Distal femoral varus osteotomy: results of the lateral open-wedge technique without bone grafting.

Background: The lateral opening wedge distal femoral osteotomy (LOWDFO) to reconstruct knee alignment in patients with genu valgum originating in the distal femur has gained importance within the last years.

Purpose: To analyze clinical and radiographic outcome of patients treated with LOWDFO with respect to bone healing without grafting and patient age.

Material And Methods: Twenty-two consecutive patients with genu valgum corrected with 23 LOWDFOs using a Tomofix-locking plate were retrospectively analyzed (mean age 23.7 years). Clinical evaluation was based on pre- and post-operative KOOS scores. A pre- and post-operative radiographic assessment, including MAD, mLDFA, LLD, bone healing, and patella parameters, was performed. Differences between subgroups (age, bone grafting) were analyzed.

Results: The restoration of MAD and mLDFA resulted in significantly improved post-operative KOOS scores in younger and older patients (p = 0.001). Bone healing without bone grafting was reliable in all patients. The leg length was significantly increased post-operatively (p = 0.001). The Blackburne-Peel ratio was significantly reduced to more normal values post-operatively (p < 0.001).

Conclusion: LOWDFO without bone grafting is a reliable procedure representing a promising treatment option particularly in young patients with genu valgum. Besides correction of the MAD, a significant leg length increase and additional patella stability can be expected.