Maximizing Muscle Function in Cuff-Deficient Shoulders: A Rehabilitation Proposal for Reverse Arthroplasty.

PURPOSE: The purpose of this review is to describe the role of altered joint biomechanics in reverse shoulder arthroplasty and to propose a rehabilitation protocol for a cuff-deficient glenohumeral joint based on the current evidence.Methods and Materials: The proposed rehabilitation incorporates the principles of pertinent muscle loading while considering risk factors and surgical complications. RESULTS: In light of altered function of shoulder muscles in reverse arthroplasty, scapular plane abduction should be more often utilized as it better activates deltoid, teres minor, upper trapezius, and serratus anterior. Given the absence of supraspinatus and infraspinatus and reduction of external rotation moment arm of the deltoid in reverse arthroplasty, significant recovery of external rotation may not occur, although an intact teres minor may assist external rotation in the elevated position. CONCLUSION: Improving the efficiency of deltoid function before and after reverse shoulder arthroplasty is a key factor in the rehabilitation of the cuff deficient shoulders. Performing exercises in scapular plane and higher abduction angles activates deltoid and other important muscles more efficiently and optimizes surgical outcomes.

Accuracy of infraspinatus isometric testing in predicting tear size and tendon reparability: comparison with imaging and arthroscopy.

BACKGROUND: The purpose of this study was to examine the accuracy of external rotation in neutral (0° external position) and in shortened position (45° external position) in relation to rotator cuff tear size, tendon reparability, and other clinical, surgical, and imaging findings. METHODS: This was a prospective blinded diagnostic study of consecutive surgical candidates for rotator cuff repair using magnetic resonance imaging and arthroscopic surgery as the "gold standards." The area under a receiver operating characteristic (AUROC) curve was calculated for each position. RESULTS: Eighty-five patients (35 female [41%] and 50 male [59%]; age, 65 years [standard deviation = 10]) were included. Sixty patients (71%) had a minor tear (4 small, 56 moderate), and 25 patients (29%) had a major tear (17 large and 8 massive). Seventy patients (82%) had a full repair, and 15 (18%) patients underwent a partial repair. There were 26 (31%) associated full-thickness tears of the infraspinatus. The isometric strength testing in both positions had good to excellent accuracy (range, 0.80-0.90) for detecting reparability, tear retraction, infraspinatus atrophic changes observed by the clinician, and infraspinatus fatty infiltration on magnetic resonance images. The shortened position had an overall higher accuracy than the neutral position and was more clinically useful for detecting an infraspinatus full-thickness tear (AUROC = 0.84 vs 0.78) and rotator cuff tear size (AUROC = 0.80 vs. 0.75). CONCLUSIONS: The isometric external rotation is an accurate test in diagnosing different aspects of rotator cuff disease and specifically of the infraspinatus muscle. The isometric strength at the shortened position was a better predictor of clinical, surgical, and imaging findings.

Convergent validity of the constant-murley outcome measure in patients with rotator cuff disease.

PURPOSE: Despite the popularity of the Constant-Murley score (CMS), a combined patient-report and objective (health professional administered) shoulder outcome measure, minimal information exists on its reliability or validity. The purpose of this study was to examine (1) internal consistency and convergent validity of the CMS and (2) the degree to which other shoulder measures explain variation in range of motion and strength components of the CMS. METHODS: In this cross-sectional study of outcome measures, 45 patients undergoing conservative or surgical treatment for rotator cuff disease participated. Two disease-specific outcome measures, one shoulder-specific measure, and one upper extremity outcome measure were compared to the CMS. RESULTS: Correlations between competing measures and relative total CMS were moderate (0.56 to 0.75). The American Shoulder & Elbow Score, the Upper Extremity Functional Index, the Western Ontario Rotator Cuff Index, and the Rotator Cuff Quality of Life index explained 38%, 28%, 26%, and 10% of variance of the objective component of the CMS respectively. CONCLUSIONS: The patient-report component of the CMS measures a multidimensional concept. The strength component had moderate correlations with isometric strength measures of the shoulder external rotators and abductors. The total CMS appears to measure a construct that is not totally captured by competing measures. The unexplained variance may be due, in part, to the lack of importance of the patient's physical impairment to symptoms or activity limitations as measured by other instruments.

Cross-sectional and longitudinal construct validity of two rotator cuff disease-specific outcome measures.

BACKGROUND: Disease-specific Quality Of Life (QOL) measures are devised to assess the impact of a specific disease across a spectrum of important domains of life. The purpose of this study was to examine the cross-sectional and longitudinal construct validity (sensitivity to change) of two rotator cuff disease-specific measures, the Rotator Cuff-Quality Of Life (RC-QOL) and the Western Ontario Rotator Cuff (WORC) index, in relation to one another and to other joint and limb specific measures in the same population of the patients suffering from rotator cuff pathology. METHODS: Participants enrolled were consecutive patients who received physical therapy for management of impingement syndrome or received treatment following rotator cuff repair, acromioplasty or decompression surgeries. All subjects received physical therapy treatment and completed four outcome measures at 3 single points (initial, interim, and final). Cross-sectional convergent validity was assessed at each of the 3 time-points by correlating the WORC and RC-QOL's scores to each other and to two alternative scales; a joint-specific scale, the American Shoulder and Elbow Surgeons (ASES) standardized shoulder assessment form and a limb-specific measure, the Upper Extremity Functional Index (UEFI). Non-parametric statistics (Spearman's rho and Wilcoxon-Mann-Whitney tests) examined the construct validity. The standardized response mean (SRM) was used to examine sensitivity to change. RESULTS: Forty-one participants entered the study and their scores were compared at 3 cross sectional single points. The correlation coefficients among the 4 measures varied from 0.60 to 0.91. Correlation between corresponding domains of the WORC and RC-QOL varied from 0.45 to 0.85. The known group validity was not significantly different among individual sub-scores and total scores. The final SRMs were (1.42), (1.43), (1.44), and (1.54) for the ASES, RCQOL, WORC, and UEFI respectively. CONCLUSION: The WORC and RC-QOL exhibit similar cross-sectional convergent validity in patients suffering from rotator cuff pathology. The sensitivity to change was very close among all scores, with the UEFI having the highest sensitivity. Further research is needed to examine the extent to which each physical or emotional domain contributes to prognostic or therapeutic decision-making.