Background: Bone anchored hearing implants (BAHI) are widely used and highly successful, accompanied with a high level of patient satisfaction across most techniques. A large UK teaching hospital switched from the previously used wide diameter titanium fixture and drilling system to the novel minimally invasive technique and laser ablated titanium implant. Before this change the rates of fixture failure and skin problems necessitating abutment change were 1% each. Methods: Retrospective case note review of consecutive BAHI patients drawn from an electronic database between January 2015 and October 2016. Results: Data from a total of 118 procedures were reviewed, with different combinations of surgical techniques and implant types. Sixty procedures were performed via the novel minimally invasive technique with 21 failures (35%). Fourty-eight modified minimally invasive technique procedures were performed with seven failures. In 64 of the procedures, laser ablated titanium fixtures were placed with 21 failures (32.8%). In 54 procedures wide diameter titanium fixtures were placed with eight failures (5%). Conclusion: Initial experience with the novel minimally invasive technique and laser ablated titanium fixture showed significantly higher failure rates than expected. This prompted a change to an open technique and subsequent abandonment of the laser ablated titanium fixture and custom drilling solution in our institution.

Objectives: This study aims to review the utility and interassessor reliability of Holgers classification by simultaneously testing various professionals of the bone-anchored implant team for their impression of a series of randomized images. Study Design: Retrospective review of a randomized series of bone-anchored implant fixture clinical photographs from the database at a tertiary referral university hospital. Raters were blinded to the contemporaneous Holgers grading assigned by the Clinical Nurse Specialist at initial assessment. Multivariate analysis was performed for correlation between scores for assessors and between grades of assessor. Setting: Queen Elizabeth Hospital, Birmingham, UK a tertiary center for BAHIs. Patients: Patients implanted from May 2012 until November 2014. Main Outcome Measure: Photographs of fixture sites of adult patients were taken following bone-anchored hearing implant surgery using either a tissue reduction (a split skin graft or linear incision technique was used) or tissue preservation approach, at 1 week, 6 months, and 12 months postoperatively. On a single occasion 263 images were reviewed by 10 assessors (2 consultants, 2 higher surgical trainees, 3 junior doctors, and 3 audiologists). Images were displayed at 10-second intervals and were scored by each assessor. Assessors were blinded to patient identity, time points and to each other's scores. Results were then compared against the real-time scoring of Holgers grades done by the BAHI specialist nurse to compare scores. Results: Overall 227 (86.2%) images were with tissue reduction technique of which 110 (41.8%) were with linear incision and 117 (44.4%) were with a split skin graft (SSG); and 36 (13.6%) were with tissue preservation technique. Of these 263 images, 104 were at 1 week (39.5%), 70 were at 6 months (26.6%), and 89 were at 12 months (33.9%). The cumulative scores for each grade scored by blinding the time points were: 0 = 1132 (43.04%), total 1 = 995 (37.83%), total 2 = 346 (13.15%), total 3 = 141 (5.36%), total 4 = 16 (0.6%). 2630 data points had a variance of only 0.6415 for each nominal. Multivariate correlation between all assessors was r =0.7230 (Pearson's R). Correlations between consultants r=0.6317, higher surgical trainees r=0.7351, junior doctors r=0.7599, and audiologists r=0.7981. There is a good correlation (r=0.89) with no statistically significant differences between the SSG and linear incision groups (p>0.05), possibly suggesting Holgers score is comparable within both these tissue reduction techniques. There is a moderate correlation (r=0.58) with statistically significant differences between tissue preservation versus tissue reduction groups (p<0.05), possibly suggesting tissue preservation gives better results with lower Holgers scores than tissue reduction. Conclusion: Holgers scoring system is a reliable tool with respect to inter-rater variability across all levels of experience. Correlation was closer with audiologists and lesser experienced assessors.

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