The O'Brien test demonstrates a higher diagnostic value in identifying posteroinferior labral tears than superior labral anterior to posterior (SLAP) tears.

Background: The primary aim was to determine the diagnostic value of the O'Brien test in localizing labral tears of the shoulder. Methods: A consecutive series of patients electing for labral repair between January 2005 and March 2021 were included in this retrospective study. Inclusion criteria were as follows: (1) any patient with a labral tear who was elected for arthroscopic labral repair and (2) had documentation of the O'Brien test in the preoperative evaluation. Exclusion criteria were patients that had a negative arthrographically enhanced computed tomography or magnetic resonance imaging scan. During arthroscopy, the localization and extension of the labral tear was documented in a standardized 12-o'clock configuration. Anteroinferior, posteroinferior, superior labrum anterior to posterior (SLAP), and combined labral tears were documented. The sensitivity, specificity, positive and negative predictive values, accuracy, positive and negative likelihood ratios, receiver operating characteristic curve, and area under the curve were calculated to determine the diagnostic value. Results: The cohort consisted of 271 patients (77% male) and included 105 anteroinferior, 86 posteroinferior, 46 SLAP, and 32 combined parts of the labrum. The mean age at time of surgery was 30 (±10.2) years. The O'Brien test was positive in 142 (52%) patients and showed the highest sensitivity and specificity for the posteroinferior tears (83% and 62%) compared to the anteroinferior (16% and 25%), combined labral parts (69% and 50%), and SLAP (65% and 50%) tears. In addition, receiver operating characteristic-analysis demonstrated a significantly higher area under the curve for posteroinferior tears compared to the other tears (P < .001). Conclusion: The O'Brien test demonstrates more diagnostic value for posteroinferior tears than other labral tears. This includes the SLAP tear, for which the O'Brien test was originally designed. Clinical Relevance: These findings are helpful towards reinterpreting the O'Brien test as well as diagnosing, and more specifically localizing labral tears in clinics.

Predictive value of Gagey's hyperabduction test in identifying inferior glenohumeral ligament lesions.

INTRODUCTION: Clinical tests that can identify inferior glenohumeral ligament (IGHL) complex injuries are indispensable for the diagnosis of shoulder instability. Gagey's hyperabduction test had been developed to diagnose IGHL hyperlaxity, however, it is unclear whether the test is able to accurately diagnose an IGHL lesion. The aim of this study was to (1) determine the diagnostic performance of the Gagey test in identifying an IGHL lesion and (2) determine if a positive Gagey test is more predictive for an anterior or posterior IGHL lesion thanks to the heatmapping of the lesions. It was hypothesized that a Gagey test can accurately predict IGHL lesions, but would not be able to distinguish between anterior and inferior IGHL lesions. METHODS: A retrospective diagnostic accuracy study was conducted including all consecutive patients who underwent glenoid labral repair between January 2005 and September 2021 with a documented Gagey test prior to surgery. Using arthroscopic findings as a reference standard, the diagnostic performance characteristics of the Gagey test for each type of IGHL lesion (anterior, posterior and combined) were calculated and labral heatmapping was used to depict its localisation. RESULTS: A total of 167 patients were included, with a mean age of 29±10 years. The sensitivity, specificity and accuracy of the Gagey test on determining an IGHL lesion were 46%, 38% and 46%, respectively. The positive and negative predictive values were 88% and 7%, respectively. Heatmapping of the labral lesions demonstrated that a positive Gagey test was most predictive of anterior IGHL and axillary pouch tears and non-predictive of posterior IGHL lesions. DISCUSSION: The Gagey test demonstrated a low sensitivity and specificity to identify an IGHL lesion and therefore the hypothesis could not be confirmed. However, the Gagey test has a high positive predictive value to diagnose anterior IGHL lesions. Further prospective research with a more evenly distribution of lesions is needed to investigate the clinical value of the Gagey test to identify these lesions. Based on this data, the Gagey test seems especially important to support the results of other clinical tests such as the apprehension, relocation and surprise tests. LEVEL OF EVIDENCE: III, Retrospective Case-Control study.

Kinematic analysis of forearm rotation using four-dimensional computed tomography.

This study aimed to quantify forearm kinematics with a focus on the forearm rotation axis. Ten healthy volunteers were included in the study. One three-dimensional computed tomographic scan and two four-dimensional computed tomographic scans were done in all the arms to capture forearm joint motion. After image processing, the rotation axis and the movement of the radius with respect to various axes were quantified. The rotation axis was calculated using finite helical axis analysis and a circle fitting approach. The mean error of the rotation axis found through circle fitting was 0.2 mm (SD 0.1) distally and 0.1 mm (SD 0.1) proximally, indicating an improvement in precision over the finite helical axis approach. The translations of the radius along the ulnar axis and the forearm rotation axis were 2.6 (SD 0.8) and 0.6 mm (SD 0.9), respectively. The rotation of the radius around the radial axis was 7.2°. The techniques presented provide a detailed description of forearm kinematics.