Prospective clinical trial of patients who underwent ankle arthroscopy with articular diseases to match clinical and radiological scores with intra-articular cytokines.

Objective: There is still a lack of reliable data on cytokine concentrations in the ankle and their value for prognosis.

Methods: In a prospective clinical trial, lavage fluids were collected from 49 patients with an arthroscopy of the ankle. The fluids were investigated by ELISA for cytokine levels. Clinical scores (FFI, AOFAS) were evaluated both pre-operatively and then again 12 months after surgery (n = 43, 88%). Radiological changes were noted with the Kellgren-Lawrence-Score (KLS) and the Ankle Osteoarthritis Scoring System (AOSS). Based on the difference between the pre- and postoperative clinical scores, two groups were defined according to whether they had benefited from the surgical therapy (Δ score ≥ 10) or not (Δ score < 10).

Results: The average clinical scores had improved to a statistically significant extent in the one-year follow-up (p < 0.01). BMP-2 (p = 0.02), IGF-1 (p = 0.04), BMP-7 (p = 0.01) and aggrecan (p = 0.04) showed significant correlations with pre-operative clinical and radiological scores (p = 0.02, p = 0.01, p = 0.01, p = 0.01). Furthermore, BMP-2 (p = 0.01), IGF-1/TPC (p = 0.03) and aggrecan (p = 0.01) correlated with scores after one year (p = 0.02, p = 0.01). High aggrecan concentrations were associated with a low clinical and a high radiological score at both time points, both indicating progress of cartilage degeneration in contrast to BMP-2 or IGF-1. Furthermore, MMP-13 concentrations were significantly higher in the non-benefit group (p = 0.02).

Conclusion: BMP-2, IGF-1, aggrecan and MMP-13 seem to be involved in the degenerative process of cartilage in the ankle joint. Additionally, high synovial MMP-13 concentrations indicate a worse clinical outcome.