COMBINED AUTOLOGOUS CHONDROCYTE IMPLANTATION AND ALLOGENIC MENISCUS TRANSPLANTATION: A BIOLOGICAL KNEE REPLACEMENT

Introduction: Before proceeding to long-term studies, we studied early clinical results of combined Autologous Chondrocyte Implantation (ACI) and Allogenic Meniscus Transplantation (AMT). Meniscus deficient knees develop early osteo-arthritis (OA) of the knee joint. Autologous Cartilage Implantation (ACI) is contraindicated in case of meniscus deficient knees. And on contrary the Allogenic Meniscus Transplantation (AMT) is contraindicated in cartilage defects in the knee joint. But a combination of the two procedures for bone on bone OA might be a solution for this problem. This was the main purpose of our study. Methods: We studied a consecutive series of eight patients (7 males and 1 female), with an average age= 43 years (29–58), presenting with painful secondary arthritis, due to premature loss of meniscus and chondral defect/s. Median size of the femoral defects was 8.16 cm2 and of the tibial side 2.69 cm2 All patients were treated with a combination of Autologous Chondrocyte implantation (ACI) and Allogenic Meniscus Transplantation (AMT). Chondral defects were covered with periosteum/ Chondroguide membrane, secured in place with in-vitro cultured autologous chondrocytes injected underneath the path. Meniscus placed as load-bearing washer on the surface of ACI of tibia. ACI rehabilitation protocol followed post-operatively. Assessment at the end of one year was done with self-assessed Lysholm score, histology and the MRI scan. Results: Mean pre-operaive Lysholm score was 49 (17–75). This increased to a mean of 66 (26–87) at 1 year, an average increase of 16.4 points. Average one-year satisfaction score was 3 and they were back to all active life style. Five out of eight patients showed significant functional improvement at last post-operative follow-up (2 to 6 years; mean of 3.2 years). Complications were aseptic synovitis in 3 cases. Three failures were noted showig persistant pain and swelling in one, rupture of meniscus in second and third patient had a knee replacement. Arthroscopy at 1 year showed a stable meniscus with all healed peripheral margins in all except in one case with some thinning with no evidence of rejection. Histology of meniscus showed a fibrocartilage well populated with viable cells and the peripheral zone was well vascularised and integrated with capsule. Biopsy of ACI site was predominantly of fibrocartilage with good basal integration with subchondral bone. On MRI scan, allogenic meniscus was well integrated with capsule along the line of repair, showing foci of variable signal intensities within the meniscus. There was no evidence of meniscal subluxation in all but one case showing mild extrusion. ACI graft site showed a varied appearance, with 3 grafts showing focal grade 3to 4 changes. Conclusion: Seven out of eight patients improved post-operatively at one year, in terms of pain relief and increased activity. It’s possible to combine these two techniques together. Short-term outcomes are satisfactory. We could not find any deleterious effects of combining these two techniques together. So we conclude that, this might act as a one step towards a biological knee replacement.