Article Text

other Versions

Long-term outcome following total knee arthroplasty: a controlled longitudinal study
  1. Janet Cushnaghan (jc{at}
  1. University of Southampton, United Kingdom
    1. James Bennett (jcb{at}
    1. University of Southampton, United Kingdom
      1. Isabel Reading (icr{at}
      1. University of Southampton, United Kingdom
        1. Peter Croft (p.r.croft{at}
        1. School of Postgraduate Medicine, United Kingdom
          1. Patricia Byng (trishbyng{at}
          1. University of Southampton, United Kingdom
            1. Ken Cox (kcc{at}
            1. University of Southampton, United Kingdom
              1. Paul Dieppe (paul.dieppe{at}
              1. University of Bristol, United Kingdom
                1. David Coggon (dnmc{at}
                1. University of Southampton, United Kingdom
                  1. Cyrus Cooper (cc{at}
                  1. University of Southampton, United Kingdom


                    Objectives: To assess long-term outcome and predictors of prognosis following total knee arthroplasty (TKA) for osteoarthritis.

                    Methods: We followed-up 325 patients from three English health districts approximately six years after TKA, along with 363 controls selected from the general population. Baseline data, collected by interview and examination, included age, sex, comorbidity, body mass index (BMI), functional status, and pre-operative radiographic severity of osteoarthritis. Functional status at follow-up was assessed by postal questionnaire. Predictors of change in physical function were analysed by linear regression.

                    Results: Between baseline and follow-up, patients reported an improvement of 6 points in median SF-36 physical function score whereas in controls there was a deterioration of 14 points (p<0.0001). Median SF-36 vitality score declined by 10 points in patients and 5 points in controls (p=0.005), while their median SF-36 mental health scores improved by 12 and 13 points respectively (p=0.2). The improvement in physical function was smaller in obese than in non-obese patients, but compared favourably with a substantial decline in the physical function of obese controls. Better baseline physical function and older age predicted worse changes in physical function in both patients and controls. Improvement in physical function tended to be greater in patients with more severe radiological disease of the knee, and was less in those who reported pain at other joint sites at baseline.

                    Conclusions: Improvements in physical function following TKA for osteoarthritis are sustained beyond five years. The benefits are apparent in obese as well as non-obese patients, and there seems no justification for withholding TKA from obese patients solely on the grounds of their body mass index.

                    Statistics from

                    Request permissions

                    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.