Factors Affecting The Outcome Of Total Knee Arthroplasty

Abstract

Many factors may affect the outcome following total knee arthroplasty (TKA). Pre operative factors were most likely to consistently predict patient reported outcome measures (PROMs). Age seems to be associated with higher risk of complications, however the absolute risk remains low. Gender, independently, has minimal effect on outcome of TKA. Increased comorbidities are consistently associated with poorer outcome. Higher body weight patients suffer a higher incidence of complications (especially infection) and worse pain and function outcomes. Patients with more severe radiological arthritis do seem to achieve greater improvements in function and pain, as measured by PROMs, up to at least 12 months post op. A considerable body of evidence now suggests that psychological factors are a significant predictor of outcome, with likely the largest impact of the factors investigated in this thesis.

Intraoperative factors, which are largely reported in the literature as new innovations in prosthesis and surgical technique, demonstrated less association with outcome after TKA compared with pre operative factors. There is some evidence of small to moderate short-term effectiveness of rehabilitation, and the setting and level of supervision does not appear to modify this.

Two original articles were reported in this thesis. A systematic review of psychological interventions in orthopaedics was performed. It provided only very low levels of evidence, of a small beneficial effect of psychological interventions (in particular, relaxation techniques), on anxiety in patients undergoing elective orthopaedic surgery.

Due to an identified lack of evidence with regard to soft tissue balance and kinematics, a study investigating how coronal balancing of posterior-stabilized TKAs, within the functional range of motion was performed. Coronal balance and laxity throughout the functional range of motion did not significantly influence the change Oxford Knee Scores one year post operatively.