Computer-Assisted Total Knee Arthroplasty for Arthritis with Extra-articular Deformity

Forty extra-articular deformities (22 femoral and 18 tibial) in 34 patients (mean age, 63.1 years) were studied. Mean coronal extra-articular deformity was 9.3 degrees; mean preoperative limb alignment was 166.7 degrees. Three limbs underwent simultaneous corrective osteotomy; the rest were treated with intra-articular correction during computer-assisted total knee arthroplasty (TKA). Mean postoperative limb alignment was 179.1 degrees. At a mean follow-up of 26.4 months, the Knee Society knee score improved from a mean preoperative score of 49.7 to 90.4 points postoperatively; function score improved from 47.3 to 84.9 points. Computer-assisted TKA is a useful alternative to conventional TKA for knee arthritis with extra-articular deformity where accurate restoration of limb alignment may be challenging because of the presence of a deformed tibia or femur or in the presence of hardware.