Cartilage interposition grafts in ossicular chain reconstructions

Abstract

Problem: Hydroxyapatite ossicular implants were designed to be placed directly on the tympanic membrane. The rate of prosthesis extrusion may be reduced by placing cartilage over the prosthesis head. This study evaluated the effects of cartilage interposition grafts in ossicular chain reconstructions (OCR) on hearing results, hearing stability, and prosthesis extrusion. Methods: Patients were identified using a prospective patient database containing all tympanoplasty and tympanomastoid surgeries performed by the senior author at an academic tertiary care practice. Patients who underwent OCR between June 1995 and June 2003 were analyzed. A retrospective chart review augmented data collected prospectively. Patients were stratified into those who underwent OCR with cartilage placed between the ossicular implant and the tympanic membrane and those who did not have cartilage placed. All ossicular implants were hydroxyapatite. The initial hearing results, hearing stability over time, and extrusion rates were analyzed. Results: A total of 243 cases of OCR were identified and analyzed. There were only 3 episodes of extrusion, and all of these extrusions occurred when there was no cartilage interposition. The short-term and long-term hearing results were similar whether or not a cartilage interposition graft was used. Hearing improvement after surgery was greater for those with larger preoperative conductive hearing loss. Hearing results were better for PORP reconstructions than for TORP cases. Conclusion: The use of cartilage grafts in OCR has a neutral effect on hearing results and hearing stability over time. The overall rate of hydroxyapatite prosthesis extrusion rate is low. The use of cartilage grafts could reduce the extrusion rates even further. Significance: In OCR, the use of cartilage grafts between the implant and tympanic membrane can lower the incidence of prosthesis extrusion. Cartilage interposition grafts in OCR do not decrease the hearing results and do not appear to have any effect on hearing stability over time. Support: None reported.