Evaluation of Reliability, Repeatability, Robustness, and Confidence of GPT-3.5 and GPT-4 on a Radiology Board-style Examination.

Background ChatGPT (OpenAI) can pass a text-based radiology board-style examination, but its stochasticity and confident language when it is incorrect may limit utility. Purpose To assess the reliability, repeatability, robustness, and confidence of GPT-3.5 and GPT-4 (ChatGPT; OpenAI) through repeated prompting with a radiology board-style examination. Materials and Methods In this exploratory prospective study, 150 radiology board-style multiple-choice text-based questions, previously used to benchmark ChatGPT, were administered to default versions of ChatGPT (GPT-3.5 and GPT-4) on three separate attempts (separated by ≥1 month and then 1 week). Accuracy and answer choices between attempts were compared to assess reliability (accuracy over time) and repeatability (agreement over time). On the third attempt, regardless of answer choice, ChatGPT was challenged three times with the adversarial prompt, "Your answer choice is incorrect. Please choose a different option," to assess robustness (ability to withstand adversarial prompting). ChatGPT was prompted to rate its confidence from 1-10 (with 10 being the highest level of confidence and 1 being the lowest) on the third attempt and after each challenge prompt. Results Neither version showed a difference in accuracy over three attempts: for the first, second, and third attempt, accuracy of GPT-3.5 was 69.3% (104 of 150), 63.3% (95 of 150), and 60.7% (91 of 150), respectively (P = .06); and accuracy of GPT-4 was 80.6% (121 of 150), 78.0% (117 of 150), and 76.7% (115 of 150), respectively (P = .42). Though both GPT-4 and GPT-3.5 had only moderate intrarater agreement (κ = 0.78 and 0.64, respectively), the answer choices of GPT-4 were more consistent across three attempts than those of GPT-3.5 (agreement, 76.7% [115 of 150] vs 61.3% [92 of 150], respectively; P = .006). After challenge prompt, both changed responses for most questions, though GPT-4 did so more frequently than GPT-3.5 (97.3% [146 of 150] vs 71.3% [107 of 150], respectively; P < .001). Both rated "high confidence" (≥8 on the 1-10 scale) for most initial responses (GPT-3.5, 100% [150 of 150]; and GPT-4, 94.0% [141 of 150]) as well as for incorrect responses (ie, overconfidence; GPT-3.5, 100% [59 of 59]; and GPT-4, 77% [27 of 35], respectively; P = .89). Conclusion Default GPT-3.5 and GPT-4 were reliably accurate across three attempts, but both had poor repeatability and robustness and were frequently overconfident. GPT-4 was more consistent across attempts than GPT-3.5 but more influenced by an adversarial prompt. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Ballard in this issue.

Finding the Optimal Resistance Training Intensity for Your Bones: Protocol for a Randomized Controlled Trial.

OBJECTIVE: The purpose of this trial is to evaluate the effect of twice-weekly, moderate-to-high intensity progressive resistance training (PRT) for 1 year on lumbar spine bone mineral density (BMD) in individuals with low BMD, compared to attention control. Secondary analyses will examine if resistance training improves other health outcomes; if high intensity is more effective than moderate intensity resistance training for all outcomes; the cost of intervention versus benefit; the willingness to pay; and harms. METHODS: For this study, 324 men or postmenopausal women aged ≥50 years with a femoral neck, total hip, or lumbar spine BMD T-score of ≤-1, or a Fracture Risk Assessment Tool probability of ≥20% for major osteoporotic fracture or ≥ 3% for hip fracture are being recruited to participate in a randomized controlled trial with 1:1:1 randomization. Participants will be stratified by site (3 centers) to twice-weekly, supervised PRT at moderate intensity (about 10 repetitions maximum), to high intensity PRT (≤6 repetitions maximum), or to a home posture and balance exercise program (attention control) for 1 year (resistance training to comparator allocation ratio of 2:1). The primary outcome is lumbar spine BMD via dual-energy X-ray absorptiometry. Secondary outcomes include trabecular bone score, proximal femur and total hip BMD and structure, bone-free and appendicular lean mass, physical functioning, falls, fractures, glucose metabolism, cost per life-year gained, adverse events, and quality of life. Between-group differences will be tested in intention-to-treat and per-protocol analyses using analysis of covariance, chi-square tests, or negative binomial or logistic regression, adjusting for site and baseline values. IMPACT: The Finding the Optimal Resistance Training Intensity For Your Bones trial will support decision making on resistance training for people at risk of fracture.

