Acromial and humeral head osteolysis following superior capsular reconstruction using autologous tensor fascia lata graft.

Abstract

Graft tear is a critical complication following superior capsular reconstruction (SCR) as it directly links with clinical outcomes. No previous reports have described acromial and humeral head osteolysis following SCR. Acromial and humeral head osteolysis may incidentally occur after SCR using autologous tensor fascia lata graft. This study aimed to demonstrate the incidence of osteolysis following SCR using autologous tensor fascia lata graft and investigate the factors that affect osteolysis. This retrospective cohort study included patients who underwent SCR for irreparable rotator cuff tears between June 2014 and June 2019. The patients were divided into 2 groups-those with no osteolysis and those with osteolysis-and were compared. For subanalysis, patients in the osteolysis group were further divided into 3 groups according to the location of the osteolysis-acromial osteolysis, humeral head osteolysis, and acromial and humeral head osteolysis-to clarify the factors determining the location of osteolyses. The shoulder range of motion was evaluated preoperatively and 24 months postoperatively. Additionally, the following items were evaluated: condition of the subscapularis tendon, Hamada classification (grade 2 or 3), critical shoulder angle, acromiohumeral distance measured preoperatively and 24 months postoperatively, graft size, and graft thickness. In addition, the graft condition was evaluated using magnetic resonance imaging 12 months postoperatively. In total, 57 patients were enrolled and followed up for a minimum of 2 years (follow-up rate, 92% [57 of 62 cases]). Overall, the incidence of osteolysis following SCR was 35.1% (20 of 57 cases; acromial osteolysis in 7, humeral head osteolysis in 3, and acromial and humeral head osteolysis in 10). Compared with the group with no osteolysis, the osteolysis group had no inferior clinical outcomes or higher graft tear rates. The proportions of Hamada grade 3 (P=.041) and involvement of the subscapularis tendon (P=.020) were significantly higher in the osteolysis group. The relative risks of subscapularis involvement and Hamada grade 3 for osteolysis were 2.9 and 5.1, respectively. In the subanalysis, the factors determining the location of the osteolysis could not be clarified. This study suggested that the progression of the Hamada classification and condition of the subscapularis tendon affect the occurrence of osteolyses. However, these osteolyses were not associated with clinical outcomes, including graft tear rate and shoulder range of motion.