A surgical apparatus includes a rotatable shaft anda turbine assembly. The rotatable shaft includes a cutterlocated thereon. The cutter is configured to cut anobject when the shaft is rotating about a rotationalaxis. The turbine assembly includes a turbine and aturbine housing. The turbine housing is configured toreceive a fluid that enters the housing parallel to therotational axis, and to steer the fluid to impinge on theturbine in a direction that is not parallel to therotational axis. The turbine is configured to rotate theshaft so as to cut the object by the cutter.