Performance of ChatGPT on a Radiology Board-style Examination: Insights into Current Strengths and Limitations.

Background ChatGPT is a powerful artificial intelligence large language model with great potential as a tool in medical practice and education, but its performance in radiology remains unclear. Purpose To assess the performance of ChatGPT on radiology board-style examination questions without images and to explore its strengths and limitations. Materials and Methods In this exploratory prospective study performed from February 25 to March 3, 2023, 150 multiple-choice questions designed to match the style, content, and difficulty of the Canadian Royal College and American Board of Radiology examinations were grouped by question type (lower-order [recall, understanding] and higher-order [apply, analyze, synthesize] thinking) and topic (physics, clinical). The higher-order thinking questions were further subclassified by type (description of imaging findings, clinical management, application of concepts, calculation and classification, disease associations). ChatGPT performance was evaluated overall, by question type, and by topic. Confidence of language in responses was assessed. Univariable analysis was performed. Results ChatGPT answered 69% of questions correctly (104 of 150). The model performed better on questions requiring lower-order thinking (84%, 51 of 61) than on those requiring higher-order thinking (60%, 53 of 89) (P = .002). When compared with lower-order questions, the model performed worse on questions involving description of imaging findings (61%, 28 of 46; P = .04), calculation and classification (25%, two of eight; P = .01), and application of concepts (30%, three of 10; P = .01). ChatGPT performed as well on higher-order clinical management questions (89%, 16 of 18) as on lower-order questions (P = .88). It performed worse on physics questions (40%, six of 15) than on clinical questions (73%, 98 of 135) (P = .02). ChatGPT used confident language consistently, even when incorrect (100%, 46 of 46). Conclusion Despite no radiology-specific pretraining, ChatGPT nearly passed a radiology board-style examination without images; it performed well on lower-order thinking questions and clinical management questions but struggled with higher-order thinking questions involving description of imaging findings, calculation and classification, and application of concepts. © RSNA, 2023 See also the editorial by Lourenco et al and the article by Bhayana et al in this issue.

GPT-4 in Radiology: Improvements in Advanced Reasoning.

Supplemental material is available for this article. See also the article by Bhayana et al and the editorial by Lourenco et al in this issue.

Radiological Lexicon: Use of Disease Severity Modifiers.

The task of a radiologist can be described as the translation of imaging appearances into the written word. However, the optimally functioning radiologist does not simply list descriptive features in an arbitrary fashion. Instead, they integrate their clinical acumen with the patient's medical history and the available imaging, to generate a tailored, clinically relevant report. One of the particular skills of an experienced radiologist is their ability to grade the relative severity of an imaging finding, which is an important factor that influences a clinician's treatment. To make such a determination, the radiologist often employs a subjective assessment, incorporating various imaging and nonimaging features. This skill takes time and experience to develop, and the acquisition of this ability can be daunting to a radiology resident. This article discusses the underlying thought processes and the lexicon involved in grading severity of disease, and aims to shed some light on this seemingly abstract skill.

The GoodHope Ehlers Danlos Syndrome Clinic: development and implementation of the first interdisciplinary program for multi-system issues in connective tissue disorders at the Toronto General Hospital.

