The geometric architecture of the subtalar and midtarsal joints in rheumatoid arthritis based on magnetic resonance imaging

Abstract

Objective. To compare in vivo the 3-dimensional (3-D) geometric architecture of the subtalar and midtarsal joints in normal and rheumatoid arthritic (RA) feet, using magnetic resonance imaging (MRI) analysis.Methods. MRI was performed on 23 patients with RA, all of whom had disease activity in the subtalar and/or midtarsal joints. Image processing techniques were used to create 3-D reconstructions of the calcaneus (C), cuboid (c), navicular (N), and talus (T) bones. Twenty-four standard architectural parameters were measured from the reconstructions and were compared with data from 10 normal subjects. These parameters defined both 3-D distance and angular relationships among the 4 bones studied. Pattern classification techniques were used to establish a geometric architecture foot profile for the RA patients. The degree of individual patient fit to the new RA foot profile and to profiles for normal, pes planus, and pes cavus foot types was derived. Logistic regression was used to examine the relationship of foot architecture to inflammatory disease characteristics and physical examination variables.Results. Subtalar or midtarsal pain was reported by all 23 patients, and 22 of the 23 patients presented with >1 clinical feature of pes planovalgus deformity. In 21 patients, ultrasonography revealed synovitis at >1 tarsal joint or surrounding tendon. In the RA group, the normalized distances between the geometric centroids were significantly closer for bone pairs Cc and cT and significantly distracted for bone pair CN compared with the distances in normal subjects. In RA patients (versus normal subjects), the angles subtended at the bone centroids were significantly decreased in 3 bone groups (CNc, TCN, and TNc) and significantly increased in 3 bone groups (CcN, CcT, NTc). The angles formed between the major principal axes of bone pairs CT and cT were significantly increased in RA patients compared with those in normal subjects. Pattern classification defined 11 RA feet as having normal structure and 12 as having abnormal structure. However, the abnormal feet did not fit consistently with structures defined for RA, pes planus, or pes cavus foot types. Logistic regression demonstrated that subtalar joint synovitis was the only predictive factor for abnormal subtalar and midtarsal architecture (odds ratio 19.2, 95% confidence interval 1.77-200.0).Conclusion. This unique 3-D MRI-based technique successfully quantified the effects of RA on the geometric architecture of the foot and the patientspecific nature of these changes. This technique can be used to provide logical therapy for correction.

Pes planovalgus in RA: a descriptive and analytical study of foot function determined by gait analysis

“…The architecture of the foot can be disrupted by repeated inflammation of synovial joints and surrounding soft tissues in rheumatoid arthritis (RA) (Bouysset et al, 1987;Jernberg et al, 1999;Woodburn et al, 2002a). In the ankle/rearfoot region this frequently leads to acquired pes planovalgus (flat foot deformity), which is associated with localized pain and stiffness and impaired ambulation (Keenan et al, 1991;Platto et al, 1991).…”

“…In the ankle/rearfoot region this frequently leads to acquired pes planovalgus (flat foot deformity), which is associated with localized pain and stiffness and impaired ambulation (Keenan et al, 1991;Platto et al, 1991). Various 2D radiographic and 3D magnetic resonance imaging (MRI) techniques have been used to quantify bony deformity while MRI and ultrasonography have usefully mapped synovial inflammation in the tarsal joints and tendons (Bouysset et al, 1987;Koski, 1993;Lehtinen et al, 1996;Jernberg et al, 1999;Woodburn et al, 2002a). Questionnaire-based tools have determined impaired foot function using metrics for localized pain, ambulation and disability (Platto et al, 1991;Garrow et al, 2000).…”

Is cavus foot affected by midfoot flattening in rheumatoid arthritis?

“…Slight hindfoot pronation is common in the general population in weightbearing, and in RA, as a consequence of inflammatory lesions, the soft supporting structures become stretched, leading to midfoot flattening and hindfoot hyperpronation [12]. Subtalar joint synovitis and talonavicular joint synovitis [13], inflammatory posterior tibial tendon dysfunction [14][15][16], and ligament lesions also play a role (talocalcaneal interosseous ligament, spring and long plantar ligament, and joint capsules) [17][18][19][20]. There was no difference in the proportion of cavus feet in the RF and CF groups, while normal feet were significantly less frequent in the RF group, and flat feet were much more frequent.…”

Natural history and imaging of subtalar and midfoot joint disease in rheumatoid arthritis

“…25 Further, low-field MRI and US were superior to clinical examination for detection of joint inflammation in RA feet. 13,37 Using MRI as the gold standard, Wakefield et al 38 reported that US was more specific in identifying hindfoot and midtarsal joint synovitis and tenosynovitis compared with clinical examination in patients with established RA. Woodburn et al 39 who utilized MRI techniques to compare geometric architecture of subtalar and midtarsal joints in normal and symptomatic feet of 23 RA patients, concluded that only subtalar joint synovitis was predictive of abnormal subtalar and midtarsal architecture.…”