Basic Science
Effects of exercise therapy for the treatment of symptomatic full-thickness supraspinatus tears on in vivo glenohumeral kinematics

https://doi.org/10.1016/j.jse.2015.08.048Get rights and content

Background

The high incidence of rotator cuff disease combined with high failure rates for nonoperative treatment of full-thickness rotator cuff tears underlines the importance of improving nonoperative management of rotator cuff tears. The study objective was to assess changes in in vivo glenohumeral kinematics of patients with a symptomatic full-thickness supraspinatus tear before and after a 12-week exercise therapy program. It was hypothesized that successful exercise therapy would result in improved kinematics (smaller translations and increased subacromial space).

Materials and methods

Five patients were recruited for the study and underwent dynamic stereoradiography analysis before and after a 12-week exercise therapy protocol to measure changes in glenohumeral joint translations and subacromial space during coronal plane abduction. Strength and patient-reported outcomes (American Shoulder and Elbow Surgeons; Disabilities of the Arm, Shoulder and Hand; Western Ontario Rotator Cuff Index) were also evaluated.

Results

After therapy, no subject went on to receive surgery. It was found that the contact path length of the humerus translating on the surface of the glenoid was reduced by 29% from 67.2% ± 36.9% glenoid height to 43.1% ± 26.9% glenoid height (P = .036) after therapy. Minimum acromiohumeral distance showed a small increase from 0.9 ± 0.6 mm to 1.3 ± 0.8 mm (P = .079). Significant improvements in strength and patient-reported outcomes were also observed (P < .05).

Conclusions

Successful exercise therapy for treatment of small full-thickness supraspinatus tears results in improvements in glenohumeral joint kinematics and patient-reported outcomes through increases in rotator cuff muscle strength and joint stability. This study may enable identification of prognostic factors that predict the response of a patient with a rotator cuff tear to exercise therapy.

Section snippets

Subject recruitment

Five subjects (3 women and 2 men; mean age, 60.2 ± 7.6 years; mean body mass index, 32.0 ± 7.8) were recruited for the study after providing written informed consent. Subjects were included in the study if they were aged between 45 and 70 years with a symptomatic small, degenerative full-thickness rotator cuff tear isolated to the supraspinatus tendon. Subjects with previous shoulder surgeries, injections within 3 months before study participation, or exercise therapy within 2 years before the

Results

All 5 subjects successfully completed the 12 weeks of therapy, and none had sought surgical treatment at 24 months of follow-up. One subject showed poor compliance with the home exercise protocol and did not give maximal effort during supervised exercise therapy sessions as determined by the supervising physical therapist (i.e., did not complete all exercises during scheduled sessions and did not follow the daily adjustable progressive resistance exercise program as the other 4 subjects did).

Discussion

The primary findings of this study were that (1) patients showed improvements in patient-reported outcomes and shoulder strength and (2) an overall decrease in the translation of the glenohumeral joint occurred with a 12-week exercise therapy program for treatment of a full-thickness supraspinatus tear. The decrease in contact path length was substantial, indicating greater joint stability during arm abduction and supporting the hypothesis that exercise therapy improves joint kinematics. This

Conclusion

Despite exercise therapy's not improving glenohumeral joint kinematics to the level of healthy individuals or to that of individuals after rotator cuff tear repair, this study shows that exercise therapy leads to satisfactory improvements in patient-reported outcomes, strength, and glenohumeral contact path length. These changes are generally sufficient to restore function and to minimize shoulder pain to satisfactory levels for patients. However, it is unknown if patient-reported outcomes

Disclaimer

The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.

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    Support from the Department of Orthopaedic Surgery, the Department of Bioengineering, The Albert B. Ferguson, Jr., MD Orthopaedic Fund of The Pittsburgh Foundation (M2012-0035), and the Pittsburgh Chapter of the ARCS Foundation is gratefully acknowledged.

    Institutional Review Board approval was provided by the University of Pittsburgh: PRO1105031.

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