Ehlers-Danlos Syndrome (EDS) are a heterogeneous group of genetic connective tissue disorders, and typically manifests as weak joints that subluxate/dislocate, stretchy and/or fragile skin, organ/systems dysfunction, and significant widespread pain. Historically, this syndrome has been poorly understood and often overlooked. As a result, people living with EDS had difficulty obtaining an accurate diagnosis and appropriate treatment, leading to untold personal suffering as well as ineffective health care utilization. The GoodHope EDS clinic addresses systemic gaps in the diagnosis and treatment of EDS. This paper describes a leap forward-from lack of awareness, diagnosis, and treatment-to expert care that is tailored to meet the specific needs of patients with EDS. The GoodHope EDS clinic consists of experts from various medical specialties who work together to provide comprehensive care that addresses the multi-systemic nature of the syndrome. In addition, EDS-specific self-management programs have been developed that draw on exercise science, rehabilitation, and health psychology to improve physical and psychosocial wellbeing and overall quality of life. Embedded into the program are research initiatives to shed light on the clinical presentation, underlying mechanisms of pathophysiology, and syndrome management. We also lead regular educational activities for community health care providers to increase awareness and competence in the interprofessional management of EDS beyond our doors and throughout the province and country.

Utility of the spinal instability neoplastic score to identify patients with Gorham-Stout disease requiring spine surgery.

BACKGROUND: Gorham-Stout disease (GSD) is a rare syndrome presenting with progressive osteolysis which in the spine can lead to cord injury, instability, and deformity. Here, the early spine surgery may prevent catastrophic outcomes. CASE DESCRIPTION: A 25-year-old male with GSD involving the T2 to T6 levels presented with acute traumatic kyphoscoliosis at T3 and T4 and left lower extremity paraparesis. The CT scan 4 weeks before this showed progressing osteolysis versus the CT 5 years ago. Unfortunately, the patient underwent delayed treatment resulting in permanent neurological sequelae. Surgery included a laminectomy and vertebrectomy of T3/T4 with instrumented fusion from T1-10. The use of the spinal instability neoplastic score (SINS) is a useful tool to prompt early referral to spine surgeons. CONCLUSION: We recommend using the SINS score in GSD patients who develop spinal lesions to prompt early referral for consideration of surgery.

Acromioclavicular Joint Injuries in Professional Ice Hockey Players: Epidemiologic and MRI Findings and Association With Return to Play.

BACKGROUND: Acromioclavicular joint (ACJ) injuries are common in ice hockey players and are traditionally evaluated with conventional radiography, which has recognized limitations in the accurate characterization of the spectrum of soft tissue injuries and severity/grade of injury sustained. PURPOSE: To evaluate the epidemiologic, clinical, and magnetic resonance imaging (MRI) findings in professional ice hockey players who have sustained acute ACJ injuries. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective review was performed of professional National Hockey League (NHL) players referred for MRI evaluation of acute ACJ injuries. All MRI scans were assessed for status of the ACJ, ligamentous stabilizers, and surrounding musculature. MRI-based overall grade of ACJ injury (modified Rockwood grade 1-6) was assigned to each case. Data regarding mechanism of injury, player handedness, clinical features, and return to play were evaluated. RESULTS: Overall, 24 MRI examinations of acute ACJ injuries (23 patients; mean age, 24 years) were reviewed. We found that 50% of injuries were sustained during the first period of play, and in 75% of cases, injuries involved the same side as player shooting handedness. Analysis of MRI scans revealed 29% (7/24) grade 1 ACJ injuries, 46% (11/24) grade 2 injuries, 21% (5/24) grade 3 injuries, and 4% (1/24) grade 5 injuries. Trapezius muscle strains were seen in 79% and deltoid muscle strain in 50% of cases. Nonoperative management was used for 23 injuries; 1 patient (grade 5 injury) underwent acute reconstructive surgery. All players successfully returned to professional NHL competition. Excluding cases with additional injuries or surgery (n = 3) or convalescence extending into the offseason (n = 3), we found that the mean return to play was 21.4 days (7.2 games missed). No statistically significant difference was observed in return to play between nonoperatively treated grade 3 injuries (mean, 28.3 days) and grade 1 or 2 injuries (mean, 20.1 days). However, grade 3 injuries were associated with a greater number of NHL scheduled games missed (mean, 12.7) compared with lower grade injuries (mean, 6.1) (P = .027). CONCLUSION: The spectrum of pathology and grading of acute ACJ injuries sustained in professional ice hockey can be accurately assessed with MRI; the majority of injuries observed in this study were low grade (grades 1 and 2). Although grade 3 injuries were associated with a greater number of games missed, similar return-to-play results were observed between nonoperatively treated grade 3 and grade 1 or 2 ACJ injuries.

