Abstract
Introduction
Torsional deformities of the femur have been recognized as a cause of femoroacetabular impingement (FAI) and hip pain. High femoral antetorsion can result in decreased external rotation and a posterior FAI, which is typically located extraarticular between the ischium and trochanter minor. Femoral osteotomies allow to correct torsional deformities to eliminate FAI. So far the mid-term clinical and radiographic results in patients undergoing femoral osteotomies for correction of torsional deformities have not been investigated.
Objectives
Therefore, we asked if patients undergoing femoral osteotomies for torsional deformities of the femur have (1) decreased hip pain and improved function and (2) subsequent surgeries and complications?
Methods
We retrospectively evaluated 21 hips (18 patients) who underwent femoral osteotomies for correction of torsional deformities between April 2005 and October 2014. Twenty hips with excessive femoral antetorsion (47.7° ± 8.6°, range 32° – 65°) had a derotational femoral osteotomy. One hip with decreased femoral antetorsion of 11° underwent rotational femoral osteotomy. Previous surgery were performed in 43% of the hips including hip arthroscopy (5 hips), acetabular osteotomy (2 hips), open reduction for high dislocation (2 hips), surgical hip dislocation (2 hips) and varus intertrochanteric osteotomy (1 hip). In 10 hips a concomitant offset correction and in 5 hips a concomitant periacetabular osteotomy were performed. The mean followup was 3.6 ± 2.3 (1 – 10) years. One patient (one hip) died from a cause unrelated to surgery at the 2 year follow-up. We used the anterior and posterior impingement test to evaluate pain. Function was assessed using the Merle d'Aubigné Postel score, WOMAC, UCLA activity score and Harris hip score.
Results
The incidence of a positive anterior impingement test decreased from preoperatively 85% to 29% at latest follow-up (p<0.001). The incidence of a positive posterior impingement test decreased from preoperatively 90% to 5% at latest follow-up (p<0.001). The mean Merle d'Aubigné Postel score increased from 13 ± 2 (11 – 16) to 16 ± 1 (13 – 17) at latest followup (p<0.0001). For the WOMAC, UCLA and Harris hip score no preoperative values existed but at latest followup they all showed fair to good values with a mean WOMAC score of 14 ± 15 (1 – 50), UCLA score of 6 ± 1 (3 – 8) and Harris hip score of 77 ± 13 (47 – 96). Subsequent surgeries included hardware removal in 14 hips (66%) and hip arthroscopy with offset creation in 1 hip. Complications occurred in 5 hips (24%) all graded Grade III according to Sink and included conversion to total hip arthroplasty in 1 hip, reosteosynthesis due to pseudarthrosis in 3 hips and hip arthroscopy for adhesiolysis in 3 hips.
Conclusion
Femoral osteotomies for the treatment of torsional deformities of the femur result in decreased pain and improved function in patients with FAI. However, these procedures are associated with a complication rate of 24% which is mainly due to pseudarthrosis and intraarticular adhesions in patients with concomitant offset correction.
