Howe, Benjamin M.

Background: Gluteus medius tears and atrophy cause lateral hip pain, limp, and functional impairment. We developed the “broken wing sign,” a novel physical examination test for detecting gluteus medius tendon tears and muscle degeneration. This study evaluated its diagnostic accuracy and clinical utility against magnetic resonance imaging (MRI) and intraoperative findings. Methods: We prospectively examined 59 patients (75 hips; mean age, 69.5 ± 10.8 years; 48 women) with suspected hip abductor insufficiency. The broken wing sign was tested with patients prone, the knee flexed at 90°, and the hip actively extended. A positive sign involved ≥10° of compensatory external hip rotation, visible as an inward drift of the foot, indicating gluteus medius (and resulting internal rotation) weakness. MRI served as the reference standard for classifying gluteus medius integrity as no tear, partial, full-thickness, or massive. Fatty infiltration was graded (Goutallier grades 0 to 4), quantified, and analyzed for a correlation with the examination findings. Diagnostic accuracy metrics were calculated. Results: The broken wing sign demonstrated high accuracy (sensitivity, 81.8%; specificity, 80.0%; positive predictive value [PPV], 91.8%; negative predictive value, 61.5%; diagnostic odds ratio, 17.8). An external rotation threshold of ≥30° yielded 100% specificity and 100% PPV for a tear. The sign detected acute tears with no or minimal fatty infiltration (100% sensitivity for massive tears). The degree of the external rotation angle was strongly correlated with muscle atrophy with fatty infiltration, showing 88.0% sensitivity for Goutallier grade ≥3 and 100% sensitivity for grade 4. Conclusions: The broken wing sign is clinically useful for diagnosing gluteus medius tendon tears and muscle atrophy, particularly massive tears and advanced fatty degeneration. It effectively guides MRI utilization and surgical planning, serving as a valuable initial diagnostic tool in the clinical setting. Level of Evidence: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Abstract Background To determine whether virtual surgical planning and three‐dimensional printed cutting guides (3D/VSP) improved radiographic bone union compared to conventional methods (CM) in fibula free flap (FFF) reconstruction of the mandibles. Methods Retrospective study from the years 2000–2018 at a tertiary hospital. Osseous union was evaluated by a radiologist blinded to each patient's treatment. Results Two hundred sixty patients who underwent FFF tissue transfer, 28 with VSP and 3D cutting guides. Bony union was not achieved in 46 (20%) patients who underwent CM compared to 1 (4%) of patients with VSP and guides ( p = 0.036). FFF complication was significantly higher in CM with 87 patients (38%) compared to three patients (11%) in 3D/VSP ( p = 0.005). Median time to bony union for patients who underwent CM was 1.4 years compared to 0.8 years in 3D/VSP. Conclusions 3D/VSP reduced the rate of radiographic nonunion and flap‐related complications in FFF reconstruction for mandibular defects.

BackgroundMR image intensity nonuniformity is often observed at 7T. Reference scans from the body coil used for uniformity correction at lower field strengths are typically not available at 7T.PurposeTo evaluate the efficacy of a novel algorithm, Uniform Combined Reconstruction (UNICORN), to correct receive coil‐induced nonuniformity in musculoskeletal 7T MRI without the use of a reference scan.Study TypeRetrospective image analysis study.SubjectsMRI data of 20 subjects was retrospectively processed offline.Field Strength/Sequence: Knees of 20 subjects were imaged at 7T with a single‐channel transmit, 28‐channel phased‐array receive knee coil. A turbo‐spin‐echo sequence was used to acquire 33 series of images.AssessmentThree fellowship‐trained musculoskeletal radiologists with cumulative experience of 42 years reviewed the images. The uniformity, contrast, signal‐to‐noise ratio (SNR), and overall image quality were evaluated for images with no postprocessing, images processed with N4 bias field correction algorithm, and the UNICORN algorithm.Statistical TestsIntraclass correlation coefficient (ICC) was used for measuring the interrater reliability. ICC and 95% confidence intervals (CIs) were calculated using the R statistical package employing a two‐way mixed‐effects model based on a mean rating (k = 3) for absolute agreement. The Wilcoxon signed‐rank test with continuity correction was used for analyzing the overall image quality scores.ResultsUNICORN was preferred among the three methods evaluated for uniformity in 97.9% of the pooled ratings, with excellent interrater agreement (ICC of 0.98, CI 0.97–0.99). UNICORN was also rated better than N4 for contrast and equivalent to N4 in SNR with ICCs of 0.80 (CI 0.72–0.86) and 0.67 (CI 0.54–0.77), respectively. The overall image quality scores for UNICORN were significantly higher than N4 (P < 6 × 10‐13), with good to excellent interrater agreement (ICC 0.90, CI 0.86–0.93).Data ConclusionWithout the use of a reference scan, UNICORN provides better image uniformity, contrast, and overall image quality at 7T compared with the N4 bias field‐correction algorithm.Level of Evidence: 4Technical Efficacy: Stage 1J. Magn. Reson. Imaging 2019;50:1534–1544.

AimsRhabdomyosarcomas of bone are extremely rare, with fewer than 10 reported cases. A very rare subtype of spindle cell/sclerosing rhabdomyosarcoma harbouring a FUS–TFCP2 fusion and involving both soft tissue and bone locations has been reported very recently. We report only the fourth case of this unusual, clinically aggressive rhabdomyosarcoma.Material and resultsA previously well 72‐year‐old male presented with a destructive lesion of the mandible. Morphological and immunohistochemical study of a needle biopsy and the subsequent resection showed a spindle cell rhabdomyosarcoma. RNA‐seq, RT–PCR and FISH confirmed the presence of the FUS–TFCP2 fusion.ConclusionsSpindle cell rhabdomyosarcomas carrying the FUS–TFCP2 fusion are very rare rhabdomyosarcoma variants with osseous predilection. The classification and differential diagnosis of this unusual molecular variant of spindle cell/sclerosing rhabdomyosarcoma are discussed.

Abstract BACKGROUND Several hypotheses have been proposed for the pathophysiology of suprascapular nerve (SSN) palsy, including compression, traction, and nerve inflammation. OBJECTIVE To provide insight into the pathophysiology of isolated nontraumatic SSN palsy by performing critical reinterpretations of electrodiagnostic (EDX) studies and magnetic resonance (MR) images of patients with such diagnosis. METHODS We retrospectively reviewed all patients referred to our institution for the past 20 yr with a diagnosis of nontraumatic isolated suprascapular neuropathy who had an upper extremity EDX study and a shoulder or brachial plexus MR scan. Patient charts were reviewed to analyze their initial clinical examination, and their original EDX study and MR images were reinterpreted by an experienced neurologist and a musculoskeletal radiologist, respectively, both blinded from the authors’ hypothesis and from each other's findings. RESULTS Fifty-nine patients were included. Fifty of them (85%) presented with at least 1 finding that was inconsistent with an isolated SSN palsy. Forty patients (68%) had signs on physical examination beyond the SSN distribution. Thirty-one patients (53%) had abnormalities on their EDX studies not related to the SSN. Twenty-two patients (37%) had denervation atrophy in other muscles than the spinati, or neural hyperintensity in other nerves than the SSN on their MR scans, without any evidence of SSN extrinsic compression. CONCLUSION The great majority of patients with presumed isolated SSN palsy had clinical, electrophysiological, and/or imaging evidence of a more diffuse pattern of neuromuscular involvement. These data strongly support an inflammatory pathophysiology in many cases of “isolated” SSN palsy.