Fresh Meniscal Allograft Transplantation Is Associated With Superior Functional Outcomes for Acetabular Labral Reconstruction in a Preclinical Canine Model.

Abstract

BACKGROUND Irreparable acetabular labral defects often require acetabular labral reconstruction (ALR) to restore hip joint health and function. Optimal graft choices for ALR have not been fully delineated. HYPOTHESIS Fresh meniscal allograft transplantation (MAT) will be associated with cellular, extracellular matrix, geometric, and integration characteristics that mimic native acetabular labrum, which results in superior functional, diagnostic imaging, gross, and histologic outcomes as compared with fresh-frozen tendon allograft transplantation (TAT) for ALR. STUDY DESIGN Controlled laboratory study. METHODS With Institutional Animal Care and Use Committee approvals, canine fresh-frozen tendon allografts and fresh meniscal allografts were recovered. Acetabular labral resection was performed in 1 hip of research hounds (n = 12). Based on random assignment, TAT (n = 4) or MAT (n = 4) ALR was performed or the resected labrums were left untreated (resected, n = 4). Contralateral hips served as healthy controls (n = 12). Preoperatively and at 1, 3, and 6 months postoperatively, dogs were assessed for pain, function, and hip range of motion. Six-month endpoint magnetic resonance imaging (MRI), gross, and histologic assessments were performed. Cohorts were compared for statistically significant differences (P < .05). RESULTS The resected cohort was associated with significantly worse hip pain (P = .028) and function (P = .036) when compared with controls and the MAT cohort at 3 and 6 months. Only the MAT cohort was superior to the resected cohort and not significantly different from controls for pain (P = .044) and function (P = .031) at all time points. MAT was judged to have superior MRI (P = .039) and histologic characteristics of joint health and labral graft integrity, integration, and healing (P < .0005) as compared with the TAT and resected cohorts, whereas TAT was superior to the resected cohort. No treatment was judged to fully restore MRI or histologic characteristics of controls. CONCLUSION This preclinical study suggests that ALR using allografts should be considered over labral resection for treatment of irreparable acetabular labral deficiency. When allograft-based ALR was performed, fresh MAT was associated with functional measures that were superior to fresh-frozen TAT and were attributed to cellular, extracellular matrix, geometric, and material property differences between the tissues. CLINICAL RELEVANCE These preclinical data suggest that this canine model can help delineate mechanisms underlying acetabular labral pathology and related treatment options for clinically relevant translational application to patients.