Outcome of Autologous Bone Grafting with Preservation of Articular Cartilage to Treat Osteochondral Lesions of the Talus with Large Subchondral Cysts

Abstract

Category: Ankle Introduction/Purpose: Treatment options for osteochondral lesion of the talus (OLT) have substantially increased over the last decade. There are a wide variety of surgical treatments for OLT, and good clinical results have been reported. However, treatment for OLT with large subchondral bone cysts remains under discussion. The combination of autologous bone grafting for subchondral bone cyst with fixation of articular cartilage would be the desirable procedure for the repair of the large subchondral cyst preserving the original cartilage with native structure and geometry. The purpose of this study is to evaluate the clinical outcome of autologous cancellous bone graft and fixation of cartilage fragment for OLT with large subchondral cysts. Methods: Patients comprised seven men and five women, aged 14–70 (mean 35.9) years. All OLTs included full-thickness articular cartilage, extended through subchondral bone and were associated with subchondral cysts. The mean size of the cysts was 9 ×8.6 ×12.3 mm on preoperative CT. Medial lesions were exposed through an oblique medial malleolar osteotomy; lateral lesions through expansion of an anterolateral arthroscopic portal. After refreshed the subchondral cyst, it was grafted with autologous cancellous bone from the distal tibial metaphysis, then cartilage fragments were fixed with nylon suture to surrounding cartilage. Postoperative MRI and CT scans were acquired for all patients at one year after surgery. Seven patients requested screw removal although none had symptoms. The screws were removed and simultaneous arthroscopic examination was performed at 1.5–2 years after surgery with the patients’ permission. The cartilage repair was assessed according to the criteria of the International Cartilage Repair Society (ICRS). Results: Functional outcome was evaluated at 25.3 (15–50) months after surgery. Mean American Orthopedic Foot and Ankle Society ankle-hindfoot outcome score improved from 65.7 to 92 (90–100) postoperatively, with 100% patient satisfaction. All follow-up CT scans showed that the grafts were well consolidated with the surrounding subchondral bone. On MRI one year after surgery, no scans showed any signs of osteochondral graft instability. The mean ICRS arthroscopic score from follow-up arthroscopy was 11.1 (8–12) points, and represented nearly normal cartilage. Conclusion: Our study demonstrated good results of autologous bone grafting in preserving articular cartilage in cases of symptomatic OLT with subchondral cysts. In seven cases, we performed follow-up arthroscopy at 1.5–2 years after primary operation and the chondral fragment showed a smooth surface and good stability. The technique of autologous bone grafting with chondral fragment fixation could be a promising option for treatment of OLT with subchondral cysts.