Nonphysician Evaluators and Recording-Based Tools in Surgical Skill Assessment: A Feasibility Study.

OBJECTIVES: To investigate the feasibility of nonmedically trained evaluators and image- and video-based tools in the assessment of surgical skills in a key orthopedic procedure. DESIGN: Orthopedic surgeons at varying skill levels were evaluated by their ability to repair a cadaveric bi-malleolar ankle fracture. Nonphysician viewers and expert orthopedic surgeons independently scored video recordings and fluoroscopy images of the procedure through Global Rating Scales (GRS) and procedure-specific checklist tools. Statistical analysis was used to determine if the evaluators and assessment tools were able to differentiate skill level. SETTING: An academic tertiary care hospital. PARTICIPANTS: The surgical procedure was completed by 3 orthopedic residents, 3 orthopedic trauma fellows, and 4 orthopedic trauma attending surgeons. The procedure was independently evaluated by 2 orthopedic surgeons and 2 nonphysicians. RESULTS: Operating participants were stratified by ≤ or >10 bimalleolar ankle fracture cases performed alone (inexperienced, n = 5 vs experienced, n = 5). Expert surgeon viewers could effectively stratify skill group through the GRS for video and fluoroscopy analysis (p < 0.05), and the video procedure-specific checklist (p < 0.05), but not the fluoroscopy procedure-specific checklist. Nonphysician viewers generally recognized skill groupings, although with less separation than surgeon viewers. These evaluators performed the best when aided by video and fluoroscopy procedure-specific checklists. Meanwhile, breakdowns of each tool into critical zones for improvement and evaluator-independent metrics such as case experience, self-reported confidence, and surgical time also indicated some skill differentiation. CONCLUSIONS: The feasibility of using video recordings and fluoroscopic imaging based surgical skills assessment tools in orthopedic trauma was demonstrated. The tools highlighted in this study are applicable to both cadaver laboratory settings and live surgeries. The degree of training that is required by the evaluators and the utility of measuring surgical times of specific tasks should be the subject of future studies.

Novel e-learning platform for orthopaedic training in LMICs: A descriptive review of the IGOT portal.

Background: While e-learning has been written about extensively within the context of orthopaedics in the United States, there are few articles describing e-learning initiatives geared towards low-and middle-income countries (LMICs). The Institute for Global Orthopaedics and Traumatology (IGOT) at the University of California, San Francisco (UCSF) developed the IGOT Learning Portal to meet this need. Methods: The IGOT Learning Portal was designed to address knowledge gaps in patient care by increasing access to high-quality orthopaedic education for surgeons and trainees worldwide. It offers 10 distinct, asynchronous courses, which are divided into a modular format. Course enrollment is free and accessible to any surgeon or trainee with a web-browsing capable device and internet connection. Results: There are more than 2700 registered users and 300 active learners enrolled in IGOT Learning Portal courses. The Surgical Management and Reconstructive Training (SMART) program is the most commonly taken course. Learners represent 32 different countries across six continents. The IGOT portal also has surgical videos available on YouTube. The IGOT Portal YouTube channel has over 2000 subscribers and over 143,000 total views. Conclusions: The IGOT Learning Portal is an innovative approach to address the global disparity in orthopaedic trauma care by improving access to high-quality surgical education for surgeons and trainees both in the US and internationally. The development of an interactive online forum may be a beneficial addition to the Portal. Future directions include assessing content retention, participant interaction, and expanding existing content to other orthopaedic subspecialties.

Effect of Institution and COVID-19 on Access to Adult Arthroplasty Surgery.

