Chronic anterior sternoclavicular instability: technique and results of corrective clavicular osteotomy

Abstract

Chronic anterior sternoclavicular (SC) instability is a rare but potentially disabling condition. It can arise in conjunction with trauma or hyperlaxity, or both. Numerous surgical techniques have been described, but no gold standard exists. SC instability is often position-dependent and can be reduced with the arm in a specific position. To directly address this issue, we used a technique of corrective osteotomy of the clavicle with the goal to reorient the articular portion of the medial end of the clavicle so that it remains stable in all functional positions of the arm. To illustrate the technique and the correction in space, we performed postoperative 3-dimensional computed tomography analyses of the shoulder girdle of 4 patients. Clinical scores were obtained at the final follow-up and compared with preoperative scores. Mean follow-up was 64 months (range, 19-191 months). The mean Constant score improved from 58 (range, 45-68) preoperatively to 73 (range, 69-84) postoperatively and the Subjective Shoulder Value from 42 (range, 15-80) to 79 (range, 50-100). All patients reported good or very good stability of the SC joint at the last follow-up. We recorded no intraoperative or direct postoperative complications. During follow-up, 3 patients underwent removal of the plate, 1 of them for plate breakage. The mean postoperative correction for combined rotations is given as a 3-dimensional angle and averaged 28.0° (range, 8.6°-39.7°). In this pilot study, medial corrective clavicular osteotomy using the described technique treated anterior SC instability with improvement of clinical shoulder function scores and good patient satisfaction. The technique appears simple and safe and deserves further evaluation.