Musculoskeletal ultrasonography delineates ankle symptoms in rheumatoid arthritis

Ankle and foot pathologies in early rheumatoid arthritis, what can ultrasound tell us?

BACKGROUND

Rheumatoid arthritis (RA) is a systemic autoimmune polyarticular disease. Despite being commonly affected in RA, the ankle and foot do not receive much attention, particularly in early disease. The precise diagnosis of their involvement and its impact on health is a clinical challenge that requires accurate assessment.

AIM

To determine the role of ultrasound in evaluation of ankle and foot pathologies and assess its impact on functional activity in newly diagnosed RA patients.

METHODS

The study was conducted on 152 RA patients and 52 healthy controls. Patients were subjected to history taking, clinical examination, and ultrasound scan. Impact on health was measured by health assessment questionnaire, as well as foot function index.

RESULTS

In a cohort of patients with early RA with median duration of 1 month, tibialis posterior (TP) tenosynovitis (45.4%) was the most common pathology, followed by tibiotalar (TTJ) synovitis (39.8%), and peroneal tenosynovitis (39.1%). In terms of disease duration, TTJ (P = .001) foot pathologies were less common in early RA and tended to worsen over time, whereas TP (P = .048) and peroneal tenosynovitis (P = .011) were more common in early RA. In multivariate analysis TTJ, subtalar synovitis, forefoot pathologies, TP tenosynovitis, and Achilles enthesitis were found to be significant predictors of functional disability. The most important predictors of ankle pain were TTJ synovitis, TP tenosynovitis, peroneal tenosynovitis, and plantar fasciitis.

CONCLUSION

Ankle and foot involvement is a common issue of early RA, and it has a significant impact on quality of life. Ultrasound is a reliable tool for evaluating various abnormalities in this complex area, allowing for better management.

[Agreement between ultrasound-detected inflammation and clinical signs in ankles and feet joints in patients with rheumatoid arthritis]

OBJECTIVE

To investigate the agreement between clinical signs (tenderness and/or swelling) in ankles and feet joints and ultrasound findings in patients with rheumatoid arthritis (RA).

METHODS

RA patients with at least 1 tender and/or swollen joint in bilateral ankles and metatarsophalangeal (MTP) joints detected by physical examination were enrolled and underwent ultrasound examination by greyscale (GS) and power Doppler (PD) mode. The agreement between clinical signs and ultrasound-detected inflammation (joint effusion, synovitis, or tenosynovitis) was analyzed.

RESULTS

In the study, 113 consecutive RA patients were included, with mean age of (52.5±12.6) years, median duration of 60 (13, 129) months, mean disease activity score in 28 joints based on erythrocyte sedimentation rate [DAS28 (ESR)] of 5.1±1.7, mean disease activity score in 28 joints based on C reactive protein[DAS28 (CRP)]of 4.6±1.5. The tenderness and swelling was most commonly detected in ankles (52.7% and 31.9%, respectively), while GS (+) synovitis was most frequently detectable in MTP2 (34.1%), followed by ankles (32.7%) and MTP1 (27.9%), and PD (+) synovitis was most frequently detectable in MTP1 (14.2%), followed by ankles (12.4%) and MTP2 (10.6%). The prevalence of tenosynovitis was 41.1%, which mostly located in tibialis posterior tendon (22.1% of GS positive and 17.6% of PD positive). The highest prevalence of joint effusion was detected in ankles (9.7%), while that of bone erosion in MTP5 (19%). The overall concordance rate between positive clinical signs and ultrasound-determined joint inflammation was poor in the above joints (κ < 0.2, P < 0.05), in which swelling had the highest κ coefficient with ultrasound-determined joint inflammation in ankles (κ=0.225, P < 0.05). Moreover, swelling had the highest κ coefficient with synovitis in ankles (κ=0.231, P < 0.05).The concordance between tenosynovitis and signs in ankles was also poor (κ < 0.20, P < 0.05). There was no significant agreement between joint effusion and clinical signs (P > 0.05).

CONCLUSION

The overall concordance between clinical signs and inflammation on ultrasound was poor in ankles and feet joints. Tenderness and swelling was more common in ankles, while more lesions were detected by ultrasound at MTP joints. Ultrasound is useful in assessing the lesions besides physical examination in patients with RA.

Sonographic and Anatomic Description of the Subtalar Joint

Our study provides a detailed anatomic and sonographic description of the subtalar joint, a single joint that, anatomically, is divided into the anterior subtalar joint (ASTJ) and the posterior subtalar joint (PSTJ). Cadaver specimens of the ankle and foot were examined in detail by ultrasound (US), and the subtalar joints of all the specimens were injected with colored latex of a contrasting color under US guidance. Compatible with other studies, examination of the sections revealed lack of communication between the ASTJ and the PSTJ and communication between the PSTJ and the posterior recess of the tibiotalar joint. A recommended list of standardized ultrasound scans was developed using a Delphi consensus process, which allows sonographers to evaluate both the ASTJ and PSTJ from the medial, lateral and posterior aspects. The recommended ultrasound scans were found to be applicable based on a test of agreement between images acquired in cadaver specimens and images acquired in four centers using healthy patients.