BACKGROUND: Although insurance status is important to patients' ability to access care, it varies significantly by race, age, and socioeconomic status. Novel coronavirus disease 2019 (COVID-19) negatively impacted access to care, while simultaneously widening pre-existing health-care disparities. The purpose of the present study was to document this phenomena within orthopedics. METHODS: Patients undergoing hip or knee arthroplasty at two medical centers in San Francisco, California, were evaluated. One cohort came from the University of California San Francisco (UCSF), a tertiary center, and the other from Zuckerberg San Francisco General Hospital (ZSFGH), a safety-net hospital. Patients who underwent arthroplasty before the pandemic (March 2020) and those after pandemic declaration were evaluated. Patient demographics, surgical wait times, and operative volumes were compared. RESULTS: Two-hundred sixty-nine (pre-COVID, 184; post-COVID, 85) cases at UCSF and 63 (pre-COVID, 47; post-COVID, 16) cases at ZSFGH met inclusion criteria. Patients at ZSFGH had a significantly higher body mass index, were more often racial minorities, and were less likely to speak English. Patients at ZSFGH were less likely to have private insurance. A comparison of case volumes showed a larger decrease at ZSFGH than at UCSF after COVID. Wait times between the two sites before and after COVID showed a larger increase in wait times at ZSFGH. Notably, wait times at ZSFGH before COVID were more than double the wait times at UCSF after COVID. CONCLUSIONS: COVID-19 worsened access to primary hip and knee arthroplasties at two academic medical centers in San Francisco. The pandemic also worsened pre-existing disparities. Racial minorities, non-English speakers, and those with nonprivate insurance were affected the most.

AP pelvis radiograph is insufficient for diagnosis of U-type sacral fractures.

PURPOSE: We investigated the sensitivity of a screening test for pelvic ring disruption, the AP pelvis radiograph, for clinically serious U-type sacral fractures which merit consultation with an orthopedic trauma specialist and may require transfer to a higher level of care. METHODS: Retrospective clinical cohort of 63 consecutive patients presenting with U-type sacral fractures at one level 1 trauma referral center from January 2006 through December 2019. The sensitivity of the first AP pelvis radiograph obtained on admission, interpreted without reference to antecedent or concomitant pelvis computed tomography (CT) by a radiologist and a panel of three blinded orthopedic traumatologists, was determined against a reference diagnosis made from review of all pelvis radiographs, CT images, operative reports, and clinical documentation. RESULTS: Sensitivity of AP pelvis radiograph for U-type sacral fractures was 2% as interpreted by a radiologist and mean 12% (range 5-27%) as interpreted by orthopedic traumatologists with poor inter-rater agreement (Fleiss' κ = 0.11). 94% of sacra were at obscured by radiographic artifact. CONCLUSION: The sensitivity of an AP pelvis radiograph is poor for U-type sacral fractures, whether interpreted by radiologists or orthopedic traumatologists. Pelvis CT should be considered as a screening test to rule out sacral fracture when the patient reports posterior pelvic pain, even if plain radiography demonstrates no injury or a minimally displaced pelvic ring disruption. LEVEL OF EVIDENCE: Diagnostic level III.

Comparison of computed tomography angiography and physical exam in the evaluation of arterial injury in extremity trauma.

BACKGROUND: CT angiography (CTA) is increasingly used in the evaluation of arterial injury in extremity trauma. While it may provide additional objective data, it comes with inherent risks and expense. The purpose of this study was to compare CTA to physical exam in the evaluation of arterial injury in extremity trauma. METHODS: We performed a retrospective review of patients who underwent CTA for evaluation of upper or lower extremity trauma at a Level 1 trauma center over a 10 month period. Patients were classified based on initial vascular exam (normal, soft signs, hard signs), and arterial injury on CTA was classified as major (named arteries) or minor (un-named arteries). We evaluated rates of vascular intervention in each group and compared the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) for physical exam and CTA in identifying arterial injury requiring intervention. RESULTS: A total of 135 CTA studies were included. On initial vascular exam, 71% of patients had a normal exam, 22% had soft signs, and 6% had hard signs. The NPVs for arterial injury requiring intervention of a normal physical exam and negative CTA were both 100%. The PPVs for arterial injury requiring intervention of major injury on CTA and hard signs on physical exam were 35% and 50%, respectively. CONCLUSION: A normal physical exam can likely rule out the need for vascular intervention and eliminate the need for CTA. Additionally, the presence of hard signs on physical exam is potentially superior to CTA in predicting the need for vascular intervention.

Comparison of Case-Based Learning and Traditional Lectures in an Orthopedic Residency Anatomy Course.

