ABSTRACT

Objective:

Hip involvement is present in 25 to 35 percent of patients with ankylosing spondylitis (AS) and is associated with higher degrees of disability and a worse prognosis. To predict the demographical, clinical and laboratory parameters related with hip involvement.

Methods:

This study included 262 AS patients. Clinical, laboratory, and radiographic data were retrospectively analyzed. Bath AS Radiology Index (BASRI) hip index was used to define the radiological hip involvement. Based on the radiographs, a score of at least 2 was used for the definition of hip joint involvement. Logistic regression analyses were used to investigate the factors associated with the severity of hip arthritis.

Results:

Fifty-seven patients (21.8%) had radiographic hip involvement and 135 (54.2%) patients had syndesmophytes. Significantly higher disease duration, male predominance, reported higher frequency of groin pain, increased BASMI, BASFI, CRP and ASDAS-CRP values had in patients with radiolagical hip involvement (p< 0.05). Male sex, disease duration, presence of syndesmophytes, history of groin pain, intermalleolar distance, BASMI, BASFI, CRP, ASDAS-CRP showed significant correlations with BASRI-hip (p< 0.05, r = 0.1, 0.2, 0.2, 0.2, -0.5, 0.4, 0.3, 0.3 and 0.2 respectively). Regression analysis showed that only male sex, history of groin pain, intermalleolar distance, and BASFI were predicting the radiological hip involvement (beta = 32.3, 5, 0.93, and 1.42, respectively).

Conclusion:

Hip involvement is present about one out of the five patients with AS and is associated with male sex, impaired functioning reflected by higher BASFI scores, limitation of hip movement assessed by intermalleolar distance and clinical history of groin pain.