Long Term Follow-up of the Ponto Wide Implant: 10 Years of Clinical Evaluation
Conditions: Survival of the Ponto Wide Implant
Sponsor: University Medical Center Nijmegen

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RESEARCH PROTOCOL  
 
Long term follow-up of the Ponto Wide implant: 10 years of clinical evaluation. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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TABLE OF CONTENTS 
 
1.INTRODUCTION AND LITERATURE REVIEW .................................................................. 5 
1.1 Background .................................................................................................................. 5 
2.OBJECTIVES ...................................................................................................................... 6 
2.1 Primary objective .......................................................................................................... 6 
2.2 Secondary objectives .................................................................................................... 6 
2.3 Hypothesis .................................................................................................................... 6 
3.STUDY DESIGN ................................................................................................................. 7 
3.1 Duration of study ........................................................................................................... 7 
2.2 Study design ................................................................................................................. 7 
4.STUDY POPULATION ........................................................................................................ 8 
4.1 Inclusion criteria ............................................................................................................ 8 
4.2 Exclusion criteria ........................................................................................................... 8 
5.INVESTIGATIONAL PRODUCT .......................................................................................... 9 
5.1Ponto Wide Implant ....................................................................................................... 9 
6.METHODS ........................................................................................................................ 10 
6.1 Study parameters ....................................................................................................... 10 
     6.1.1 Primary study parameters ................................................................................... 10 
     6.1.2 Secondary study parameters .............................................................................. 10 
6.2 Study procedures ........................................................................................................ 11 
    6.2.1 Investigation outline ............................................................................................. 11 
    6.2.2 Long term survival of implant ............................................................................... 11 
    6.2.3 Implant stability quotient (ISQ) ............................................................................. 11 
    6.2.4 Holgers' classification ........................................................................................... 11 
    6.2.5 IPS-score ............................................................................................................. 12 
    6.2.6 Daily usage and the number of hours of use of the sound processor ................... 13 
    6.2.7 Quality of life ........................................................................................................ 13 
    6.2.8 Phone call ............................................................................................................ 13 
    6.2.9 Withdrawal of individual subjects ......................................................................... 14 
7.STATISTICAL ANALYSIS ................................................................................................. 15 
8.ETHICAL CONSIDERATIONS .......................................................................................... 16 
8.1 Regulation statement .................................................................................................. 16 
8.2 Recruitment and consent ............................................................................................ 16 
8.3 Benefits and risks assessment, group relatedness ..................................................... 16 
9.AMINISTRATIVE APSECTS AND PUBLICATION ............................................................ 17 
9.1 Handling and storage of data and documents  ............................................................ 17 
9.2 Publication  ................................................................................................................. 17 
10.REFERENCES ................................................................................................................ 18 
 
 
 
 

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LIST OF ABBREVIATIONS AND RELEVANT DEFINITIONS  
 
BAHI  
Bone-anchored hearing implant  
ISQ  
 
Implant stability quotient  
CTc 
 
Central Ethics Review Committee / Centrale ethische Toetsingscommissie    
                       (Dutch) 
IC 
 
Informed consent  
IOI-HA  
International Outcome Inventory for Hearing Aids  
LIT-TR  
Linear incision technique with tissue reduction 
LIT-TP  
Linear incision technique with tissue preservation 
pBCD   
Percutaneous Bone Conduction Device  
tBCD   
Transcutaneous Bone Conduction Device 
APHAB  
Abbreviated Profile of Hearing Aid Benefit 
GBI 
 
