Chondral defects of the knee treated by transplantation of autogenous osteochondral plugs

Objective  Complete, lasting coverage of chondral defects of femoral condyles with hyaline cartilage. Indications  Pain, disturbance of function due to chondral defects of weight-bearing joint sections grade III and IV according to Outerbridge and osteochondritis dissecans stage 4 and 5 according to Rodegerdts & Gleissner. Contraindications  Arthritis, infection, preexisting and persisting instability, axial malalignment. Surgical Technique  Anteromedial or anterolateral arthrotomy to evaluate the size of the chondral defect, removal of the cartilage defect by cutting out cartilage-bone cylinders with the Twin Diamond Transplantation Technique (TDTT). Harvesting of appropriately sized cartilage-bone cylinders with healthy hyaline cartilage from non-weight-bearing areas of the posterior or anterior articular surface with the TDTT. Transplantation of the cartilage-bone cylinder “press-fit” into the prepared defect without further fixation. Refilling of the defects caused by harvesting with corresponding periosteum-covered bone cylinders from the iliac crest or with bone substitute materials. Results  In 1996 and 1997, 20 patients with cartilage damage of a femoral condyle were treated by osteochondral cylinder transplantation. All 20 patients were questioned as to their subjective assessment of the outcome and reexamined 6, 12, and 24 months postoperatively. The evaluation of the results was performed using Meyers and Lysholm scores and the Tegner activity scale 3, 6, 12, and 24 months postoperatively. Five women and 15 men had cartilage defects measuring from 3.22 to 4.25 cm². 24 months postoperatively, 17 patients felt significant and three patients slight improvement. According to the evaluation criteria of the Meyers score, results in five patients were considered excellent, in 13 good, and in two moderate. According to the Lysholm score, 15 patients were judged as being excellent and five as being good, and according to the Tegner activity scale, nine were considered excellent, nine good, and two moderate. Reasons for the two moderate results were remaining activity-related pain and knee flexion limited to 120°. In both patients an additional osteochondral cylinder had been harvested from the posterior aspect of a femoral condyle.