Abstract
BACKGROUND
Our modified procedure for rotational acetabular osteotomy (RAO) aimed to reduce operative invasion of soft tissue and to minimize incision length.
SURGICAL TECHNIQUE
A shortened skin incision (10–15 cm versus 20–30 cm in traditional RAO) is curved over greater trochanter and exposed by transtrochanteric approach. Medial gluteus muscle is retracted to expose the ilium without detachment from iliac crest. Similarly the rectus femoris muscle tendon was retracted, not excised, from the anterior inferior iliac spine. The lateral part of the osteotomized ilium is cut in lunate and trapezoid shape to form the bone graft instead of the outer cortical bone of the ilium.
PATIENTS
We performed RAO on 66 patients (75 hips) using this modified procedure between 2000 and 2009. Follow-up rate was 95% (71/75 hips). Of 71 hips, 28 had early-stage, and 43 had advanced-stage osteoarthritis. Mean patient age was 39.7 years at time of surgery. Mean length of follow-up was 5.3 years. Clinical assessment was performed using the Merle d'Aubigne & Postel scores. Radiographically, the lateral center-edge (CE) angle, the Sharp angle and acetabular head index (AHI) were evaluated pre- and post-operatively.
RESULTS
Mean CE angle, Sharp angle and AHI improved pre- to post-operatively from −1.3 degrees to 36.5 degrees (p<0.00001), 50.3 degrees to 39.4 degrees (p<0.00001), 54.0 % to 95.7 % (p<0.00001), respectively. Clinical hip scores at latest follow-up were significantly improved. No progression of osteoarthritis was seen in hips with early-stage osteoarthritis. Ten hips with advanced-stage osteoarthritis preoperatively had radiographic evidence of progression of osteoarthritis, and six of those were converted to total hip arthroplasty. Complications included two transient lateral femoral cutaneous nerve palsies and ectopic bone formation in 15 hips, one of which required excision 1.5 years post-RAO. Kaplan-Meier survivorship analysis, with decreased clinical scores from pre-operatively and radiographic signs of progression of osteoarthritis as the end point, predicted a 10-year survival rate of 100% for early-stage osteoarthritis hips and 72.1 % for advanced-stage osteoarthritis.
CONCLUSIONS
Less invasive surgical procedure for RAO preserved function of hip abductor muscle and did not adversely influence on clinical or radiographic outcome.
