FEMOROACETABULAR IMPINGEMENT SYNDROME AND EARLY HIP OSTEOARTHRITIS FINDINGS ARE NOT RELATED TO SELF-REPORTED BURDEN IN FOOTBALL PLAYERS WITH HIP/GROIN PAIN

M. Scholes¹, J. Kemp¹, B. Mentiplay¹, A. Semciw¹, J. Heerey¹, M. King¹, P. Lawrenson², K. Crossley¹

Background: Femoroacetabular impingement syndrome (FAIS) is a cause of hip and/or groin (hip/groin) pain in football players.  Symptoms (hip/groin pain), clinical findings (positive flexion-adduction-internal-rotation (FADIR) test) and imaging findings (cam or pincer morphology) are required for a FAIS diagnosis. Cam morphology is prevalent in football players and its increasing size is related to the severity of early hip osteoarthritis (OA) (cartilage and labral damage) in those who seek surgery for FAIS. However, the relationship between FAIS, early hip OA features, and self-reported pain and functional impairment (burden) remains unknown.

Methods: Football (soccer and Australian football) players (N=163; 34 women; mean age=27.5 (SD 6.3) years) with hip/groin pain (≥6months of hip/groin pain, positive FADIR test) and no radiographic hip OA (Kellgren and Lawrence (KL) grade <2) were recruited. Participants completed the International Hip Outcome Tool-33 (IHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS) and underwent hip radiographs (anteroposterior (AP) pelvis and Dunn 45°) and 3-Tesla magnetic resonance imaging (MRI).  Alpha angle (AA) and lateral-centre-edge-angle (LCEA) were used to define the presence of cam and pincer morphology, respectively. An AA>60° and/or LCEA>40° on hip radiographs determined FAIS presence. Cartilage defects and labral tears were scored semi-quantitatively (present/absent) from MRI. Linear regression models were used to investigate the relationship between independent variables (IVs) of FAIS and early OA features (present/absent) and PROM subscale scores (dependent variable). The covariates sex, age, KL (0 or 1), body mass index (BMI), and symptom duration were included in each model. Interactions between IVs and covariates were examined and dropped if not significant. For the second aim, participants with an AA>60° were investigated (n=117). Linear models were used for each PROM subscale; however, the FAIS variable was replaced with a continuous AA measurement variable.

Results: Femoroacetabular impingement syndrome and MRI-defined features of early hip OA were not related to self-reported burden in football players with hip/groin pain (P=0.059-0.985). Linear models explained only small variances in HAGOS and IHOT-33 scores (R2 value range 0.041-0.102). Increasing cam morphology size was associated with IHOT-Job (-0.459(95%CI -0.855,-0.063), P=0.023) and IHOT-Social (-0.430(95%CI -0.782,-0.077), P=0.017) subscale scores.    

Conclusion(s): Football players with FAIS and/or early hip OA features did not report worse hip/groin pain burden than football players without either imaging feature. Small R2 values indicate that imaging findings explain little of the hip/groin pain burden in football players. Larger cam morphology size was associated with worse IHOT-Job and IHOT-Social scores; however, the clinical importance of this finding may be questionable considering the small magnitudes of the relationships and the absence of this finding in remaining subscales.

Implications: The presence of imaging findings (FAIS/early hip OA features) does not appear to be related to worse self-reported burden in football players with hip/groin pain.

Funding, acknowledgements: Project support received from the National Health and Medical Research Council. MS received an Australian Postgraduate Research Training Programme scholarship.  

Keywords: Femoroacetabular impingement syndrome, Hip pain, Patient-reported outcome measures

Topic: Musculoskeletal: lower limb

Did this work require ethics approval? Yes

Institution: La Trobe University

Committee: La Trobe University Human Ethics Committee

Ethics number: 015-019