THE SIGNIFICANCE OF INFLAMMATORY CHANGES IN THE TARSOMETATARSAL JOINTS LEADING TO DEVELOPMENT OF SPLAYFOOT IN RHEUMATOID-ARTHRITIS - A RADIOLOGICAL STUDY OF PROGRESSION

The involvement of foot joints is a common finding in more than 90% of the patients with rheumatoid arthritis. The typical deformity of the forefoot is the splayfoot with hallux valgus or hallux rigidus and def ormities of the lesser toes. 70 feet of 36 patients with rheumatoid ar thritis were observed radiologically over a period between 5 years/1 m onth and 6 years/1 month. The x-rays were analyzed for arthritic chang es of the various joints and changes of the foot statics. The question was whether the splay of the forefoot is caused by an arthritis of th e metatarsophalangeal or tarsometatarsal joints with a consequent weak ening of joint capsules and ligaments, or statistically by a flattenin g of the longitudinal arch owing to arthritic changes of the hindfoot. The statistic analysis showed that the splay of the forefoot appears between the first and second metatarsal bones. The arthritis of the ta rsometatarsal joints II-IV could be identified as a statistically sign ificant factor for the development of a splayfoot in rheumatoid arthri tis. The influence of arthritic changes of the tarsometatarsal joints I and V was striking, but not statistically significant. The arthritis of the tarsometatarsal joints caused a flattening of the transverse a rch already at an early stage. An arthritis of the metatarsophalangeal joints and the flattening of the longitudinal arch with arthritides o f the rear foot had no statistically significant influence on the fore foot. From the results, we must draw the conclusions that orthopedic a ids like shoe supports with retrocapital metatarsal bars should be rec ommended already at an early stage of the disease and that the support of the longitudinal arch is not sufficient to prevent a splayfoot.