This study sought to determine whether intensity and duration of standard exercise therapy are associated with changes in function following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Standard rehabilitation (hands-on physiotherapy, group exercise therapy, strength training, cycle ergometer therapy, continuous passive motion therapy, and water exercise therapy) were administered. The individual rehabilitation period varied between 12-25 days and included 48.1 ± 12.5 (THA) or 41.9 ± 9.7 (TKA) exercise interventions with intensities between 9.6 and 14.0 points on the Borg Rate of Perceived Exertion Scale. WOMAC pain (P< .001), stiffness (P < .001), and function (P < .001), as well as hip (P < .001) and knee (P < .001) ROM, improved significantly in THA and TKA patients. Analysis of covariance exhibited that these changes could not be accounted for by the total duration or mean intensity of exercise therapy.
The findings of the study display a low dose-response relationship between early postoperative exercise therapy and the improvements in function or ROM after THA and TKA. Although the findings raise questions about the effectiveness of existing rehabilitation programs, the small sample size, single setting, and geographic differences in postoperative treatment standards limit the generalizability of findings.