Background The impairment of hip joints has significant prognostic value on functional status of patients with Ankylosing spondylitis (AS) . One of possible yearly marker of hip joints structure damage in patients with AS may be changing in volume of hyaline cartilage . But clinical significance of this marker in monitoring of hip joint structure changes during treatment is underinvestigated.
Objectives To investigate changes in width of hyaline cartilage of hip joints in patients with AS under treatment with sulfasalazine and adalimumab during 12 month.
Methods The 53 patients with AS (42 male, 9 female, average age is 37.6 years old, duration of disease is 14–152 month) were included into study. All patients were treated by NSAIDs and sulfasalazine (2 g per day) at least 3 month before study. In treatment of 27 patients (1st group) was added adalimumab (40 mg subcutaneously every 2 weeks), other 26 patients (2nd group) were left on previous treatment regime. Patients were observed during 12 months of treatment including measurements of pain visual analog scale (VAS) in hip movements, maximal distance between ankles, pelvic X-ray and sonography of hip joints by 10–18 MHz probe. BASRI-Hips index was applied for radiographic estimation of structural damage of hip joints . During sonography width of hip joint capsule and hyaline cartilage were measured. The Mann-Whitney-U test was used for comparison of changes in clinical and sonographic data between two groups of patients.
Results After 12 month treatment period in patients of 1st group in comparison with patients of 2nd group more significant decrease of pain VAS during hip movements (on 27.3 [18.8; 32.5] mm vs 4.7 [0.5; 9.6] mm, p<0,01), increase of maximal distance between ankles (on 124.3 [92.3;145.6] mm vs 3.5 [1.2; 6.5] mm, p<0,05) and decrease of joint capsule width (on 2.4 [1.0; 3.6] mm vs 0.4 [0.0;1.1] mm, p<0,05) had been determined. In patients of 1st group width of hyalinic cartilage had been increased on 0.15 [0.4; 0.22] mm, while in patients of 2nd group width of hyalinic cartilage had been decreased on 0.8 [0.0; 1.4] mm (p<0,05). These cartilage changes were accompanied by decrease of mean BASRI-Hips index on 1 point in 2nd group and absence of changes of BASRI-Hips index in 1st group. The correlation between changes in width of hip hyalinic cartilage and pain VAS during movement in hip joints (r=-0.52 [0.38; 061]) and maximal distance between ankles (r=+0.47 [0.32; 0.60]) had been revealed.
Conclusions Treatment with adalimumab leads to decrease of clinical and sonographic signs of coxitis and improvement of hyaline cartilage structure. The increase of width of hip hyalinic cartilage correlates with clinical effect of treatment of coxitis in patients with AS. More prolonged observation is needed for analysis of correlation between changes in hyaline cartilage structure and radiographic progression of hip joints damage in AS.
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Disclosure of Interest None declared