A cohort of 214 patients, who were operated on to insert implants in the mastoid process for the retention of bone-anchored hearing aids and auricular prostheses, was followed-up over a five-year period. About half the group were operated on using the conventional two-stage procedure allowing three to four months for osseointegration. In the second group (one-stage group) the skin penetrating coupling was connected at the time of the implant insertion. The success rate for stable implants was found to be the same in both groups. In the one-stage group four out of 161 implants inserted were lost and in the two stage group three out of 120. The cumulative success rate was also found to be the same. A ‘worst case’ table where patients lost to follow-up, patients who died during the study period, and patients who for some reason left the study is also included. The importance of this ‘worst case’ scenario when follow-up data are presented is discussed.
