Acetabular retroversion is a well-documented cause of femoro-acetabular impingement (FAI). There are few reports of long-term outcomes following correction of retroversion. We hypothesized that correction of acetabular retroversion with peri-acetabular osteotomy (PAO) in young adults with symptomatic FAI can lead to symptomatic relief, improvement of function and thus potentially delay the progression of osteoarthritis.

Twenty-two patients (29 hips) underwent Bernese PAO for treatment of symptomatic FAI with acetabular retroversion between April 1997 and August 1999. Mean age at surgery was 23 years (14–41). Mean duration of symptoms was 17 months (6–24). All pre-operative radiographs demonstrated Tönnis grade 0 of degenerative changes. Mean follow up was 127 months (109–142). Clinical, functional and radiographic outcomes are presented.

The overall mean Merle d’Aubigné score improved from 14.0 points (12–16) pre-operatively to 16.3 points (14 to 18) at the time of last follow-up. There were three reoperations due to loss of correction, posterior impingement and cam impingement. There were no major vascular or neurologic complications and none related to non- healing of the osteotomies. All patients had symptomatic relief at final follow-up. Range of motion and functional scores improved in all cases (even in those with repeat procedures). The vast majority of patients continued to demonstrate no signs of osteoarthritis (Tönnis greade 0) at final follow-up.

Acetabular retroversion is a mechanical factor that can lead to FAI. In symptomatic cases, PAO is a safe and reliable method for correction of the retroversion and can relief symptoms, improve function and prevent rapid progression of osteoarthritis.