Treatment of Severe Varus Deformity in Primary Total Knee Arthroplasty using Metal Augment

Background: Osteoarthritic knee with varus deformity is by far the commonest indication for total knee replacements in adults. Management of bone defects in severe varus deformity in primary TKR is still a challenge for orthopedic surgeons. Various techniques are available to compensate for bone defects in primary TKR including lower tibial resection, cement filling, autologous bone graft, allograft, wedges or augments and custom implants. So, we aimed to evaluate functional outcome of metal augmnets for management of tibial bony defect in primary TKR. Methods: A prospective study was conducted in Orthopedic Surgery Department, Faculty of Medicine, Zagazig University in the period between April 2020 and June 2022 involving 16 patients with 18 knees who underwent primary TKR due to osteoarthritis with severe varus deformity and tibial bone defects. All cases were followed up for a minimum of 24 months post operatively Results: Degree of deformity significantly decreased from 23.56±3.94 to 5.12±1.62. FD significantly decreased from 19.62±6.85 to 1.87±0.74. ROM significantly increased from 64.06±17.81 to 108.12±9.81. Pain score significantly increased from 16.25±5.19 to 42.93±6.63. Walking score significantly increased from 12.5±4.25 to 38.75±8.85. AIDS score significantly increased from -6.87±2.63 to -1.01±0.358. Proximal medial tibia angle significantly increased from 67.62±3.79 to 90.0±0.0. KSS significantly improved from pre to post except 1 case still poor KSS after intervention. 87.5% of cases had no complications. Conclusion: Metal augments can be considered as a simple and effective method for the treatment of tibial bony defect in primary TKR.