Unilateral total hip replacement patients with symptomatic leg length inequality have abnormal hip biomechanics during walking

Abstract

BackgroundSymptomatic leg length inequality accounts for 8.7% of total hip replacement related claims made against the UK National Health Service Litigation authority. It has not been established whether symptomatic leg length inequality patients following total hip replacement have abnormal hip kinetics during gait.MethodsHip kinetics in 15 unilateral total hip replacement patients with symptomatic leg length inequality during gait was determined through multibody dynamics and compared to 15 native hip healthy controls and 15 ‘successful’ asymptomatic unilateral total hip replacement patients.FindingMore significant differences from normal were found in symptomatic leg length inequality patients than in asymptomatic total hip replacement patients. The leg length inequality patients had altered functions defined by lower gait velocity, reduced stride length, reduced ground reaction force, decreased hip range of motion, reduced hip moment and less dynamic hip force with a 24% lower heel-strike peak, 66% higher mid-stance trough and 37% lower toe-off peak. Greater asymmetry in hip contact force was also observed in leg length inequality patients.InterpretationThese gait adaptions may affect the function of the implant and other healthy joints in symptomatic leg length inequality patients. This study provides important information for the musculoskeletal function and rehabilitation of symptomatic leg length inequality patients.

Identifying clinically meaningful benchmarks for gait improvement after total hip arthroplasty

“…The MCII for HROM was 13.3( 12.1˚, 14.8˚). 16.6% (11.0%, 22.8%) subjects attained this MCII (Fig. 4B).…”

“…Unfortunately, between 14 and 22% of patients report limitations in walking function and other physical activities, or do not have clinically meaningful functional improvement . Abnormal gait mechanics may be a barrier to full restoration of physical function . In recent reviews, the most consistently reported spatiotemporal, kinematic, and kinetic gait deficits, are, respectively, reduced walking speed, reduced dynamic hip range of motion in the sagittal plane and reduced dynamic abductor function compared to control subjects.…”

“…[6][7][8] Abnormal gait mechanics may be a barrier to full restoration of physical function. [9][10][11][12][13][14][15][16][17] In recent reviews, 18,19 the most consistently reported spatiotemporal, kinematic, and kinetic gait deficits, are, respectively, reduced walking speed, reduced dynamic hip range of motion in the sagittal plane and reduced dynamic abductor function compared to control subjects. These aspects of gait are directly associated with self-reported gait function in THA patients.…”

Preoperative gait mechanics predict clinical response to total hip arthroplasty

“…Function can be objectively and specifically characterized using quantitative gait analysis. Many studies have shown that gait mechanics do not fully return to normal after THA . However, work linking gait mechanics to clinical outcomes is still emerging.…”

“…Many studies have shown that gait mechanics do not fully return to normal after THA. [19][20][21][22][23][24][25][26][27][28][29][30] However, work linking gait mechanics to clinical outcomes is still emerging. We know that higher values of walking speed, 31,32 stride length, 31 dynamic range of motion, and some external moments 33 are related to clinical improvement, but the relationship between gait mechanics and clinical response has not been investigated.…”