EFFECT OF MECHANICAL TRAUMA ON THE STAPEDIAL FOOTPLATE AFTER STAPEDOTOMY - A SCANNING ELECTRON-MICROSCOPIC STUDY

The possible occurrence of inner-ear trauma linked to stapedectomy was studied by scanning electron microscopy of the medial (or labyrinthine) side of human stapedial footplates after performing a hole with different instruments. The anatomic variations induced experimentally by the different procedures are presented in detail and discussed. Manual instruments were shown to induce irregularities on the rim of the hole, whilst the utilization of either electric or pneumatic drills produced more regular margins. Finally, laser-produced holes were also examined. Rather neat rims were observed, but the thermal effect produced by this device has to be considered the major parameter involved in a possible inner-ear postoperative trauma.