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.