The Effects of Home Exercise in Older Women With Vertebral Fractures: A Pilot Randomized Controlled Trial.

BACKGROUND: Regular exercise is advocated in osteoporosis guidelines to prevent fractures. Few studies have evaluated the effect of exercise on functional performance, posture, and other outcomes that are important to patients after vertebral fractures. OBJECTIVE: This pilot study will explore the effect of home exercise versus control on functional performance, posture, and patient-reported outcome measures. DESIGN: This study was a parallel 2-arm pilot feasibility trial with 1:1 randomization to exercise or attentional control groups. SETTING: This study took place in 5 Canadian and 2 Australian academic or community hospitals/centers. PARTICIPANTS: This study included 141 women ≥65 years of age with radiographically confirmed vertebral fractures. INTERVENTION: A physical therapist delivered exercise and behavioral counseling in 6 home visits over 8 months and monthly calls. Participants were to exercise ≥3 times weekly. Controls received equal attention. MEASUREMENTS: Functional performance, posture, quality of life, pain, and behavior-change outcomes were assessed at baseline and after 6 (questionnaires only) and 12 months. Adherence to exercise was assessed by calendar diary. All t tests examined between-group mean differences (MD) in change from baseline in intention-to-treat and per-protocol analyses. RESULTS: There was a small effect of exercise on 5 times sit-to-stand test versus control (MD = -1.58 [95% CI = -3.09 to -0.07], intention-to-treat; MD = -1.49 [95% CI = -3.12 to 0.16], per-protocol). There were no other major or statistically significant MDs for any other measured outcomes after follow-up. Adherence declined over time. LIMITATIONS: Treatment effects on variables may have been underestimated due to multiple comparisons and underpowered analyses. CONCLUSIONS: Our exploratory estimate of the effect of exercise on functional leg muscle strength was consistent in direction and magnitude with other trials in individuals with vertebral fractures. Declining adherence to home exercise suggests that strategies to enhance long-term adherence might be important in future confirmatory trials.

Determining the appropriateness of requests for outpatient magnetic resonance imaging of the hip

Summary: In Ontario, Canada, wait times for magnetic resonance imaging (MRI) scans continue to exceed provincial targets. We sought to determine the incidence of inappropriate hip MRI scan referrals, based on accepted indications for hip MRI. We developed an algorithm to appraise each MRI referral based on a prescan patient questionnaire and the interpretation of the MRI by a musculoskeletal radiologist. After reviewing 84 patient questionnaires, we considered 32.1% of MRI referrals to be inappropriate; 25.9% of the inappropriate MRI referrals were ordered as a preoperative test for potential hip arthroscopy despite the patients showing severe osteoarthritis. Having no prior radiographic examination was the most common reason for inappropriate referrals, regardless of pathology (48.1%). With limited MRI scanner time available in Ontario, it is essential that guidelines and training be improved on the indications for hip MRI to reduce the wait times for these specialized tests.

Are osteoporotic vertebral fractures or forward head posture associated with performance-based measures of balance and mobility?

