Analysis of the functional state of the hip joints before total hip replacement in patients with ankylosing spondylitis: Data from a retrospective study

Abstract

Coxitis belongs to the extraaxial manifestations of ankylosing spondylitis (AS) and is considered as an unfavorable prognostic factor that may play a significant role in the development of functional limitations. The aim of the study – to evaluate the functional status of the hip joints (HJ) before total hip replacement (THR) in AS patients. Materials and methods. The retrospective study included 170 patients with AS who met the modified New York criteria of 1984, who were hospitalized in the traumatology and orthopedics department of the V.A. Nasonova Research Institute of Rheumatology from 1998 to 2020, and all patients underwent scheduled THR. Most of them were males (80.6%). The average age of the patients was 38,1±11,3 years, duration of the disease from the moment of the first symptoms appearance – 17,0±8,5 years, duration of pain in HJ before THR – 7,4±4,8 years. Disability was established in 80% of cases: in 14,1% – group 1, in 50% – group 2, in 15,9% – group 3. Did not work due to the disease – 64% of patients. The preoperative functional state of HJ was determined using the modified Harris scale. Results and discussion. The preoperative total Harris score averaged 38.0±15.4 points and the pain score averaged 15.6±8.4 points. In the vast majority (82.9%) of patients it ranged from 10–20 points (“severe” and “moderate constantly”). The intensity of pain according to VAS was 72,3±14,0 mm. The median severity of lameness in the HJ was 5 [0; 5] points. Claudication was absent in 2.4% of patients, moderate in 42.9% of cases, severe in another 42.9%, and mild in 11.8%. Additional support was needed in the majority of patients (69.4%). One (29.4%) or two (26.5%) crutches were more frequently required. There was no need for additional support in 30.6% of patients. In 68.8% of cases, there were varying degrees of limitation in distance walking. Climbing stairs caused difficulties in 167 (98.2%) patients, only 3 (1.8%) of them did not use a handrail. Only 1 in 4 patients could use public transportation. Various anatomical deformities were determined in 88.8% of cases. Almost all patients were found to have pronounced restrictions in the volume of movements in the HJ. Conclusion. The result of function assessment according to the Harris scale, as well as the presence of deformities and significant limitation of the range of motion indicate a high degree of severity of the HJ lesion in patients with AS before THR.