Early spatial pain contraction and moderate-to-severe knee pain 12 months after total knee arthroplasty: a retrospective cohort study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background While total knee arthroplasty (TKA) generally provides excellent pain relief, a substantial minority of patients develop persistent postsurgical pain. This study investigated whether the early postoperative contraction rate of whole-body spatial pain extent was associated with moderate-to-severe knee pain 12 months after TKA. Methods In this retrospective cohort study of patients undergoing primary unilateral TKA, participants completed whole-body pain drawings at 2 weeks, 6 weeks, and 3 months postoperatively. The Pain Extent Index (PEI) was calculated using a semiautomated image-processing workflow. The primary exposure was the patient-specific rate of PEI change between week 2 and month 3, determined via linear mixed-effects modeling. The primary outcome was moderate-to-severe operated-knee pain at 12 months. Logistic regression evaluated this association, adjusting for baseline covariates and static pain measures. Results At 12 months, 92 patients (14.7%) reported moderate-to-severe knee pain. Slower spatial pain contraction was significantly associated with higher odds of 12-month pain (adjusted odds ratio per 1-SD slower contraction, 1.42; 95% CI, 1.03–1.95). This association remained significant even after adjusting for baseline risk factors and static pain intensity and extent at both week 2 and month 3. Slower contraction was also correlated with poorer 12-month joint-related functional outcomes, including lower KOOS-JR scores ( P < 0.001). Conclusion Slower contraction of spatial pain extent during the subacute recovery phase was associated with moderate-to-severe knee pain and inferior functional outcomes 1 year after TKA.
Source: Frontiers in Pain Research
Authors: Jun Liu, Wenheng Chen, Shan Gao
Institution: Zhumadian Central Hospital
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,077
OpenAlex ID: W7221503118