[Variable length titanium prostheses for type III tympanoplasty. Intraoperative length adjustment and fixation of the cartilage overlay].
BACKGROUND
For type III tympanoplasty by partial ossicular replacement prosthesis (PORP) or total ossicular replacement prosthesis (TORP), the length of the prosthesis must match the individual intraoperative anatomical and physiological characteristics.


METHODS
Databanks were used to determine the necessary sizer length of the sizer disc. The measurement template for the size of the cartilage to overlay the prosthesis headplate was derived from the headplates of the Tübinger titanium prostheses (TTP) and the Dresdener titanium prostheses. Finally all functions were integrated into a synthetic plate.


RESULTS
The result was a simple and reasonably priced disposable multifunctional instrument (Tübinger sizer disc TSD) which allowed an exact measurement for every prosthesis in TORP and PORP. For the TTP-Variac, the TSD enabled the simple intraoperative production of prostheses with the length desired by the surgeon. For PORP the TSD enabled an adaptation of the diameter of the prosthesis foot for TTP, TTP-Vario and TTP-Variac and provided a template for the size determination of the cartilage overlay of the titanium prosthesis head. The sizers and the resulting prostheses were used for initial tympanoplastic operations. Audiometric investigations carried out 6 weeks postoperatively gave results corresponding to those previously obtained in a study with TTP and TTP-Vario using the old instrumentation.


CONCLUSIONS
The new instrumentation leads to an improvement of the intraoperative practicability and a simplification. The audiological results remain the same.
Universitäts-Hals-Nasen-Ohren-Klinik, Elfriede-Aulhorn-Str. 5, 72076 Tübingen. zenner@uni-tuebingen.de
H-P
HP
Zenner
R
R
Zimmermann
U
U
Steinhardt
M M
MM
Maassen
D004209:Disposable Equipment; D006801:Humans; D009998:Ossicular Prosthesis; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000295:instrumentation*; D013525:Surgical Instruments; D014025:Titanium; D014433:Tympanoplasty / Q000295:instrumentation*
D014025:Titanium