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Inflammatory changes in osteoarthritis knees undergoing total knee arthroplasty: a prospective clinical and
Bushu Harna1, Shivali Arya2, Ankush Nayyar3
1Indus International Hospital, Mohali, India. bushu.edu@gmail.com.
Introduction:
Osteoarthritis (OA) is classically a degenerative joint disease; however, subclinical inflammation may coexist in a subset of patients, contributing to pain and poor outcomes following total knee arthroplasty (TKA). Identifying occult inflammatory changes in radiologically degenerative knees can refine postoperative management. The objectives of this study were to determine the prevalence of inflammatory changes in OA knees undergoing TKA and to correlate histopathological findings with inflammatory markers and postoperative outcomes.
Methods:
A prospective observational study was conducted on 168 knees with varus deformity and tricompartmental OA undergoing TKA. Patients with known inflammatory arthritis, prior intra-articular injection, or post-traumatic arthritis were excluded. ESR, CRP, and radiographic evaluation were performed preoperatively. Intraoperative suprapatellar synovial biopsy was analysed histologically using the Krenn synovitis score (0-9). Patients were categorised as inflammatory (score ≥ 5) and non-inflammatory (score < 5). Postoperative pain (VAS), swelling, and functional recovery were assessed at six months.
Results:
Of 168 knees, 35 (20.8%) demonstrated histopathological features of chronic synovitis (mean synovitis score: 6.2 ± 1.1), while 133 (79.2%) showed purely degenerative changes (mean score: 3.4 ± 1.0). The inflammatory group had significantly higher mean ESR (25.8 ± 6.4 mm/hr) and CRP (7.1 ± 2.4 mg/L) than the degenerative group (ESR 17.6 ± 5.8 mm/hr, CRP 4.8 ± 1.9 mg/L; p < 0.001). Postoperative VAS pain scores at six months were higher in the inflammatory group (3.8 ± 1.1 vs. 2.1 ± 0.9; p < 0.01). Mild-to-moderate swelling persisted in 28.5% of the inflammatory subset compared to 6.8% of the degenerative group (p = 0.02).
Conclusion:
Approximately one-fifth of radiologically degenerative OA knees harbour occult inflammatory changes. Borderline ESR/CRP values and persistent pain after TKA may indicate hidden inflammation. Selective synovial biopsy in patients with suspected inflammatory OA may improve identification of inflammatory phenotypes and assist in postoperative evaluation.
