SLR - May 2014 - Robert J. Toomey
Reference: Matsumoto T, Nakamura I, Miura A, Momoyama G, Ito K. Radiologic Patterning of Joint Damage to the Foot in Rheumatoid Arthritis. Arthritis Care Res (Hoboken). 2014 Apr; 66(4): 499-507.
Scientific Literature Review
Reviewed By: Robert J. Toomey, III, DPM
Residency Program: Medstar Washington Hospital Center
Podiatric Relevance: Identifying plain film radiographic manifestations of rheumatoid arthritis (RA) in the foot has often been a source of academic query and examination to the podiatric physician. This knowledge becomes necessary once the clinician in practice must be able to identify RA from various types of arthritides as well as RA disease progression. Interestingly, despite being able to identify manifestations radiographically, no correlation between RA foot deformities and their functional impact on the patients have been identified. This article addresses both radiologic patterns of joint damage in the RA foot as well as the impact of each identified pattern.
Methods: A total of 274 RA patients were included in the study after exclusion of previous foot surgery. Of these patients, 212 were assessed for functional disability using questionnaires. Grades were evaluated and given using Larsen’s standard film system for joints including ankle, subtalar, interphalangeal and MTPJ of great toe and MTPJ of lesser toes. Grades of the remaining joints of the foot were evaluated using original standard films created by the authors using Larsen’s scoring system. Clinical status for pain, walking ability, and ADL were evaluated using scoring system of the Japanese Society for Surgery of the Foot - RA foot and ankle scale. Functional capacity in patients was assessed according to the Modified Health Assessment Questionnaire.
Results: Five hundred forty-two sets of radiographs were analyzed grading all of the joints of the foot. The greatest effected joints of the foot in order were the 1st MTPJ, 5th MTPJ, and talo-navicular joint. Results also suggested that sites of joint involvement in the RA foot were concentrated to specific lesion sites: the forefoot, the midfoot, and the hindfoot. The characteristic distribution of joint destruction was named and divided into five ‘clusters.’ Cluster I (normal), Cluster II (forefoot), Cluster III (midfoot), Cluster IV (mid-hindfoot), Cluster V (combined type). Radiographic measurements revealed a characteristic deformity for each cluster. Cluster II-Splay foot, Cluster III- Flatfoot, Cluster IV- hindfoot malalignment, Cluster V- Mixture. Cluster I involvement peaked within the first five years then decreased in incidence. Cluster II deformity gradually increased with disease progression after the first five years. Clusters IV & V showed significant changes in functional disability when compared to Cluster III. Cluster III cases peaked in the 5-10 year disease duration and decreased with time followed by increases of incidence within Clusters IV & V with time.
Conclusions: This report is the first to reveal the pattern of RA foot deformities using statistical measures in a large series. The associated between pattern of foot deformity and disabilities in patients with RA was also identified. Interestingly, changes in degree of joint involvement and foot deformity were observed with differences in the duration of the disease process. Ideally this report may serve as a guide for identifying and correlating the degree of joint destruction with treatment or for future additional creation of treatment strategies in the RA foot.