A detachable blade cartridge for a scalpel is provided. The cartridge includes a body configured for attachment to a scalpel handle, a scalpel blade and a blade cover engaged to the body for travel along the body between a closed position covering the blade and a retracted position to expose said blade for use. The cartridge includes a releasable catch for selectively retaining the cover in the open position or the closed position. The cartridge also includes a one-way catch comprising a detent in one of the cover or the body and a recess in the other of the cover or body to restrict movement of the cover relative to the body in a distal direction past a limit position while permitting movement in an opposed proximal direction.