Functional testing provides unique insights into the pathomechanics of femoroacetabular impingement and an objective basis for evaluating treatment outcome

Abstract

Femoroacetabular impingement (FAI) has been recognized as a significant clinical problem. While hip reshaping surgery for treating FAI has had positive clinical outcomes, there remains a need for objective functional outcomes of FAI treatment. We tested the hypothesis that during walking and stair climbing significant changes in hip kinematics would occur following hip reshaping surgery that indicate restoration of normal function post-operatively. Hip and pelvic kinematics were collected for 17 FAI patients preand 1 year post-operatively and compared to 17 healthy matched controls. Prior to surgery, FAI patients had significantly reduced hip internal rotation and hip sagittal plane range of motion during walking (p ¼ 0.01, p < 0.001, respectively) and stair climbing (p ¼ 0.01, p < 0.001, respectively) as compared with controls. Post-operatively, these motions were restored to normal during walking (p ¼ 0.70, p ¼ 0.46, respectively), but remained significantly reduced in the FAI patients during stair climbing (p ¼ 0.03, p < 0.001, respectively). These results have important implications for understanding the functional pathomechanics of FAI and providing an objective basis for evaluating treatment outcome. The stair climbing results indicate that problems still exist in the hip joint for activities requiring higher ranges of hip motion and suggest a basis for exploring future improvements for the treatment of FAI. ß

Hip joint biomechanics during gait in people with and without symptomatic femoroacetabular impingement

“…M a n u s c r i p t Five studies have compared gait biomechanics between people with and without symptomatic FAI. Our observed 4°reduction in sagittal plane ROM in those with symptomatic FAI is consistent with two previous studies that also reported deficits in sagittal plane motion of 4° [ 13,19]. Although statistically different from the disorder-free participants, the clinical significance of this hip ROM impairment is unknown.…”

“…Gait is the most common repetitive voluntary movement of the lower limbs and an essential activity of daily living. There is limited and conflicting evidence regarding alterations to hip ROM during gait in individuals with symptomatic FAI [13,[17][18][19][20]. Interpretation of current evidence is limited by the use of narrow patient samples that render it difficult to generalize results to the broader FAI population, and the failure to use diagnostic imaging to ensure healthy controls in the comparison groups have no evidence of asymptomatic morphological FAI.…”

Kinematics and kinetics during stair ascent in individuals with Gluteal Tendinopathy

“…While hip abductor muscle weakness is common to GT (Allison et al, 2016a;Woodley et al, 2008), hip OA (Loureiro et al, 2013) and FAI (Casartelli et al, 2011), its relationship with kinematics of stair ascent may differ. No frontal plane differences in stair kinematics have been identified between individuals with and without FAI, but this analysis excluded evaluation of the trunk (Rylander et al, 2013). Conversely, a recent study by Meyer et al(2015) of individuals with mostly advanced hip OA (mean age 49.9 years) identified lower HADM and greater ipsilateral trunk lean during stair ascent (step height -184 mm).…”

“…Although stair ascent has not been studied in participants with GT, previous studies have included individuals with intra-articular hip pathology, including hip OA (Meyer et al, 2015), femoroacetabular impingement (FAI) (Rylander et al, 2013). While hip abductor muscle weakness is common to GT (Allison et al, 2016a;Woodley et al, 2008), hip OA (Loureiro et al, 2013) and FAI (Casartelli et al, 2011), its relationship with kinematics of stair ascent may differ.…”

CORR Insights®: Subject-specific Patterns of Femur-labrum Contact are Complex and Vary in Asymptomatic Hips and Hips With Femoroacetabular Impingement

“…Many studies have attempted to better understand how sometimes subtle morphologic differences can lead to the eventual painful injury associated with FAI, but each is with their weaknesses. Motion-capture methods have been utilized to understand the dynamic presentation of FAI during common activities of daily living, and to assess surgical treatment of the condition quantitatively [5,8]. However, motion-capture alone cannot directly visualize the interactions of the internal structures.…”