[Open-wedge osteotomy of the glenoid for treatment of posterior shoulder instability with increased glenoid retroversion].

OBJECTIVE: Treatment of posterior shoulder instability with increased retroversion of the glenoid using open-wedge osteotomy of the glenoid neck stabilized with an autologous bone block. INDICATIONS: Symptomatic, atraumatic posterior shoulder instability with increased retroversion (>20°) of the glenoid and previously failed conservative or surgical treatment. CONTRAINDICATIONS: General contraindications against surgery. Relative contraindications: osteoporosis, nicotine abuse, or suspected patient noncompliance. SURGICAL TECHNIQUE: Posterior approach with a 7 cm long incision starting medial of the posterolateral corner of the acromion heading to the posterior axillary fold and subsequent preparation of the deltoid muscle and the infraspinatus muscle. The posterior glenohumeral capsule is incised by performing a capsular T‑shift. The osteotomy is performed intracapsulary medial to the genoid rim. The wedge bone graft, harvested from spina scapulae or iliac spine, is placed "press fit" in position. Additional fixation of the graft is not necessary if the anterior cortex is intact. For reinforcing the posterior capsule, a posterior capsule shift should be performed. Insertion of extracapsular wound drainage. Successive wound closure. POSTOPERATIVE MANAGEMENT: Postoperative immobilization in a 0° shoulder orthesis for 6 weeks; avoidance of horizontal abduction for 8 weeks. After removing the wound drainage, start of limited active-assisted range of motion. Over-head sports after 6 months.
RESULTS: From 2009-2015, 6 posterior open wedge glenoid osteotomies were performed. Postoperative retroversion of the glenoid was 11.2 ± 9.4° compared to 26.0 ± 8.6° before surgery. Of 6 shoulders, 2 showed postoperative signs of persistent posterior instability; the other 4 shoulders were free of complaints. No revision surgery was needed.