2015 ISAKOS Biennial Congress ePoster #1709

Femoral Derotation Osteotomies in Adults for the Treatment of Version Abnormalities

Robert Leon Buly, MD, MS, New York, NY UNITED STATES
Hospital for Special Surgery, New York, NY, USA

FDA Status Cleared

Summary: A subtrochanteric derotation osteotomy of the femur is a safe and effective procedure to treat either femoral retroversion or excessive femoral anteversion. Excellent or good results were obtained in 93%.

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Abstract:

Introduction

Version abnormalities of the femur, either retroversion or excessive anteversion, cause pain and hip joint damage due to impingement or instability respectively. A retrospective clinical review was conducted on patients undergoing a subtrochanteric derotation osteotomy for either excessive anteversion or retroversion of the femur.

Methods

A total of 49 derotation osteotomies were performed in 39 patients. There were 32 females and 7 males; the average age was 29 years (range 14 to 59 years). The osteotomies were performed closed with an intramedullary saw; fixation was performed with a variety of intramedullary nails. Patients requiring a varus or valgus intertrochanteric osteotomy were excluded; pure rotational corrections only were performed. Twenty-four percent of patients had a retroversion deformity (average -8° of retroversion), 76% had excessive anteversion of the femur (average +36° of anteversion). The etiology was post-traumatic in 5 (10%), diplegic cerebral palsy in 4 (8%), fibrous dysplasia in 2 (4%), Prader-Willi Syndrome in 1 (2%) and idiopathic in 37 (76%). Previous surgery had been performed in 51% of the hips. Fifty-seven percent underwent concomitant surgery with the index femoral derotation osteotomy, including hip arthroscopy in 39% (labral debridement alone or with femoral neck osteochondroplasty), a tibial derotation osteotomy in 12% and a periacetabular osteotomy in 6%. The concomitant tibial osteotomies were performed to correct a compensatory excessive external tibial torsion that would be exacerbated in the correction of excessive femoral anteversion. The modified Harris hip score was used to assess the results in patients with a minimum of 12 months follow-up.

Results

There were no nonunions; the average time to union was 3.3 months. There were no nerve injuries, one late infection occurred 10 months after surgery, treated successfully with hardware removal and antibiotics. One patient was converted to a total hip replacement after 15 months due to the failure of a periacetabular osteotomy in the patient with Prader-Willi syndrome. At an average follow-up of 5.4 years (range 9 months to 17.8 years), the modified Harris Hip Score improved by 26 points (p< 0.001, Wilcoxon signed-ranks test). The results were rated as excellent in 71%, good in 22%, fair in 5% and poor in 3%. Subsequent surgery was required in 59%, 90% of which were hardware removals.

Conclusion

A closed, subtrochanteric derotation osteotomy of the femur is a safe and effective procedure to treat either femoral retroversion or excessive anteversion. Excellent or good results were obtained in 93%, despite the need for subsequent hardware removal in more than half of the patients.