The Laryngoscope C 2015 The American Laryngological, V
Rhinological and Otological Society, Inc.
A Ten-Year Review of Soft Tissue Reactions Around Percutaneous Titanium Implants for Auricular Prosthesis Sevasti Tzortzis, MBChB, BMedSci, MSc; Konstantina Tzifa, MPhil, FRCS(ORL-HNS), DLO; Theofano Tikka, MD; Steve Worrollo, FIMPT; Joanne Williams, MSc, RGN, RSCN, DPSN, PgDip; Andrew P. Reid, FRCS(ORL-HNS), DLO; David Proops, BDS(Hons), MBChB, FRCS, FRCS Ed Objectives/Hypothesis: Soft tissue reactions around abutments are the most common complications of percutaneous osseointegrated implants. The main objective of this study was to review our series of osseointegrated implants, evaluate the degree of adverse skin reactions around the auricular abutments, and compare with skin reactions in the pediatric boneanchored hearing aid (BAHA) population. The reason for comparing these two groups was the difference in abutment shape and position in skin with different characteristics. Study Design: A retrospective case analysis of 131 patient notes. Methods: We retrospectively studied 131 pediatric and adult patients who underwent an osseointegrated auricular prosthesis over a 10-year period (1997–2007). Results: There were 95 adults and 36 children who had been implanted and fitted with an auricular prosthesis during the 10-year study period. All patients were followed up postoperatively for a 2-year minimum up to a 14-year maximum follow-up. Thirteen (13/36, 36%) children and seven adults (7/95, 7%) had a skin reaction around the ear prosthesis. Conclusions: The literature review has supported our study results and has shown that children have higher skin reactions in both BAHA and auricular prostheses than adults. Adverse skin reactions in the pediatric auricular group were significantly lower that the pediatric BAHA group. Key Words: Auricular implants, bone-anchored hearing aid, pediatric, skin reactions. Level of Evidence: 4 Laryngoscope, 125:1934–1939, 2015
INTRODUCTION Osseointegration in otolaryngology launched revolutionary and exciting applications with hearing amplification (bone-anchored hearing aid [BAHA]) and craniofacial rehabilitation prostheses. Bra˚nemark et al. first described the principle of osseointegrated implantation in the dental region.1 Reyes et al. reported the fitting of their first patient in 1977 with a BAHA using a Bra˚nemark implant.2 The implant in the skull enables sound vibrations to be transmitted to the cochlea (bone conduction) in patients with conductive, mixed hearing loss and single-sided sensorineural hearing loss and has been a well-established treatment for over 25 years. In 1979, the technique of osseointegration was also used to retain a craniofacial prosthesis.2
From the Ear, Nose, and Throat Department (T.T., J.W.), Prosthetics Department (S.W.), and Department of Otolaryngology (S.T., D.P.); and the Department of Paediatric ENT (K.T., A.R.), Birmingham Children’s Hospital, University Hospital Birmingham, Birmingham, United Kingdom. Editor’s Note: This Manuscript was accepted for publication January 20, 2015. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Sevasti Tzortzis, Department of Otolaryngology, Birmingham Children’s Hospital, Steelhouse Lane, B4 6NH Birmingham, United Kingdom. E-mail: [email protected] DOI: 10.1002/lary.25211
Laryngoscope 125: August 2015
1934
Soft tissue reactions around abutments are the most common complication of percutaneous osseointegrated implants. The main objective of this study was to review our series of osseointegrated implants, evaluate the degree of adverse skin reactions around the auricular abutments, and compare with skin reactions in the BAHA population. The reason for comparing these two groups was that the abutments have different shapes, and the skin characteristics where the abutments are positioned are different. The auricular and BAHA implant/abutment device are made of titanium. The BAHA implant system has a flange fixture with a diameter of 3.75 mm, and the abutment has a conical design, which became more rounded in 2007 (Fig. 1). The auricular prosthesis has a hexagonal connection, and there is a crestal flange enhancing the loading area. The shape of the abutment is cylindrical and has a larger neck that connects to the implant compared to the BAHA design (Fig. 2). A bar construction with clips acts as retention for the auricular prosthesis. During the prosthetic work, a gold bar is attached to the gold cylinders and the clips are incorporated into the prosthesis. Auricular prosthesis position varies greatly among cases. The position of the auricular implant/abutment is generally through a non–hair bearing area in contrast to the abutment for BAHA. One implant is required for BAHA prosthesis, whereas in auricular prostheses, two implants are necessary. In addition, unlike the BAHA, Tzortzis et al.: Skin Reactions in Auricular Prosthesis
Fig. 1. Self-tapping implant with hex lock and snap abutment and gold screw to connect. (Left) BAHA 2004. (Right) BAHA 2007. Pictures courtesy of Cochlear. BAHA 5 bone-anchored hearing aid.
