The mini-incision mid-vastus approach for total knee arthroplasty.

Objective: Rapid functional recovery and improved range of motion after total knee arthroplasty (TKA) without compromising implant position.

Indications: Osteoarthritis of the knee requiring TKA.

Contraindications: Preoperative flexion < 80 degrees. Flexion contracture > 20 degrees. Body mass index > 40 kg/m(2). Fixed valgus deformity > 15 degrees. Relative: previous open surgery on the knee; systematic steroids (skin fragility); tall muscular males.

Surgical Technique: Straight skin incision over the medial third of the patella from 2 cm proximal to the patella, and then to the level of the tibial tuberosity. Extension of capsular incision 2 cm into the vastus medialis muscle from a point 2 cm proximal to the patella. Deep incision around the medial border of the patella and distally to the level of the tibial tuberosity. The patella is displaced laterally but is not everted in flexion. Knee flexion and extension as necessary to move the soft-tissue surgical window for proximal or distal exposure. Hyperflexion of the knee only for insertion of the tibial component.

Postoperative Management: Knee flexion exercises extension/flexion 0-0-70 degrees using continuous passive motion the day after surgery. Weight bearing to tolerance allowed at 1st day after surgery (walker, two crutches). Thrombosis prophylaxis.

Results: 69 patients with 74 TKAs done through the mini-incision mid-vastus approach were available with a minimum 1-year follow-up. A control group was evaluated retrospectively including 52 patients with 57 total knee replacements in which a standard medial parapatellar arthrotomy with patella eversion was used. At all clinical evaluations flexion and the ability to climb stairs were significantly superior in the mid-vastus group indicating a faster recovery and return to functional activities. There were no complications and the radiographic evaluation found no implant or limb malalignment, or signs of early loosening.