Percutaneous bone-anchored hearing implant surgery: dermatome versus linear incision technique

The bone anchored prostheses for amputees - Historical development, current status, and future aspects

In the past 50 years, bone anchored prostheses have evolved from a concept for experimental treatment to a rapidly developing area in orthopedics and traumatology. Up to date, there are dozens of centers in the world providing osseointegration amputation reconstructions and more than a thousand patients using the bone anchored prostheses. Compared with conventional socket prostheses, the bone anchored prosthesis by osseointegration avoids the debilitating problems related with soft tissues. It also provides physiological weight bearing, improved range of motion, and sensory feedback, all of which contribute to the improvement on quality of life for amputees. The present article briefly reviews the historical development of osseointegration surgery for amputation reconstruction and the current challenges. The implant design characters and surgical techniques of the two types of implants; the screw-type implant (presented by the OPRA system), and the press-fit implants (presented by EEP and OPL systems) are described. The major complications, infections and mechanical failures, are discussed in detail based on the latest evidence. Future aspects and experimental trials aiming to overcome the current challenges are presented.

Long-Term Outcomes of the Minimally Invasive Ponto Surgery vs. Linear Incision Technique With Soft Tissue Preservation for Installation of Percutaneous Bone Conduction Devices

Objective: Comparing the surgical outcomes of the Minimally Invasive Ponto Surgery (MIPS) technique with the linear incision technique with soft tissue preservation (LITT-P) for bone conduction devices after a follow-up of 22 months.

Methods: In this multicenter randomized controlled trial, there was the inclusion of 64 adult patients eligible for unilateral surgery. There was 1:1 randomization to the MIPS (test) or the LITT-P (control) group. The primary outcome was an (adverse) soft tissue reaction. Secondary outcomes were pain, loss of sensibility, soft tissue height/overgrowth, skin sagging, implant loss, Implant Stability Quotient measurements, cosmetic scores, and quality of life questionnaires.

Results: Sixty-three subjects were analyzed in the intention-to-treat population. No differences were found in the presence of (adverse) soft tissue reactions during complete follow-up. Also, there were no differences in pain, wound dehiscence, skin level, soft tissue overgrowth, and overall quality of life. Loss of sensibility (until 3-month post-surgery), cosmetic scores, and skin sagging outcomes were better in the MIPS group. The Implant Stability Quotient was higher after the LITT-P for different abutment lengths at various points of follow-up. Implant extrusion was nonsignificantly higher after the MIPS (15.2%) compared with LITT-P (3.3%).

Conclusion: The long-term results show favorable outcomes for both techniques. The MIPS is a promising technique with some benefits over the LITT-P. Concerns regarding nonsignificantly higher implant loss may be overcome with future developments and research.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT02438618.

Punch vs open surgical techniques for placement of bone-anchored hearing implants: a systematic review and meta-analysis of skin reactions and operating time

PURPOSE

Several authors have reported their experience with the punch technique as compared to open surgical methods for bone-anchored hearing implants (BAHI). However, no study has attempted to aggregate current evidence. We aimed to compare post-operative skin complications and operating time between punch and open surgical techniques of BAHI via a systematic review and meta-analysis.

METHODS

Databases of PubMed, Embase, Scopus, BioMed Central, Ovoid, and CENTRAL were screened up to 15th February 2020 to include studies comparing punch and open surgical technique for BAHI.

RESULTS

Eight studies were included. Punch technique was compared with dermatome and linear incision techniques with and without soft tissue reduction. There was no difference in normal-to-moderate skin reaction between the punch and open surgical techniques (OR: 0.86 95% CI 0.23, 3.28 I² = 0%). The incidence of adverse skin reactions were also not different between the two groups. Meta-regression for different follow-up periods did not demonstrate any statistically significant results. Our results also indicated that punch technique requires less operating time, however, the inter-study heterogeneity in the analysis was very high. Similar results were seen on sub-group analysis based on the type of open surgical technique.

CONCLUSION

There may be no difference in skin tolerance between the punch technique and open surgical techniques. Operating time may be significantly reduced with the punch technique. Strong conclusions cannot be drawn owing to a limited number of studies. Further large-scale randomized trials are required.

Five year clinical outcomes and evaluation following implantation of the Oticon™ wide bone anchored hearing system in 47 children

OBJECTIVES

The Oticon™ wide implant system was launched in 2009 and used at Birmingham Children's Hospital from 2014. To evaluate clinical outcomes of the Oticon™ wide implant (Oticon Medical), with a focus on skin complication rates and fixture loss over a 5-year period in a tertiary paediatric hospital in the UK.

METHODS

Retrospective 5-year longitudinal case record review of 47 children who were implanted with the Oticon™ wide implant system at Birmingham Children's Hospital (BCH) between January 2014 and January 2016.

