Acetabular labral reconstruction using autografts reduces osteoarthritis development compared with labral resection in a porcine model

摘要

Acetabular labral tears are common in patients presenting with hip or groin pain. When the labrum is irreparable, labral reconstruction procedures are warranted. A circumferentially intact labrum is essential for joint health, whereas labral deficiency may predispose hip joints to osteoarthritis (OA). We aimed to determine whether labral reconstruction provides a benefit in terms of reduced OA development compared with labral resection. We performed labral reconstructions, labral resections, and sham operations in a porcine model. We assessed subsequent OA development by macroscopic observation, scanning electron microscopy, nanoindentation, histology, magnetic resonance imaging of cartilage in the acetabulum and femoral head, and enzyme-linked immunosorbent assays for inflammatory cytokines in the synovial fluid. We subjected the postoperative implants to biomechanical, histological, and mRNA expression analyses. At 24 weeks after surgery, the resected joints displayed apparent degenerative changes, in which the labral defects were filled with tiny amounts of loose, fibrous scar tissue. Compared with the resected joints, the reconstructed joints showed smooth and homogeneous geomorphology of cartilage surfaces; increased cartilage extracellular matrix (type II collagen and proteoglycans) content, elastic modulus, and hardness; and decreased type X collagen content, macroscopic and histological pathology scores, and inflammatory cytokines in the synovial fluid. The postoperative implants had compression, tensile, and histological features similar to those of the native labrum, which may have helped to attenuate OA development following labral reconstruction. Labral reconstruction using autografts greatly reduced OA progression compared with labral resection. The autologous implants used for reconstruction effectively restored the biomechanical and histological features of the labrum, contributing to hip joint homeostasis.