there are no vibrations transmitted in auricular prosthesis. The technique to insert the BAHA prosthesis involves a raised flap with a dermatome and subcutaneous tissue reduction around the position of the implant. To insert an auricular prosthesis, a curved incision is made over the mastoid to raise a flap, and subcutaneous tissue thinning is performed. Often there is an existing scar that needs to be incorporated in the surgical planning. All of the surgeons in this study used the same technique to insert the BAHA implants and the same technique to insert the auricular implants. The differences between the two techniques are that a dermatome is used for the BAHA prosthesis and a U-shaped incision is made, unlike the auricular where a curved C-shaped incision is made.
Fig. 2. Self-tapping abutment. Titanium and gold screw for abutment and with hex lock (Vistafix 2004). Pictures courtesy of Cochlear.
with a range of 3 to 12 months. The postoperative follow up period was between 2 and 14 years, with the surgical team, prosthetics team, and specialist nurse.
Postoperative Instructions Post-BAHA or Auricular Prosthesis A head bandage is left on for 24 hours postoperatively, and the patient may return to work 48 hours after the operation. An appointment is made 5 to 6 days following surgery with a specialist nurse, and the white disc and healing cap stays on until then. If possible, we recommend avoiding washing the hair until the day of the appointment with the nurse. Teaching is then given to the patient and caregiver on how to clean and care for the operation site.
MATERIALS AND METHODS This was a retrospective case analysis of 131 pediatric and adult patients who underwent an osseointegrated auricular prosthesis over a 10-year period (1997–2007). The study was conducted in 2009 to allow for a minimum 2-year follow-up. Data collected included indication for prosthesis, radiotherapy exposure, skin reactions, implant/fixture failures, BAHA surgery, and complications. Holgers classification 0 to 4 was used to scale the skin reactions around the prosthesis (Holgers 0 5 1 mm redness, reddish discoloration around skin surrounding the implant; Holgers 2 5 moist surface around the skin surrounding the implant; Holgers 3 5 formation of granulation tissue around implant; Holgers 4 5 extensive soft tissue reaction requiring removal of implant).3 A previous study conducted in the department studied the rates of BAHA abutments skin reactions in our pediatric population, and the results were compared with the auricular prosthesis rates from this study (Figs. 3 and 4).
RESULTS There were 95 adults and 36 children who were implanted and fitted with an auricular prosthesis during the 10-year study period. There were 79 male and 52 female patients, of whom 67 were right sided, 47 left sided, and 17 bilateral. Of the 36 children, 14 children had a BAHA and auricular prosthesis. The mean time between the first and second stage was 3 to 4 months, Laryngoscope 125: August 2015
Fig. 3. Skin reaction around the bone-anchored hearing aid abutment. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
Tzortzis et al.: Skin Reactions in Auricular Prosthesis
1935
TABLE II. Skin Reactions in Children With an Auricular Prosthesis. Holgers Grade
Children (n 5 36)
Percentage %
0 1
23 3
64 8
2
9
25
3 4
1 0
3 0
Skin Reactions Holgers classification of skin reactions is widely recognized for classification of skin reactions postimplantation. The documentation of postoperative skin reactions was a subjective record prior to 2002, and this was translated into Holgers classification for the purpose of this study. Holgers classification is now a standard method of documenting skin reactions in BAHA and auricular prostheses. Fig. 4. Skin reaction around auricular abutment. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
Children
We instruct the patients to ensure their hands have been thoroughly washed prior to cleaning the BAHA site with cooled water that had previously been boiled. We advise to moisten a cotton bud or use a baby wipe to clean around the affected area and within the abutment removing any debris/crusting. We recommend tearing off a strip from the baby wipes to use as a dental floss around the abutment using the remainder of the wipe to clean the skin around the abutment. The patients are supplied with a special brush to clean around the abutment and instructed to always dry the area thoroughly. The patients and their caregivers are aware that if they have any concerns to contact the specialist nurse.
There were 36 children included in the study. Thirteen (36%) had a skin reaction around the ear prosthesis. Three children had stage 1 Holgers skin reactions, nine had stage 2 Holgers, and one child had stage 3 Holgers (Table II). There were four skin reductions due to skin overgrowth and three keloid scar formations. Fourteen children had a unilateral or bilateral BAHA fitted in addition to the auricular prosthesis. Six children required a change of BAHA abutment. Four children with auricular abutment skin reactions had simultaneous BAHA reactions. One patient had BAHA Holgers 1 and 2 without ear prosthesis skin reactions. There was one BAHA fixture failure and three (3/36, 8%) children had loss of their auricular prosthesis fixture (Table III).
