Preoperative Pain Sensitivity Has a Greater Impact on Clinical Outcomes Than Coronal Alignment Strategy in Robotic-Assisted Total Knee Arthroplasty
In brief
High pre-op pain sensitivity predicts poorer knee scores, outweighing alignment choice
In 244 robotic-assisted total knee arthroplasty patients, a higher Pain Sensitivity Questionnaire score was linked to lower Forgotten Joint and Oxford Knee scores at two years, while functional versus mechanical alignment made no difference overall. Only patients with low pain sensitivity fared better with functional alignment, gaining roughly 13 points on the Forgotten Joint Score. The finding is exploratory and needs confirmation.
- Journal
- The Journal of arthroplasty (Q1)
- Published
- 22 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Kohei Kawaguchi, Mei Lin Tay, William J Farrington, Rupert van Rooyen, Ali Bayan, Simon W Young
- PMID
- 42772427
- DOI
- 10.1016/j.arth.2026.09.037
Why clinicians should know about it
- Picked for Orthopedics and Sports Medicine (paper of the day, 24 September 2026): Preoperative pain sensitivity predicts TKA outcomes more than alignment
Abstract
BACKGROUND: Both preoperative pain sensitivity and coronal alignment philosophy may influence patient-reported outcome measures (PROMs) after total knee arthroplasty (TKA). This study investigated whether pain sensitivity predicts PROMs in robotic-assisted TKAs randomized to functional alignment (FA) or mechanical alignment (MA) and whether high pain sensitivity obscures differences between strategies. METHODS: This was a substudy of a prospective, single-blinded randomized controlled trial. A total of 244 patients were allocated to FA (n = 123) or MA (n = 121). Pain sensitivity was assessed preoperatively using the Pain Sensitivity Questionnaire (PSQ). The Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) were collected two years postoperatively. Multivariable stepwise regressions evaluated the influence of PSQ on PROMs, with adjustment for demographic and radiographic factors. Patients were stratified into high (PSQ ≥ 5.2) and low (PSQ less than 5.2) pain sensitivity groups, and FA and MA outcomes were compared. Baseline PSQ did not differ between FA and MA groups (5.7 ± 1.9 versus 5.6 ± 1.8; P = 0.58). RESULTS: The PSQ was a negative predictor of both FJS (P = 0.02) and OKS (P < 0.01), whereas alignment strategy was not. Among low pain sensitivity patients, FA yielded a higher FJS than MA (74.9 ± 25.8 versus 61.9 ± 31.4; P = 0.03). In high pain sensitivity patients, FJS did not differ (FA 66.8 ± 25.0 versus MA 65.8 ± 29.5; P = 0.80). CONCLUSIONS: Preoperative pain sensitivity exerted a stronger influence on PROMs than coronal alignment strategy in TKA. Alignment philosophy had no discernible effect on outcomes in patients who have high pain sensitivity, whereas patients who have low pain sensitivity showed higher FJS with FA than with MA. As these findings were derived from exploratory subgroup analyses, they should be interpreted cautiously and require confirmation in future prospective studies. Level of evidence Level I (Prospective randomized study).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.