Efficacy of splinting the wrist and metacarpophalangeal joints for the treatment of Carpal tunnel syndrome: an assessor-blinded randomised controlled trial

Abstract

Objectives To compare the efficacy of a traditional cock-up splint, which supports the wrist only, with a modified splint that supports the wrist and the metacarpophalangeal (MCP) joints of the medial four digits in the treatment of carpal tunnel syndrome (CTS).Design An assessor-blind randomised controlled trial.Setting Hospital-based hand therapy clinics.Participants Fifty-nine adults with mild-to-moderate CTS were randomly assigned to wear a wrist splint (control group) or an MCP splint (intervention group) for 6 weeks.Outcome measures The standardised outcome measures used included grip and pinch strength, the static two-point discrimination test, Phalen’s manoeuvre test, Tinel’s sign and the Boston CTS Questionnaire.Results Both groups improved significantly from splint use in some clinical features. The wrist splint and the MCP splint groups had significant improvements in lateral pinch strength (p=0.032 and p=0.002, respectively), two-point discrimination of the thumb (p=0.003 and p=0.041, respectively), two-point discrimination of the index (p=0.035 and p=0.023, respectively) and the Phalen’s manoeuvre symptoms (p=0.025 and p=0.002, respectively). The MCP splint group had additional improvements over the wrist splint group in tip pinch (p=0.012) and Palmar pinch (p=0.011) strength.Conclusion Splinting is a practical and effective intervention option for improving the symptoms of CTS. A wrist splint that incorporates the MCP joints is more effective than the traditional wrist-only splint, with long-lasting improvements that remained consistent after 6 months of the splint intervention. Using the more effective MCP splint may consequently reduce disability, facilitate return to work and lower the associated costs.Trial registration number ISRCTN13189602.