Title

Effects of asymptomatic rotator cuff pathology on in vivo shoulder motion and clinical outcomes.

Document Type

Article

Publication Date

6-1-2017

Publication Title

Journal of shoulder and elbow surgery

Abstract

BACKGROUND: The incidence of asymptomatic rotator cuff tears has been reported to range from 15% to 39%, but the influence of asymptomatic rotator cuff pathology on shoulder function is not well understood. This study assessed the effects of asymptomatic rotator cuff pathology on shoulder kinematics, strength, and patient-reported outcomes.

METHODS: A clinical ultrasound examination was performed in 46 asymptomatic volunteers (age: 60.3 ± 7.5 years) with normal shoulder function to document the condition of their rotator cuff. The ultrasound imaging identified the participants as healthy (n = 14) or pathologic (n = 32). Shoulder motion was measured with a biplane x-ray imaging system, strength was assessed with a Biodex (Biodex Medical Systems, Inc., Shirley, NY, USA), and patient-reported outcomes were assessed using the Western Ontario Rotator Cuff Index and visual analog scale pain scores.

RESULTS: Compared with healthy volunteers, those with rotator cuff pathology had significantly less abduction (P = .050) and elevation (P = .041) strength, their humerus was positioned more inferiorly on the glenoid (P = .018), and the glenohumeral contact path length was longer (P = .007). No significant differences were detected in the Western Ontario Rotator Cuff Index, visual analog scale, range of motion, or acromiohumeral distance.

CONCLUSIONS: The differences observed between the healthy volunteers and those with asymptomatic rotator cuff pathology lend insight into the changes in joint mechanics, shoulder strength, and conventional clinical outcomes associated with the early stages of rotator cuff pathology. Furthermore, these findings suggest a plausible mechanical progression of kinematic and strength changes associated with the development of rotator cuff pathology.

Medical Subject Headings

Adult; Aged; Asymptomatic Diseases; Case-Control Studies; Female; Humans; Imaging, Three-Dimensional; Incidence; Male; Middle Aged; Muscle Strength; Range of Motion, Articular; Retrospective Studies; Rotator Cuff; Rotator Cuff Injuries; Shoulder Joint; Tomography, X-Ray Computed; Ultrasonography; United States

PubMed ID

28131679

Volume

26

Issue

6

First Page

1064

Last Page

1072

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