Medial closing wedge distal femoral osteotomy with patient-specific instrumentation: surgical technique, accuracy, and preliminary outcomes

Introduction and aim: Medial closing wedge distal femoral osteotomy (MCW-DFO) is a surgical technique used to treat symptomatic valgus knee deformity. This retrospective study aims to evaluate the reliability of Patient-Specific Instrumentation (PSI) in reproducing preoperative planning and to assess preliminary clinical and radiographic outcomes in patients treated with MCW-DFO using the PSI technique compared to conventional instrumentation. This research was conducted within the framework of the Italian National Recovery and Resilience Plan (PNRR), Mission 6-Health, as part of the PNRR-MAD-2022-12375978-PEARL Project, supporting the development of precision-based surgical strategies to prevent early osteoarthritis progression. Materials and methods: Between 2012 and 2023, 34 patients underwent MCW-DFO, of whom 16 were treated with NewClip Technics PSI and met the study's inclusion and exclusion criteria. Preoperative planning was performed using TraumaCad® software, identifying preoperative and planned mechanical femorotibial angle (mFTA) and mechanical lateral distal femoral angle (mLDFA) values. Postoperative measurements were obtained to determine the difference between planned and achieved alignment as an index of surgical reproducibility. Results: The difference between planned and postoperative values for mFTA and mLDFA angles differed significantly between the two groups. In the PSI group, mean postoperative values differed from planned values by 0.46° for mFTA and 0.66° for mLDFA. In contrast, in the conventional instrumentation group, the difference exceeded 2° for both angles. Conclusions: The PSI technique proved to be significantly more reliable than traditional instrumentation in adhering to preoperative planning in MCW-DFO. The integration of patient-specific technologies represents a precision-surgery approach consistent with PNRR objectives, potentially improving alignment accuracy and contributing to joint preservation strategies in patients at risk of early osteoarthritis.