OBJECTIVE: The impact of new pedagogical methods such as case-based learning (CBL) rather than traditional lectures in graduate medical education is poorly defined. We hypothesized that using CBL in lieu of lectures in an orthopedic surgery residency anatomy course would lead to increased resident engagement, improved resident satisfaction, and similar knowledge acquisition. DESIGN: A prospective, observational study design was used. CBL sessions were developed for an orthopedic surgery residency anatomy course. Content was delivered in 6 sessions (3 traditional lecture-based and 3 CBL) taught by the same attending surgeon. Engagement was measured every 10 minutes by 2 trained observers using a standardized protocol. Resident satisfaction was surveyed and knowledge acquisition tested. Data from the course were scored separately for CBL verses lectures and compared statistically. SETTING: Orthopedic surgery residency program at the University of California, San Francisco. PARTICIPANTS: Orthopedic surgery interns and residents (n = 35). RESULTS: No significant differences were measured in resident engagement (83% vs 85%, p = 0.664) or in knowledge acquisition (84% vs 78%, p = 0.056) in CBL verses lecture sessions, respectively. CBL sessions were judged equally valuable compared to lectures with high satisfaction rates across all survey measures. CONCLUSIONS: Residents demonstrated similar engagement and satisfaction with CBL compared to lectures with equivalent knowledge acquisition, suggesting both pedagogical methods are effective for a highly motivated group of learners.

Does Implant Removal Across the Sacroiliac Joint Improve Pain and Outcomes?

OBJECTIVES: To determine if removal of previously inserted iliosacral screws improved posterior pelvic pain and Short Musculoskeletal Form Assessment (SMFA) scores. DESIGN: Retrospective database review. SETTING: Level-1 trauma center. PATIENTS/INTERVENTION: Twenty-five patients who underwent iliosacral screw removal. MAIN OUTCOME MEASURE: SMFA score. RESULTS: Eighty-eight percent of patients stated that they were satisfied with the procedure and would undergo screw removal again. SMFA functional and bothersome scores decreased (improved) after the screw removal procedure, both at 3 months and at the final follow-up. Two-eight percent of the patients required narcotics before surgery compared with 8% after screw removal. No surgical complications occurred during screw removal. CONCLUSION: A select group of patients who have symptomatic screws across the sacroiliac joint may benefit from elective screw removal. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

An Assessment of Normal Tibiofibular Anatomy on Lateral Fluoroscopy.

BACKGROUND: Intraoperative identification of syndesmotic malreduction during ankle fracture fixation can be challenging. Prior studies describe the normal tibiofibular relationship on anteroposterior and mortise views to aid assessment, but the normal anatomic variation on the lateral view has not been well defined. The aim of this study was to describe the normal anatomy of the lateral radiographic view of the ankle, focusing on the relative position of the fibula and tibial plafond. METHODS: We retrospectively identified consecutive adults undergoing ankle fracture open reduction internal fixation in 2011-2018. Two independent observers assessed the tibiofibular relationship on perfect lateral images of the uninjured side. Measurements were made in pixels, converted into millimeters using published parameters, and averaged for analysis. Reliability was calculated using Pearson correlation coefficients. RESULTS: Of 751 cases of adult ankle fracture fixation identified, 50 patients had perfect lateral images of the contralateral side. In 11 patients (22%), the posterior border of the fibula intersected precisely at the posterior edge of the tibial plafond. Ten patients (20%) had anterior intersections, whereas 29 (58%) had posterior intersections. The intersection was within ±2 mm of the plafond edge in 27 patients (54%). Intrarater reliability was 0.86 and 0.93. Interrater reliability was 0.88. CONCLUSION: In most ankles, the posterior border of the fibula intersects the posterior extent of the tibial plafond within 2 mm. If more than 2 mm away, one should query malreduction, especially if anterior. This method of intraoperative assessment may decrease the occurrence of syndesmotic malreduction. LEVEL OF EVIDENCE: Level III, comparative series.

Automatic Hip Fracture Identification and Functional Subclassification with Deep Learning.