Glasgow Benefit Inventory  
GCP 
 
Good Clinical Practice  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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SUMMARY 
Rationale: Since the introduction of the bone-anchored hearing implant (BAHI) in 1977 (1), 
implants have evolved over the years. The implant design has changed, resulting in wider 
diameter implants. In 2011, the 4.5-mm-wide implant was introduced. This implant has a larger 
contact surface between the implant and the bone compared to prior implants. Previous studies 
have shown that there is a high survival rate with the use of the 4.5-mm-wide implant at 6 
months and 3 years after implantation (2, 3). Similar results were observed for a follow-up 
duration of 5 years (4). While the outcomes for this duration are positive, there is limited data 
available concerning the long-term follow-up duration (>10 years) of the 4.5-mm-wide implant.  
Objective: The primary objective is to investigate the survival of the Ponto Wide Implant at 
least 10 years after implantation.   
Study design: A single center, prospective study with a single follow-up visit performed at least 
10 years after Ponto Wide implantation. This study is a continuation of previously conducted 
clinical trials of which 6-months, 3- years and 5-years results have been published (3-7). 
Study population: The study population consists of patients with a Ponto Wide implant 
(diameter 4.5 mm, length 4.0 mm) previously participating in one of two already completed 
studies (3, 7).  
Main study parameter: The main parameter is implant survival and will be assessed at least 
10 years after implantation. 
Nature and extent of the burden and risks associated with participation, benefit and 
group relatedness: The study consists of a single follow-up visit. Except for an additional 
check-up, there will be no further benefit to participating in the study. Since the follow-up visit is 
comparable to a regular visit and does not involve any invasive procedures, there are also no 
risks associated with participating in the study. 
 
 
 
 
 
 
 
 
 
 

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1. INTRODUCTION AND LITERATURE REVIEW 
1.1 Background  
Percutaneous bone-anchored hearing implants have been used for patients with conductive 
hearing loss, mixed hearing loss, and single-sided deafness since their introduction in 1977 
(1). The percutaneous implant is placed in the temporal bone behind the ear. Sound is 
detected by the vibrating bone conduction device and transmitted through the implant to the 
postauricular temporal bone, eventually reaching the cochlea. The implant penetrates 
through the skin, forming the connection between the vibrating bone conduction device and 
the postauricular temporal bone (1). Critical to the proper functioning of a percutaneous 
implant is the creation of a reaction-free cutaneous-implant junction (8). Research on dental 
implants has shown that the metal titanium is highly suitable as an implant, as it is well 
tolerated by the body (9). Several follow-up studies with titanium implants outside the oral 
cavity ensued. Research showed a permanent and reaction-free rigid penetration of the skin  
(1, 10). As a result, it can be concluded that titanium can also be used in other bones of the 
body (11), such as the temporal bone in case of a percutaneous bone-anchored hearing 
implant. 
  
However, despite the use of titanium implants other complications emerged, including 
skin reactions, infections, and skin growth over the abutment (12-14). These complications, 
as well as failure of osseointegration, can lead to loss of the hearing implant. Over the 
years, various adjustments have been made to surgical techniques and implant design to 
minimize the risk of complications and ensure optimal osseointegration. Subtle changes in 
shape, length, and width of dental implants were found to influence success rates (15). The 
use of wide-diameter implants facilitates increased bone-to-implant contact (16) resulting in 
higher implant stability and survival (17). In 2011, titanium hearing implants with a wider 
diameter were introduced: the 4.5-mm-wide implant. This implant, which has increased in 
diameter by 0.75 mm, resulted in higher implant survival rates compared to previous 
designs (2, 18). Oticon Medical, one of the producers of percutaneous bone-anchored 
hearing implants, introduced their wider-diameter implant in 2011: the Ponto Wide implant. 
Subsequent studies in the following years have shown a high survival rate with the use of 
the 4.5-mm-wide implant at 6 months, 3 years, and 5 years after implantation (2-4). Similar 
positive outcomes were observed when examining implant stability. Although these outcome 
measures appear positive within a 5-year duration post-implantation, this study examines 
various outcome measures of the Ponto Wide implant during long-term follow-up of at least 
10 years. 
 
 
 

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2. OBJECTIVES 
2.1 Primary objective  
The primary objective is to investigate the survival of the Ponto Wide Implant at least 10 
years after implantation.   
 
2.2 Secondary objectives 
1. To determine the amount and causes of implant loss and implant and/or abutment 
removal.  
2. To establish the stability of the implant. 
3. To assess skin complications. 
4. To investigate daily usage and the number of hours of use of the sound processor. 
5. To determine the quality of life. 
 
