Hearing results with the Dornhoffer ossicular replacement prostheses

The "ideal" prosthesis for ossicular reconstruction should, from a surgical standpoint, require easy manipulation, reduce surgeries to partial or total variants, and be constructed of stable, biocompatible material. From an acoustic standpoint, a prosthesis should weigh 10 to 40 mg, provide proper tension between the tympanic membrane (TM) and stapes, form less than a 30-degree angle with the TM, and accommodate the malleus. Work was conducted with Smith & Nephew Richards, Inc. (Memphis, TN), to develop a partial ossicular replacement prosthesis (PORP) and a total ossicular replacement prosthesis (TORP) that combined the majority of these features. This retrospective study used a computerized otologic database to identify patients implanted with a Dornhoffer HAPEX PORP or TORP from June 1995 to March 1997. The surgical procedures utilizing these prostheses were primary cholesteatoma and revision surgery of previously performed modified or radical mastoidectomies complicated by poor hearing or chronically draining cavities. Preoperative and postoperative air and bone conduction four-frequency (500, 1000, 2000, and 3000 Bz) pure-tone averages (PTAs) were used to calculate the PTA air-bone gaps (ABGs). Results in 52 cases (follow-up, 1 year) showed a statistically significant improvement in hearing (P < 0.05) for each group. Excellent hearing results (less than or equal to 10 dB PTA-ABC;) were seen in 69% of PORP cases and in 35% of TORP cases, and good results (11 to 20 dB PTA-ABG) were seen in 31% and 50% of PORP and TORP cases, respectively. Designing an ossicular replacement prosthesis with both surgical and acoustic factors in mind has led to encouraging shortterm hearing results.