O3258: Femoral derotational osteotomy for idiopathic excessive femoral anteversion: a comparison of surgical techniques

Background: Children with excessive femoral anteversion can present with pain and in-toeing. In symptomatic cases refractory to conservative treatment, patients may undergo femoral derotational osteotomy. The preferred technique for femoral derotational osteotomy in otherwise healthy individuals remains controversial. The goal of this study was to compare outcomes and indications between two techniques for femoral derotational osteotomy in idiopathic femoral anteversion.

Methods: This retrospective cohort study included patients 6 years and older with idiopathic femoral anteversion, who underwent either proximal osteotomy using plate or diaphyseal osteotomy using intramedullary nail at a single, tertiary pediatric hospital between 2005 and 2022. Femur and patient characteristics were summarized for the cohort by frequency and percent, mean and standard deviation (SD), or median and interquartile range (IQR). Means, SDs, and p-values for comparisons across groups were calculated using a fixed-effects regression model to account for the correlation between bilateral measurements within the same patient.

Results: One hundred twenty-four femurs in 73 patients that underwent derotational osteotomy were analyzed. The mean age was 13.3 (SD, 5.1) years with median follow-up of 30 months (IQR, 12-64).
Eighty-four femurs underwent osteotomy with plate and 40 femurs underwent osteotomy with nail. No differences were detected across treatment groups with respect to age, sex, race, BMI, laterality, surgery duration, or follow-up time. However, patients in the nail group were more likely to have had pain in the knee (80% vs 38%; p< 0.001), and patients in the plate group were more likely to have been operated on by a hip surgeon (70% vs 25%; p< 0.001).
Patients in the nail group returned to full weight bearing about 3 weeks sooner than those in the plate group (median, 11 vs 14; p< 0.001), however, no significant difference was detected between groups in the time to return to activities, complications, gait, or pain at follow-up (Table 1).

Conclusion: This study suggests proximal osteotomy using a plate and diaphyseal osteotomy using an intramedullary nail have comparable outcomes apart from earlier return to full weight bearing when using an intramedullary nail. Patients treated with diaphyseal osteotomy are more likely to have knee pain and those treated with proximal osteotomy are more likely to be operated on by a hip specialist.
Our study is the first study comparing indications and outcomes between two different surgical techniques to treat idiopathic femoral anteversion. Given comparable outcomes found in the study, the choice of surgical technique for femoral derotational osteotomy in idiopathic femoral anteversion may depend on pain location and surgeon expertise. Future prospective studies are needed to further evaluate the different surgical techniques.