Editorial Commentary: There's More Meat on That Bone! Labral Hypertrophy Normalizes Femoral Head Coverage in Dysplastic Hips.

The size of the acetabular labrum has been shown to be larger in patients with acetabular hip dysplasia and smaller in patients with acetabular overcoverage. Compensatory morphologic changes to the acetabular labrum are potentially useful as an imaging biomarker of hip stability, and with additional future outcomes investigation, imaging measures may be used to guide the type and extent of hip preservation surgery.

Lateral acetabular labral length is inversely related to acetabular coverage as measured by lateral center edge angle of Wiberg.

Patients with developmental dysplasia of the hip often have compensatory labral hypertrophy, which presumably lends stability to an unstable joint. Conversely, patients with acetabular overcoverage may have small or ossified labra. The purpose of this study is to explore the interaction of labral length with the degree of acetabular hip coverage. A retrospective cohort of patients with hip pain presenting to a hip preservation center, who had undergone hip magnetic resonance imaging and AP pelvis radiographs were studied. General linear multivariate models were used to assess the association between three measures of labral length (lateral, anterior and anterior inferior locations along the acetabular rim) and the X-ray derived lateral center edge angle (LCEA) of Wiberg. Of the three acetabular labral locations measured, only the lateral labrum was associated with LCEA Wiberg (P = 0.0008). Lateral labral length increases as LCEA of Wiberg decreases. The anterior and anterior inferior labral locations did not show a predictable increase in labral length as LCEA Wiberg decreased.

Knee pain · no popping · no previous trauma · Dx?

A 36-year-old man sought care at our family medicine clinic for knee pain that he'd had for the past year. He denied any previous injury or trauma to the knee. The pain affected the posterolateral left knee and was aggravated by squatting and deep flexion. Daily activities did not bother him, but skiing, golfing, mountain biking, and lifting weights worsened the pain. His pain had gradually become more severe and frequent. He denied any mechanical symptoms such as catching, popping, or locking.

Introduction of a virtual workstation into radiology medical student education.

OBJECTIVE. This article describes the creation of a virtual workstation for use by medical students and implementation of that workstation in the reading room. CONCLUSION. A radiology virtual workstation for medical students was created using OsiriX imaging software to authentically simulate the experience of interacting with cases selected to cover important musculoskeletal imaging diagnoses. A workstation that allows the manipulation and interpretation of complete anonymized DICOM images may enhance the educational experience of medical students.

Brief report: airways abnormalities and rheumatoid arthritis-related autoantibodies in subjects without arthritis: early injury or initiating site of autoimmunity?

OBJECTIVE: To evaluate the presence of pulmonary abnormalities in rheumatoid arthritis (RA)-related autoantibody-positive subjects without inflammatory arthritis. METHODS: Forty-two subjects who did not have inflammatory arthritis but were positive for anti-cyclic citrullinated peptide antibodies and/or ≥2 rheumatoid factor isotypes (a profile that is 96% specific for RA), 15 autoantibody-negative controls, and 12 patients with established seropositive early RA (<1-year duration) underwent spirometry and high-resolution computed tomography (HRCT) lung imaging. RESULTS: The median age of autoantibody-positive subjects was 54 years, 52% were female, and 38% were ever-smokers; these characteristics were not significantly different from those of autoantibody-negative control subjects. No autoantibody-positive subject had inflammatory arthritis based on joint examination. HRCT revealed that 76% of autoantibody-positive subjects had airways abnormalities including bronchial wall thickening, bronchiectasis, centrilobular opacities, and air trapping, compared with 33% of autoantibody-negative controls (P = 0.005). The prevalence and type of lung abnormalities among autoantibody-positive subjects were similar to those among patients with early RA. In 2 autoantibody-positive subjects with airways disease, inflammatory arthritis classifiable as articular RA developed ∼13 months after the lung evaluation. CONCLUSION: Airways abnormalities that are consistent with inflammation are common in autoantibody-positive subjects without inflammatory arthritis and are similar to airways abnormalities seen in patients with early RA. These findings suggest that the lung may be an early site of autoimmune-related injury and potentially a site of generation of RA-related autoimmunity. Further studies are needed to define the mechanistic role of lung inflammation in the development of RA.

Normal anatomy and anatomical variants of the elbow.

This article provides a brief review of the normal osseous, ligamentous, muscular, and neurovascular imaging anatomy of the elbow. Special attention is paid to the normal structures that may simulate pathology, as well as anatomical variants that may lead to pathology. This review will help clarify distinctions between normal anatomy and abnormal anatomy, as well as elucidate pathological consequences of a seemingly normal structure.

Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit.

PURPOSE: To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images. MATERIALS AND METHODS: This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance. RESULTS: The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65 degrees (SD 27 degrees) for the controls and 94 degrees (SD 38 degrees) for the athletes (P = 0.002). CONCLUSIONS: Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement.