The Mediating Effect of Baseline Expectations of Conservative Care and Surgery Outcomes on Fulfillment of Expectations for Patients With Femoroacetabular Impingement Syndrome

FAI Syndrome is a morphological hip condition that can cause hip/groin pain and impaired performance.1 FAI Syndrome is caused by abnormal morphology of the femoral head (referred to as cam FAI Syndrome), excessive acetabular coverage of the femoral head (referred to as pincer FAI Syndrome) or a combination of the two (mixed FAI Syndrome).2 Not only can FAI Syndrome give rise to symptoms and impair function, the repetitive bony contact can also lead to a cascade of structural damage including tearing at the chondrolabral junction, full thickness cartilage delamination, and potentially hip osteoarthritis.

Presently, there is uncertainty involving the best treatment approach for symptomatic FAI Syndrome.2 The principal two management options are 1) physical therapy management of impairments and function and/or 2) surgery. Although presently, both modalities have been shown to improve symptoms in the short term,2 surgery is by far the most commonly incorporated approach.1, The incidence of the surgery has notably increased in recent years. There has been an 18-fold increase in surgical procedures for FAI Syndrome between 1999 and 2009, varying by geographic region in the USA.3

As an elective procedure, surgery for correction of FAI Syndrome is likely influenced by patients' perspectives and expectations of outcome.4 The extent to which these expectations influence specific treatment choices, as well as subsequent outcomes is currently unclear, although recent findings suggest that across various pathologies both patients5 and clinicians6 rarely have accurate expectations of treatment benefits or harms.

Non-operative, conservative treatments may have a role in managing FAI Syndrome to alleviate symptoms, potentially resulting in postponement or avoidance of surgery. Bony morphological changes can be present without symptoms, and nearly all participants with symptomatic FAI Syndrome undergo a variable asymptomatic period in the presence of structural FAI Syndrome. Recent studies have been hampered by retrospective and case cohort design, very small sample sizes, short-term follow up, and self-report measures only.4 A recent systematic review stated "although the available literature with experimental data is limited, there is a suggestion that physical therapy and activity modification confer some benefit to patients. Non-operative treatment regimens, particularly physical therapy, need to be evaluated more extensively and rigorously".6 Further, it is well known that patient expectations can mediate outcomes. Those who have high expectations about the potential benefit of the conservative approach are more likely to experience improvements. Conversely, those who have low expectations are more likely to fail to see improvement.

4. Design & Procedures: Reporting of the study will conform to STROBE guidelines for observational studies. The proposed study is a prospective case series: