Osteoarthrosis after the Max Lange procedure for unstable shoulders

Thirty-four patients were followed for a mean of 14.4 years after the Max Lange operation for instability of the shoulder. This procedure consists of an anterior capsulorraphy with lateralisation of the subscapularis tendon and the insertion of a bone block at the inferior and anterior part of the glenoid. The Rowe score showed 87% good and excellent results. External rotation and abduction were significantly limited as compared to the normal side. Radiographs revealed osteoarthrosis in 47%. Double contrast computed tomography in 18 cases showed a bony defect in the anterior and inferior part of the humeral head in 12 who had significantly limited external rotation as compared to those without the defect. Lateralisation of the subscapularis tendon with limitation of external rotation may lead to increased contact stress and shear forces at the anterior rim of the glenoid which contributes to the development of osteoarthrosis.