The Use of Navigation in Total Knee Arthroplasty for Patients With Extra-Articular Deformity☆

Computer-assisted navigation for total knee arthroplasty provides high technology instrumentation that may improve the technique for restoring the normal lower limb mechanical axis. This study evaluated the use of computer-assisted navigation in 7 patients (9 total knee arthroplasties) with a radiographic femoral extra-articular deformity. Postoperatively, the mechanical axis deviated medially by a mean of 1.3° ± 0.9° (range, −0.2° to 2.5°). Early patient outcomes showed an increase in the average preoperative to postoperative Knee Society Scores (from 62 to 92, P < .05), function scores (from 52 to 83, P < .05), and range of motion (from 4°-74° to 0.6°-98°, P < .05). These results support the use of computer-assisted navigation as effective high technology instrumentation in recreating an acceptable mechanical axis in patients with distorted anatomical landmarks.