Risk factors for the development of femoroacetabular impingement in physically demanding occupations: a systematic review

Background: Femoroacetabular impingement (FAI) syndrome, or hip impingement, is a musculoskeletal condition affecting the hip joint. It involves motion- or position-related pain originating from an abnormal, premature contact between the femoral head-neck junction (femur) and the acetabular rim (rim around the hip socket). Cumulative and repetitive mechanical overloads at the hip joint appear to contribute to the development of FAI. However, occupational exposures to such loads in potential high-risk occupational groups (e.g., military personnel and athletes) and the relationships between these exposures and the development of FAI remain unclear. Therefore, the aim of this review was to identify and synthesise findings from studies which have reported on the occurrence rates and risk factors between occupations or occupational tasks in physically demanding occupations, and the development of FAI.

Method: This review was conducted according to the PRIMSA-P guidelines and registered on the Open Science Framework. PubMed, EBSCO, Scopus, Web of Science, CINAHL and ProQuest databases were systematically searched using the following key themes: ‘femoroacetabular impingement’, ‘work’ and ‘risk’. Key findings from the included studies were extracted, including risk factors, prevalence or incidence and risk ratios (e.g., relative risk, hazard ratios, and incidence rate ratios). Included studies were critically appraised using the Joanna Briggs Institute tools.

Results: Six studies met the eligibility criteria, with the average methodological quality generally indicating ‘good’ quality overall. The findings from this review indicate that FAI is more prevalent in occupations involving high physical activity, such as professional soccer and hockey players and military personnel compared to the general population. While specific occupational tasks were not highlighted in the included studies, the occupational demands described for each occupation suggest that occupations involving repetitive hip flexion (e.g., kicking and squatting) and sustained positions in extreme hip joint ranges were associated with FAI. Occupations where these loads are, or have been, experienced prior to skeletal maturity (e.g., professional, or elite athletes) and workers with a history of high-level sport or physical activity participation (e.g., military personnel) are at higher risk of developing FAI. The review also found military personnel with FAI were observed to have lower hip joint space measurements when compared to civilians with FAI, and this may further compound the development of FAI in military personnel by bringing the bone structures within the joint closer together and so making impingement more likely.

Discussion: The findings of this systematic review found occupations where individuals are constantly exposed to high-intensity and high-impact physical activity as well as repetitive and supra-physiologic hip loading conditions are more prone to developing FAI. However, the studies identified in this review unfortunately did not contribute to elucidating which specific occupational tasks, at which frequencies and durations, would increase the likelihood of developing FAI, particularly in physically demanding occupations.

Impact: Professional athletes and military personnel are at a higher risk of developing FAI. As FAI is a precursor for hip osteoarthritis, specific risk factors for FAI need to be more accurately identified and managed to reduce the incidence of FAI in these populations.My co-authors and I acknowledge we have no conflict of interest.