The overall goal of this project is to improve the accuracy and cost-effectiveness of the diagnosis of superior glenoid labral pathology. Tears of the glenohumeral labrum are common in both work- and sport-related activities, but diagnosis of these lesions can be difficult. At least seventeen different provocative maneuvers meant to be performed during physical examination have been described to help doctors diagnose pathology of the superior glenoid labrum. Existing physical examination tests for superior labral tears have repeatedly been shown to be insensitive and/or nonspecific, and therefore arthroscopy is still the gold standard for diagnosis of labral lesions. Because the long head of the biceps brachii muscle originates from the superior labrum, provocative maneuvers often try to elicit labral symptoms (pain and/or joint sounds) either by 1) causing tension in the long head of the biceps which in turn pulls on the labrum, or 2) by applying compression to the joint which stresses the labrum by deforming it with the femoral head. Our hypothesis is that many existing clinical tests function poorly because they either do not reliably produce adequate stresses in the glenohumeral labrum to elicit symptoms, or because they produce stresses in various other tissues that can confound results. This proposal aims to test this hypothesis through biomechanical evaluation of a subset of twelve provocative maneuvers that are used in physical examination and that were developed specifically for detecting labral pathology. The long term goal of this research is to provide clinicians with effective physical examination tools to quickly and accurately diagnose superior labral lesions, thereby reducing time spent in clinical examination and decreasing reliance on expensive and invasive contrast-enhanced medical imaging or arthroscopic techniques.
The specific aims of this proposal are 1) to quantify the amplitude and specificity of activation of the long head of the biceps brachii in existing provocative maneuvers for labral pathology using electromyography (EMG), and 2) to quantify the superior migration of the humeral head relative to the glenoid in the same provocative maneuvers. The data will quantify the effectiveness of each test in actively stressing the superior labrum through recreating the proposed mechanisms of superior labral injury. Taken together, these specific aims will allow the investigators to identify physical examination tests that have a sound biomechanical basis and that are most likely to be sensitive and specific in diagnosing superior labral pathology. In doing so, this work will aid the National Institutes of Health in achieving its mission of improving health and diagnosis of human disease. A major challenge facing the public health system is to provide exceptional care while limiting costs. This study is aimed at improving diagnosis of musculoskeletal injury while reducing medical costs by eliminating expensive, invasive, and often unnecessary tests. ? ?
| Wood, Vanessa J C; Sabick, Michelle B; Pfeiffer, Ron P et al. (2011) Glenohumeral muscle activation during provocative tests designed to diagnose superior labrum anterior-posterior lesions. Am J Sports Med 39:2670-8 |
