Biomet stock temporomandibular joint prosthesis: Long-term outcomes of the use of titanium condyles secured with four or five condylar fixation screws.

PURPOSE: The aim of this study was to determine the long-term outcomes following TMJ replacement using the stock Zimmer-Biomet TMJ device. In particular, investigated whether the titanium condylar implant and number of screws used to fixate it to the mandibular ramus had any impact on outcomes.

METHODS

Subjects who underwent surgical implantation of a stock Zimmer-Biomet TMJ prosthesis were identified for this retrospective study. All patients received a titanium condylar component secured with four or five screws and ultra-high molecular weight polyethylene (UHMWPE) fossa with no metal reinforcement. Pre- and postoperative pain scores (VAS) and maximum interincisal opening (MIO) data were collected. Additional data included patient demographics, as well as operative, postoperative and follow-up details. Data were analysed with IBM SPSS 2.0 through the use of paired t-tests, and ANOVA and ANCOVA analysis.

RESULTS

190 subjects were identified. Following exclusions, the remaining study population (n = 60) consisted of 58 females and two males with a mean age of 53.5 years at time of surgery. Preoperative VAS and MIO values were 6.08 (SD = 2.24) and 31.88 mm (SD = 7.38 mm), respectively. 90% of the cohort required four screws to fix the prosthetic condylar component in place. After a median follow up of 5.2 years (95% CI: 4.73-5.62 years), with a range of 2-9 years, the VAS was 0.91 (SD = 1.89; p < 0.001) and the MIO was 34.8 mm (SD = X; p = 0.015). Only one device failed over the 9-year study period.

CONCLUSION

The results of this study demonstrate good VAS and MIO outcomes following the implantation of a stock Zimmer-Biomet TMJ device. Additionally, good long-term outcomes were obtained with a titanium condylar component, fixed to the mandibular ramus with only four or five screws, and a UHMWPE fossa with no metal reinforcement.