RESULTS

47 children (27 M:20F) were implanted with 70 Oticon wide implants 23 bilateral, 27 unilateral. Mean age at the time of implantation was 9y 6 m. The follow up was for a mean of 5.4 years. Significant soft tissue complications requiring treatment was found in 11% (n = 8) of loaded fixtures, abutment tightening on two patients, abutment exchange 6% (n = 4) and a 10% (n = 7) fixture failure.

CONCLUSION

The Oticon™ wide implant system produces favourable results with regards to peri-abutment skin complications, fixture stability and revision surgery rates when compared to similar cohorts of children studied at Birmingham Children's Hospital.

Clinical Outcomes of Soft Tissue Preservation Surgery With Hydroxyapatite-Coated Abutments Compared to Traditional Percutaneous Bone Conduction Hearing Implant Surgery-A Pragmatic Multi-Center Randomized Controlled Trial

Background: Soft tissue preservation using a hydroxyapatite-coated abutment in bone conduction hearing implant surgery may lead to improved clinical outcomes over the short (1 year) and long term (3 years).

Methods: In this open multi-center, randomized (1:1), controlled clinical trial, subjects with conductive, mixed hearing loss or single-sided sensorineural deafness were randomly assigned to receive the conventional intervention, a titanium abutment with soft tissue reduction surgery (control), or a new intervention, a hydroxyapatite-coated abutment with soft tissue preservation surgery (test). The primary efficacy outcome was the combined endpoint of numbness, pain, peri-abutment dermatitis, and soft tissue thickening/overgrowth after 1 and 3 years.

Results: The Intention-to-treat (ITT) population consisted of 52 control subjects and 51 test subjects. The difference between the groups after 1 year of follow-up as measured by the primary efficacy outcome was not statistically significant (p = 0.12) in the ITT population (n = 103), but did reach statistical significance (p = 0.03) in the per-protocol (PP) population (n = 96). It showed an advantage for the test group, with over twice as many subjects (29%) without these medical events during the first year compared to the control group (13%). After 3 years, the difference between the two groups had declined and did not reach statistical significance (24 vs. 10%, ITT p = 0.45). Secondary outcome measures which showed a statistical significant difference during the first year, such as surgical time (15 vs. 25 minutes, p < 0.0001), numbness (90 vs. 69% of subjects experienced no numbness at 1 year, p < 0.01), neuropathic pain at 3 months (p = 0.0087) and the overall opinion of the esthetic outcome (observer POSAS scale at 3 months, p < 0.01) were favorable for the test group. More soft tissue thickening/overgrowth was observed at 3 weeks for the test group (p = 0.016). Similar results were achieved for the long term follow up.

Conclusions: Soft tissue preservation with a hydroxyapatite-coated abutment leads to a reduction in the combined occurrence of complications over the first year which is not statistically significant in the ITT population but is in the PP population. This effect decreased for the long-term study follow up of 3 years and did also not reach statistical significance.

Wide diameter bone-anchored hearing system implants: a comparison of long-term follow-up data between tissue reduction and tissue preservation techniques

OBJECTIVE

To present long-term data on the Wide Ponto implant bone-anchored hearing system (BAHS) in regards to implant stability, soft tissue reaction and implant loss for two case series undergone either the tissue reduction- or the tissue preservation surgical technique.

METHODS

Comparison of two consecutive, prospective case series. Each case series enrolled 24 patients. The case series underwent one-stage implantation of the Wide Ponto implant BAHS using either a linear incision technique with subcutaneous reduction or a linear incision technique without subcutaneous reduction. Implant stability quotient (ISQ) values were measured using resonance frequency analysis and soft tissue reactions were graded according to Holgers' classification system. Follow-up visits were performed at 10 days, 6 weeks, 6 months, 12 months and annually up to 4 years (tissue preservation) or 5 years (tissue reduction) postoperatively.

RESULTS

The two case series had homogenous patient populations and followed an identical postoperative scheme. The ISQ values increased consistently the first 12 months for both groups (p ≤ 0.001), and were higher in the tissue preservation case series, (p = 0.04, 9 mm abutment). More than 91% of the soft tissue observations were assessed as Holgers' grade 0 or 1. One implant (2.1%) was lost due to trauma.

CONCLUSION

In both case series, the Wide Ponto implant showed increasing implant stability during the follow-up period from the time of surgery, irrespective of surgical technique, indicating good osseointegration. Soft tissue reactions were rare and of minor severity. Implant survival was high.

The Cleating Stitch: An Adjunctive Technique for Percutaneous and Revision Osseointegration Screws

OBJECTIVE

The bone anchored hearing aid (BAHA) has become a widely used and successful option in treatment of conductive and mixed hearing loss, and single sided deafness. Despite improvements in technique and cosmesis, complications remain that can result in implant revision or removal. Herein we describe a unique adjunctive technique, the cleating stitch, in placement of osseointegration screws and examine its impact on complication rates.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary academic medical center.

PATIENTS

A total of 66 implants in 65 patients (35 men, 30 women) with an average age of 54 years (15-81 yr). Average follow up 10.8 months.

