Objective. DIP joint OA is common but has few cost-effective, evidence-based interventions. Pain and
deformity [radial or ulnar deviation of the joint or loss of full extension (extension lag)] frequently lead to
functional and cosmetic issues. We investigated whether splinting the DIP joint would improve pain,
function and deformity.
Methods. A prospective, radiologist-blinded, non-randomized, internally controlled trial of custom splinting
of the DIP joint was carried out. Twenty-six subjects with painful, deforming DIP joint hand OA gave
written, informed consent. One intervention joint and one control joint were nominated. A custom gutter
splint was worn nightly for 3 months on the intervention joint, with clinical and radiological assessment at
baseline, 3 and 6 months. Differences in the change were compared by the Wilcoxon signed rank test.
Results. The median average pain at baseline was similar in the intervention (6/10) and control joints
(5/10). Average pain (primary outcome measure) and worst pain in the intervention joint were significantly
lower at 3 months compared with baseline (P = 0.002, P = 0.02). Differences between intervention and
control joint average pain reached significance at 6 months (P = 0.049). Extension lag deformity was significantly
improved in intervention joints at 3 months and in splinted joints compared with matched
contralateral joints (P = 0.016).
Conclusion. Short-term night-time DIP joint splinting is a safe, simple treatment modality that reduces DIP
joint pain and improves extension of the digit, and does not appear to give rise to non-compliance,
increased stiffness or joint restriction.