Superior capsular reconstruction for irreparable supraspinatus tendon tears using the long head of biceps: A biomechanical study on cadavers.

INTRODUCTION

The superior articular capsule complements the rotator cuff's function in shoulder stability. With irreparable rotator cuff tears, superior capsular reconstruction (SCR) improves dynamic glenohumeral (GH) joint kinematics. We present a novel method of SCR in cadaveric shoulders using the long head of bicep (LHB) tendon instead of previously explored fascia lata autograft, thereby reducing harvest site and suture anchor associated complications.

HYPOTHESIS: This novel method of SCR using the LHB is feasible biomechanically in restoring shoulder stability in irreparable supraspinatus tendon tear.

MATERIALS AND

METHODS

Seven cadaveric shoulders were tested in a custom shoulder testing system. Superior translation of the humerus, subacromial contact pressure and area, and glenohumeral range of motion were tested at 0°, 30°, and 60° of glenohumeral abduction in the following conditions: (1) intact shoulder, (2) simulated complete supraspinatus tendon tear, (3) modified SCR using LHB, (4) and modified SCR using LHB and side-to-side repair augmentation.

RESULTS

The complete cuff tear shifted the humeral head superiorly as compared to the intact shoulder. Subacromial peak contact pressure was also increased at 30° and 60° while contact area was increased at 0° and 30°. The modified SCR both with and without side-to-side repair shifted the humeral head inferiorly at 30° and 60°, with contact area further reduced at 60°. Both techniques had comparable results for contact pressure and total rotational range of motion.

CONCLUSION

The LHB with appropriate distal insertion on the greater tuberosity restores shoulder stability in irreparable rotator cuff tears by re-centering the humeral head on the glenoid.

LEVEL OF EVIDENCE: Basic science study, biomechanical testing.