[Evaluation of the virtual endoscopy on traumatic ossicular chain disruption pre- and post-operation]

To evaluate the clinical use of virtual endoscopy in the traumatic ossicular chain disruption with intact tympanum pre- and post-operation.

The series consisted of 17 cases with temporal bone fracture and 4 cases with tympanum contusion. All were examinated with a high resolution spiral CT by axial and oblique coronal planes of the temporal bone. Three-dimensional reconstruction was processed using the virtual endoscopy software. Ten cases of traumatic ossicular chain disruption were performed with intact canal wall epitympanum approach Ossicular reposition. Eleven patients with facial paralysis were performed ossiculoplasty and facial nerve decompression. Nine cases re-examinated virtual endoscopy after operation.

Seventeen cases with temporal bone fractures and traumatic ossicular chain disruption, including 3 cases with the long process of the incus fracture, 9 cases with incus bone dislocation, and 5 cases with incus shedding. In the 4 cases of tympanum contusion, 2 cases with incus bone dislocation, 2 cases with incus bone shedding. The axial plane of temporal bone CT could only showed the fracture line and the hammer and incus bone irregular shape. Perioperatively virtual endoscopy showed hammer incus joint separation, incus stirrup dislocation and joint deformation. Surgery confirmed that the incus body was torn off below the hammer following bone displacement, soft tissue wrapped articular surface, incus and stapes just connected with soft tissue. During the tympanum contusion operation could see incus bone-shedding was valgus. Three to six months after surgery, re-examinated virtual endoscopy showed incus bone dislocation ossicular chain was restored to normal, temporal bone shedding ossicular chain connecting almost intact Hearing increased significantly to the level of practical hearing. The coincidence of traumatic disruption of the ossicular chain by virtual endoscopy and surgery was 100%.

Virtual endoscopy was valuable for providing accurate assessment and individual program for treating and following-up the traumatic ossicular chain disruption.