Early Radiographic Knee OA to Joint Arthroplasty: Factors of Structural Progression

More than half of patients with either no or mild radiographic knee osteoarthritis (OA) prior to knee replacement surgery progressed to severe radiographic OA over 4 years of follow-up, according to the results of a secondary analysis in the Osteoarthritis Initiative cohort published in Arthritis Care & Research.

The objectives of the study were to assess: structural progression in patients with no or mild radiographic OA who will undergo knee replacement surgery during a 5-year period; differences in structural damage on magnetic resonance imaging (MRI) between patients with no or mild radiographic OA and patients with severe radiographic OA at baseline; and differences in pain levels between these patient groups.

Participants who underwent knee replacement surgery from baseline to 60 months were assessed from the Osteoarthritis Initiative. MRIs were evaluated for bone marrow lesions and synovitis at baseline and at the time point prior to knee replacement. Researchers used the Western Ontario and McMaster Universities Arthritis (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain characterization. WOMAC Activity of Daily Living and KOOS Quality of Life scores were used to characterize functional status.

A total of 181 knees were included in the analysis. The majority of the participants (57.8%) were women; mean age was 64.4 years. Overall, 28.2% of the patients had no or mild radiographic OA at baseline; of these, 51.0% progressed to severe radiographic OA.

Patients with no or mild radiographic knee OA demonstrated a higher likelihood of bone marrow lesions in the patellofemoral joint at baseline (odds ratio [OR], 7.92; 95% CI, 3.45-18.16) and at the time point before knee replacement surgery (OR, 9.44; 95% CI, 4.00-22.28) compared with patients with severe radiographic OA. Moreover, patients with no or mild radiographic OA were associated with change from “no pain” to “pain” from baseline to the time point before knee replacement surgery (adjusted OR, 5.48; 95% CI, 1.25-24.00).

The investigators concluded that more than half of all patients with no or mild radiographic OA prior to knee replacement surgery progressed to severe radiographic OA knees over 4 years of follow-up. Bone marrow lesions in the patellofemoral joint were more often observed in patients who had either no or mild radiographic OA. Worsening pain levels and progression of symptoms over time may contribute to knee replacement surgery in patients with no or mild radiographic OA.

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Reference

Roemer FW, Kwoh CK, Fujii T, et al. From early radiographic knee osteoarthritis to joint arthroplasty: determinants of structural progression and symptoms [published February 13, 2018]. Arthritis Care Res (Hoboken). doi:10.1002/acr.23545