Background Large joints affection including the hip in RA has significant impact on patient's activity. Unfortunately, clinical detection of hip synovial hypertrophy and effusion is difficult, while Ultrasound is reliable and effective to compensate for such problem¹.

Objectives Identify clinical and Laboratory characteristics associated with Ultrasonographic hip synovitis among RA Patients

Methods We conducted an observational cohort study on 60 RA adult patients fulfilling the 1987 ACR classification Criteria for RA. Exclusion criteria include those with non- RA related Hip Arthritis (Degenerative, Traumatic, Metabolic and referred pain from the back). Grouping: Group I, 30 patients complaining of hip pain and Group II 30 without hip pain. All patients had full history and clinical examination including DAS28, SJC66, TJC68, Patient and Physician Global Assessment of disease activity (PTGA, PGA); and Lab includes ESR, CRP and RF. Ultrasound examination was done according to the standard EULAR guidelines.

Results The following table shows the demographic, clinical and lab characheteristics of both groups.

The initial intra-group analysis showed no statistically significant difference in all the measurable demographic, clinical and laboratory data between patients with Normal and Abnormal US. Except for duration of symptoms of hip pain in Group I (16.3±9.6 weeks in those with abnormal US vs 4.4±2.3 weeks in those with normal US Scan (P<0.001) by using point Biserial correlation. Regarding US, Synovial Hypertrophy/ effusion (Abnormal US) was found in 14 out of 30 patients (46.7%) in Group I and 10 out of 30 (33.33%) in group II with no significant difference (P=0.29).

Further whole group analysis showed that CRP was statistically significantly higher in patients with abnormal Hip US (24/60 patients) 8.25±5.25 mg/dl than those with normal Hip US (36/60 patients) 5.17±5.58 mg/dl (P=0.036). In addition, Knee effusion and synovial thickening detected by clinical examination was more frequent in patients with abnormal Hip US (than those with normal hip US, 41.7% vs 13.8% (P=0.015).

Conclusions Hip joint is frequently affected in RA and searching for hip joint involvement should not be limited to those complaining of hip pain to exclude subclinical hip involvement.

Apart from CRP, duration of hip symptoms and knee affection, there was no significant correlation between abnormal US and demographics or laboratory data.

1. Di Geso L1, Filippucci E, Riente L, et al. (2012) Ultrasound imaging for the rheumatologist XL. Sonographic assessment of the hip in rheumatoid arthritispatients. Clin Exp Rheumatol. 30(4):464–8.

Disclosure of Interest None declared