Management of bone deficiency of the medial tibial plateau during primary total knee arthroplasty

Objective To investigate the short-term clinical result of structural and particulate bone graft for bone defects of the medial tibial plateau during primary total knee arthroplasty. Methods The clinical data of 13 patients(13 knees) of genu varum (> 25°) with serious medial tibial plateau bone defects (9 cases AORI Ⅱ, 4 cases Ⅲ) were treated in primary total knee arthroplasty at the First Affiliated Hospital of Bengbu Medical College from May 2005 to February 2012. During operation, the depth of the lateral tibial plateau resection was from 9 mm to 11 mm and the average depth of bone defects was 9.1 mm, ranging from 6 mm to 19 mm. In order to manage the bone deficiency, the bone removed from the proximal tibia was attached as structural bone grafting and the remaining cavitary deficits were filled with particulate cancellous graft removed from the distal femur or proximal tibia. Most knee arthroplasties were cemented at the interfaces between the stemmed tibial base plate and the bone, and sometimes the tibial base plate with stem extension were used in a fully cemented technique. Results The bone defects of the medial tibial plateau were reconstructed well, which markedly provided the initial stability of the prostheses. The prostheses were fixed well and the deviation of limb alignment was usually under 2°. The average follow-up time was 63 months. Bone absorption and loosening of the prostheses were not found in all cases at the latest follow-up. The American Knee Society score(KSS) improved from preoperative 42.3 to postoperative 92.1. Conclusions For genu varum patients, serious medial tibial plateau bone defects can be reconstructed by using structural bone graft and particulate bone graft removed from the distal femur or proximal tibia, which can reserve knee bone in primary total knee arthroplasty. Key words: Arthroplasty, replacement, knee; Bone transplantation; Tibia