Ultrasound-detected osteophytes predict the development of radiographic and clinical features of hand osteoarthritis in the same finger joints 5 years later

BACKGROUND Structural pathology may be present in joints without radiographic evidence of osteoarthritis (OA). Ultrasound is a sensitive tool for early detection of osteophytes. Our aim was to explore whether ultrasound-detected osteophytes (in radiographically and clinically normal finger joints) predicted the development of radiographic and clinical hand OA 5 years later. METHODS We included finger joints without radiographic OA (Kellgren-Lawrence grade (KLG)=0; n=301) or no clinical bony enlargements (n=717) at baseline and examined whether ultrasound-detected osteophytes predicted incident radiographic OA (KLG ≥1, osteophytes or joint space narrowing (JSN)) or incident clinical bony enlargement (dependent variables) in the same joints 5 years later. We applied logistic regression with generalised estimating equations adjusted for age, sex, body mass index and follow-up time. RESULTS Ultrasound demonstrated osteophytes in 86/301 (28.6%) joints without radiographic OA and 392/717 (54.7%) joints without clinical bony enlargement. These osteophytes were confirmed in the majority of joints where MRI assessment was available. Significant associations were found between ultrasound-detected osteophytes and development of both radiographic OA (OR=4.1, 95% CI 2.0 to 8.1) and clinical bony enlargement (OR=3.5, 95% CI 2.4 to 5.1) and also incident radiographic osteophytes (OR=4.2, 95% CI 2.1 to 8.5) and JSN (OR=5.3, 95% CI 2.1 to 13.4). CONCLUSION Ultrasound-detected osteophytes predicted incident radiographic and clinical hand OA 5 years later. These results support the use of ultrasound for early detection of OA.