whether there are any differences in clinical outcomes with inlay versus onlay tibial components., Patients and Methods: We identified 39 inlays and 45 onlays, with average 2.7- and 2.3-year follow-up, respectively, from a prospective robotic-assisted surgery database. The primary outcome was the Western Ontario and McMaster University Arthritis Index (WOMAC), subcategorized by the pain, stiffness, and function subscores, at 2 years postoperatively. The secondary outcome was the need for secondary or revision surgery., Results: Postoperative WOMAC pain score was 3.1 for inlays and 1.6 for onlays (p = 0.03). For 25 inlays and 30 onlays with both preoperative and postoperative WOMAC data, pain score improved from 8.3 to 4.0 for inlays versus from 9.2 to 1.7 for onlays (p = 0.01). Function score improved from 27.5 to 12.5 for inlays versus from 32.1 to 7.3 for onlays (p = 0.03). Four inlays and one onlay required a secondary or revision procedure (p = 0.18)., Conclusions: We advise using metal-backed onlays during UKA to improve postoperative clinical outcomes.

We used a large prospective institutional registry to determine if there is a 'safe zone' that exists for acetabular component position within which the risk of hip dislocation is low and if other patient and implant factors affect the risk of hip dislocation. Patients who reported a dislocation event within six months after hip arthroplasty surgery were identified, and acetabular component position was measured with anteroposterior radiographs. The frequency of dislocation was 2.1% (147 of 7040 patients). No significant difference was found in the number of dislocated hips among the radiographic zones (±5°,±10°,±15° boundaries). Dislocators <50 years old were less active preoperatively than nondislocators (P=0.006). Acetabular component position alone is not protective against instability., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Patellofemoral crepitation and clunk (PCC) is an important potential complication of total knee arthroplasty. Numerous factors, including implant design, range of motion, and certain radiographic parameters, may contribute to the development of PCC. Although the diagnosis is primarily clinical, imaging modalities may be helpful in cases of diagnostic uncertainty. Arthroscopic débridement is the preferred method of treating PCC in patients whose symptoms require intervention. A full understanding of the diagnosis, management, and prevention of PCC is essential for orthopedic surgeons who perform total knee arthroplasties.

In a consecutive series of 536 unilateral primary total hip arthroplasties (THAs) and 598 unilateral primary total knee arthroplasties (TKAs), the use of a post-operative drain was associated with $538 additional cost per THA, and $455 for TKA. The use of a drain increased hospital length of stay (LOS) for THA, but not for TKA. In both groups, the use of a drain increased estimated blood loss (EBL) and increased the amount of allogeneic blood transfused. Over the 10-week period, drain use was associated with a total cost of $432,972 for our institution. Data from this study would favor a selective approach to the use of drains in primary joint arthroplasties., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Patellar crepitation and clunk (PCC) is an important and modifiable complication of total knee arthroplasty (TKA). We calculated the incidence of PCC using a modern fixed-bearing TKA prosthesis, assessed whether PCC is associated with knee range of motion, and determined if there were any radiographic variables associated with the development of PCC in this prosthetic design. Five hundred seventy primary TKAs were evaluated after a mean follow-up of 24 months (range 12-81). Thirty-four knees developed PCC (6%); 6 required arthroscopic debridement. With each degree increase in the flexion angle, the likelihood of developing PCC increased by 4.2%. The incidence of PCC was low but increased with postoperative flexion ≥ 110°. No radiographic parameters were associated with the development of PCC., (© 2014.)

Background: Constrained primary total knee arthroplasty (TKA) can provide stability in the face of incompetent collateral structures or irreconcilable flexion-extension imbalances. However, little is known about its effect on overall knee range of motion (ROM). This study determines whether TKA with increased constraint affects postoperative ROM., Methods: Patients undergoing primary TKA using either posterior stabilized (PS) or constrained condylar knee (CCK) inserts were match-paired based on body mass index, preoperative ROM, and direction and severity of the coronal deformity, yielding 68 pairs. ROM and Knee Society Score (KSS) were obtained preoperatively and at 6 weeks, 4 months, and 1 year., Results: When the 68 matched pairs were considered, all outcome variables related to ROM between the PS and CCK groups at each of the postoperative intervals were similar. Additionally, both the individual items and combined scores of the KSS were similar between groups at all time points., Conclusions: We demonstrate that the use of increased constraint does not affect ROM, relief of pain, or function after TKA., Level of Evidence: Level III (retrospective case-controlled study, based on prospectively collected data)., (© 2013.)

