Outcomes of scapulothoracic fusion in patients with facioscapulohumeral dystrophy: a comparison of allograft versus autograft bone grafting.

Abstract

Scapulothoracic (ST) fusion for facioscapulohumeral muscular dystrophy (FSHD) is an established treatment that corrects scapular instability, although it has high reported complication rates. The purpose of our study was to characterize the outcomes of ST fusion for FSHD in a large patient cohort and compare the outcomes based on bone graft type and fixation technique. Our hypothesis was that union rates would not differ by bone graft type during ST fusion. A retrospective chart review was undertaken to identify patients who underwent ST fusion at multiple institutions performed by a single surgeon between 2013 and 2019 with minimum 2-year follow-up. Patient demographic characteristics, surgical technique, time to union, complications, and clinical outcomes including patient-reported outcome measures were recorded. Univariate and multivariate statistical analyses including regression analyses were performed to compare preoperative and postoperative outcomes. A total of 50 patients with 54 ST fusions (bilateral in 4 patients) and an average follow-up period of 5.8 years (standard deviation, 1.6 years) were included for analysis. Active forward elevation (77° vs. 124°, P<.00001) and abduction (60° vs. 90°, P<.00001) both improved significantly after fusion. Average internal rotation after fusion was at spinal level L3-L4. The visual analog scale pain score (2.6 vs. 1.2, P<.00001), Subjective Shoulder Value score (33 vs. 76, P<.00001), and American Shoulder and Elbow Surgeons (ASES) score (41.8 vs. 76.1, P<.00001) all improved significantly postoperatively. Of the shoulders, 50% (27 of 54) received treatment with cerclage wires and 50% (27 of 54) received treatment with Luque wires. Femoral head allograft was used in 53.7% of shoulders (29 of 54), whereas iliac crest autograft was used in 46.3% (25 of 54). Average radiographic time to healing was 11.1 weeks (standard deviation, 3.2 weeks), with no incidence of nonunion, and did not significantly differ by bone graft type (P=.26) or technique (P=.20). The complication rate was 24.1%, including seroma (n=3), superficial infection (n=2), transient neurologic injury (n=2), hemothorax (n=1), rib fracture (n=1), pneumothorax (n=1), and shortness of breath (n=1), although none requiring reoperation. There was no significant difference in the rate of postoperative complications when compared by surgical technique (P=.81) and bone graft type (P=.93). There were no independently predictive factors influencing the rate of postoperative complications by multivariate regression. Regression analysis showed that the postoperative ASES score was independently associated with the preoperative ASES score (P<.0001), use of iliac crest autograft (P<.011), and presence of complications (P<.043). Patients receiving ST fusion for FSHD demonstrate globally improved active motion and patient-reported outcome measures. Fusion construct or type of bone graft does not affect time to union or complication rates. Surgeons should be aware of a relatively high complication rate in the early postoperative period.