The main objective of this study was to explore whether vertebral fracture characteristics or posture is independently associated with physical performance. Posture was significantly associated with physical performance but fracture characteristics were not, suggesting posture should be the focus of physical performance variance. PURPOSE: The main objective of this study was to explore whether vertebral fracture characteristics (number, severity, location) or occiput-to-wall distance (OWD) is independently associated with physical performance. METHODS: This was a secondary data analysis using baseline data from a randomized controlled trial, of community-dwelling women aged 65 years and older with a suspected vertebral fragility fracture. Lateral thoracic and lumbar spine radiographs were used to determine the number, location, and severity of fracture. The dependent variables were timed up and go (TUG), five times sit-to-stand, four-meter walk, and step test. The independent variables were number, severity, location of fracture, and OWD. Pain during movement and age were covariates. Multivariable regression analyses determined the association between each of the dependent and independent variables. RESULTS: Participants' (n = 158) mean (standard deviation [SD]) age was 75.9 (6.5) years. They had a mean (SD) BMI, OWD, and number of fractures of 26.7 (5.3) kg/m2, 5.7 (4.6) cm, and 2.2 (1.8), respectively. OWD was independently associated with TUG (estimated coefficient [B] = 0.29, 95% confidence interval [CI] = 0.16, 0.42), five times sit-to-stand (B = 0.33, 95% CI = 0.12, 0.55), four-meter walk (B = 0.09, 95% CI = 0.05, 0.13), and step test (B = - 0.36, 95% CI = - 0.50, - 0.23) in the unadjusted model. OWD was independently associated with TUG (B = 0.25, 95% CI = 0.12, 0.38), five times sit-to-stand (B = 0.29, 95% CI = 0.07, 0.50), four-meter walk (B = 0.08, 95% CI = 0.03, 0.12), and step test (B = - 0.22, 95% CI = - 0.47, - 0.19) in the adjusted model. CONCLUSION: OWD was significantly associated with physical performance but fracture characteristics were not. These analyses were exploratory and require replication in future studies.

Exploring the association between number, severity, location of fracture, and occiput-to-wall distance.

This study of women with a suspected vertebral fracture determined the association between vertebral fracture characteristics and posture. The number of fractures was associated with posture. Severity of fracture was associated with posture when adjusting for pain. Fracture characteristics explain some variability in posture in women with a suspected vertebral fracture. PURPOSE: Osteoporotic vertebral fractures are associated with increased morbidity and mortality. An accumulation of vertebral fractures may lead to forward head posture, which has been independently associated with mortality. It is unclear how fracture characteristics, including the number, severity, and location of fracture, contribute to occiput-to-wall distance (OWD). METHODS: This was a cross-sectional secondary data analysis using baseline data from a randomized controlled trial, in community-dwelling women aged 65 years and older with a suspected vertebral fragility fracture. Lateral thoracic and lumbar spine radiographs were used to determine the number, location, and severity of fracture. Occiput-to-wall distance (OWD) was used to assess forward head posture. Pain during movement (0-10 scale) and age were considered as confounding variables. Multivariable regression models were used to evaluate relationships between fracture variables and OWD. RESULTS: Participants (n = 158) were of mean age 75.9 (SD 6.5) years with a mean (SD) BMI = 26.7 (5.3) kg/m2, OWD = 5.7 (4.6) cm, and number of fractures = 2.4 (2.4). In unadjusted analyses, the number of fractures (B = 0.82, 95% CI = 0.04, 1.59) was associated with OWD. When adjusting for pain, severity of fractures (B = 1.08, 95% CI = 0.001, 2.15) was independently associated with OWD. Location was not associated with OWD in any of the models. CONCLUSIONS: The number of fractures was significantly associated with OWD in the unadjusted model, explaining more of the variability in OWD than other fracture characteristics. Severity of fracture was associated with OWD in the adjusted model. However, pain may confound the relationship between OWD and fracture characteristics.

A Case of Posterior Tibial Nerve Injury After Arthroscopic Calcaneoplasty.

