Background The shoulder involvement in rheumatoid arthritis (RA) is common. It can be subclinical and compromise the function of the upper limb. Clinical evaluation of shoulder does not offer an accurate assessment of this joint and conventional radiography ascertains tardily the diagnosis. Owing to the necessity of early treatment in RA patients before the damage occurrence, musculoskeletal ultrasonography has a great role in detecting subclinical abnormalities in rheumatoid shoulder.
Objectives Our aim was to assess the prevalence of ultrasound abnormalities in rheumatoid shoulder, and investigate their association with demographic, clinical and laboratory parameters.
Methods It was a cross-sectional study including 37 patients with RA, meeting the ACR/EULAR 2010 classification criteria, who were enrolled at our rheumatology center during a month. A questionnaire with sociodemographic, clinical and laboratory data was filled in for all patients. Ultrasound evaluation was performed by a single experienced operator with a 14 MHz linear probe. For each patient, both of shoulders were evaluated looking for synovitis in B-mode and Doppler, effusion, bursitis, erosion and osteophyte. The synovial hypertrophy (GSUS) and Doppler signal (PDUS) were evaluated semi-quantitatively on a scale from 0 to 3. Comparative statistical tests were used to look for associations between ultrasound parameters and those of RA. Statistical significance was set at p<0.05.
Results 37 RA patients were enrolled. Mean age was 50.3±10.9 years with 32 female (86.5%). Median disease duration of RA was 7.5 [3.3, 19.3] years. All patients had a seropositive form of RA. Mean VAS pain was 51.4±20.9%. Mean clinical DAS28 was 5.1±1.5. Mean HAQ was 1.2±0.7.
Thirty-one (83.8%) patients had involvement of the shoulder: unilateral in 9 (24.3%) cases and bilateral in 22 (59.5%) cases. Synovitis was found in 16 (43.2%) patients with Doppler in 4 (10.8%) cases. Sub-acromial bursitis was noted in 14 (37.8%) cases and the effusion in 20 (54.1%). Erosion was visualized in 24 (64.8%) patients and osteophytes in 5 (13.5%).
Presence of synovitis was noted especially in elderly individuals (p:0.01).The power Doppler was visualized in elderly patients (p:0.01), in patients with a shorter disease duration (p:0.02) and when the disease had a high activity assessed by SDAI (p:0.006). The absence of SAD bursitis was associated with a high SDAI (p:0.02), elevated VS (p:0.05) and CRP (p:0.03) and with limited shoulder (p:0.05). US inflammatory findings in anterior recess of GHJ were linked to a higher synovial index (p:0.03) and a higher level of rheumatoid factor (p:0.01).
Conclusions 59.5% of our RA patients had bilateral involvement of the shoulder which was related to the disease activity. Ultrasound should be a systematic tool to look for the involvement of this joint in RA in order to identifie a subgroup of patients with higher disease activity that could benefit from a more aggressive treatment approach.
Disclosure of Interest None declared