Preliminary effectiveness and production time and costs of three-dimensional printed orthoses in chronic hand conditions: an interventional feasibility study.

This was a feasibility study and was not powered to determine effectiveness. Only 21 people were included and 19 completed follow-up, so the results are preliminary. Participants served as their own controls; there was no random assignment and no wash-out period because they depended on their orthosis. Selection bias may have occurred if people unhappy with their conventional orthosis were more willing to join. The conventional orthoses being compared were already in use, while conventional production time was measured only on newly made prototype copies. Cost analysis included only labour time for the first 3D-printed orthosis and direct manufacturing costs, not remakes, healthcare costs, informal costs, or productivity losses. Five participants needed a new 3D-printed orthosis scan or reprint, and one conventional orthosis was remade, so the cost comparison may underestimate time and cost. New comorbidities during follow-up were not assessed, which may explain individual differences in daily hand use.

The authors reported no conflicts of interest. Participants were recruited from OIM Orthopedie branches, and the 3D-printed orthoses were designed and printed by Spentys.

Do not read this as proof that 3D-printed orthoses improve hand function. The main daily hand use outcome was not significantly better than conventional orthoses at 1 or 4 months, and one daily hand use score decreased from 1 month to 4 months. The satisfaction and cost findings are useful, but this was a small feasibility study not powered to show effectiveness.