INTERVENTION

All patients underwent BAHA implant placement by a single surgeon between April 2012 and June 2017 using the linear incision or punch techniques with soft tissue reduction and placement of a cleating stitch.

MAIN OUTCOME MEASURE

Main outcome measures include rates of revision surgery, overgrowth, extrusion, and Holgers reaction ≥2. Secondary outcome measures include associations between main outcome measures and outlying factors (obesity, smoking, diabetes mellitus, coronary artery disease, age).

RESULTS

The overall rate of revision was 3%, rate of overgrowth 1.5%, rate of extrusion 1.5%, and Holgers reaction ≥2 10.6%. Overgrowth and extrusion both required revision. Older age was associated with decreased risk of Holgers reaction ≥2 (p = 0.03) with a hazard ratio of 0.95 (confidence interval 0.9-1.0). There were no other statistically significant associations between primary outcome measures and outlying factors.

CONCLUSION

The cleating stitch is an effective adjunctive technique in placement of osseointegration screws associated with low rates of overgrowth and overall revision surgery.

Percutaneous bone-anchored hearing implant surgery: linear incision technique with tissue preservation versus linear incision technique with tissue reduction

OBJECTIVES

To identify differences in skin thickening and soft tissue reactions between the linear incision technique with tissue reduction (LITT-R) and the linear incision technique with tissue preservation (LITT-P).

STUDY DESIGN

Retrospective cohort study.

METHODS

All adult patients who underwent the LITT-R or LITT-P between August 2005 and December 2016 at a large general teaching hospital with a minimum follow-up of 6 months were included.

RESULTS

A total of 83 implants were included using the LITT-R with a median follow-up of 74.0 months. In the LITT-P cohort 58 implants were included with a median follow-up of 16.5 months. Skin thickening was seen in seven implants (8.4%) in LITT-R cohort and 11 implants (19.0%) in the LITT-P cohort in the first 2 years of follow-up (p = 0.024). Skin thickening in need of treatment was registered in 5 (6.0%), respectively, 6 (10.3%) implants (p = 0.100). Moreover, treatment was successful in all cases. A soft tissue reaction (Holgers ≥ 1) was noticed in 28 (33.7%) implants in the LITT-R group compared to 16 implants (27.6%) in the LITT-P group (p = 0.679). An adverse soft tissue reaction (Holgers ≥ 2) was registered in 16 (19.2%), respectively, 2 (3.4%) implants. This difference was significant (p = 0.040).

CONCLUSION

LITT-P has a significantly higher rate of skin thickening and LITT-R has a significantly higher proportion of adverse soft tissue reactions. Nevertheless, combined with the advantages of LITT-P described in other studies, this can be advocated as the preferred technique.

Investigating the race for the surface and skin integration in clinically retrieved abutments with two-photon microscopy

Bone conduction hearing implants can rehabilitate some types of hearing loss. A hydroxyapatite (HA)-coated skin-penetrating abutment was developed to allow for soft tissue preservation and increased skin-abutment adherence. Inflammation is thought to relate to bacterial infection of pockets around the abutment. Upon integration, the host's ability to cover the abutment surface ("race for the surface"), and thus control and prevent competitive bacteria from colonizing it, is improved. However, the attachment mechanisms behind it are not clear. In this study, we applied two-photon microscopy to visualize tissue attachment on abutments retrieved from patients. Skin integration markers were validated and applied to four HA-coated abutments. Evidence of skin integration was found, including the presence of hemidesmosomes, a basement membrane, dermal collagen and vascularization. Cases with clinical signs of severe inflammation and evident biofilm formation showed limited skin integration based on these indicators, confirming the applicability of the "race for the surface" model.

Baha implant as a hearing solution for single-sided deafness after retrosigmoid approach for the vestibular schwannoma: surgical results

Skull base tumors and, in particular, vestibular schwannoma (VS) are among the etiological reasons for single-sided deafness (SSD). Patients with SSD have problems in understanding speech in a noisy environment and cannot localize the direction of sounds. Baha is one of the most frequently used systems for SSD compensation. Out of 38 patients with SSD after retrosigmoid removal of VS who underwent testing with Baha softband, 16 were satisfied and were indicated for Baha implantation. Two surgical approaches have been used-the Nijmegen linear incision technique with subdermal thinning (Group I, implant BI300) and fast surgery technique without subdermal thinning (Group II, implant BIA400). The duration of the surgery, the implant stability measured by Ostell, and skin or soft tissue reactions in long range follow-up were evaluated and compared between Group I and II. There was a difference in duration of surgery, in Group II procedures averaged significantly faster (p > 0.001). In both groups, there was a similar trend of the gradual increase of implant stability. In the Group I and II, there was comparable rate of the skin or soft tissue reactions grade 0, I, II, or III. We have proved Baha to be a suitable possibility for SSD patients after the removal of VS, regardless of the approach. After the retrosigmoid approach to the VS, the key step of Baha implantation must be to reach intact healthy bone to avoid implantation into scar tissue.