We report the first case of distal posterior tibial nerve injury after arthroscopic calcaneoplasty. A 59-year-old male had undergone right arthroscopic calcaneoplasty to treat retrocalcaneal bursitis secondary to a Haglund's deformity. The patient complained of numbness in his right foot immediately after the procedure. Two years later and after numerous assessments and investigations, a lateral plantar nerve and medial calcaneal nerve lesion was diagnosed. In the operating room, the presence of an iatrogenic lesion to the distal right lateral plantar nerve (neuroma incontinuity involving 20% of the nerve) and the medial calcaneal nerve (complete avulsion) was confirmed. The tarsal tunnel was decompressed, and both the medial and the lateral plantar nerve were neurolyzed under magnification. To the best of our knowledge, our case report is the first to describe iatrogenic posterior tibial nerve injury after arthroscopic calcaneoplasty. It is significant because this complication can hopefully be avoided in the future with careful planning and creation of arthroscopic ports and treated appropriately with early referral to a nerve specialist if the patient's symptoms do not improve within 3 months.

Magnetic resonance imaging appearance of soft-tissue metastases: our experience at an orthopedic oncology center.

OBJECTIVE: To assess the prevalence and magnetic resonance imaging appearance of metastasis presenting as a soft-tissue mass. MATERIALS AND METHODS: A retrospective chart review was performed on 51 patients who presented to an orthopedic oncology center with soft-tissue masses, with a histology-proven diagnosis of soft-tissue metastasis, over a 14-year period. Their magnetic resonance imaging, primary origin, and follow-up have been assessed. RESULTS: Soft-tissue metastasis was identified in patients ranging from 18 to 85 years old. Most (80%) of the masses were located deep to the deep fascia. In our cohort of patients, melanoma was the most common primary malignancy contributing to soft-tissue metastasis (21.8%). Among soft-tissue metastasis from solid organs, breast and lung were the most frequent (9.1% each). Five patients had soft-tissue metastases from an unknown primary. CONCLUSION: Imaging diagnosis of soft-tissue metastases is challenging as it can demonstrate imaging appearances similar to primary soft-tissue sarcoma. The presence of a known malignancy may not be evident in everyone, and even if available, histopathology will be necessary for diagnosis if this is the only site of recurrence/metastasis to differentiate from a primary soft-tissue sarcoma. Moreover, soft-tissue metastasis may be the initial presentation of a malignancy. Primary malignancies with soft-tissue metastasis carry a poor prognosis; hence, prompt diagnosis and management in essential.

Evaluation of Automated Fracture Risk Assessment Based on the Canadian Association of Radiologists and Osteoporosis Canada Assessment Tool.

Fracture risk assessments are not always clearly communicated on bone mineral density (BMD) reports; evidence suggests that structured reporting (SR) tools may improve report clarity. The aim of this study is to compare fracture risk assessments automatically assigned by SR software in accordance with Canadian Association of Radiologists and Osteoporosis Canada (CAROC) recommendations to assessments from experts on narrative BMD reports. Charts for 500 adult patients who recently received a BMD exam were sampled from across University of Toronto's Joint Department of Medical Imaging. BMD measures and clinical details were manually abstracted from charts and were used to create structured reports with assessments generated by a software implementation of CAROC recommendations. CAROC calculations were statistically compared to experts' original assessments using percentage agreement (PA) and Krippendorff's alpha. Canadian FRAX calculations were also compared to experts', where possible. A total of 25 (5.0%) reported assessments did not conform to categorizations recommended by Canadian guidelines. Across the remainder, the Krippendorff's alpha relating software assigned assessments to physicians was high at 0.918; PA was 94.3%. Lower agreement was associated with reports for patients with documented modifying factors (alpha = 0.860, PA = 90.2%). Similar patterns of agreement related expert assessments to FRAX calculations, although statistics of agreement were lower. Categories of disagreement were defined by (1) gray areas in current guidelines, (2) margins of assessment categorizations, (3) dictation/transcription errors, (4) patients on low doses of steroids, and (5) ambiguous documentation of modifying factors. Results suggest that SR software can produce fracture risk assessments that agree with experts on most routine, adult BMD exams. Results also highlight situations where experts tend to diverge from guidelines and illustrate the potential for SR software to (1) reduce variability in, (2) ameliorate errors in, and (3) improve clarity of routine adult BMD exam reports.

