Impact of Central Sensitization and Pain Catastrophizing on Patient-Reported Outcomes Differs Between Unicompartmental and Total Knee Arthroplasties.

BACKGROUND

Psychological factors have been reported to influence postoperative clinical outcomes following knee arthroplasties. The present study aimed to examine the association between preoperative central sensitization and pain catastrophizing and postoperative outcomes in patients undergoing unicompartmental knee arthroplasty (UKA) vs total knee arthroplasty (TKA).

METHODS

This prospective cohort study included 353 patients divided into 2 groups according to the surgical procedure: UKA (n = 72) and TKA (n = 281). The Central Sensitization Inventory (CSI) and Pain Catastrophizing Scale (PCS) questionnaires were administered preoperatively, and patient-reported outcome measures (PROMs) were evaluated according to the subscales of the Knee Injury and Osteoarthritis Outcome Score 1 year postoperatively. Preoperative CSI and PCS scores were compared between patients undergoing UKA vs TKA, and the correlations with PROMs were analyzed.

RESULTS

The mean (± standard deviation) preoperative CSI and PCS scores were 21.4 ± 10.5 and 27.3 ± 10.8 for the UKA group, and 22.6 ± 14.1 and 26.2 ± 12.9 for the TKA group; however, the differences in these scores between the groups were not statistically significant (P = .51 and P = .53, respectively). CSI and PCS scores exhibited no correlation with any postoperative subscale in PROMs (all subscales in Knee Injury and Osteoarthritis Outcome Score) in UKA. However, CSI and PCS scores exhibited negative correlations with all subscales in PROMs in TKA.

CONCLUSIONS

There were no statistical differences in preoperative central sensitization and pain catastrophizing between patients who underwent UKA vs TKA. However, these psychological factors negatively affected postoperative PROMs in patients who underwent TKA, whereas, they were not found to significantly affect postoperative PROMs in the UKA group; however, this finding may reflect limited sample size rather than a true absence of effect.