Functional movement compensations persist in individuals with hip osteoarthritis performing the five times sit-to-stand test 1 year after total hip arthroplasty

Abstract

Background: Methods to quantify and evaluate function are important for development of specific rehabilitation interventions. This study aimed to evaluate functional movement compensation in individuals with hip osteoarthritis performing the five times sit-to-stand test and change following total hip arthroplasty. To this end, trajectories of the body's center of mass in the medial-lateral and anterior-posterior dimensions were quantified prior to and 1 year after total hip arthroplasty and compared to a healthy control group. Methods: Twenty-eight individuals with hip osteoarthritis and 21 matched healthy controls were enrolled in this prospective study. Within 1 month prior to and 1 year after total hip arthroplasty, performance on the five times sit-to-stand test was evaluated using three-dimensional motion analysis and perceived pain using a visual analog scale. The center of mass trajectories for the medial-lateral and the anterior-posterior dimensions were identified, and the area under the curve was calculated, respectively. Repeated measures ANOVA were used to evaluate differences in the area under the curve, between pre-and postoperative performance, and between participants with hip osteoarthritis and controls. Results: Preoperatively, individuals with hip osteoarthritis displayed a larger contralateral shift (p < 0.001) and forward displacement of the center of mass (p = 0.022) compared to controls. After surgery, deviations in both dimensions were reduced (medial-lateral p = 0.013; anterior-posterior p = 0.009). However, as compared to controls, the contralateral shift of the center of mass remained larger (p = 0.010), indicative of persistent asymmetric limb loading. Perceived pain was significantly reduced postoperatively (p < 0.001). Conclusions: By quantifying the center of mass trajectory during five times sit-to-stand test performance, functional movement compensations could be detected and evaluated over time. Prior to total hip arthroplasty, individuals with hip osteoarthritis presented with an increased contralateral shift and forward displacement of the center of mass, representing a strategy to reduce pain by unloading the affected hip and reducing required hip and knee extension moments. After surgery, individuals with total hip arthroplasty displayed a persistent increased contralateral shift as compared to controls. This finding has implications for rehabilitation, where more focus must be directed towards normalizing loading of the limbs.

Balance and proprioception impairment, assessment tools, and rehabilitation training in patients with total hip arthroplasty: a systematic review

“…Static balance/postural stability was assessed in 20 studies [ 11 , 35 , 37 – 53 , 63 ]; dynamic balance was assessed in 10 studies [ 34 , 36 , 41 , 52 , 54 – 59 ]; proprioception in terms of sense of joint position was assessed in 2 studies [ 60 , 61 ]; clinical scales and other test batteries for balance assessment were used in 10 studies [ 11 , 13 , 40 , 41 , 52 , 59 , 60 , 62 – 64 ].…”

“…Two studies investigated dynamic balance during the performance of a 5-times-sit-to-stand [ 54 ] and a 5-times-squat [ 55 ] on force plates. Within 1 month after surgery, THA patients showed a higher asymmetrical loading and higher anterior-posterior (AP) and medial-lateral (ML) COP displacement during squatting movements when compared with healthy age-matched controls [ 55 ].…”

“…Within 1 month after surgery, THA patients showed a higher asymmetrical loading and higher anterior-posterior (AP) and medial-lateral (ML) COP displacement during squatting movements when compared with healthy age-matched controls [ 55 ]. Asymmetry and COP displacement were found to be significantly different from healthy controls 1 year after surgery during sit-to-stands movements [ 54 ].…”

“…However, almost all the studies comparing results of THA patients with healthy controls reports significant differences between-groups, with THA patients have worse balance performance than healthy controls. Impairments have been reported during static [ 38 , 39 , 41 , 44 , 47 , 51 , 63 ] and dynamic balance assessments [ 36 , 54 , 58 ], as well as with the assessment by means of clinical scales or tests batteries [ 41 , 51 , 62 – 64 ].Only 4 studies reported no differences between THA patients and controls in balance during the single-limb phase of walking [ 56 ], the Berg-balance scale results 5 year after surgery [ 62 ], and in response to balance perturbations [ 34 , 58 ]. Further studies with control groups of healthy participants are needed to better clarify these results.…”

“…Some studies with more than one assessment in the post-surgical follow-up reported a balance improvement across time [ 45 , 58 , 64 ], while other did not [ 40 , 46 , 49 ]. However, there are many studies reporting balance impairments also years after surgery [ 40 , 41 , 45 , 51 , 54 , 62 , 63 ], and persistent differences with healthy controls despite the improvements [ 57 ], thus it is likely to think that balance impairments are never completely addressed following THA. These observations are confirmed by the results of the study by Ninomiya et al [ 51 ], which observed a 2.8 times higher fall rate in THA patients compared to healthy controls in the 10 years after surgery.…”