Functional outcomes and complications following scapulothoracic arthrodesis in patients with facioscapulohumeral dystrophy

Abstract

Background: Facioscapulohumeral dystrophy (FSHD) is an autosomal-dominant myopathy characterized by facial and shoulder girdle muscle weakness with scapular winging. Scapulothoracic arthrodesis is a successful treatment approach for patients with <90° of shoulder elevation. The purpose of the present study was to assess functional outcomes and complications following scapulothoracic arthrodesis in patients with FSHD.

Methods: We retrospectively reviewed the records of 40 patients (64 shoulders) in whom scapulothoracic arthrodesis was performed. To achieve fusion, multiple multifilament cables were used together with autologous bone and allograft bone. Preoperative and postoperative shoulder elevation and abduction; Disabilities of the Arm, Shoulder and Hand (Quick version, qDASH) scores; and pulmonary function were compared. Recorded complications were classified as pulmonary or scapular.

Results: The mean age of the patients at the time of the operation was 25.4 years (range, 15 to 60 years), and the mean duration of follow-up was 71.2 months (range, 12 to 185 months). When the preoperative values were compared with those at the latest follow-up, significant improvement was noted in terms of elevation (from a mean [and standard deviation] of 60.6° ± 17.2° to 123.7° ± 26.7°; p < 0.001), abduction (from 52.7° ± 15.8° to 98.8° ± 20.3°; p < 0.001), and qDASH scores (from 34.7 ± 11.4 to 13.3 ± 13.1; p < 0.001). The overall complication rate was 26.6%. There were 7 pulmonary complications (4 pneumothoraxes, 2 pleural effusions, and 1 major atelectasis), and 5 chest tube placements were required. Ten complications (including 3 rib fractures, 1 brachial plexus palsy, 2 cases of implant irritation, 2 nonunions, 1 delayed union, and 1 scapular fracture) were related to the scapular fixation, and 7 revision procedures were required. Scapulothoracic fusion was achieved in all patients but 1, who had a scapular fracture. Pulmonary function tests were performed for 19 patients, and no difference was observed between preoperative and postoperative results.

Conclusions: Scapulothoracic arthrodesis with use of multifilament cables is a successful surgical technique with high fusion rates and low morbidity. Pulmonary complications are common but resolve with careful attention.

Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Facioscapulohumeral dystrophy (FSHD), the third most frequent muscular dystrophy, is characterized by autosomal-dominant inheritance and complete penetrance by the age of 20 years1,2. It has 2 genetic variants, FSHD1 and FSHD2, which are clinically indistinguishable. While the infantile-onset form can involve specific systems, with more rapid progression and greater severity, the later-onset form more frequently presents with orthopaedic manifestations3.

FSHD is characterized by progressive weakness of the facial and shoulder girdle musculature, with the latter leading to scapular winging. Marked scapular winging is observed in patients with deficient scapular stabilization and a functional deltoid4. In a healthy shoulder, the scapula is stabilized during deltoid contraction so that the deltoid origin is stable while the muscle shortens, resulting in effective arm elevation. Deficient scapular stabilization resulting from FSHD causes anterior scapular tilt during deltoid shortening, and arm elevation is reduced as a result of this paradoxical motion. Successful fusion prevents winging and facilitates deltoid and rotator cuff function. Typically, patients with FSHD present with impaired shoulder function with <90° of arm elevation and poor posture due to abnormal scapular tilt.

Scapulothoracic arthrodesis is the gold standard for the treatment of patients who have scapular winging secondary to the loss of function of the scapular stabilizers in the presence of a functional deltoid and rotator cuff (Fig. 1)4. Different surgical techniques involving various methods of fixation (e.g., cerclage wires, screws with or without plates, and multifilament cables along with autologous cancellous bone graft or fibular strut allograft to facilitate union) have been described. Reports in the literature have demonstrated good feasibility and efficacy for all of these techniques, with a high rate of fusion and successful functional outcomes4–14. However, the numbers of cases in those studies were relatively small (Table I).