Clinical and radiological outcomes between superior capsule reconstruction using allografts or xenografts: a 2-year retrospective comparison study

Abstract

BackgroundTreating symptomatic, massive, irreparable rotator cuff tears remains challenging and controversial. Superior capsule reconstruction (SCR) using the tensor fascia lata has shown promising clinical results; however, due to donor site morbidity, interest in SCR using other grafts has increased. Yet, no studies have compared allografts with xenografts. In addition, the clinical results of graft tears remain controversial. This study compared the clinical and radiological outcomes of SCR between those with allografts and xenografts. MethodsSixty-seven patients who had undergone SCR with allografts or xenografts between January 2016 and December 2020 were included in this retrospective study. Furthermore, 62 patients were evaluated 2 years postsurgery, with five patients excluded due to loss to follow-up or conversion to reverse shoulder arthroplasty. The Constant, American Shoulder and Elbow Surgeons (ASES), and visual analog scale (VAS) scores, range of motion, and radiological outcomes were evaluated before the surgery and at 6 and 24 months after surgery. ResultsThe graft tear rate was 23.08% in the allograft group and 42.86% in the xenograft group at 6 months after surgery; at 2 years postsurgery, the gap further widened to 32.43% and 64.00%, respectively, showing a significant difference. The graft in the allograft group was thicker than that in the xenograft group, and there were significant differences on the humeral side and in the midsubstance area. The allograft group showed significantly better VAS, Constant, and ASES scores than the xenograft group 2 years postsurgery. However, the difference in clinical outcomes between the two groups did not surpass minimal clinically important differences (MCID). ConclusionAlthough ASCR using xenografts had significantly lower clinical outcome than allografts, this difference did not reach MCID. ASCR using xenografts showed higher graft tear rates than allografts. Even with partial tears, better results were obtained if the graft continuity was maintained. Additionally, after surgery, the xenograft showed less thickness than the allograft and resulted in more tears, specifically in the midsubstance area.