Lateral Parapatellar Approach Without Tibial Tubercle Osteotomy for Fixed Valgus Deformity Correction in Total Knee Arthroplasty.

INTRODUCTION: The lateral parapatellar approach provides direct access to the pathological area in a valgus knee deformity and allows sequential titrated release of contracted lateral soft tissues during total knee arthroplasty. STEP 1 PREOPERATIVE PLANNING: Differentiate the flexible and fixed components of the valgus deformity by clinical and radiographic examination. STEP 2 EXPANSILE LATERAL ARTHROTOMY: Open the knee joint from the lateral side by coronal z-plasty of the lateral retinaculum, oblique lateral tenotomy of the quadriceps tendon, and iliotibial band release. STEP 3 QUADRICEPS SNIP AND JOINT EXPOSURE: Perform a quadriceps snip and expose the knee joint. STEP 4 TIBIAL AND DISTAL FEMORAL CUTS: Make proximal tibial and distal femoral cuts in appropriate alignment. STEP 5 EXTENSION GAP BALANCING: A rectangular extension gap is the goal. STEP 6 FLEXION GAP BALANCING: Determine the femoral component size and femoral rotation, and balance the flexion gap. STEP 7 COMPONENT FIXATION: Confirm tibial rotational alignment, fix the components, and assess patellar tracking. STEP 8 PROSTHETIC JOINT CLOSURE: Perform closure of the prosthetic joint with expanded lateral structures. RESULTS: Between 2003 and 2009, thirty-two knees with clinical valgus deformity of >10° underwent total knee arthroplasty with an expansile lateral arthrotomy technique11.IndicationsContraindicationsPitfalls & Challenges.

Efficacy and mid term results of lateral parapatellar approach without tibial tubercle osteotomy for primary total knee arthroplasty in fixed valgus knees.

The lateral parapatellar approach, despite providing direct access to the pathological area has not been widely accepted for knee arthroplasty in valgus deformities. We performed a modified lateral (Keblish) approach which consisted of coronal z plasty of lateral retinaculum, quadriceps snip, titrated sequential lateral release and closure with expanded lateral structures in 32 arthritic fixed valgus knees. In 30 knees, either tendon of popliteus or lateral collateral ligament or both could be preserved. At an average follow-up of 5 years, the valgus alignment improved from 25.4° (11°-60°) to 4° (0°-10°) and knee society score improved from 34 to 95 points. There was no late instability or revisions. This approach is rational, eliminates patella maltracking, is applicable in severe deformities and with titrated release, can preserve the posterolateral knee stabilizers that are necessary for long term implant survival.