Less Severe Preoperative Synovitis is Associated With Higher Self-reported Pain Intensity 12 Months After Total Knee Arthroplasty—An Exploratory Prospective Observational Study
Synovitis is one of the possible pain generators in osteoarthritis (OA) and is associated with upregulation of proinflammatory cytokines, which can lead to worsening of the postoperative pain. This exploratory study aimed to investigate the association between perioperative synovitis and self-reported pain 12 months after total knee arthroplasty (TKA) in patients with OA.
Materials and Methods:
Twenty-six knee OA patients were included in this analysis. The perioperative volume of synovitis in predefined locations was assessed by contrast-enhanced magnetic resonance imaging (CE-MRI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Perioperative synovitis was assessed histologically from biopsies of the synovium. Highest pain intensity within the last 24 hours (Visual Analog Scale, VAS, 0 to 100) was assessed before and 12 months after TKA. Patients were divided into a low-pain intensity (VAS≤30) and a high-pain intensity (VAS>30) group on the basis of 12 months postoperative VAS.
The high-pain intensity group had significantly lower perioperative contrast-enhanced-synovitis (P=0.025), DCE-synovitis (P<0.04), and a trend toward lower histologically assessed synovitis (P=0.077) compared with the low-pain intensity group. Perioperative synovitis scores were inversely correlated with pain intensity 12 months after TKA (P<0.05), indicating that more severe perioperative synovitis is associated with less severe pain intensity at 12 months.
Higher degrees of perioperative synovitis scores are found to be associated with less postoperative pain 12 months after TKA. Further, correlation analysis revealed that less severe perioperative CE-MRI and DCE-MRI synovitis was associated with higher pain intensity 12 months after TKA, suggesting that CE-MRI and DCE-MRI synovitis grades could be used as imaging markers for prediction of chronic postoperative pain after TKA.
Document Type: Research Article
Affiliations: 1: Department of Health Science and Technology, Center for Sensory Motor Interaction (SMI), Department of Health Science and Technology, Center for Neuroplasticity and Pain, Faculty of Medicine 2: Department of Health Science and Technology, Center for Sensory Motor Interaction (SMI) 3: Department of Clinical Medicine, Aalborg University, Departments of Rheumatology 4: Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Department of Physiotherapy and Occupational Therapy, Næstved-Slagelse-Ringsted Hospitals, Region Zealand 5: Department of Clinical Medicine, Aalborg University, Pathology 6: Department of Radiology 7: Department of Radiology, The Parker Institute, Bispebjerg and Frederiksberg Hospital Copenhagen University, Copenhagen, Denmark 8: Department of Clinical Medicine, Aalborg University, Orthopedic Surgery, Aalborg University Hospital, Aalborg
Publication date: January 9, 2020