LOWER EXTREMITY DEROTATIONAL OSTEOTOMIES ARE EFFECTIVE IN HELPING PATIENTS WITH LOWER EXTREMITY TORSIONAL ABNORMALITIES

Derotational osteotomies of the femur or tibia may be indicated in patients with torsional abnormalities (increased femoral anteversion, increased tibial torsion) that do not respond to nonsurgical management1. To clarify surgical indications and recommend optimal treatment algorithms, the surgical impact on mobility, pain, and function must be elucidated. This study aims to quantify the level of pain, function, mobility, and gait patterns of patients with torsional deformities of their lower limbs. The changes associated with surgery were also measured. Patients between 14 and 21 years-old with a combination of increased femoral anteversion and external tibial torsion who underwent a derotational osteotomy of their femurs and/or tibias were recruited. Their rotational profiles were measured with CT scan before surgery. Before and at one-year post-surgery, the Pediatric Data Collection Instrument (PODCI), a patient-reported outcome score, was collected. In addition, quantitative gait analysis and clinical examinations were completed. Paired t-test or Wilcoxon-Signed Rank test were used to assess pre-post-surgery changes. To assess the kinematic and kinetic gait analysis data, statistical parametric mapping (SPM) was performed. Ten female participants aged 17 ± 2 years completed the study. Participants had a femoral anteversion of 29° ± 10° and external tibial torsion of 45° ± 11°. For the physical examination, participants improved towards norms following the surgery for the ROM assessing rotation: hip internal rotation (pre: 65°±12°; post: 49°±8°), hip external rotation (pre: 30°±12°; post: 48°±11°), and the transmalleolar axis (pre: 31°±8°; post: 23°±7°). The major deviations found in the kinematic were observed in the transverse plane and they improved towards norms at one-year post-surgery (figure 1). Statistically significant improvements were observed in the following domains of the PODCI (score/100): sports and physical function (pre-surgery: 50 ± 18, post-surgery: 70 ± 20), pain and comfort (pre-surgery: 35 ± 16, post-surgery: 76 ± 19), and global function (pre-surgery: 68 ± 10, post-surgery: 86 ± 11). Results from this study suggest that this condition causes radiological, gait and physical abnormalities that impact the quality of life of individuals with torsional deformities of their lower limbs. Post-surgery results at one-year, demonstrate that derotational osteotomy is effective to alleviate pain, restore physical function, and normalize gait pattern. For any figures or tables, please contact the authors directly.