Slipped capital femoral epiphysis (SCFE) and Legg-Calve-Perthes (LCP) disease are developmental conditions (1, 2) with SCFE being described as a common source of pain and disability, and the most common cause of degenerative hip disease in middle-aged patients (3, 4). Proximal femoral osteotomies following SCFE aim to restore more normal anatomy, improve function and reduce the morbidity and complications of pain, reduced range of movement, early arthritis and leg length discrepancy (3). Up to 50% of involved hips do well with no intervention but these hips are always at risk of developing secondary arthritis and similarly adult hip joints of patients with SCFE are more prone to develop advanced osteoarthritis (5). In general outcomes of osteotomies are associated with more than 50% morbidity (6) and significant complications (7-11).
The management of end stage arthritis in patients with LCP and SCFE is total hip replacement (12). In young patients with end stage arthritis following SCFE and LCP, good prognosis and an implant survival rate of 80% at a follow-up of 10 years has been reported for Charnley prosthesis in the Norwegian arthroplasty register (13). Other studies have reported similar implant survival ranging from 78.1% to 90.7 % (14, 15), which is encouraging but is compounded by problems arising from an active lifestyle such as early failure and revision. The average age in these published reports was 50 years which means that 10 to 20% patients will undergo a revision at 60 years of age and further re-revision surgery there after.
Due to its bone conserving nature, ability to confer joint stability and ease of conversion to a total hip replacement in the event of implant failure, hip resurfacing arthroplasty is gaining popularity as a treatment option for young patients (15). Although Amstutz et al(16) and Boyd et al (17) have published results for hip resurfacing arthroplasty for end stage arthritis following SCFE and LCP, they had small numbers ( n=25 and 19 respectively) and short follow-up( 32-97 and 26-72 months respectively). In this study we independently reviewed ten year outcomes in a multicentre cohort of 70 patients (73 hips) following hip resurfacing for end stage arthritis following SCFE and LCP.
Patients and methods
In 1997 the Oswestry Outcome centre was setup to serve as an independent international register for the collection, analysis and reporting of outcomes following hip resurfacing arthroplasty. Between 1997 and 2002, 4535 patients were recruited by 139 surgeons from different centres in 38 countries. We selected 70 patients (73 hips) which included 58 patients (59 hips) with SCFE and 12 patients (14 hips) with LCP. These patients were age and gender matched to a group of 73 patients with primary osteoarthritis whose outcomes were unknown to us. The selected patients in both groups were operated by 39 surgeons from 4 countries. The primary osteoarthritis group was labeled as group OA and secondary arthritis...