Role of HRCT temporal bone in predicting prosthesis length and evaluating facial nerve overhang before stapedotomy

Abstract Background Choosing the correct prosthesis length is key to achieving a successful stapedotomy and avoiding revision surgery. This depends on accurately measuring the distance from the long process of the incus to the stapes footplate. High-resolution computed tomography (HRCT) of the temporal bone offers a way to obtain this measurement before surgery. In this study, we examined how well HRCT measurements correlate with the prosthesis length chosen during surgery and explored its value in detecting facial nerve overhang to help with operative planning. Methods We reviewed 75 patients who underwent stapedotomy or stapedectomy. Preoperative HRCT scans were assessed to measure the distance from the long process of the incus to the stapes footplate and to check for facial nerve overhang. These measurements were then compared with the prosthesis lengths selected during the operation. Correlation was evaluated using the intraclass correlation coefficient (ICC). Results The study included 40 men and 35 women; 55.4% had surgery on the left ear. HRCT piston lengths ranged from 3.2 to 4.8 mm (mean 3.969 mm), while intraoperatively chosen prostheses ranged from 3.5 to 5.0 mm (mean 4.193 mm) (Fig. 3). A moderate but statistically significant correlation was found between HRCT and surgical measurements (ICC = 0.43, p < 0.01). HRCT also detected facial nerve overhang in 13.3% of patients, giving surgeons the opportunity to anticipate possible challenges. Conclusion Preoperative HRCT of the temporal bone can provide useful guidance for selecting prosthesis length and identifying facial nerve overhang in stapedotomy patients. Using these measurements as part of surgical planning may improve preparedness and help lower revision rates.