THE IMPACT OF NEUROPATHIC PAIN ON OUTCOMES FOLLOWING TOTAL KNEE ARTHROPLASTY

One in 5 patients continue to experience pain following total knee arthroplasty (TKA)1. It has been suggested that presence of preoperative neuropathic pain (NP) may negatively impact patient reported outcome measures (PROMs), however there are sex differences2,3. Therefore, this study aims to assess whether the presence of preoperative NP is associated with differences in the Knee Injury and Osteoarthritis Outcome Score (KOOS) and its five specific domains or Timed Up and Go (TUG) test at 12 months following TKA. This study will also examine whether there are sex differences in the associations between preoperative NP and KOOS or TUG test at 12 months following TKA. This is a cohort study retrospectively analysing prospectively collected data of all patients who consecutively underwent primary unilateral TKA at a single academic institution from November 2013 to April 2019. All patients who were screened preoperatively for NP using the PainDETECT questionnaire (PDQ) were included and patients with possible or probable NP were compared to those unlikely to have NP. Patients with inflammatory arthritis or undergoing revision TKA were excluded. Multivariable linear regression modelling was utilized for KOOS and TUG test and subsequently stratified by sex. A total of 785 patients were included with 444 (56.5%) females and a mean age of 66.2±9.1 years. One-hundred and eight (13.8%) patients with 74 (68.5%) female, screened positive for ‘probable’ NP. Those with ‘probable’ NP were more likely to be female, have less than high-school education, be temporarily or permanently unemployed, have higher Hospital Anxiety and Depression Scale (HADS) scores (p 0.05). Eoperative PDQ score can be important factor in predicting patient reported outcome measures in multiple domains at 12 months in patients who have undergone TKA. However, preoperative PDQ scores may not correlate with objective function following TKA. Preoperative NP screening with PDQ could support clinicians in predicting patient outcomes with TKA and assist in setting patient expectations prior to surgery.