Comparison of Synovial Fluid Cytokine Levels between Traumatic Knee Injury and End-Stage Osteoarthritis.
Degenerative osteoarthritis (OA) has been associated with elevated synovial fluid cytokines. It is unclear whether traumatic knee injuries are a trigger to the chemical process that leads to OA. The purpose of this study was to compare the synovial fluid cytokine levels between knees undergoing arthroscopy due to a documented inciting injury and knees undergoing primary arthroplasty due to end-stage OA without a previous inciting injury. Synovial fluid samples were prospectively collected from knees undergoing arthroscopic surgeries due to ligamentous or meniscal knee injuries (knee injury group,n= 16) and primary arthroplasty due to OA (end-stage OA group,n= 14). In the knee injury group, patients had none or minimal OA and at least 30 days from the inciting injury. Exclusion criteria for both groups included inflammatory arthropathy (n= 1) and insufficient fluid for analysis (n= 1). In addition to synovial fluid cytokines, preoperative demographic, clinical, and functional data (Knee Injury and Osteoarthritis Outcome Score [KOOS]) were collected and compared between the groups. The end-stage OA group had higher age (p< 0.0001), body mass index (p= 0.0061), Charlson comorbidity index (<0.0001), and OA classification (p< 0.0001). Preoperative KOOS were similar between the groups. Interleukin-6 (IL-6) and IL-8 were elevated in the end-stage OA group compared with the knee injury group (p= 0.04 and 0.006, respectively). Granulocyte-macrophage colony-stimulating factor, interferon gamma, IL-1β, IL-12p70, IL-2, IL-10, and tumor necrosis factor alpha were not statistically different between the groups. A similar synovial fluid cytokine profile was found between the two groups. The elevation of IL-6 and IL-8 in the end-stage OA group indicates the potential role that these proinflammatory cytokines may have in long-term cartilage damage.
Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio.
Marcelo B P
MB
Siqueira
Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio.
Salvatore
S
Frangiamore
Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio.
Alison K
AK
Klika
Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio.
Nicholas
N
Gajewski
Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio.
Wael K
WK
Barsoum
Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio.
Carlos A
CA
Higuera
D000293:Adolescent; D000328:Adult; D000368:Aged; D001182:Arthroscopy; D016207:Cytokines / Q000032:analysis* / Q000276:immunology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis / Q000276:immunology; D016209:Interleukin-8 / Q000032:analysis / Q000276:immunology; D007718:Knee Injuries / Q000276:immunology* / Q000601:surgery; D007719:Knee Joint / Q000276:immunology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000276:immunology* / Q000601:surgery; D013582:Synovial Fluid / Q000737:chemistry* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000276:immunology; D055815:Young Adult
D016207:Cytokines; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha