Abstract
Objective: The purpose of this study was to evaluate the clinical outcome after open wedge high tibial osteotomy (OWHTO) with osteochondral autologous transplantation for spontaneous osteonecrosis of the knee.
Methods: Between 2009 and 2012, seven knees in seven patients who underwent OWHTO with osteochondral autologous transplantation, were enrolled in this study. Inclusion criteria involved patients who had persistent pain due to spontaneous osteonecrosis of the medial femoral condyle. There were two women and five men with a mean age of 61 years at the time surgery. All patients were evaluated by clinical, radiological, and arthroscopic examinations preoperatively and over 1 year postoperatively. Statistical evaluation was performed using the Student's paired t-test. The significance level was set at p = 0.05.
Results: All the patients achieved radiographic union at the osteotomy site and underwent the second surgery for removal of the fixation plate. The mean Japan Orthopaedic Association score significantly improved from 64 points preoperatively to 89 points at final follow-up. The mean femorotibial angle significantly reduced from 181° to 169° at the final follow-up. The weight-bearing line significantly shifted to 65% from 23%. Concerning articular cartilage lesions, the preoperative International Cartilage Repair Society grades (II: 1 case III: 5 cases, IV: 1 case) were improved (I: 1 case, II: 6 cases) postoperatively. Conversely, the range of motion, tibial slope and the Insall-Salvati ratio showed no significant differences between the two examination periods.
Conclusion: The present study demonstrated that OWHTO with osteochondral autologous transplantation significantly improved the short-term clinical result of spontaneous osteonecrosis of the knee. Radiological examination also showed that the knee alignment procedures had been performed correctly. In addition, postoperative cartilage repair assessment was dramatically improved. These results suggest that OWHTO with osteochondral autologous transplantation may be a useful treatment for spontaneous osteonecrosis of the knee.
