Radiologic Patterning of Joint Damage to the Foot in Rheumatoid Arthritis

SLR - June 2014 - Nilesh Patel

 Reference: Matsumoto T, Nakamura I, Miura A, Momoyama G, and Ito K. American College of Rheumatology 2014 66: 499-507.
 
Scientific Literature Review
 
Reviewed By: Nilesh Patel, DPM
Residency Program: St. Vincent Hospital WMC, MA
 
Podiatric Relevance: The aim of the study was to reveal the pattern of destruction of the rheumatoid arthritis (RA) foot with duration of disease and its impact on patients.
 
Methods: The study was a cross sectional analysis of RA patients (274 patients and 542 feet) using radiographs. Larsen’s grading system for 12 joints of the foot and ankle were used to assess and grade joint destruction. Cluster analysis was performed using the K-means method to classify the pattern of joint destruction. 212 out of 274 patients were assessed for functional disability using questionnaires.
 
Results: Cluster analysis divided 542 feet into five cluster, named according to the characteristics distribution of joint destruction: cluster I (normal type), cluster II (forefoot type), cluster III (midfoot type), cluster IV (mid-hindfoot type), and cluster V (combined type). Radiographic measurements revealed the characteristic deformities of each cluster: splay foot for cluster II, flat foot for cluster III, hindfoot malalignment for cluster IV, and mixtures of these characteristics for cluster V. Each cluster based on disease duration was mapped revealing that cluster III peaked in cases of 5-10 years disease duration and subsequently decreased, followed by a gradual increase of cluster IV and cluster V as the duration of disease increased.
 
Conclusions: This report is the first large series to relate the pattern of RA foot deformities to duration of disease and its impact on patients with statistical measures.