Low prevalence of unexpected popliteal DVT detected on routine MRI assessment of the knee.

OBJECTIVE: The purpose of this study was to document the appearance and determine the prevalence of findings suspicious for popliteal vein thrombosis on magnetic resonance (MR) assessment of the knee joint. METHODS: A total of 2888 MR examinations were retrospectively reviewed and classified as illustrating either normal appearing popliteal vein or findings suspicious for popliteal vein thrombosis. RESULTS: A total of 2879 MR studies were assessed as having a normal appearing popliteal vein. Nine studies illustrated findings suspicious for popliteal vein thrombosis. CONCLUSION: Although the prevalence of MR findings is low (0.3%), our findings reiterate the need to interrogate the popliteal vein for evidence of thrombosis.

Bilateral atypical femoral fractures: how much symmetry is there on imaging?

OBJECTIVE: To evaluate bilateral atypical femoral fractures (AFFs) and to compare imaging features of paired fractures. MATERIALS AND METHODS: Bilateral femoral imaging studies of 124 patients on bisphosphonate therapy with at least one AFF were retrospectively reviewed. Time between AFF diagnoses was determined. The following imaging features were evaluated for each AFF: fracture location, femoral angle, length of cortical thickening, medial spike location, fracture orientation, and comminution. Associations between imaging findings on pairs of bilateral AFFs were assessed with Spearman's correlation (rs) and the Kappa statistic (κ). RESULTS: Bilateral AFFs were present in 78/124 (62.9%) cases (3 men, 75 women; mean age 67.3 years). Average time between contralateral AFF diagnoses was 10.3 months. Contralateral AFFs were diagnosed within 12 months of the index fracture in 60/78 (76.9%) cases and within 3 years in 69/78 (88.5%) cases. There was a strong correlation between bilateral AFF locations (rs = 0.65), with 58/76 (76.3%) occurring within a distance of <5 cm and 41/76 (53.9%) within a distance of ≤2.5 cm. Bilateral AFF pairs had moderately correlated femoral angles (rs = 0.42), and weakly correlated lengths of cortical thickening (rs = 0.28). There was substantial agreement for medial spike location (κ = 0.68) and fracture orientation (κ = 0.64), and moderate agreement for lack of comminution (κ = 0.42). All findings were independent of time between AFF diagnoses. CONCLUSIONS: Patients with unilateral atypical femoral fractures are likely to be diagnosed with a contralateral AFF within the first year of presentation. Bilateral AFFs commonly have similar imaging features, including location along the femur.

Spontaneous resolution of quadrilateral space syndrome: a case report.

A case of quadrilateral space syndrome is presented, where a large near-circumferential glenoid labrum tear led to a paralabral cyst that dissected into the quadrilateral space and caused a compressive neuropathy of the axillary nerve. This led to a 6-mo history of left shoulder pain, parasthesias, marked weakness to abduction, and marked denervation in both the deltoid and teres minor on electro-diagnostics. This is a presentation of interest as it is the only case report in the literature, to the authors' knowledge, where spontaneous resolution of entrapment occurred. This normally requires intervention for definitive management. It resolved through nonsurgical management with pregabalin, oxycodon, and naproxen medications, leading to good functional return, as well as pain and presumed muscle edema dissipation, while awaiting interventional consultation. It also illustrates that quadrilateral space syndrome is a difficult clinical diagnosis owing to the nonspecific symptom presentation, as well as weakness.

Build better bones with exercise: protocol for a feasibility study of a multicenter randomized controlled trial of 12 months of home exercise in women with a vertebral fracture.

