Background Osteoarthritis (OA) is currently the most prevalent joint disease, and hand OA is one of its most characteristic subtypes. For diagnosis and follow-up of hand OA, conventional radiography is used, although this exam gives us insight into only two planes of articulation, and it does not provide a reliable approach to assess the tendons, muscles, and other periarticular structures. More sensitive techniques are required for the accurate assessment of disease progression. Ultrasound (US) imaging appears to be an emerging technique.

Objectives To assess the correlation/association between inflammatory gray scale synovial hypertrophy ultrasonography (GSSH) findings (quantitative and semiquantitative measures) and clinical and functional assessment in symptomatic interphalangeal joints (IPs) hand osteoarthritis (OA). We also aimed to assess the intra and interobserver reliability of the ultrasound (US) findings among these patients.

Methods A prospective study was conducted in the most symptomatic IP joint of 60 hand OA patients. They were assessed for a total of six times (T0, T1, T4, T8, T12, and T48 weeks) by “blinded” observers (a clinician and an ultrasonographer). The intra and interobserver reliability analysis was performed in 25% of the sample.

Results A total of 360 GSSH were performed in the dorsal and palmar joint recesses, for a total of 720 measurements. Proximal interphalangeal joint (PIP) quantitative GSSH measurements of the dorsal recess showed a statistical correlation with the Visual Analog Scale swelling (VASs) score (p=0.043) and pinch strength pulp-to–pulp (p=0.043). Palmar PIP recess quantitative GSSH showed a statistical correlation with the VASs score (p=0.007), AUSCAN-funtion Index (0.044), and grip/finger strength (p=0.037; 0.003; 0.019; 0.017). In the semiquantitative GSSH assessment of dorsal PIPs, there was association between US findings and VASs score (p=0.010) and pinch strength (p=0.027; 0.003; 0.014). In palmar PIPs, we found this association with AUSCAN-function Index (0.048) and grip and finger strength (p=0.031;0.006;0.041). No correlations/associations were found in DIPs. With the exception of the palmar semiquantitative GSSH assessment in distal interphalangeal joints (DIPs) (p=0.623), the US findings were reliable (ICC: 0.474–0.857; k=0.390–0.673).

Conclusions VASs score, grip and pinch strength, and the AUSCAN–function Index were weakly correlated/associated with GSSH findings in the PIPs of hand OA patients. Intra and interobserver ultrasonography assessments were reliable.

References

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Disclosure of Interest None declared