Verra M.L.1, Angst F.2, Benz T.2, Lehmann S.2, Winteler B.1, Aeschlimann A.3
1Bern University Hospital, Department of Physiotherapy, Bern, Switzerland, 2Rehabilitation Clinic 'RehaClinic', Research, Bad Zurzach, Switzerland, 3Rehabilitation Clinic 'RehaClinic', Rheumatology, Bad Zurzach, Switzerland
Background: Knee osteoarthritis affects mobility, the most important physical function leading to substantial loss of quality of life. Various treatment options are available to persons with knee osteoarthritis. Physiotherapy and strength training are the most effective conservative therapies with highest evidence. When the conservative treatments fail to relieve pain and improve activity limitation, total knee arthroplasty is usually considered as an effective option.
Purpose: To
(1) quantify effects on pain, function, and health-related quality of life up to 5 years after a comprehensive rehabilitation program of knee osteoarthritis, and
(2) to identify risk factors associated with receiving knee arthroplasty during the observation period.
(1) quantify effects on pain, function, and health-related quality of life up to 5 years after a comprehensive rehabilitation program of knee osteoarthritis, and
(2) to identify risk factors associated with receiving knee arthroplasty during the observation period.
Methods: A prospective cohort study with assessments at admission to the clinic and at 1, 2, 3, 4, and 5 years after discharge was conducted. Participants were 205 persons with knee osteoarthritis (age 65.7±10.3 years). The intervention at the start of the study was a 2-6 week lasting in- or outpatient program consisting of patient education, individual physiotherapy (mainly strengthening), group therapies (mainly endurance training and swimming with flippers), and various passive therapies (massage, fango packs). Changes in health state were measured with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). For the relative risk of getting knee arthroplasty, odds ratios (OR) were calculated by multivariate logistic regression analysis.
Results: Over the 5 year follow up, comprehensive rehabilitation of knee osteoarthritis showed effects sizes (ES) of 0.13 to 0.79 in pain, -0.12 to 0.42 in function and -0.25 to 0.21 in psychosocial health. In this period, 48 persons (23.4%) were referred to knee arthroplasty. Measured at the last time point before knee arthroplasty, worsening on WOMAC pain (ES = -0.42; p = 0.001) and function (ES = -0.54; p = 0.002) predicted the need for knee joint replacement surgery. Female sex (OR = 3.30), higher educational level (OR = 3.54), higher number of comorbidities (OR = 0.71) and WOMAC factor ascending / descending (OR = 1.60) were identified as significant risk factors for knee arthroplasty.
Conclusion(s): This study showed that comprehensive in- or outpatient rehabilitation in persons with unilateral knee osteoarthritis may improve pain and physical function during up to 5 year follow up. However, in the course of this degenerative disease about one quarter of the persons (23.4%) were referred for knee arthroplasty: the WOMAC is sensitive to deterioration of pain and function and may predict the need for knee arthroplasty in a subgroup of persons with knee osteoarthritis. Finally, sex female, high educational level, high number of comorbidities and a worsening of the WOMAC factor ascending / descending at the last follow up were identified as significant risk factors for being referred for knee arthroplasty.
Implications: The results of this study witness the positive effects of mainly physiotherapy in the long-term conservative management of knee osteoarthritis. Moreover, physiotherapists have access to pragmatic and validated tools to participate in the shared decision process concerning time point of knee arthroplasty.
Funding acknowledgements: This study was supported by the Zurzach Rehabilitation Foundation SPA, Bad Zurzach, Switzerland.
Topic: Musculoskeletal: peripheral
Ethics approval: This study was approved by the ethics committee of Aarau, canton Aargau, Switzerland (EK AG 2008/026).
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