gms | German Medical Science

Introduction: The suitability of middle ear implants for reconstruction of the ossicular chain can be proven by a long-term survey. Titanium prostheses (TP) for the middle ear were introduced by Stupp in 1996. The present study investigates whether titanium has proved its worth in particular compared with homologous ossicles (HO), which used to the material of choice for decades, before the era of titanium implants.

Method: Out of 12,000 middle ear surgeries with approx. 8000 tympanoplasties those datasets were evaluated that related to patients who between 1996 and 2007 received a TP (KURZ Medizintechnik, Dusslingen, Germany). The audiologic data was shown with Box-Whisker-Plots with the aid of a weighted mean value of the air-bone-gap (abg) of 5 frequencies, and the protrusion rate was determined. The TP results were compared with the HO used between 1983 and 2007.

Results: During the mentioned periods1306 TP (508 Partial, 798 Total) and 1353 HO (867 PORP, 486 TORP) were implanted. Out of the TP, 42% (Partial) and 44% (Total) came for a follow-up (FU) after 2 to 9 years (mean 5.3 years). Out of the HO, 56 % (PORP) and 41% (TORP) showed up for a FU (mean 7 years). In patients with TP, the abg improved (pre-op to post-op) in 41% (Partial) and 39% (Total). It remained stable over the entire FU-period. In patients with HO the initial abg-improvement deteriorated during the FU-period from 35% to 19% (PORP) and from 25% to 6% (TORP) compared with the preoperative abg-value. Within the first two years, the protrusion rate of TP was 11.8% and then stabilized at 1.6%. In comparison, the protrusion rate of HO was slightly lower at 0.6%.

Conclusion: From an audiological point of view, TP are significantly superior to HO, in particular over a long survey period. The protrusion rate of TP can be reduced to an acceptable figure after a learning phase, respective modification of the surgical technique, and the crucial use of a cartilage cover.