Critical Angles of Deformity in Dupuytren's Contracture of the Little and Ring Fingers.

Background: We aimed to determine the degree of contracture in the ring and little fingers at which hand function became importantly impaired.

Methods: Five activities of daily living were incorporated into a newly developed and validated Dupuytren's assessment tool (DAT). Sixty healthy participants were assessed with the DAT wearing a range of 12 dorsal blocking splints. Half wore them on their right little finger, the other half on their ring finger. These induced flexion deformities mimicking DC of the MCPJ, PIPJ and a combination of the two. The angles of flexion deformity at which important hand disability occurred were calculated using receiver operating characteristic curves.

Results: Clinically important hand disability occurred for the little finger MCPJ, PIPJ and combined MCPJ and PIPJ angulation at 52.5, 67.5, and 75 degrees respectively. For the ring finger joint, the angulations were 52.5, 67.5 and 75 degrees respectively.

Conclusions: This information will provide information for clinicians and patients as to when clinically important disability tends to occur in DC.