Histologic case series of human acellular dermal matrix in superior capsule reconstruction

Abstract

Background: Acellular dermal matrix (ADM) allografts are commonly used in the surgical treatment of complex and irreparable rotator cuff tears. Multiple studies report that superior capsule reconstruction (SCR) using ADM has resulted in short-term clinical success as assessed via radiographic and patient-reported outcomes. However, limited information is available regarding the biologic fate of these grafts in human subjects. This case series describes histologic results from 8 patients who had reoperations, during which the previously implanted ADMs were removed. These explanted ADMs were subjected to histologic analysis with the hypothesis that they would have evidence of recellularization, revascularization, and active remodeling. Methods: Eight patients, 38-82 years old, underwent reoperation 6-38 months after undergoing SCR. ADM explants were voluntarily shipped to the manufacturer for histologic analysis. Each graft's structure and composition were qualitatively evaluated by 1 or more of the following histologic stains: hematoxylin and eosin, safranin O, and Russell-Movat pentachrome. Pan-muscle actin staining also assessed the level of neovascularization, potential myoblast or myocyte infiltration, and muscle tissue development in the graft, and was analyzed to determine the proportion of graft that had been recellularized in situ. Results: Grafts showed varying levels of gross and microscopic incorporation with the host. An uneven, but high, overall degree of recellularization, revascularization, and active remodeling was observed. The degree of remodeling correlated with implant duration. These results are consistent with successful biologic reconstruction of the superior shoulder capsule. Conclusions: The present histologic analysis suggests that ADMs used in SCR undergo active recellularization, revascularization, and remodeling as early as 6 months after implantation, and that graft recellularization positively correlates with duration of implantation. These results represent a significant advancement in our knowledge regarding biologic incorporation of ADMs used in SCR.Institutional review board approval was not required for this basic science study.

Superior Capsule Reconstruction Using an Acellular Dermal Matrix Allograft Combined With Remnant Tendon Augmentation for Irreparable Rotator Cuff Tear

“…Soft tissue augmentation using the remaining rotator cuff tendon to enhance the biological healing response to the ADM also provided a biologic scaffold for graft bone healing and increased the strength of the reconstructed superior capsule. 10 …”

Editorial Commentary: Human Dermal Allograft Is Preferable to Fascia Lata Autograft Based on Similar Outcomes Without Donor-Site Morbidity

“…In addition, concerns about the limited biological potential of HDA have recently been addressed to some extent by a retrieval study from Lederman et al, which demonstrated that it is a "hospitable scaffold" for host cell infiltration and remodeling. 8 The authors reported that all grafts had evidence of cellular infiltration, neovascularisation, and active remodeling. Furthermore, in a rabbit model of irreparable cuff tear, Yildiz et al demonstrated no significant differences between FLA and HDA grafts in terms of macroscopic healing rates, and subsequent biomechanical properties (failure loads, stiffness, and displacement) between FLA and HDA grafts.…”

Advances on the modification and biomedical applications of acellular dermal matrices

“…Regardless of the patient age or time after implantation, all grafts have shown evidence of cellular infiltration, neovascularization, and active remodeling. The results have also suggested that there is a relationship between implant duration and the extent of recellularization, as well as that human ADM materials can be successfully incorporated into host tissue when used in superior capsule reconstruction [67]. For example, Chu et al [68] grafted MSCs onto an ADM scaffold to treat diabetic cutaneous wounds, and found that the MSC-ADM treatment significantly increased angiogenesis and rapidly completed the re-epithelialization of newly formed skin on diabetic mice.…”