PURPOSE: To investigate the feasibility of automatic identification and classification of hip fractures using deep learning, which may improve outcomes by reducing diagnostic errors and decreasing time to operation. MATERIALS AND METHODS: Hip and pelvic radiographs from 1118 studies were reviewed, and 3026 hips were labeled via bounding boxes and classified as normal, displaced femoral neck fracture, nondisplaced femoral neck fracture, intertrochanteric fracture, previous open reduction and internal fixation, or previous arthroplasty. A deep learning-based object detection model was trained to automate the placement of the bounding boxes. A Densely Connected Convolutional Neural Network (or DenseNet) was trained on a subset of the bounding box images, and its performance was evaluated on a held-out test set and by comparison on a 100-image subset with two groups of human observers: fellowship-trained radiologists and orthopedists; senior residents in emergency medicine, radiology, and orthopedics. RESULTS: The binary accuracy for detecting a fracture of this model was 93.7% (95% confidence interval [CI]: 90.8%, 96.5%), with a sensitivity of 93.2% (95% CI: 88.9%, 97.1%) and a specificity of 94.2% (95% CI: 89.7%, 98.4%). Multiclass classification accuracy was 90.8% (95% CI: 87.5%, 94.2%). When compared with the accuracy of human observers, the accuracy of the model achieved an expert-level classification, at the very least, under all conditions. Additionally, when the model was used as an aid, human performance improved, with aided resident performance approximating unaided fellowship-trained expert performance in the multiclass classification. CONCLUSION: A deep learning model identified and classified hip fractures with expert-level performance, at the very least, and when used as an aid, improved human performance, with aided resident performance approximating that of unaided fellowship-trained attending physicians.Supplemental material is available for this article.© RSNA, 2020.

Risk Factors for Conversion to Total Hip Arthroplasty After Acetabular Fractures Involving the Posterior Wall.

OBJECTIVES: Identify risk factors for early conversion to total hip arthroplasty (THA) in an effort to aid in counseling patients and selecting the optimal treatment for patients who sustain a fracture involving the posterior wall of the acetabulum. DESIGN: Retrospective cohort analysis. SETTING: Level I trauma center. PATIENTS: Patients with acetabular fractures involving the posterior wall managed with open reduction internal fixation at least 4 years out from surgery. INTERVENTION: Preoperative and postoperative computed tomography scans were reviewed for injury characteristics and reduction quality. Participants were contacted by telephone to document reoperations and functional outcomes including the SF-8 and modified Merle d'Aubigne Hip Scale. MAIN OUTCOME MEASURE: Conversion to THA. RESULTS: The overall rate of conversion to THA was 5% at 2 years, 14% at 5 years, and 17% at 9 years. Presence of 5 specific radiographic features was associated with a 50% rate of conversion to THA in contrast to 11% if 4 or less features were present. Among cases with less than 1 mm of diastasis/step-off on postoperative computed tomography scan, there were no THA conversions, 10% conversion for 1-4 mm, and 54% if 4 mm or more of malreduction. There was no difference in SF-8 or modified Merle d'Aubigne scores comparing patients who underwent THA and those who did not. CONCLUSIONS: Acetabular fractures with posterior wall involvement are associated with a significantly higher rate of conversion to THA if reduction is not near-anatomic. A combination of clinical/radiographic findings is associated with poorer reductions and higher rate of conversion to THA. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Minimally invasive plate osteosynthesis versus conventional open insertion techniques for osteosynthesis.

Osteosynthesis has evolved theoretically and practically throughout its evolution. Similar to trends in other surgical fields, surgical techniques in fracture fixation, such as minimally invasive plate osteosynthesis (MIPO), have moved from large dissections to more tissue sparing methods. These plating techniques have been developed for a variety of bones, but more universal clinical adoption will rely upon improved clinical outcomes. The current review will describe minimally invasive techniques, evaluate their rationale, and summarize evidence for their efficacy.

Critical-Sized Bone Defects: Sequence and Planning.

Bone defects associated with open fractures require a careful approach and planning. At initial presentation, an emergent irrigation and debridement is required. Immediate definitive fixation is frequently safe, with the exception of those injuries that normally require staged management or very severe type IIIB and IIIC injuries. Traumatic wounds that can be approximated primarily should be closed at the time of initial presentation. Wounds that cannot be closed should have a negative pressure wound therapy dressing applied. The need for subsequent debridements remains a clinical judgment, but all nonviable tissue should be removed before definitive coverage. Cefazolin remains the standard of care for all open fractures, and type III injuries also require gram-negative coverage. Both induced membrane technique with staged bone grafting and distraction osteogenesis are excellent options for bony reconstruction. Soft tissue coverage within 1 week of injury seems critical.