The purposes of this study were to describe a method for measuring tibiofemoral subluxation in UKA, and to report the mean amount of tibiofemoral subluxation seen both preoperatively and postoperatively in a cohort of patients undergoing UKA. Two hundred thirty-five patients who received a medial UKA, and 39 patients who received a lateral UKA, were reviewed. In the medial UKA cohort, the mechanical alignment was corrected from 7.7° ± 5.9° preoperatively, to 2.9° ± 2.5° postoperatively, while the tibiofemoral subluxation was corrected from 4.5 mm ± 3.0 mm preoperatively, to 2.3 mm ± 2.7 mm postoperatively. In the lateral UKA cohort, the mechanical alignment was corrected from -5.5° ± 3.8° to -1.6° ± 3.4°, while the tibiofemoral subluxation was corrected from 4.3 mm ± 2.7 mm to 2.8 mm ± 2.5mm. This study presents a novel method for measurement of tibiofemoral subluxation, the mean amount of tibiofemoral subluxation present preoperatively, and the amount of correction that can be expected during both medial and lateral unicondylar knee arthroplasty., (Copyright © 2013 Elsevier Inc. All rights reserved.)

This is a prospective randomised study comparing the clinical and radiological outcomes of uni- and bipedicular balloon kyphoplasty for the treatment of osteoporotic vertebral compression fractures. A total of 44 patients were randomised to undergo either uni- or bipedicular balloon kyphoplasty. Self-reported clinical assessment using the Oswestry Disability Index, the Roland-Morris Disability questionnaire and a visual analogue score for pain was undertaken pre-operatively, and at three and twelve months post-operatively. The vertebral height and kyphotic angle were measured from pre- and post-operative radiographs. Total operating time and the incidence of cement leakage was recorded for each group. Both uni- and bipedicular kyphoplasty groups showed significant within-group improvements in all clinical outcomes at three months and twelve months after surgery. However, there were no significant differences between the groups in all clinical and radiological outcomes. Operating time was longer in the bipedicular group (p < 0.001). The incidence of cement leakage was not significantly different in the two groups (p = 0.09). A unipedicular technique yielded similar clinical and radiological outcomes as bipedicular balloon kyphoplasty, while reducing the length of the operation. We therefore encourage the use of a unipedicular approach as the preferred surgical technique for the treatment of osteoporotic vertebral compression fractures.

Reduction of bone turnover with bisphosphonate treatment alters bone mineral and matrix properties. Our objective was to investigate the effect of bisphosphonate treatment on bone tissue properties near fragility fracture sites in the proximal femur in postmenopausal women with osteoporosis. The mineral and collagen properties of corticocancellous biopsies from the proximal femur were compared in bisphosphonate-naive (-BIS, n = 20) and bisphosphonate-treated (+BIS, n = 20, duration 7 ± 5 years) patients with intertrochanteric (IT) and subtrochanteric (ST) fractures using Fourier transform infrared imaging (FTIRI). The mean values of the FTIRI parameter distributions were similar across groups, but the widths of the parameter distributions tended to be reduced in the +BIS group relative to the -BIS group. Specifically, the widths of the cortical collagen maturity and crystallinity were reduced in the +BIS group relative to those of the -BIS group by 28% (+BIS 0.45 ± 0.18 versus -BIS 0.63 ± 0.28, p = 0.03) and 17% (+BIS 0.087 ± 0.012 versus -BIS 0.104 ± 0.036, p = 0.05), respectively. When the tissue properties were examined as a function of fracture morphology within the +BIS group, the FTIR parameters were generally similar regardless of fracture morphology. However, the cortical mineral:matrix ratio was 8% greater in tissue from patients with atypical ST fractures (n = 6) than that of patients with typical (IT or spiral ST) fractures (n = 14) (Atypical 5.6 ± 0.3 versus Typical 5.2 ± 0.5, p = 0.03). Thus, although the mean values of the FTIR properties were similar in both groups, the tissue in bisphosphonate-treated patients had a more uniform composition than that of bisphosphonate-naive patients. The observed reductions in mineral and matrix heterogeneity may diminish tissue-level toughening mechanisms., (© 2012 American Society for Bone and Mineral Research)

Bone mineral density is considered to be the standard measure for the diagnosis of osteoporosis and the assessment of fracture risk. The majority of fragility fractures occur in patients with bone mineral density in the osteopenic range. The Fracture Risk Assessment Tool (FRAX) can be used as an assessment modality for the prediction of fractures on the basis of clinical risk factors, with or without the use of femoral neck bone mineral density. Treatment of osteoporosis should be considered for patients with low bone mineral density (a T-score of between -1.0 and -2.5) as well as a ten-year risk of hip fracture of > or = 3% or a ten-year risk of a major osteoporosis-related fracture of > or = 20% as assessed with the FRAX. Biochemical bone markers are useful for monitoring the efficacy of antiresorptive or anabolic therapy and may aid in identifying patients who have a high risk of fracture. An approach combining the assessment of bone mineral density, clinical risk factors for fracture with use of the FRAX, and bone turnover markers will improve the prediction of fracture risk and enhance the evaluation of patients with osteoporosis.