Morton's metatarsalgia in rheumatoid arthritis.

Findings in a follow-up study of 66 operations Morton's metatarsalgia performed on 52 patients suffering from rheumatoid arthritis during the years 1954-1977 were in many respects different from those described as "classic" Morton's neuroma. The incidence was one to 520 in rheumatoid patients. The ratio of females to males was 9.4 to one. Histology revealed inflammatory or degenerative changes of the walls of synovial cavities often in connection with typical rheumatoid nudules. The changes of the nerves were non-specific alterations caused by chronic compression. Surgical removal of the tumor-like formations gave uniformly good results. Early metatarsophalangeal synovectomy for rheumatoid arthritis decreased in need of operations for Morton's metatarsalgia from 4.5 to 0.6 operations per year and can be recommended as a prophylactic procedure.