MRI and ultrasonography for detection of early interphalangeal osteoarthritis.

OBJECTIVES

To assess the interest of MRI and ultrasonography (US) in identifying early and advanced interphalangeal (IP) OA.

METHODS

We conducted a case-control study including patients with symptomatic hand OA (n=33) and young healthy volunteers (n=26). Proximal and distal IP joints were graded according to Kellgren and Lawrence (KL) grades. In OA patients, we separated IP joints into 2 groups: "at risk of OA" joints (potential early pre-radiographic OA joints, KL=0) and OA joints (KL=2-4). All IP joints from healthy participants were KL=0 and were considered strictly normal IP joints. Concurrently, synovitis, effusion, erosions, osteophytes, bone marrow lesions, cysts and cartilage space loss were graded by MRI and/or US. We assessed their prevalence, severity and diagnostic performance in hand OA and then compared normal IP joints from healthy participants and "at risk of OA" IP joints from OA patients as well as "at risk of OA" and OA IP joints from OA patients.

RESULTS

The prevalence and grade of most MRI/US-detected lesions were higher in IP joints from OA patients than healthy participants. Except for osteophyte assessment, MRI seemed more sensitive than US. We found more MRI/US-detected lesions in "at risk of OA" IP joints than normal joints but also in OA than "at risk of OA" joints from OA patients. US appeared both sensitive and specific for detecting osteophytes in joints without radiographic abnormalities.

CONCLUSIONS

MRI and US give good performance for detecting radiographic and pre-radiographic OA lesions and could be interesting tools to identify early hand OA.