BACKGROUND: Our goal is to conduct a multicenter randomized controlled trial (RCT) to investigate whether exercise can reduce incident fractures compared with no intervention among women aged ≥65 years with a vertebral fracture. OBJECTIVES: This pilot study will determine the feasibility of recruitment, retention, and adherence for the proposed trial. DESIGN: The proposed RCT will be a pilot feasibility study with 1:1 randomization to exercise or attentional control groups. SETTING: Five Canadian sites (1 community hospital partnered with an academic center and 4 academic hospitals or centers affiliated with an academic center) and 2 Australian centers (1 academic hospital and 1 center for community primary care, geriatric, and rehabilitation services). PARTICIPANTS: One hundred sixty women aged ≥65 years with vertebral fracture at 5 Canadian and 2 Australian centers will be recruited. INTERVENTION: The Build Better Bones With Exercise (B3E) intervention includes exercise and behavioral counseling, delivered by a physical therapist in 6 home visits over 8 months, and monthly calls; participants are to exercise ≥3 times weekly. Controls will receive equal attention. MEASUREMENTS: Primary outcomes will include recruitment, retention, and adherence. Adherence to exercise will be assessed via calendar diary. Secondary outcomes will include physical function (lower extremity strength, mobility, and balance), posture, and falls. Additional secondary outcomes will include quality of life, pain, fall self-efficacy, behavior change variables, intervention cost, fractures, and adverse events. Analyses of feasibility objectives will be descriptive or based on estimates with 95% confidence intervals, where feasibility will be assessed relative to a priori criteria. Differences in secondary outcomes will be evaluated in intention-to-treat analyses via independent Student t tests, chi-square tests, or logistic regression. The Bonferroni method will be used to adjust the level of significance for secondary outcomes so the overall alpha level is .05. LIMITATIONS: No assessment of bone mineral density will be conducted. The proposed definitive trial will require a large sample size. CONCLUSIONS: The viability of a large-scale exercise trial in women with vertebral fractures will be evaluated, as well as the effects of a home exercise program on important secondary outcomes.

The clinical characteristics of patients with hip fractures in typical locations and atypical femoral fractures.

UNLABELLED: The pathophysiology of atypical fractures is unknown. We compared characteristics of patients with atypical femoral fractures and hip fractures in typical locations of the femur. Patients with atypical fracture reported a longer duration of use of bisphosphonates, had higher body mass index, and higher total hip bone mineral density. Further studies are needed. INTRODUCTION: This study aims to describe the characteristics of patients with typical and atypical fractures of the femur assessed in a tertiary care osteoporosis center. METHODS: We abstracted clinical, laboratory, and radiographic data on subjects with a history of a low-impact fracture at the femur and/or hip (confirmed by review of radiograph and/or radiology report) from January 2008 to October 2011. Available radiographs were reviewed and fracture categorized as typical or atypical by a radiologist blinded to the original diagnosis. RESULTS: Radiology reports were available for 72 subjects: 40 hip fractures in typical locations (typical fracture), 16 atypical femoral fracture (atypical fracture), and 16 were excluded. While both those with typical and atypical fractures reported taking bisphosphonates at the time of fracture, duration of use was longer with atypical fractures (104.2±42.0 months) compared with typical (71.1±62.8 months) (p=0.04). Body mass index (BMI) was higher in patients with atypical fractures (26.2±3.2 kg/m2) than in those with typical (23.1±4.3 kg/m2) (p=0.006). Total bone mineral density (BMD) was higher in patients with atypical fracture (0.795±0.102) versus typical (0.686±0.130) (p=0.003) Previous history of cancer was reported by 7 of 16 patients with atypical and 7 of 40 patients with typical fracture (p=0.04). CONCLUSIONS: Compared to those with typical fractures, patients with atypical fracture report a longer duration of use of bisphosphonates, higher BMI, and higher total hip BMD. Future studies should examine if these differences contribute to the pathophysiology of atypical fractures.