脛骨内側に骨移植を併用したセメントレス人工膝関節置換術の治療成績

抄録

Of the 112 cementless primary total knee replacement (TKR) performed between 1993 and 2000, 22 knees with severe varus deformity, all of which were osteoarthritis, required autogeneic bone graft of the tibial defect, and 15 of the knees (10 patients) were followed for 17 to 85 months (mean, 34 months). The mean age at operation was 71 years. PFC type (Osteonics 3000 & 7000) PCL retaining prosthesis for 13 knees, and posterior-stabilized prosthesis for 2 knees were used in the procedure. In 7 knees with the defect greater than 8mm in height, bone grafting was performed with screw fixation. Preoperatively, the mean knee score according to the Japanese Orthopaedic Association was 46.7 points. At the time of latest follow-up, it was 82.3 points. The mean preoperative and postoperative ranges of motion were 113.7 and 116.0 degrees, respectively. In one knee, 2° residual varus deformity remained, but no implants were loosened. Radiographs were evaluated for clear zone, sinking, and the state of the grafted bone every half year. Clear zone less than 1mm on the tibial plateau at high rate, and sinking less than 2mm on the anterior margin of tibia at 5 knees were noted, but none was progressive. Incorporation of the grafts was present in all knees. Of the 5 bone grafts that demonstrated 1 or 2mm of collapse, two were accompanied by peripheral bone resorption. The surgical technique to reinforce the initial stability of the prosthesis is necessary to permit early rehabilitation. Cementless TKR with bone graft seemed to be a successful procedure even for the severely deformed knees with osteoarthritis in the current study.