Cementless reconstruction of massive tibial bone loss in revision

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total knee arthroplasty. Whiteside-LA DePaul Biomechanical Research Lab, Bridgeton, MO 63044. Clin-Orthop. 1989 Nov(248): 80-6 Reconstruction of massive proximal tibial defects caused by failed cemented total knee arthroplasty (TKA) was evaluated using cancellous allograft and a rigidly fixed tibial component. Twenty patients with massive tibial defects requiring revision TKA were operated on using this technique from December 1984 to December 1986. All these had tight mediolateral capsular structures so that satisfactory varus-valgus stability was achieved. Only three had competent posterior cruciate ligaments. The tibial component had a cobalt chromium tray with a six-inch-long smooth stem, porous undersurface, and peripheral smooth pegs. Fixation was augmented with four cancellous screws that passed through the periphery of the tray and penetrated the cortical surface of the tibia. Good fixation of the tibial component was achieved in all cases at the time of surgery. All patients achieved full weight bearing within six months, and all but two were free of walking aids at one year postoperation. None of the patients developed apparent loosening of the femoral or tibial components. Two patients complained of mild pain and one who had revision of a painful but nonloosened cemented TKA complained of severe pain. Range of motion was 93 degrees +/- 7.6 degrees. Roentgenographic evaluation showed progressive increase in radiodensity in the grafted areas one year after surgery in all knees. One knee was revised for recurrent dislocation one year postoperation and had a biopsy of the allografted area. This biopsy showed trabeculae with empty lacunae surrounded by viable new bone. Allograft reconstruction of the proximal tibia for failed cemented TKA was highly successful using morselized allograft and rigid fixation of the tibial component.(ABSTRACT TRUNCATED AT 250 WORDS)