Functional Outcome Analysis of Cubitus Varus Deformity Treatment in Children undergoing Modified French Osteotomy with Technical Modification: A Retrospective Cohort Study

Introduction: Lateral closing wedge osteotomy is an accepted correction method for cubitus varus deformity. The techniques used to fix the osteotomy mostly lead to either angulation or loss of correction during the final tightening of the Stainless Steel (SS) wire at the osteotomy site. The records for patients undergoing two modifications in a conventional modified French Osteotomy were analysed. Four wires, two proximal and two distal to the osteotomy site for precision and guided compression over the other additional Kirschner wire (K-wire) at the osteotomy site, were the two modifications in these patients.

Aim: To analyse the functional outcome of cubitus varus deformity in children treated with technical modifications of modified French osteotomy.

Materials and Methods: This was a retrospective cohort study done at the Department of Orthopaedics, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India. The study duration was three years (from April 2019 to April 2022). A total of 34 cubitus varus deformity patients were included in this study who were operated with lateral closing wedge-modified French osteotomy with technical modification by K-wires. The patients were followed-up for a minimum of six months. The results were analysed using Quick Disabilities of the Arm, Shoulder and Hand (DASH) and Flynn’s criteria. Statistical Package for the Social Sciences (SPSS) version 21.0 was used and p-value<0.05 was considered statistically significant.

Results: Twenty-three (67.65%) cases were male, and 11 (32.35%) were female. Twenty-eight (82.4%) patients were children aged 5 to 10 years, 20 (58.8%) cases involved a right-sided deformity, while the remaining 14 (41.2%) had left-side involvement. The mean age was 7.58±2.49 years (ranging from 3 to 12 years). The mean time since they had initial trauma was 2.42±1.28 years. The preoperative mean cubitus varus angle was 11.73±2.39°, the mean hyperextension was 13.27±2.69°, and the mean internal rotation was 36.48±5.01°. Postoperative six months’ corrective mean carrying angle (valgus) was 5.79±2.46°, corrective hyperextension was 2.18±1.06°, and corrective internal rotation was 5.39±2.74°. Out of 34 cases, all had excellent results as analysed by Quick DASH and Flynn’s criteria.

Conclusion: The technical modifications by K-wires in conventional modified French osteotomy provided guided compression over the osteotomy site, ensured perfect implant placement without cutting out the screw, and improved 3D (Dimensional) correction of cubitus varus deformity. So, it’s safe, simple, and effective.