The Histology of a Healed Superior Capsular Reconstruction Dermal Allograft: A Case Report

Acellular human dermal allograft commonly is used in the surgical treatment of complex rotator cuff tears, but little information is known about the biological fate of these grafts in human subjects. In this case report, the authors describe a patient who presented with a radiographically healed acellular human dermal allograft superior capsular reconstruction but had humeral head avascular necrosis. The healed superior capsular reconstruction, including graft-bone interfaces, was explanted after 7 months and sent for histologic analysis. A successful biological reconstruction of the superior capsule was found. The graft demonstrated gross and microscopic incorporation with the host, including a tendon-like structure, aligned collagen fibers, fibroblast-like cells, and no clear graft-host distinction. Cellular infiltration ranged from 5% to 14% (central graft) to 65% to 92% (sutured attachment points). Neovascularization and active graft remodeling were confirmed histologically. LEVEL OF EVIDENCE: V, case report.