2.3 Hypothesis  
Regarding this study, it is hypothesized that the survival of the implant will be equal to the 
implant survival at 6 months, 3 years, and 5 years after implantation. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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3. STUDY DESIGN 
3.1 Duration of study  
Given that it is a study with a single follow-up visit, a study duration of 3-6 months is 
expected. All patients who participated in one of the two previously published studies will be 
approached (3, 7). The inclusion of patients will start after approval from the Central Ethics 
Review Committee and will take place within one month. After obtaining approval, a physical 
appointment is scheduled for all patients who agree to participate in the study to conduct the 
measurements. The expected end date of the study will be between the end of 2024 and 
March 2025. 
 
3.2 Study design  
All patients who participated in the previously published studies (3, 7) will be screened 
through their medical files to determine if there has been any implant loss, implant and/or 
abutment removal, or if they have passed away. If this information is not documented, 
patients will be contacted. Interested patients will receive information about the study, after 
which they will have a two-week period to consider their participation. When informed consent 
(IC) is obtained, the patient's medical file will be reviewed for baseline characteristics and a 
physical appointment will be scheduled. During this physical appointment, various variables 
are measured and patients are asked to complete two questionnaires. If the patient is unable 
to attend a physical follow-up visit but still willing to participate, a telephone appointment will 
be scheduled. In this way, experiences regarding the implant, wearing the sound processor, 
and quality of life can still be obtained. 
The telephone questions are described in section 5.2.8. An overview of how the variables will 
be obtained is shown in Table 1. 
 
Table 1. Obtaining the variables during the study  
 
Patient file 
Single follow up visit  
Phone call  
Baseline characteristics  
X 
 
 
Implant removal  
X 
X 
X 
Implant loss 
X 
X 
X 
ISQ measurement 
 
X 
 
Skin status  
 
X 
 
IPS-score 
 
X 
 
Use of sound processor  
 
X 
X 
Quality of life  
 
X 
X 
Hearing status 
X 
X 
 

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4. STUDY POPULATION 
The study population consists of patients with a Ponto Wide implant (diameter 4.5 mm, 
length 4.0 mm) who previously participated in one of two already conducted and completed 
studies (3, 7). 
4.1 Inclusion criteria 
1. Implantation with Ponto Wide implant (diameter 4.5 mm, length 4.0 mm) 
2. Ten or more years of post-operative follow-up.  
3. Valid informed consent 
 
Based on the inclusion criteria, there is a maximum of 64 available patients that can be 
included.  
 
4.2 Exclusion criteria  
No specific exclusion criteria have been set for the study. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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5. INVESTIGATIONAL PRODUCT  
5.1 Ponto Wide Implant  
In this study we want to investigate the long-term survival of the Ponto Wide implant 
(diameter 4.5 mm, length 4.0 mm, Oticon Medical AB, Askim, Sweden). 
The Ponto Wide implant has a wider diameter and a different cutting geometry and 
threading compared to previous implants. Ponto abutments of lengths 6, 9, and 12 mm were 
used, depending on skin thickness.  
 
 
 
 
 
 
 

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6. METHODS  
6.1 Study endpoints  
6.1.1 Primary study endpoint 
Implant survival of the Ponto Wide Implant at least 10 years after implantation.   
 
6.1.2 Secondary study endpoints 
- 
Evaluation of reasons for implant loss and implant and/or abutment removal.  
- 
Implant stability at >10-year follow-up . 
- 
Skin complication rates at >10-year follow-up. 
- 
Average sound processor usage (hours per day; days/week) >10 years post-surgery. 
- 
Glasgow Benefit Inventory (GBI) scores >10 years post-surgery 
- 
International Outcome Inventory for Hearing Aids (IOI-HA) score >10 years post-surgery 
 
Demographics and (baseline) variables: 
- 
Gender 
- 
Age at surgery 
- 
Etiology of hearing loss at surgery 
- 
Ethnical background 
- 
Type of surgery  
• 
Linear incision technique with tissue reduction (LIT-TR) 
• 
Linear incision technique with tissue preservation (LIT-TP) 
- 
Revision surgery (skin revision, abutment change, re-implantation) 
- 
Type and length of abutment 
- 
Indication left/right ear 
- 
Time since surgery (follow-up) 
 
