Stabilometric assessments of two rehabilitation protocols on postural parameters after posterior total hip arthroplasty: A prospective randomized comparative study

Abstract

Introduction: After total hip arthroplasty (THA), patients continue to have muscular, functional and postural deficits. The literature seems to support the use of postoperative rehabilitation, especially self-directed programs. However, there is no set protocol for the management of postural disorders. Therefore, the purpose of this study was to compare postural parameters of a group of patients who underwent posterior THA followed by 2 different types of rehabilitation (stabilometric platform (SP) and home-based self-directed protocols) with a control group of operated patients who did not undergo rehabilitation and a control group of age-matched asymptomatic subjects.

Hypothesis: We hypothesized that rehabilitation would normalize the stabilometric parameters.

Patients and methods: A total of 67 subjects were enrolled in this study (mean age 67.85±1.22years) and divided into 4 groups. Forty-one of these subjects had undergone a posterior THA were randomly assigned between D10 and D21 to one of the following 3 groups: no rehabilitation control group (THACG=14), supervised rehabilitation with a stabilometric platform group (RSPG=16), and a self-directed home-based rehabilitation group (SDHRG=11). The 4th group was a control group made up of 26 age-matched asymptomatic nonoperated subjects (CG55-80). These rehabilitation protocols lasted 3weeks. At the end of the 3weeks, the groups performed the same stabilometric single leg and double leg stance tests (considering lower limb dominance) on an SP.

Results: No significant differences were observed between groups in the bipedal stance, except between the CG55-80 and the THACG, where a higher energy expenditure was observed in the THACG during the static stance with eyes open (EO) and eyes closed (EC): increase in the path length (P_length) covered by the center of pressure (COP) (EO: p=01; EC: p=03) and the average velocity (V_avg) of the COP (EO: p=01; EC: p=03). These differences were not observed in the SDHRG and RSPG whether they were compared with one another or with both control groups. In the unipedal stance, subjects in the RSPG and SDHRG showed greater muscle activity in the anterior and posterior chains and hip abductors, and used less energy to maintain the stance than those in the CG55-80, regardless of lower limb dominance: decrease in the mediolateral range of COP displacement (X_range) (hip abductor muscles) (p=02) and anteroposterior range of COP displacement (Y_range) (anterior and posterior chains) (p=3.49.10^-3), 95% confidence ellipse area (E_area) of COP data (p=1.47.10^-3), P_length (p=04) and V_avg (p=04). The RSPG had a smaller E_area than the SDHRG (p=04), demonstrating a better postural stability during the unipedal stance performed on the dominant operated leg.

Discussion: Our results were consistent with the literature on the benefits of rehabilitation after THA, thus confirming our hypothesis that rehabilitation normalized stabilometric parameters between D31-D45, depending on the subjects. These results provide new information regarding rehabilitation techniques to be implemented postoperatively after a THA. A home-based self-directed rehabilitation program is just as effective as an SP program in managing postural disorders.

Level of evidence: II; randomized controlled trial with low statistical power.

Keywords: Postural parameters; Rehabilitation; Self-directed rehabilitation; Stabilometric platform; Total hip arthroplasty.