Clinical outcome and physical activity measured with StepWatch 3™ Activity Monitor after minimally invasive total hip arthroplasty

Abstract

BackgroundSubjective data and physical examinations of patients after total hip arthroplasty are used to assess the outcome. But regarding the physical activity, no objective data can be delivered by existing scores. The level of activity can be measured objectively by counting gait cycles. The aim of this study was to measure activity levels of patients before and after total hip arthroplasty (THA).MethodsForty-six patients were included in this prospective study. Western Ontario and McMaster Universities Arthritis Index (WOMAC), Harris Hip Score (HHS), and physical activity level based on the number of steps per day were assessed 1 week before surgery, 6 weeks postoperatively, and 3 months postoperatively. To assess the general constitution of the patients, the American Society of Anesthesiologists (ASA) score and BMI were determined. The physical activity level was measured by StepWatch 3™ Activity Monitor (SAM; Orthocare Innovations, Seattle, WA, USA). The number of GCs per day was assessed. Spearman’s rank correlation coefficients were used to identify an association between age, body mass index (BMI), and American Society of Anesthesiologists classification with the number of gait cycles and to detect correlation between GCs and HHS and GCs and WOMAC.ResultsFrom preoperatively to 6 weeks postoperatively, the number of gait cycles did not alter significantly. Three months postoperatively, the number of GC/d and GC/h improved significantly. HHS and WOMAC improved significantly from before surgery to 6 weeks and to 3 months follow-up. The number of gait cycles per day did not correlate with the HHS and the WOMAC score at any point of measurement. Age, BMI, and ASA classification did not influence the results.ConclusionBy using a StepWatch 3™ Activity Monitor objective data about physical activity before and after THA can be measured reliable. Subjective and objective data in the postoperative period show different results. Physical activity seems to take longer to reach significantly improved values. By counting gait cycles, surgeons do have an additional tool to measure success after THA.

Do Physical Activity and Sleep Correlate with Patient-Reported Outcomes in Total Hip Arthroplasty?

“…In contrast, Höll et al studied 46 patients undergoing MIS-THA and reported that patients significantly improved their number of gait cycles per day at 3 months and 6 months, possibly attributed to the MIS approach. 19 Other studies have also shown increases in physical activity after THA and TKA at 6 months. 24,25 De Groot et al prospectively followed 80 patients with osteoarthritis undergoing TJA and determined that patients experience a small increase in actual physical activity, defined as movement-related activities (for example, walking, cycling), body postures (for example, sitting and standing), and changes in body posture (for example, sit-to-stand movement), after 6 months (7%), albeit not clinically significant.…”

“…These findings are well supported by the literature as many studies have reported the lack of correlation between subjective clinical evaluation scores and objective measures in physical activity. 6,16,19,23,25 Patientreported activity via questionnaires has been shown to have poor reliability and demonstrate several validity issues. 11 Therefore, our findings further strengthen previous reports that suggest that subjective clinically reported improvements do not necessarily correlate to increased objective levels of physical activity after THA.…”

“…[16][17][18] To our knowledge, only two studies attempt to elucidate this relationship in total joint arthroplasty (TJA). 6,19 In one study, the sample size was limited to 19 THA cases. 6 In the other study, physical activity was assessed in patients following minimally invasive surgery THA (MIS-THA) only, which may limit the external validity of their findings.…”

“…6 In the other study, physical activity was assessed in patients following minimally invasive surgery THA (MIS-THA) only, which may limit the external validity of their findings. 19 Neither study assessed the relationship between objective sleep measures and PROMs following THA.…”

Why Do People Undergo THR and What Do They Expect to Gain—A Comparison of the Views of Patients and Health Care Professionals

“…Despite concerns over standardization ( 19 ), studies have shown an association between presurgical values and postoperative outcomes ( 20 – 22 ). However, discrepancies between PROMs and performance-based function are seen ( 23 ) and a number of studies have suggested caution when only using subjective data as the measure of recovery ( 23 – 25 ). Additionally, compared with preoperative function, postoperative activity levels are low and many individuals become socially isolated following surgery ( 26 , 27 ).…”