{
  "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.\n\nMethods: 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.\n\nResults: 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).\n\nConclusion: 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.",
  "abstract_shown": true,
  "affiliations": [
    "Department Joint Surgery, Zhumadian Central Hospital, Zhumadian, China"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Jun Liu"
    },
    {
      "affs": [
        0
      ],
      "name": "Wenheng Chen"
    },
    {
      "affs": [
        0
      ],
      "name": "Shan Gao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/b6mtwaqksv1ss.bib",
  "cited_by": 0,
  "doi": "10.3389/fpain.2026.1948322",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13696397/",
  "id": "b6mtwaqksv1ss",
  "issns": [
    "2673-561X"
  ],
  "landing_url": "https://doi.org/10.3389/fpain.2026.1948322",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Original Research"
    ],
    [
      "openalex",
      "2746|Total Knee Arthroplasty Outcomes"
    ]
  ],
  "openalex": "W7221503118",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13696397/pdf/?tool=EBI",
  "pmcid": "PMC13696397",
  "pmid": "42935588",
  "published": "2026-10-12",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/b6mtwaqksv1ss.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:45Z",
      "native_id": "PMC13696397",
      "source": "pmc",
      "url": "https://doi.org/10.3389/fpain.2026.1948322"
    },
    {
      "first_seen": "2026-10-30T12:21:25Z",
      "native_id": "PMC:PMC13696397",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13696397"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2746|Total Knee Arthroplasty Outcomes",
      "subfield": "surgery"
    }
  ],
  "title": "Early spatial pain contraction and moderate-to-severe knee pain 12 months after total knee arthroplasty: a retrospective cohort study",
  "title_text": "Early spatial pain contraction and moderate-to-severe knee pain 12 months after total knee arthroplasty: a retrospective cohort study",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:33:44Z",
  "url": "https://research.draconitic.com/paper/b6mtwaqksv1ss",
  "venue": "Frontiers in Pain Research",
  "versions": []
}