In a bid to save costs and stem a rising tide of medical waste, hospitals are recycling a growing number of medical devices labeled as single-use, from scissors and scrubs to the sharp blades surgeons use to saw through bones.

Recycling medical devices labeled for single use is legal as long as certain Food and Drug Administration guidelines are followed. But the practice, which involves shipping devices to reprocessing facilities to be cleaned, sterilized and tested for reuse, has raised concerns about safety. Medical device...