Importance of forefoot involvement in RA | Arthritis Information

 Researchers from The Netherlands report a high prevalence of metatarsophalangeal (MTP) joint damage and walking disability in patients with recent onset rheumatoid arthritis (RA).

“Synovitis of the MTP joints is believed to be the main cause of foot pain in early RA and is usually accompanied by joint swelling,” note Marike Van Der Leeden (Jan van Breeman Institute, Amsterdam) and associates.

“Knowledge of the prevalence of forefoot involvement during the disease process is important for further research and early diagnosis and treatment.”

Van der Leeden and team assessed the prevalence of forefoot damage at initial presentation and for a maximum of 8 years of follow-up in 848 patients with recent onset RA. Pain and swelling, erosion, and joint space narrowing of the MTP joints, as well as walking disability, were all measured.

At initial presentation, 67.6% of patients reported pain and 69.9% reported swelling in at least one MTP joint. This percentage decreased to between 40% and 50% in the first 2 years and then remained constant.

The prevalence of forefoot erosion and joint space narrowing were 19.1% and 18.7%, respectively, at baseline. Approximately 9% of patients were suffering from both impairments.

In the first 2 years after initial presentation, the percentage of new patients with erosions in the forefoot increased markedly to 39.3%. By year 8, the prevalence had risen to 55.7%.

Meanwhile the mean foot erosion score increased from 1.3 to 7.9 over the 8-year period.

Walking disability was present in 57% of patients at baseline, with 4% reporting a severe walking disability. The prevalence stabilized at 40% after an initial decrease in the first year.

“The results of the present study quantitatively emphasize the importance of forefoot involvement in patients with RA,” conclude van der Leeden et al in the journal Arthritis Care and Research.

“The prevalence rates for pain and swelling of the MTP joints and walking disability are initially high and then stabilize, while the prevalence and severity of forefoot joint damage increase during an 8-year course of RA.”

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