Anatomic Knowledge and Perceptions of the Adequacy of Anatomic Education Among Applicants to Orthopaedic Residency.

BACKGROUND: The time dedicated to the study of human anatomy within medical school curriculums has been substantially reduced. The effect of this on the knowledge of incoming orthopaedic trainees is unknown. The current study aimed to evaluate both the subjective perceptions and objective anatomic knowledge of fourth-year medical students applying for orthopaedic residency. METHODS: A multicenter prospective study was performed that assessed 224 students during the course of their interview day for an orthopaedic residency. Participants provided demographic data and a subjective assessment of the quality of their anatomic education, and completed either an upper or lower extremity anatomic examination. Mean total scores and subscores for various anatomic regions and concepts were calculated. RESULTS: Students on average rated the adequacy of their anatomic education as 6.5 on a 10-point scale. Similarly, they rated the level of importance their medical school placed on anatomic education as 6.2 on a 10-point scale. Almost 90% rated the time dedicated to anatomy as good or fair. Of six possible methods for learning anatomy, dissection was rated the highest.On objective examinations, the mean score for correct answers was 44.2%. This improved to 56.4% when correct and acceptable answers were considered. Regardless of anatomic regions or concepts evaluated, percent correct scores did not reach 50%. There were no significant correlations between performance on the anatomic examinations and either prior academic performance measures or the student's subjective assessment of their anatomic education. CONCLUSIONS: Current students applying into orthopaedic residency do not appear to be adequately prepared with the prerequisite anatomic knowledge. These deficits must be explicitly addressed during residency training to produce competent, safe orthopaedic surgeons.

Humeral shaft fractures: results of operative and non-operative treatment.

PURPOSE: There has been little direct comparison between non-operative and operative management of humeral shaft fractures. The present study aimed to compare union rates and complication rates between these two modalities of treatment. METHODS: A retrospective cohort study was performed at a regional level 1 trauma centre. A total of 296 patients with humeral shaft fractures met inclusion criteria; 69 patients were treated with a functional brace and 227 with surgical intervention. The primary end point was radiographic union. Nonunion was defined as failure of radiological union at six months, requiring surgical intervention. Time to union, nerve palsy rate, and rate of infection were also examined. RESULTS: The nonunion rate was significantly higher in the non-operative group (23.2 % vs 10.2 %) despite higher rates of open fractures and high energy mechanisms of injury in the operative group. No significant difference in time to union was found. Nerve palsy was more common in the operative group (20 % vs 39 %); however, only two cases (1 %) of radial nerve palsy in the operative group were iatrogenic and both were transient. Infection rates were higher for the operative group (3.5 % vs 0 %). CONCLUSIONS: Conservative treatment of humeral shaft fractures has a higher rate of nonunion, while operative treatment is associated with a low incidence of iatrogenic nerve palsy but higher rates of infection.

Anterior corpectomy via the mini-open, extreme lateral, transpsoas approach combined with short-segment posterior fixation for single-level traumatic lumbar burst fractures: analysis of health-related quality of life outcomes and patient satisfaction.

