The Utility of Numeric Grading Scales of Middle Ear Risk in Predicting Ossiculoplasty Hearing Outcomes.

OBJECTIVE

To assess the usefulness of numeric grading scales of middle ear risk in predicting ossiculoplasty hearing outcomes.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care, academic medical center.

PATIENTS

Adults and children undergoing ossiculoplasty between May 2013 and May 2019 including: synthetic ossicular replacement prosthesis, autograft interposition, bone cement repair, and mobilization of lateral chain fixation.

INTERVENTION

Cases were scored via middle ear risk index (MERI), surgical prosthetic infection tissue eustachian tube (SPITE) method, and ossiculoplasty outcome scoring parameter (OOPS) scale. Preoperative and postoperative hearing outcomes were recorded.

MAIN OUTCOME MEASURE

Statistical correlation between risk score and postoperative pure-tone average air-bone gap (PTA-ABG).

RESULTS

The 179 included cases had average pre and postoperative PTA-ABGs of 30.3dB (standard deviation [SD] 12.7) and 20.3dB (SD 11.1), respectively. Mean MERI, SPITE, and OOPS scores were 4.5 (SD 2.3), 2.8 (SD 1.7), and 3.1 (SD 1.8), respectively. Statistically significant correlations with hearing outcome were noted for all three methods (MERI r = 0.22, p = 0.003; OOPS r = 0.19, p = 0.012; SPITE r = 0.27, p < 0.001). No scale predicted poor (PTA-ABG > 30dB) outcomes; only low SPITE scores predicted excellent (PTA-ABG < 10dB) outcomes (odds ratio [OR] 0.74 [Confidence Interval: 0.57 - 0.97], p = 0.032).

CONCLUSIONS

Significant weak correlations between each middle ear risk score and hearing outcomes were encountered. Although only the SPITE method predicted postoperative PTA-ABG, it was not overwhelmingly superior. Current grading scale selection may be justified by familiarity or ease of use.