The "Inside-Out" Technique for Correcting a Fixed Varus Deformity with Flexion Contracture in Total Knee Arthroplasty.

Abstract

The inside-out technique is a safe and reproducible method to effectively correct a fixed varus-flexion deformity during total knee arthroplasty by performing a posteromedial capsular release and so-called pie-crust lengthening of the superficial medial collateral ligament (sMCL). Analyze preoperative radiographs as a key step in planning the surgery for the required amount of osseous cuts and soft-tissue release. Obtain adequate exposure for proper visualization and assessment. Adequate bone cuts with proper alignment are an essential step of this technique. This is the most important step for extension balancing in knees with flexion contracture; the posteromedial aspect of the capsule in varus deformity should be safely incised at the level of the tibial cut. Perform pie-crusting followed by serial manipulations in a controlled manner to avoid overrelease of the sMCL. This is a key step for proper balancing, femoral sizing, rotation, lateralization, and patellofemoral tracking. From October 2006 to December 2009, thirty-one consecutive patients (thirty-four knees) with a severe fixed varus-flexion deformity (varus alignment of ≥15° and flexion contracture of ≥5°) underwent total knee arthroplasty with the inside-out technique. IndicationsContraindicationsPitfalls & Challenges.