OBJECTIVE: The authors present clinical outcome data and satisfaction of patients who underwent minimally invasive vertebral body corpectomy and cage placement via a mini-open, extreme lateral, transpsoas approach and posterior short-segment instrumentation for lumbar burst fractures. METHODS: Patients with unstable lumbar burst fractures who underwent corpectomy and anterior column reconstruction via a mini-open, extreme lateral, transpsoas approach with short-segment posterior fixation were reviewed retrospectively. Demographic information, operative parameters, perioperative radiographic measurements, and complications were analyzed. Patient-reported outcome instruments (Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12]) and an anterior scar-specific patient satisfaction questionnaire were recorded at the latest follow-up. RESULTS: Twelve patients (7 men, 5 women, average age 42 years, range 22-68 years) met the inclusion criteria. Lumbar corpectomies with anterior column support were performed (L-1, n = 8; L-2, n = 2; L-3, n = 2) and supplemented with short-segment posterior instrumentation (4 open, 8 percutaneous). Four patients had preoperative neurological deficits, all of which improved after surgery. No new neurological complications were noted. The anterior incision on average was 6.4 cm (range 5-8 cm) in length, caused mild pain and disability, and was aesthetically acceptable to the large majority of patients. Three patients required chest tube placement for pleural violation, and 1 patient required reoperation for cage subsidence/hardware failure. Average clinical follow-up was 38 months (range 16-68 months), and average radiographic follow-up was 37 months (range 6-68 months). Preoperative lumbar lordosis and focal lordosis were significantly improved/maintained after surgery. Patients were satisfied with their outcomes, had minimal/moderate disability (average ODI score 20, range 0-52), and had good physical (SF-12 physical component score 41.7% ± 10.4%) and mental health outcomes (SF-12 mental component score 50.2% ± 11.6%) after surgery. CONCLUSIONS: Anterior corpectomy and cage placement via a mini-open, extreme lateral, transpsoas approach supplemented by short-segment posterior instrumentation is a safe, effective alternative to conventional approaches in the treatment of single-level unstable burst fractures and is associated with excellent functional outcomes and patient satisfaction.

Plate fixation of midshaft clavicular fractures: patient-reported outcomes and hardware-related complications.

BACKGROUND: Recent studies report high hardware removal rates after plate fixation of midshaft clavicular fractures. Precontoured clavicle plates may decrease hardware-related complications while improving healing rates and patient-reported outcomes (PROs). METHODS: Using a private-payer national database, we identified 7826 patients who underwent clavicle open reduction and internal fixation (ORIF) in 2007 to 2011. Database patients were tracked for 2 years to assess hardware removal and revision fixation. In addition, we retrospectively identified 73 patients who underwent plate fixation of midshaft clavicular fractures at our institution. These patients completed the Disabilities of Arm, Shoulder and Hand (DASH) assessment, the EQ-5D (EuroQol, Rotterdam, The Netherlands) quality of life assessment, and a hardware-related outcomes survey. RESULTS: Among 7826 database patients, 994 (12.7%) underwent hardware removal and 78 (1%) required revision ORIF. The annual incidence of clavicle ORIF increased 61.5% between 2007 and 2011. In our institutional cohort, 56 patients (77%) were fixed with precontoured plates and 17 (23%) with standard plates. At a mean follow-up of 4.2 years, 11 patients (15%) underwent hardware removal and 1 patient (1.4%) experienced nonunion. Patients reported excellent outcomes, with average DASH of 4.0 ± 8.9 and EQ-5D of 0.89 ± 0.19. There were no differences in PROs, hardware removal, or union rate between plate types, although our study was underpowered for these outcomes. Patients who underwent hardware removal reported lower DASH, EQ-5D, satisfaction, and shoulder function compared with patients with hardware retained. Women were more likely to undergo hardware removal in the institutional (P = .009) and the database (P < .001) cohorts. CONCLUSION: Displaced midshaft clavicle fractures have high union rates with precontoured plate fixation. Women are 4 times more likely than men to have hardware removed. Patients undergoing clavicle hardware removal report worse long-term outcomes than patients with hardware retained.

Periprosthetic Fractures: A Common Problem with a Disproportionately High Impact on Healthcare Resources.

The present study evaluated the frequency of periprosthetic fractures and tested the hypothesis that this population's demographics and outcomes are unique as compared with other arthroplasty patients. The National Hospital Discharge Survey provided the raw data. Individuals admitted with a primary TKA, primary THA, or revision TJA were selected. Annual rates were then calculated and demographics and outcomes compared. 30,624 patients were reviewed. The proportion of admissions for periprosthetic fractures ranged from 4.2% to 7.4% annually. As compared to patients admitted for other TJA diagnoses, individuals admitted with periprosthetic fracture were older, were more often female, were more often admitted emergently/urgently, had longer lengths of stay, had higher rates of discharge to places other than home, and had a significantly elevated mortality.

