Incidence and risk factors for chronic pain following primary total knee arthroplasty in an irish surgical population.

OBJECTIVES

To identify the incidence and characteristics of chronic post-surgical pain (CPSP) following total knee arthroplasty and determine peri-operative influencing factors.

METHODS

A representative, retrospective random sample was taken of patients who underwent total knee arthroplasty in the South Infirmary University Hospital Cork for an 18-month period. Two hundred fourteen patient charts were reviewed out of a total of 507 charts for that period to provide a 90% confidence interval.

RESULTS

The incidence of CPSP in an Irish population 6 months after total knee arthroplasty was found to be 36.5%. The following factors were found to be statistically significant with respect to the incidence of CPSP: female sex, lack of multimodal analgesia (consisting of paracetamol, NSAID, and opioids), general anaesthesia, and lower Oxford Knee Scores at 6 months post-surgery. Age, the knee operated on, ASA grade, or greatest acuity pain, were not found to be statistically significant factors in the development of CPSP.

CONCLUSIONS

CPSP is common after total knee arthroplasty with an incidence of 36.5% at 6 months post procedure. Female sex, lack of multimodal analgesia, and lower Oxford Knee Scores were associated with increased CPSP.