Magnetic resonance imaging as an additional tool for treatment tactics for osteoarthritis

I.Z. Gaidukova^1,2, V.I. Mazurov^1,2, O.V. Inamova^1,2

¹North-Western State Medical University named after I.I. Mechnikov, Saint-Petersburg

²Clinical Rheumatology Hospital No. 25, Saint-Petersburg

Aim: to establish the association between the intensity of pain in knee osteoarthritis (OA) and inflammatory changes in the knee detected by MRI with an assessment of changes in dynamics during treatment with NSAIDs.

Patients and Methods: in 46 patients with knee OA (n=46) and pain not less than 4.0 (according to NRS), pain intensity and WOMAC index were measured at baseline and 3 months after NSAIDs treatment (±10 days). MRI of the knee was performed in T1 STIR sequence. During MRI, the following patterns were assessed: the presence of subchondral bone marrow edema (SBME), the number and size of its foci, and the presence of synovitis / tenosynovitis. MRI was repeated after 3 months ± 10 days in patients with inflammatory changes.

Results: initially, signs of inflammatory changes in the knee joints were observed in the majority of patients (72%) with knee OA and joint pain not less than 4.0 poi nts. 39 patients completed the study. 3 months after treatment with NSAIDs, there was a positive trend in all parameters of the WOMAC index — the total index decreased from 64.4±15.4 to 24.12±11.1 points (n=39, p<0.05). According to the results of repeated MRI, the number of patients with SBME significantly reduced, while the number of patients with synovitis and tenosynovitis decreased slightly. The reduction degree in the total WOMAC index and joint pain was greater in patients who initially had signs of subchondral bone inflammation, compared with patients who did not have SBME before the treatment (p<0.05 for all comparisons).

Conclusions: patients with knee OA and severe pain had inflammatory changes in the subchondral bone in 72% of cases according to MRI; synovitis occurred in 91.3% of cases. The presence of inflammatory foci (but not synovitis) in the subchondral bone was associated with an increase in pain in the knee joint and a good response to NSAIDs, the  effect of which was manifested both clinically (pain reduction) and visually (disappearance or decrease of osteitis in the subchondral bone).

Keywords: osteoarthritis, low-grade inflammation, joint pain, MRI-detected inflammation, non-steroidal anti-inflammatory drugs, NSAIDs.

For citation: Gaidukova I.Z., Mazurov V.I., Inamova O.V. Magnetic resonance imaging as an additional tool for treatment tactics for osteoarthritis. RMJ. 2020;11:43–48.