AAOS/ORS co-sponsored research symposium explores challenges, implications for clinical practice
Femoroacetabular impingement (FAI) in young adults can lead to the development of osteoarthritis (OA) of the hip, a leading cause of reduced quality of life and loss of function. In addition, arthroplasty to treat lower extremity OA is both common and costly—the number of total hip arthroplasty procedures is expected to increase by 200 percent over the next two decades. As a result, interest in treatment innovations focused on early detection of FAI and interventions to prevent or halt disease progression and preserve the natural hip joint is growing.
The recent 2012 AAOS/Orthopaedic Research Society (ORS) FAI Research Symposium emphasized a multidisciplinary approach and focused on summarizing current knowledge, developing consensus, and identifying research strategies for several key issues related to the condition. Under the direction of co-chairs John C. Clohisy, MD, of Washington University School of Medicine in St. Louis, and Young-Jo Kim, MD, PhD, of Children’s Hospital Boston, the 2-day symposium addressed, among other topics, disease definitions, radiographic and clinical assessment methods, treatment strategies, clinical outcome methods, and possible clinical trial designs to study the treatment efficacy for FAI.
FAI is a biomechanical abnormality of the hip that results in abnormal contact between the femur and acetabulum leading to joint damage. Often, femoral or acetabular structural abnormalities may predispose a hip to FAI; however, in rare instances even in a structurally normal hip, excessive motion and activity may lead to damage. Due to its diverse nature, it has been difficult to precisely define this condition for epidemiologic and clinical studies. Rapid advancements in open and arthroscopic techniques to correct the structural abnormalities have been made recently. However, no controlled studies to date demonstrate the efficacy of surgical treatment to relieve symptoms, let alone prevent or delay the development of OA.
It is becoming increasingly clear that some of the typical cam deformity that may lead to FAI is highly prevalent in the asymptomatic male population. According to Michael Leunig, MD, of Schultess Clinic in Zurich, Switzerland, the cam deformity may be present in up to 25 percent of the male population. Furthermore, according to Michael Nevitt, PhD, of University of California San Francisco, even in early OA, femoral bony remodeling can lead to femoral shape change that may mimic a cam deformity; however, it now seems clear that there are proximal femoral shape abnormalities that are a cause of OA rather than the result of OA. Furthermore, according to Siôn Glyn-Jones, MBBS, DPhil, of Oxford, England, longitudinal data demonstrate that although an obvious cam deformity is a risk factor for the development of OA, it does not destine the hip to eventual joint failure. Therefore, due to the high prevalence of these predisposing hip deformities in the normal asymptomatic population, care must be taken to correlate radiographic and clinical data when making a clinical diagnosis of FAI.
Treatment of FAI has transitioned from open surgical dislocation to arthroscopic and less-invasive open techniques, closely paralleling treatment of the meniscus and anterior cruciate ligament in the knee and instability in the shoulder, according to Thomas Byrd, MD, of Nashville Sports Medicine and Orthopaedic Center. The advantages of less-invasive approaches to correcting FAI are definitely appealing. Yet, according to Dr. Byrd, the biggest challenge lies not in whether effective bone correction can be achieved, but what type and how much bony correction is necessary to solve the problem.
In the end, reliable correction can be accomplished with each of the techniques—surgical dislocation, arthroscopic, and mini-open. “The best method is whichever one is best in the individual surgeon’s hands,” said Dr. Byrd.
Dr. Clohisy emphasized that FAI encompasses a wide spectrum of disease patterns/severity, diverse patient populations, and treatment options that range from conservative to surgical. He added that each surgical procedure has distinct advantages, disadvantages, indications, and contraindications. Therefore, careful patient evaluation is critical to characterize disease patterns and to optimize the surgical procedure. Moreover, larger clinical trials are needed to address current limitations and provide scientific guidance for evidence-based clinical practice, he said.
It is increasingly clear that FAI is an important cause of hip dysfunction. The rate of hip arthroscopy performed in the United States is increasing at an exponential rate. However, there is minimal investigation into the role of nonsurgical treatment modalities according to Heidi Prather, DO, of Washington University. Furthermore, good quality clinical studies such as a randomized control trial would seem necessary to demonstrate the efficacy of treatment for FAI, according to Stefan Lohmander, MD, PhD of Lund, Sweden. The purpose of this symposium was to facilitate further study into orthopaedic surgeons’ understanding of FAI in the development of hip OA and provide a framework for larger clinical trials that may guide future treatment of FAI.
About the symposium
Held May 9–11, 2012, in Chicago, the AAOS/ORS FAI Research Symposium assembled dozens of national and international leading orthopaedic researchers, outstanding young investigators, and representatives from government and industry. The forum included presentations, breakout discussions, and Q & A sessions on the following topics:
- Etiology of Hip Osteoarthritis
- Hip Osteoarthritis Disease Burden
- Current Knowledge Regarding FAI
- Basic Science of FAI
- Treatment of FAI: Technical Overviews and Clinical Results
- Challenges and Strategies to Better Understand and Treat FAI
- Future Clinical Studies on FAI: How Should We Move Forward?
The 2012 AAOS/ORS FAI Research Symposium was supported in part by a grant from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (1R13AR061918-01). It is another in a series of collaborative efforts involving the AAOS, governmental agencies, industry, specialty societies, the Orthopaedic Research and Education Foundation (OREF), ORS, leading researchers, and clinicians. Educational support was provided by Smith & Nephew, Biomet, and Zimmer.