Ultrasound imaging for the rheumatologist XL. Sonographic assessment of the hip in rheumatoid arthritis patients.

The aim of the present study was to correlate clinical and laboratory data with those obtained by ultrasound (US) evaluation of the hip in a cohort of patients with rheumatoid arthritis (RA).Fifty-two RA patients attending the Rheumatology Departments involved in the present study were enrolled. Demographic (age, gender), clinical (body mass index, disease duration, treatments, history or current hip pain, tenderness by internal or external hip rotation or palpation of the greater trochanteric region), laboratory (erythrosedimentation rate, C-reactive protein, rheumatoid factor and antibodies anti-citrullinated peptides) and clinimetric data (disease activity score 28 - DAS28, Health Assessment Questionnaire - HAQ, Lequesne index) were collected. All patients underwent an US examination of both hips according to international guidelines.A total of 100 hips were scanned in 52 patients with RA. Approximately half of the patients reported a history of hip pain, one fourth complained of current pain, and the physical examination (internal and/or external rotation and palpation of the greater trochanteric region) evocated pain up to 19\% and 22\% of the patients, respectively. US examination found signs of hip joint abnormalities in 42\% of the patients; US changes indicative of hip joint inflammation and damage were detected respectively in 24\% and 32\% of the cases. No patient presented power Doppler signal in the hip joint. A significant correlation between US pathological findings at hip level was found with clinical data (current pain and evocated pain by internal or external hip rotation). Furthermore, US cartilage lesion correlated with age of the patient, and US bone erosions with the disease duration. No correlation was found between the sonographic assessment and laboratory data, DAS 28, and Lequesne index.US abnormalities at hip joint level obtained in the present study correlated with clinical findings, while no correlation was found with DAS28 or laboratory data. Further investigations are encouraged to clarify the US additional value at hip level in patients with RA.