Is simultaneous bilateral total hip arthroplasty deleterious in a biomechanical point of view? A comparative gait analysis study

Abstract

Abstract Purpose: Uni- or bilateral hip osteoarthritis is a common disease generating pain, stiffness, and functional disabilities. Changes in the normal walking with higher energy expenditures are observed. Facing a cruel lack of biomechanical data, we decided to analyse the impact on the walking of single and simultaneous bilateral total hip arthroplasties (THA).Method: We conducted a prospective monocentric study, comparing two matched groups of 15 patients able to walk with symptomatic isolated uni- (group 1) or bilateral HO (group 2) and treated respectively by unilateral THA (UTHA) or simultaneous bilateral THA (SBTHA). Surgery was performed by a single surgeon with a direct anterior approach and approved by local ethical committee. Walking was assessed by a « 3D Gait analysis motion » pre and at 6 months post operatively.Result: In the UTHA group, recovery, i.e., efficiency of locomotor mechanism (p-value <0.001) and pelvis sagittal balance (p-value 0.03) improved, while external and total work (p-value 0.01) decreased post operatively. In the SBTHA group, speed (p-value 0.03), step length (p-value 0.04), range of motion of knee sagittal stance (p-value 0.009) and hip frontal (p-value 0.03), and internal work are significatively higher (p-value >0.001) post operatively. Conclusions: This original study attests that THA has a positive impact on walking and energetics outcome in UTHA and SBTHA.