What ape proximal femora tell us about femoroacetabular impingement: a comparison.

BACKGROUND: Human hip morphology is variable, and some variations (or hip morphotypes) such as coxa profunda and coxa recta (cam-type hip) are associated with femoroacetabular impingement and the development of osteoarthrosis. Currently, however, this variability is unexplained. A broader perspective with background information on the morphology of the proximal femur of nonhuman apes is lacking. Specifically, no studies exist of nonhuman ape femora that quantify concavity and its variability. QUESTIONS/PURPOSES: We hypothesized that, when compared with modern humans, the nonhuman apes would show (1) greater proximal femoral concavity; (2) less variability in concavity; and (3) less sexual dimorphism in proximal femoral morphology. METHODS: Using identical methods, we compared 10 morphological parameters in 375 human femora that are part of the Hamann-Todd collection at the Cleveland Museum of Natural History with 210 nonhuman ape femora that are part of the collection of the Royal Museum for Central Africa, Tervuren, Belgium, and the Muséum National d'Histoire Naturelle, Paris, France. RESULTS: The nonhuman apes have larger proximal femoral concavity than modern humans. This morphology is almost uniform without large variability or large differences neither between species nor between sexes. CONCLUSIONS: Variability is seen in human but not in nonhuman ape proximal femoral morphology. An evolutionary explanation can be that proximal femoral concavity is more important for the nonhuman apes, for example for climbing, than for modern humans, where a lack of concavity may be related to high loading of the hip, for example in running.

A biomechanical comparison of superior and anterior positioning of precontoured plates for midshaft clavicle fractures.

With recent studies suggesting improved outcomes in displaced midshaft clavicle fractures treated with open reduction and internal fixation, debate has increased over the preferred plate positioning. Biomechanical studies have yielded conflicting results and have been limited by the almost exclusive use of a simple transverse fracture model. We conducted a study to biomechanically compare superior and anterior plate positioning for clinically relevant midshaft clavicle fracture patterns. Oblique, bending wedge, and complex comminuted fracture patterns were created sequentially in 12 synthetic clavicles. Half were plated with precontoured superior plates and half with precontoured anterior plates. Constructs were loaded in axial compression, torsion, and cantilever bending to determine construct stiffness for comparison of plate positioning. Results showed that, for all fracture patterns, more construct stiffness was achieved in axial compression and torsion (except for the oblique fracture pattern in clockwise torsion) with a superior plate, whereas more construct stiffness was achieved in cantilever bending with an anterior plate. Oblique fractures were significantly stiffer than bending wedge and complex comminuted fractures. Given the unknown relative importance of loading conditions, absolute recommendations for either superior or anterior plates cannot be made.

Where is the neck? Alpha angle measurement revisited.

BACKGROUND AND PURPOSE: The alpha angle is the most used measurement to classify concavity of the femoral head-neck junction. It is not only used for treatment decisions for hip impingement, but also in cohort studies relating hip morphology and osteoarthritis. Alpha angle measurement requires identification of the femoral neck axis, the definition of which may vary between studies. The original "3-point method" uses 1 single point to construct the femoral neck axis, whereas the "anatomic method" uses multiple points and attempts to define the true anatomic neck axis. Depending on the method used, the alpha angle may or may not account for other morphological characteristics such as head-neck offset. METHODS: We compared 2 methods of alpha angle measurement (termed "anatomic" and "3-point") in 59 cadaver femora and 83 cross-table lateral radiographs of asymptomatic subjects. Results were compared using Bland-Altman plots. RESULTS: Discrepancies of up to 13 degrees were seen between the methods. The 3-point method had an "equalizing effect" by disregarding femoral head position relative to the neck: in femora with high alpha angle, it resulted in lower values than anatomic measurement, and vice versa in femora with low alpha angles. Using the anatomic method, we derived a reference interval for the alpha angle in normal hips in the general population of 30-66 degrees. INTERPRETATION: We recommend the anatomic method because it also reflects the position of the femoral head on the neck. Consensus and standardization of technique of alpha angle measurement is warranted, not only for planar measurements but also for CT or MRI-based measurements.