 

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6.2 Study procedures  
6.2.1 Investigation outline  
Patient inclusion involves actively approaching patients who participated in one of the two 
previously published studies (3, 7). If it is known in advance that a patient has experienced 
implant loss or has passed away, they will not be contacted. Interested patients will receive 
information about the study, after which they will have a two-week period to consider their 
participation. When informed consent (IC) is obtained, a physical appointment is scheduled. 
During this physical appointment, various variables are measured and patients will be asked 
to complete two questionnaires. If the patient is unable to attend a physical follow-up visit, a 
telephone appointment will be scheduled. All data will be stored on a secured network drive. 
 
6.2.2 Long term survival of implant 
All patients will be asked if they have experienced any implant-related problems that could 
have affected the longevity of the implant in the last 5 years. If implant loss and implant 
and/or abutment removal has occurred, the number of implants/abutments involved and the 
time between implantation and the event will be noted. Additionally, the reason for implant 
removal and the most likely cause of implant loss will be documented.  
 
6.2.3 Implant stability Quotient (ISQ) 
ISQ will be measured at the visit. The resonance frequency analysis renders an ISQ value 
ranging from 1 to 100. Measurements shall be performed at the abutment level. 
Perpendicular measurements result in two values, where the lowest and highest values are 
recorded as an ISQ-low value and an ISQ-high value, respectively. The measurement 
should preferably be done by the same Osstell instrument (Osstell, Gothenburg, Sweden) 
that was used in the previous completed study. SmartPeg 55 will be used during the 
measurement (Osstell, Gothenburg, Sweden).  
 
6.2.4 Holgers’ classification 
The Holgers classification shows different grades of inflammation of the skin around the 
titanium abutments (19). The skin will be assessed during a visit according to the Holgers 
classification. The following adjusted scale will be used: 
0. No irritation. Epithelium debris removed if present. 
1. Slight redness, local treatment. 
2. Red and slightly moist tissue. No granuloma formation noted. Local treatment. Extra 
controls.  
3. Status as in 1 and 2 but local revision became necessary  

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4. Removal of skin-penetrating implant necessary due to infection.  
R   Removed implant for reasons not related to skin problems.  
 
6.2.5 IPS-score 
The Holgers’ classification has long been used to report on soft tissue reactions around 
percutaneous implants for bone conduction devices (BCDs). However, in addition to signs of 
inflammation/infection of the skin around the abutment, other parameters have also shown 
important. The IPS score was therefore developed to include also parameters such as pain 
and skin height (20). Moreover, the IPS scoring system can be used not only for 
percutaneous bone conduction devices (pBCD) but also for transcutaneous bone 
conduction devices (tBCD). Depending on the IPS score, a treatment recommendation is 
provided. The IPS-score must be completed during the physical appointment The skin 
around the implant will be assessed based on the following components: 
1. Inflammation:  
- 
Skin Integrity (intact = 0 / not intact = 1)  
- 
Erythema (none = 0 / present = 1)  
- 
Edema (none = 0 / present = 1)  
- 
Granulation tissue formation (none = 0/ present = 1)  
 
2. Pain:  
- 
None = 0  
- 
Present, but no increase during manipulation abutment AND <6 wks present = 1  
- 
Present, and increase during manipulation abutment AND/OR >6 wks present = 2  
 
3. Skin height:  
- 
Normal = 0  
- 
Increased, but able to couple sound processor = 1  
- 
Above rim abutment/unable to couple sound processor =2  
 
The IPS-scale offers a standardized treatment advice for each IPS-scale:  
- 
I0-1P0S0-1 = no treatment  
- 
I0P1S0-1 = no treatment  
- 
I1P1S0-1 = local topical treatment  
- 
I2-3P0-1S0-1 = local topical treatment  
- 
I0-4P2S0-1 = consider adding systemic treatment for possible peri-implantitis  

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- 
I0-4P0-2S2 / I4P0-1S0 = consider revision/removal surgery or longer abutment (in 
combination with antibiotic treatment depending on I and P-score)  
 
During a visit, both the Holgers classification and the IPS score will be used to allow for    
the best possible comparison with previously published studies.  
 
