A Modified Reverse Planning Method for Correction of Distal Femoral Valgus Deformity: Surgical Technique and Early Results

Abstract

Background: A reverse planning method is an option for distal femur deformity correction. However, the accuracy of the technique hinges on the precision of the initial guidewire placement. This study describes a modification to the reverse planning method designed to simplify the surgical procedure for retrograde femoral nailing to correct valgus deformities. The steps of the surgical technique and the early results are presented. Materials and Methods: After IRB approval, patients with distal femoral valgus deformity treated with retrograde nails using the modified reverse planning method were identified. Data obtained retrospectively included basic demographics, pre and postsurgery mechanical lateral distal femoral angle, the magnitude of limb length discrepancy if present, the duration of surgery, and the occurrence of any complications. Results: We analyzed 17 limbs in 15 patients (10 females). The mean age at surgery was 18 years. Four patients had an additional limb length discrepancy (mean value of 2.8 ± 0.9 cm). The mean pre and postoperative mechanical lateral distal femoral angle was 83 degrees and 90 degrees, respectively (P < 0.0001). The mean duration of surgery was 90 minutes. Conclusions: This study demonstrates that the modified reverse planning concept can be applied successfully to achieve accurate correction and healing of distal femoral valgus deformities. Furthermore, by adjusting the level of the osteotomy, this modified approach simplifies the surgical technique in several ways: (1) it creates a reproducible visual cue for the surgeon, (2) it decreases the surgical time by eliminating the need for fixator assistance, and (3) it reduces the need for multiple coronal planes blocking screws.