First ray resection arthroplasty versus arthrodesis in the treatment of the rheumatoid foot.

BACKGROUND: Different options exist for the operative treatment of forefoot problems and deformities in rheumatoid arthritis (RA). The current study compared first ray and resection arthroplasty with respect to patient satisfaction, clinical and functional outcome. MATERIALS AND METHODS: In a retrospective study 53 RA patients were investigated with a minimum followup of 2 years after corrective forefoot surgery. Two patient groups were distinguished: One group had been treated with arthrodesis of the first metatarsophalangeal (MTP) joint whereas the other group had been treated with a first ray resection arthroplasty. Both groups underwent resection arthroplasty at the lesser metatarsal heads. Our arthrodesis patients were significantly younger than patients with resection arthroplasty. Five patients had been treated bilaterally so that the results of 58 feet were analyzed. RESULTS: Patient satisfaction was lower in the arthrodesis group as compared to the resection arthroplasty patients. However, the arthrodesis patients revealed better functional results and showed a push-off from the hallux. No significant radiographic difference was seen in the mean hallux valgus angles. Younger patients revealed a higher disease activity and a worse general health status than older patients. Pedobarographic results demonstrated significant differences in selected foot regions, predominantly in the hallux. Peak pressures were significantly higher in the lateral midfoot and the hallux after arthrodesis as compared to the resection arthroplasty group. CONCLUSION: Patients with arthrodesis revealed better foot function during the dynamic roll-over process even though the resection arthroplasty patients were subjectively more satisfied.

Cluster analysis to classify gait alterations in rheumatoid arthritis using peak pressure curves.

OBJECTIVE: To detect gait alterations in rheumatoid arthritis (RA) patients using peak pressure curves (PPC) and normalized force curves (NFC) instead of clinical classification based on the health assessment questionnaire (HAQ). METHODS: Three RA groups--30 patients each--were classified according to their HAQ score. Cluster analysis based on a k-means algorithm was applied to PPCs and NFCs in order to classify RA patients with respect to amplitude and shapes of such gait parameters. RESULTS: The best gait pattern identification was obtained by clustering PPCs into three clusters. Peak pressures of the three identified patterns were 1169.5+/-99.4 kPa for cluster 1, 885.8+/-165.2 kPa for cluster 2 and 402.0+/-128.5 kPa for cluster 3 (statistically different, Student's t-test, p<0.001). 41 patients were included in cluster 3, 31 in cluster 2 and only 18 patients in cluster 1. Most RA3 patients--17 out of 30--showed low peak pressures and almost normal PPCs (cluster 3). Cluster 2, which incorporated altered PPCs, was mainly formed by RA1 and RA2 patients. CONCLUSIONS: PPC appears as a reliable gait parameter for a shape-based clustering algorithm. The proposed cluster analysis was proved to be reliable and the delivered classifications stable. The distribution of RA patients among the three identified PPC clusters showed only a partial agreement between clinical and functional classification, thus revealing the development of specific gait strategies related to the pathology more than to its clinical level of severity. This finding may be clinically relevant and support effective treatment of RA gait related pathologies.

Assessment of foot impairment in rheumatoid arthritis patients by dynamic pedobarography.

OBJECTIVES: Impaired foot function may jeopardize the mobility of patients with rheumatoid arthritis (RA). However, there are still no guidelines concerning the adequate early treatment of painful rheumatoid feet which do not yet require surgery. An assessment method for RA feet appears necessary in order to detect foot problems before functional limitations develop. Therefore, the aim of the present study was to evaluate the use of pedobarographic measurements for detecting changes in plantar loading characteristics and their relationship to foot pain in patients with RA. METHODS: One hundred and twelve patients with RA (55.0+/-11.0 years of age) were divided into three groups according to their Health Assessment Questionnaire (HAQ) Score and compared to a control group of 20 healthy adults (CG). Thirty-six patients with good physical capacity belonged to group 1 (RA1; HAQ-score: 0-1.0), 38 patients with moderate capacity to group 2 (RA2; score: 1.1-2.0) and 38 patients with low capacity to group 3 (RA3; score: 2.1-3.0). Each patient's foot pain was clinically assessed. Pedobarography was used to analyze foot loading parameters while walking barefoot. RESULTS: In the forefoot, average pressures under the lateral forefoot were higher in RA1 patients than in RA2 patients and controls (p<0.05) despite an inconspicuous clinical examination of the foot in RA1 patients. RA1 patients also demonstrated higher plantar pressures than RA2 under the second metatarsal head (p<0.05). In contrast, no significant differences in maximum force could be demonstrated between patient groups. Furthermore, in RA3 patients with lower physical capacity, foot pain was increased as compared to RA1 and RA2 patients. CONCLUSION: In RA patients, pedobarographic patterns show specific changes which characterize the level of functional capacity. In patients with foot involvement, pedobarographic measurements can be useful during the earlier stages of the disease, when clinical examination does not yet indicate the need for more aggressive treatment or orthopedic interventions.