Radiological-audiological correlation in type II tympanoplasty with glass ionomer cement.

AIM: To assess the CT scan aspect of cement bridges used to repair incudostapedial joint discontinuity (ISD) and correlate these observations to audiometric data over time.

MATERIAL AND

METHODS

A retrospective study in 12 patients with cement rebridging for ISD compared pre- and post-operative pure-tone average thresholds, Hounsfield units (HU), and bridge size and position on postoperative CT scans.

RESULTS

Mean pre- and post-operative air-bone gap (ABG) was 24.5 and 16dB, respectively. HU did not vary over time post-surgery, with no significant correlation between HU and time to postoperative CTnscan up to 24months (p=0.219). However, a "suggestive" correlation was found between postoperative ABG and HU (p=0.004, r=-0.7). High cement density correlated with good functional outcome: HU <500 indicating functional failure and >1000 indicating ABG closure.

CONCLUSION

Immediate cement polymerization quality (high HU) was stable over time and a marker of ossiculoplasty success, correlating with good functional outcome. Particular care should be taken in preparing the cement, and solidification needs to be on dry mucosa-free ossicles.