Reconstruction of the Superior Glenoid Labrum With Biceps Tendon Autograft: A Cadaveric Biomechanical Study

Abstract

To describe 2 superior labral reconstruction techniques using long head of the biceps (LHB) autograft and to investigate the ability of the 2 reconstruction techniques to restore superior restraint to the glenohumeral joint compared with superior labrum-deficient models. In this biomechanical study, 10 cadaveric shoulders were cycled on a servohydraulic machine while the force required to cause superior subluxation was recorded. Each specimen was cycled under 4 conditions: intact labrum, SLAP tear, posterior (9- to 12-o'clock position) labral reconstruction using LHB autograft (superior labral reconstruction 1 [SLR1]), and 180° (9- to 3-o'clock position) labral reconstruction using LHB autograft (superior labral reconstruction 2 [SLR2]). The mean peak force required to cause superior subluxation in the intact labrum was 32.75N versus 19.75N in the SLAP tear (P= .0120). SLR1 required a mean peak force of 31.23N versus 44.09N for SLR2 (P= .0175). SLR1 required 94.96% of the force needed in the intact labrum to cause subluxation, whereas SLR2 required 140.6%. SLR1 and SLR2 required 34.21% higher (P= .0074) and 79.84% higher (P= .0033) forces, respectively, to generate subluxation compared with the SLAP tear state. Both proposed superior labral reconstruction techniques increased the force needed for humeral head superior migration in the setting of a labral tear. SLR1 (posterior labral reconstruction) closely matched the constraint of an intact labrum, whereas SLR2 (180° labral reconstruction) provided greater superior constraint than an intact labrum. The natural history of irreparable rotator cuff tears results in superior glenohumeral escape and eventual arthrosis. The superior glenoid labrum is an important contributor to superior glenohumeral constraint and is often degenerated in this setting. Clinical application of the 2 described superior labral reconstruction techniques may improve glenohumeral superior stability in patients with rotator cuff disease and superior labral deficiency.