To what extent is foot pain related to biomechanical changes and ultrasound-detected abnormalities in rheumatoid arthritis?

OBJECTIVES: To investigate the presence of biomechanical abnormalities and ultrasound (US)-detected inflammation and damage in low disease or remission status rheumatoid arthritis (RA) patients with foot complaints. METHODS: We recruited 136 subjects with foot complaints. Sixty-two were biologic disease-modifying antirheumatic drug-treated RA patients presenting Disease Activity Score-determined remission or low disease activity while the remaining 74 were gender matched controls without rheumatic or musculoskeletal disorders. Both groups underwent a comprehensive podiatric, biomechanical and B-mode and Doppler US assessment of the feet. RESULTS: Most RA patients and controls were female (77.4% and 83.8%, respectively). There was no statistical difference in the proportion of obese subjects in either group (p=0.792). Inappropriate shoes were used by 50.0% of RA patients and 33.8% of controls (p=0.080). Talalgia, particularly heel pain, was more frequent in the control group, with associated talalgia and metatarsalgia being more prevalent in the RA group (p<0.05). The RA patient group was also more likely to present greater foot deformity, more limited joint movement and biomechanical abnormalities than the controls (p<0.05). US inflammatory and structural changes were significantly more frequent in RA patients than in controls (p<0.05). US structural involvement was significantly associated with limited joint mobility and pathologic biomechanical tests only in RA patients (p<0.05). CONCLUSIONS: RA foot complaints seemed to be linked to US-detected RA involvement and biomechanical abnormalities. Podiatric and US assessments can be useful to help the clinician to optimise the management of RA patients in remission/low disease activity with foot complaints.

The feet in systemic lupus erythematosus; are we underestimating their involvement and functional impact?

OBJECTIVES: To evaluate biomechanical and ultrasound (US) abnormalities in SLE patients as compared with controls and to assess the relationship between these abnormalities and SLE activity. METHODS: Fifty-four consecutive female patients with SLE with and without foot pain and 60 female controls (30 with foot pain and 30 without foot pain) were recruited. SLE activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). SLE patients and controls blindly underwent a comprehensive podiatric, biomechanical and US evaluation of the feet. US assessment included detection of B-mode synovitis, tenosynovitis, enthesopathy, bone changes and synovial, tenosynovial and entheseal power Doppler (PD) signal. RESULTS: Thirty-one (57.4%) SLE patients had bilateral foot pain and 5 (9.3%) had unilateral foot pain. Metatarsalgia was the most common location for pain but without significant difference between groups (p=0.284). Toe joint deformities were significantly more common in SLE feet as compared with control feet (p<0.0005). SLE feet showed significantly more biomechanical abnormalities than control feet (p<0.05). B-mode synovitis in the tibiotalar joint was strongly associated with having SLE (p<0.0005) and the presence of synovial PD signal in the MTP joints was found only in painful feet of SLE patients. SLEDAI was significantly higher in patients with foot pain than in those with painless feet (p=0.008). However, SLEDAI did not discriminate between patients with and without biomechanical or US abnormalities. CONCLUSIONS: SLE patients showed more biomechanical and US abnormalities in the feet than controls, which were not captured by standardised assessment of the disease activity.

Personalized orthoses as a good treatment option for Charcot neuro-osteoarthropathy of the foot.

BACKGROUND: We sought to assess the biomechanical characteristics of the feet of patients with Charcot neuro-osteoarthropathy and to determine reulceration rates before and after personalized conservative orthotic treatment. METHODS: A longitudinal prospective study was performed in 35 patients with Charcot's foot. Although some patients had a history of ulcers, at the study outset no patient had ulcers. All of the patients underwent biomechanical testing and a radiographic study. A radiophotopodogram was prepared by superimposing an imprint of the sole on a plantar radiograph. Based on the results of these tests, an orthopedic insole was prepared and therapeutic footwear prescribed for each foot. The following variables were compared between the Charcot and unaffected feet: previous ulcers and ulcer sites, reulcerations produced after treatment, type of foot (neuropathic/neuroischemic), ankle mobility, first-ray mobility, and relaxed calcaneal stance position. Treatment efficacy was determined by comparing ulcers presenting in patients in the year leading up to the study period and the year in which treatment was received. RESULTS: In a 1-year period, 70 feet received orthotic treatment, of which 41 were Charcot's feet. Ulceration rates before the study were 73.2% in feet with Charcot's and 31.0% in those without. After 1 year of wearing the customized orthoses, rates fell significantly to 9.8% in the Charcot feet and 0% in the feet without this condition. CONCLUSIONS: Conservative customized orthotic treatment was effective at preventing ulcers and the complications that often lead these patients to surgery.

Validating the probe-to-bone test and other tests for diagnosing chronic osteomyelitis in the diabetic foot.

OBJECTIVE: To compare the diagnostic characteristics of tests used for a prompt diagnosis of chronic osteomyelitis in the diabetic foot, using bone histology as the criterion standard. The tests assessed were probe-to-bone (PTB), clinical signs of infection, radiography signs of osteomyelitis, and ulcer specimen culture. RESEARCH DESIGN AND METHODS: A prospective study was performed on patients with foot ulcers referred to our diabetic foot clinic. Ulcer infection was diagnosed by recording clinical signs of infection and taking specimens for culture. The presumptive diagnosis of osteomyelitis was based on these results and the findings of a plain X-ray and PTB test. All patients with a clinical suspicion of bone infection were subjected to surgical treatment of the affected bone. During surgery, bone specimens were obtained for a histological diagnosis of osteomyelitis. RESULTS: Over 2.5 years, 210 foot lesions were consecutively examined and 132 of these wounds with clinical suspicion of infection selected as the study sample. Of these, 105 (79.5%) lesions were diagnosed as osteomyelitis. Among the tests compared, the best results were yielded by the PTB test including an efficiency of 94%, sensitivity of 98%, specificity of 78%, positive predictive value of 95%, and negative predictive value of 91% (P < 0.001, κ 0.803); the positive likelihood ratio was 4.41, and the negative likelihood ratio was 0.02 (95% CI). CONCLUSIONS: In our outpatient population with a high prevalence of osteomyelitis, the PTB test was of greatest diagnostic value, especially for neuropathic ulcers, and proved to be efficient for detecting osteomyelitis in the diabetic foot.