Autologous Chondrocyte Implantation.

Abstract

Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage lesions of the knee joint provides successful and durable long-term outcomes. Obtain standing radiographs and magnetic resonance imaging (MRI) scans to identify all associated abnormalities (background factors). Evaluate the knee joint systematically and harvest cartilage tissue from the non-weight-bearing area. Use a medial or lateral parapatellar arthrotomy and expose the lesion adequately. Debride all fissured and unstable articular cartilage surrounding the full-thickness chondral injury down to healthy contained cartilage. Address associated abnormalities (predisposing background factors) to optimize recovery and a successful outcome. Orient the membrane patch with the rough surface to the subchondral bone and the smooth surface toward the articular surface; then sew it, tying the sutures knots on the membrane and not the cartilage, to tension it adequately throughout the entire defect. Gently deliver the cells and fill the defect. (1) Initiate range-of-motion exercises to enhance chondrocyte regeneration and decrease the likelihood of intra-articular adhesion, (2) protect the graft from loading for 6 to 12 weeks after surgery to prevent graft overload and central degeneration or delamination of the graft, and (3) initiate isometric muscle exercises to regain muscle tone and prevent atrophy. ACI provided durable outcomes in 210 patients followed prospectively for 10 to 17 years after treatment with the first-generation ACI-periosteum technique⁶.