Removal of titanium implants from the temporal bone: histologic findings.

OBJECTIVE

This study aimed to evaluate the histologic examination of bone tissue surrounding three titanium implants, which were removed since the patients presented with long-standing pain in the implant area. The histologic examination was both qualitatively and quantitatively performed. Furthermore, could an explanation be obtained for the pain in the implant area, which, after removal of the percutaneous implant, disappeared immediately?

STUDY DESIGN

Retrospective case review; clinical histomorphometric.

SETTING

University Hospital Nijmegen, Göteborg University, Sweden.

PATIENTS

Three patients of a consecutive series of 189; 1 man and 2 women who had received a bone-anchored, percutaneous, skin-penetrating, commercially pure titanium implant in the temporal bone, on which a transducer was mounted. The implants were removed because of pain in the implant area from the three patients after 31 months, 18 months, and 8 months, respectively.

MAIN OUTCOME MEASURES

The percentage of direct bone-to-metal contact was 81%, 59%, and 42%, respectively. The percentage of bone volume between the threads of the screw was 90, 78, and 75, respectively.

RESULTS

The qualitatively histologic findings showed no major differences among the three investigated samples. Quantitatively, the amount of osseointegration depended on the duration of implantation.

CONCLUSIONS

Direct bone-to-metal contact and the bone volume between the threads increased as the implantation time increased. No explanation was found for the longstanding pain in the implant area and the relief of pain after removal of the percutaneous implant.