POS0379 THE EFFECT OF METHOTREXATE IN PATIENTS WITH KNEE OSTEOARTHRITIS, COMPLICATED WITH RECURRENT KNEE SYNOVITIS

Background:

Knee Osteoarthritis is an important cause of discomfort and invalidity among patients. It is usually treated with NSAIDs (non-steroid anti-inflammatory drugs) and analgesics, but in some cases, it is difficult to treat patients who develop recurrent synovitis. Methotrexate is the most common DMARD (disease modifying anti-rheumatism drugs) used in rheumatic inflammatory diseases, and may be used in cases with knee osteoarthritis, resistant to NSAIDs treatment[1].

Objectives:

The aim of this case-control study was to evaluate the effectiveness of Methotrexate in recurrent knee synovitis in patients with knee osteoarthritis, in terms of pain reduction and ultrasound-proven synovitis remission.

Methods:

This study was conducted over a period of 4 years. It consists of 145 patients with knee osteoarthritis complicated with knee synovitis. The population was divided into 2 groups: the control group consisted of 45 patients with recurrent knee synovitis secondary to osteoarthritis, treated with naproxen (2x 250 mg/daily) and acetaminophen (2x 500mg/daily) daily for 6 months. The case group included 100 patients treated with naproxen, acetaminophen, and Methotrexate 10mg per week plus Folic acid 10 mg per week, for 6 months. Hepatitis B, C and HIV were excluded in every patient in which Methotrexate was started. Patients with high transaminases and chronic kidney disease were excluded. None of the patients had concomitant Rheumatoid Arthritis. Each patient was evaluated with knee ultrasound and was followed up for 6 months and asked about their pain. It was considered in remission for every patient, whose US exam revealed none/minimal Doppler signal, and no excessive fluid was detected. Pain score and synovitis presence in every patient at the end of 6 months therapy and was compared to the time of the beginning of therapy.

Results:

After gathering and evaluating our data, it was seen that, in the control group, 17 out of 45 patients achieved US-proven synovitis remission (37.8%), while in the case group, 71 out of 100 patients achieved remission (71%). The Chi square test was applied in this study. Statistical analysis shows that there exists a significant statistical difference between two groups regarding synovitis remission (p < 0.05). Regarding pain score, after 6 months of therapy, in the control group, 26 out of 45 (57.8%) patients achieved a pain score < 5/10, meanwhile in the case group, 83 out of 100 patients (83%) achieved a pain score < 5/10. Statistical analysis shows that there exists a significant difference between two groups regarding pain scale (p < 0.05).

Conclusion:

Based on the results of our study, it appears that the addition of Methotrexate to the treatment regimen of patients with knee osteoarthritis complicated by recurrent synovitis is associated with a higher likelihood of achieving synovitis remission and a pain score < 5/10 compared to treatment with naproxen and acetaminophen alone. This effect was evident in terms of ultrasound exams and in clinical outcomes.

REFERENCES:

[1] Zhu, Z., Yu, Q., Leng, X. et al. Can low-dose methotrexate reduce effusion-synovitis and symptoms in patients with mid- to late-stage knee osteoarthritis? Study protocol for a randomised, double-blind, and placebo-controlled trial. Trials21, 795 (2020). https://doi.org/10.1186/s13063-020-04687-3.

Acknowledgements:

NIL.

Disclosure of Interests:

None declared.