6.2.6 Daily usage and the number of hours of use of the sound 
processor 
All patients will be asked if they wear their sound processor daily and for how many hours per 
day and how many days per week. Additionally, patients will be asked if they experience or 
previously have experienced any deficiencies or complaints regarding the sound processor 
and whether the sound processor has been replaced in the past. The brand and model 
number of the sound processor will be recorded.  
 
6.2.7 Quality of life 
Patients are asked if they want to complete two questionnaires regarding their hearing-
related quality of life.  
The International Outcome Inventory for Hearing Aids (IOI-HA) is a seven-item questionnaire 
designed to be generally applicable in evaluating the effectiveness of hearing aid treatments 
(21). These questions provide understanding into how satisfied patients are with their hearing 
aid. Additionally, patients are asked to complete the Glasgow Benefit Inventory (GBI) 
questionnaire (22). This questionnaire is used to evaluate the quality of life after a medical 
intervention. The questionnaire consists of 18 items that correspond to different aspects of the 
patient's well-being: quality of life, self-confidence, support, general health, and social 
involvement. 
 
6.2.8 Phone call  
The outcomes of all the above variables will be obtained during a physical consultation. If this 
is not possible, attempts will be made to contact the patient by phone and ask the following 
questions:  
- 
‘Is the abutment still in place?’ 
- 
‘Do you use the sound processor daily?’ If this is not the case, ‘What is the reason you 
do not wear the sound processor daily?’ 
- 
‘How many hours per day do you use the sound processor?’ 
 

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- 
‘How many days per week do you use the sound processor? 
- 
‘Do you, or have you previously, experienced any deficiencies or complaints?’ 
- 
‘Has the sound processor been replaced in the past due to upgrades or possible 
problems?’ 
- 
Has the implant, along with the sound processor, improved your quality of life 
compared to not using them?  
 
 
6.2.9 Withdrawal of individual subjects  
Subjects can leave the study at any time for any reason if they wish to do so without any 
consequences 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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7. STATISTICAL ANALYSIS  
All patients from the previous investigations will be asked to participate. Therefore, no 
sample size calculation was performed. The Wilcoxon signed-rank test will be used to 
analyze changes within groups over time. Implant survival will be analyzed using a Kaplan-
Meier survival curve. A significance level of 0.05 will be used and the test will be two-tailed.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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8. ETHICAL CONSIDERATIONS  
8.1 Regulation statement  
The investigation will be conducted in accordance with applicable local regulations, e.g. data 
protection legislation. Valid informed consent will be ensured before data collection and 
inclusion. Due to the nature of this study, a written approval of the local Ethics Committee is 
necessary. The study will not start until approval from the Ethics Committee is obtained. 
This investigation will be conducted in accordance with the ISO 14155, the ethical principles 
as described in the latest version of the Declaration of Helsinki, and Good Clinical Practice 
(GCP). The study will be registered at ClinicalTirals.gov.  
 
8.2 Recruitment and consent  
All patients who have participated in one of the two previously completed studies (3, 7) are 
eligible to take part in the study and will be contacted. Information about the study will be 
sent to the potential study participant, after which they will have a two-week period to 
consider their participation. If patients are willing to participate after the consideration period, 
the informed consent form will be signed by both the patient and the researcher.  
 
8.3 Benefits and risks assessment, group relatedness  
The study consists of a single follow-up visit. Except for an additional check-up, there will be 
no further benefit to participating in the study. Since the follow-up visit is comparable to a 
regular visit and does not involve any invasive procedures, there are also no risks 
associated with participating in the study. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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9. ADMINISTRATIVE APSECTS AND PUBLICATION  
9.1 Handling and storage of data and documents  
Data will be captured in an electronic data capture (EDC) system using electronic case 
report forms (eCRFs). Patient information (i.e., name, initials, birth date) will be manually 
processed and stored on a secured network that requires a code for access. All data 
obtained during the study period will be stored for 15 years after the completion of the study. 
 
9.2 Publication  
The result of this investigation will be submitted (aiming to publish) into a peer-reviewed 
journal and for presentation at relevant conference(s).  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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