Background Total hip replacement (THR) is a favorable treatment option for severe ankylosing spondylitis (AS). However, THR may be an option for another spondyloarthritis (SpA) such as psoriatic arthritis (PsA) and enteropathic arthritis. Sometimes, patients and physicians may be delayed THR operation time for different reasons.
Objectives Objective of this study was to assess frequency of THR and hip involvement in a single center spondyloarthritis (SpA) biological database. Second objective was to evaluated unmet THR operation ratio in SpA.
Methods HÜR-BİO (Hacettepe University Rheumatology Biologic Registry) is a single center biological registry since 2005. HÜR-BİO biological database included demographic data, co-morbidities, smoking status, baseline and follow-up disease activity parameters (such as BASDAI, BASFI, CRP, ESR, global VAS). Available digital radiographic imaging of pelvis in this database were reassesed for hip inolvement and THR by a physician (UK). The need of THR was based on the presence of one or two replaced hips. Kaplan-Meier plots and log rank tests were used to assess TNFi drug survival in patients with and without hip involvement.
Results Seven hundred sixty eight of 1290 (59.5%) SpA patients had available pelvis radiography. Four hundred fifty of 768 (58.6%) patients were male and mean age was 41±11 years old, mean disease duration 8.6±6.9 years, mean TNFi duration was 32±29 months. Patients with AS, non-radiographic axial SpA (nr-axSpA), PsA and enteropathic arthritis were 556 (72.4%), 91 (11.8%), 84 (10.1%) and 37 (4.8%), respectively (Table 1). Frequency of THR and need of THR were shown in table 1. Radiological hip involvement and severe hip involvement found in 125 (16.3%) and 65 (8.4%) patients, respectively. Patients with severe hip involvement was older age 47±11 vs 41±11, p<0.001, longer disease duration 15±9 vs 8±6 years, p<0.001, more frequently male (47/65 (72.3%) vs 402/702 (57.3), p=0.018), more frequently advanced spinal disease 18/52 (34.6%) vs 74/576 (12.8%), p<0.001. Baseline disease activity parameters were similar with and without severe hip involvement, however, last visit CRP (2.56±2.75 vs 1.06±1.97 mg/dl, p<0.001), ESR (24±25 vs 13±14 mm/hour, p<0.001) and BASFI (4.7±2.8 vs 2.4±2.1, p<0.001) were higher in severe hip involvement. Disease duration was found independent risk factor for severe hip inolvement (OR 1.13 ((95%CI 1.09-1.17). In all SpA patients, TNFi drug survival was similar with and without severe hip involvement.
Conclusions Severe hip involvemet was demonstrated either AS or other spondyloarthritis such as PsA, enteropathic arthritis. THR performed almost 5 percent of AS, PsA and enteropathtic arthritis under TNFi treatments. On the other hand, substantial of AS patients who need THR were not operated yet. The reasons of this delay may be responsible of patients' perspective (e.g fear of operation) or physicians (e.g ignore of patients' pain and functional impairment). TNFi may not reflect any major unfavorable effect of THR.
Disclosure of Interest None declared