AB0840 Comparative analysis of macroscopic changes in bone tissue of heads and acetabulums of the hip joints (HJ) in patients with ankylosing spondylitis (AS): data from a retrospective analysis

Background According to the results of Russian studies, coxitis occurs in 56% patients (pts) with AS. At same time, need for total hip arthroplasty (THA) is only 8%, which associated use biologic disease-modifying anti-rheumatic drugs (bDMARDs). Objectives The aim study was compare macroscopic changes bone tissue femoral heads (FH) and acetabulums pts AS who received did not receive bDMARDs. Methods retrospective included 170 a verified diagnosis AS, met modified New York criteria 1984, were treated traumatological orthopedic department period from 1998 2020, THA routinely performed all pts. Most them male (80.6%). average age 38.1±11.3 yrs. 82.9% had low activity disease according BASDAI index at time surgical treatment 17.1% high activity. Nonsteroidal anti-inflammatory by 61.7% pts, sulfasalazine - 20.6%, methotrexate 7.7%, systemic glucocorticoids 8.8%, bDMARDs -53 (31.1%). Results: Parameter All (n=170) (+) n=53 (-) n=117 Average duration disease, years, M±ϭ 17,0±8,5 16,2±8,0 17,5±8,7 Age diagnosis, 27,6±9,1 27,6±10,0 27,6±8,9 Necessity THA, 7,4±4,8 6,0±2,8 8,0±5,4 Osteophytes (Yes/No),% 90/10 96/4 88/12 Protrusion 75/25 68/32 78/12 Granulation 91/9 95/5 89/11 Ankylosis 47/53 48/52 37/53 (Fibrous/Osseous),% 77/23 80/20 Cysts 39/61 36/64 (Single/multiple),% 78/22 70/30 71/29 Erosion heads,% 47 39 50 Osteonecrosis 75,5 75* 45 *p<0,05 vast majority (85.9%) III grade secondary coxarthrosis 14.1% IV before THA. Complete absence cartilage on surface acetabulum revealed 71.7% cases, there either partial abrasions places maximal load (6.5%), or chondromalacia (21.8%) rest Deformity FH detected 98.2% while as result osteonecrosis (ONFH) 75.5%. 130 (76.5%) (11.2%), (12.3%) There no significant differences picture lesion HJ without intake bDMARDs, except higher frequency ONFH receiving Conclusion arose after 7.4±4.8 yrs appearance pain joint (HJ). Macroscopic characterized 75.5% almost half cases ankylosis HJ, mainly fibrous (77.2%) complete acetabular FH. HF bDAMRDs differ, but significantly group bDAMRDs. Disclosure Interests None declared.