As the North American population ages, the prevalence of knee osteoarthritis and the surgical interventions (ie, total knee arthroplasty [TKA]) aimed at correcting pain and disability will also rise proportionally. Therefore, efforts to better understand the factors associated with surgical outcomes are warranted. To date, no studies have examined the impact of psychosocial factors on acute postoperative TKA pain.
The primary objective was to examine the associations among catastrophizing, negative mood, demographics and acute postoperative pain following TKA. Ancillary analyses examined the association of preoperative psychological variables with postoperative pain.
Patients completed questionnaire packages 2 h before their surgery and on three consecutive postoperative days while in the hospital. The questionnaire packages included the Short Form - McGill Pain Questionnaire, the Pain Catastrophizing Scale and the Shortened Version of Profile of Mood States. The Mini-Mental State Examination was also administered. Demographic data were extracted from patients' medical charts.
Associations among catastrophizing, negative mood and pain were established. Regressions showed that younger age predicted greater preoperative and postoperative day 1 pain; catastrophizing predicted preoperative and postoperative day 2 pain; and negative mood predicted postoperative day 3 pain. Catastrophizing and negative mood were highly correlated at several assessment points. Preoperative variables did not predict postoperative pain.
These results have postoperative pain management implications. Heightened attention to psychosocial variables, such as postoperative catastrophizing and negative mood, may be useful in identifying patients at risk for greater postoperative pain.