Femoroacetabular impingement (FAI) is a bony condition of the hip caused by repetitive abnormal contact between the femoral head and the acetabulum of the pelvis and has been found to be highly prevalent in young athletes with a peak risk ae of 12-13 year of age, before the epiphyseal plates fuse. Repetitive movements, mainly involving flexion, adduction, and internal rotation lead to bony overload causing asymmetrically fusion and bony overgrowth. Typical symptoms of FAI include deep anterior groin pain and progressive hip stiffness which are often exacerbated during sporting activity and some suggest might lead to a degradation in performance without factoring in the pain caused in acute presentations.
The aim of this study was to identify areas of athletic performance which might be negatively affected in young athletes by bony hip change and to identify any magnitude of possiblereductions in performance. The study was based on the hypothesis that athletes with FAI would show deficits in performance compared with healthy controls.
The authors FAI group (n = 54) consisted of 18- to 35-year-old (mean age 25.28 ± 4.7 years) competitive sportsmen with preoperative symptomatic FAI. ( Far from adolescent) and Healthy control participants (n = 66, mean age 24.08 ± 6.5 years)
The testing protocol consisted of a timed 10-m sprint from a standing start, a timed modified agility T-test, a single leg drop jump for the calculation of reactive strength index, a deep squat, and a measurement of passive hip mobility. All hip ROM testing (flexion, abduction, and internal rotation at 90 degree hip flexion) was performed with the participant in the supine position on the floor using a goniometer. All participants were asked to report any groin pain or stiffness during the tests.
Participants within the FAI group with unilateral FAI were analyzed both as part of the main FAI group and as an independent subgroup where symptomatic versus nonsymptomatic limbs were assessed, using a paired samples T-test for reactive strength index and each hip ROM measurement. In addition, the unilateral FAI patient group scores were compared with matched unilateral control group scores (matched for age, sport, playing level, and leg dominance).
In the FAI group, 24 subjects were diagnosed with symptomatic bilateral impingement yielding 78 hips in total; 57 (73%) of these hips were diagnosed with combined impingement, 18 (23%) were identified as having an isolated pincer impingement, and 3 (4%) were diagnosed with pure cam impingement on x-ray.
The FAI group were 3% slower than controls over 10 m (P = 0.002) and 8% slower on the modified agility T-test (P < 0.001). Fifty-four percent of the FAI group reported anterior groin pain while performing the 10-m sprint test, with a further 8% reporting stiffness. For the modified agilityT-test, 62% of the group reported groin pain during the test, whereas 8% reported stiffness; no control participant reported either pain or stiffness for either test (P < 0.001). The FAI group had 4%, 25%, and 38% lower values for flexion, abduction, and internal rotation, respectively, compared with the control group (P = 0.001).
No significant differences between groups were identified for squat depth or reactive strength index. However, 56%of FAI athletes reported anterior groin pain while squatting, with a further 18% reporting stiffness; no control reported any such discomfort while performing the squat (P < 0.001).
The authors concluded that athletic performance measures of speed, agility, and hip ROM are significantly reduced in the presence of underlying FAI.
But that is not really what they were able to demonstrate – almost all the subjects with FAI were symptomatic ( many are not) and so pain was a significant limiting factor, and also no detail was provided about the level of sport participation prior to testing – almost all the changes seen could be explained by a reduction in training load.
Sadly it is easy to see how the study conclusions could be misinterpreted by those unfamiliar with the wider literature – laid management of these athletes at pre adolescence and appropriate strengthened conditioning should be the focus to prevent these groups becoming symptomatic and studies are underway globally looking athletes just these intervention rather than operative interventions.
Mullins K et al. (2017) Differences in Athletic Performance Between Sportsmen With Symptomatic Femoroacetabular Impingement and Healthy Controls. Clin J Sport Med.