Indications
Adults
One hundred two (67%) patients had a congenital anomaly of their auricle due to isolated ear atresia or syndromes including Treacher Collins syndrome, Goldenhar syndrome, trisomy 21, Okihiro syndrome, Moebius syndrome, and hemifacial microsomia. Twenty-seven (26 adults and one child) sustained trauma resulting from burns, traffic accidents, and human and dog bites, and two adult patients had an arteriovenous malformation (Table I).
Congenital. The main indication for an auricular prosthesis in the adult population was a congenital deformity, which included 67 patients. There were five skin reactions around the auricular prosthesis. One
Cleaning Regime Daily/Alternate Days
TABLE I. Indication for Prosthesis. Indications (n 5 131)
Adults (n 5 95)
Children (n 5 36)
Congenital
67
35
Trauma
26
1
Arteriovenous malformation
2
–
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1936
TABLE III. Fixture Failures in the Children Population. Fixture Failure
Holgers Grade
Percentage
BAHA patient
2
Auricular prosthesis patient
2
1/14 (7%) children with a BAHA 3/36 (8%) children with an auricular prosthesis
Auricular prosthesis patient
2
Auricular prosthesis patient
3
BAHA 5 bone-anchored hearing aid.
Tzortzis et al.: Skin Reactions in Auricular Prosthesis
TABLE IV. Skin Reactions in Adults. Holgers Grade
Adults (n 5 95)
Percentage
0 1
88 4
93 4
2
2
2
3 4
1 0
1 0
patient had a keloid scar formation, one developed a sinus, and one had a sebaceous cyst next to the wound. There were four implant fixture failures, and four (4/67, 6%) patients required skin reduction (Table IV). Trauma. Twenty-six patients required an auricular prosthesis secondary to trauma. In this group, two patients had a skin reaction.
Vascular Ear Anomalies Two patients with a history of auricular vascular anomalies required an auricular prosthesis. One patient developed an ulcer from the prosthesis. There were no skin reactions.
BAHA and Auricular Prosthesis Twenty-nine adult patients had BAHA and auricular prosthesis on the same side. In this group, seven (24%) patients had a skin reaction around the auricular prosthesis and six (20%) around the BAHA abutment.
Auricular Prosthesis Fixture Failures In this study, there were a total of four (4%) adult patient fixture failures in 112 ears (3.5%) and three (8%) fixture failures in the pediatric population.
Prosthesis Use Two children became nonusers of their prosthesis (2/36). One child had previous fixture failure and Holgers 3 skin reactions. It is unclear why the other child became a nonuser.
Statistical Analysis The percentage of adverse skin reactions reported in the pediatric Birmingham BAHA paper was 17%, whereas the total percentage of auricular skin reactions in our study was 36%, but from these only 3% would be considered adverse or Holgers 3 and above (Fig. 5).4 From the above, there appears to be an association between the type of prosthesis and the patients having an adverse skin reaction, because raw percentages are different between the auricular and BAHA subgroups (3% and 17%, respectively). To test this association, we assessed whether the percentages of patients developing adverse skin reactions after the auricular implantation (3%) was significantly different to the percentage of patients who underwent BAHA placement and develLaryngoscope 125: August 2015
Fig. 5. Comparison of adverse skin reactions in the pediatric Birmingham bone-anchored hearing aid (BAHA) and auricular implants. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
oped adverse skin reactions (17%). A v2 test was used to examine whether there was an association between the two categorized variables. Our null hypothesis was that there is no statistically significant difference in the number of patients developing adverse skin reactions for the BAHA and auricular implant, with an alternative hypothesis of a statistically significant difference between the numbers of adverse reactions between the two implants. The P value for the Pearson v2 statistic was .026, with .05 as the level of significance, so we can reject the null hypothesis. We can conclude that there is statistically significant evidence of an association between the number of adverse skin reactions and type of operation. The patients in the BAHA group were more likely to develop an adverse skin reaction compared to the patients who had an auricular implant. Although we determined that there is a significant association, we needed to find out the strength of the observed association. The Cramer’s V statistic (0.145) indicated that the association was relatively weak (Cramer’s V statistic near the zero value). This suggested that even though there was a statistically significant association, it was probably detected due to the small sample size in the auricular implant subgroup. Thus, we needed to continue recording skin reactions in the auricular subgroup to demonstrate a stronger significant association. The risk difference (RD) for adverse skin reactions for an auricular prosthesis versus a BAHA prosthesis was calculated to be 20.14 (P 5.0002 in the .05 level of significance, with a 95% confidence interval of 20.22 to 20.07). This suggests once again that there is a statistically significant association between type of operation and adverse skin reaction, with patients in the auricular subgroup less prone to develop adverse reactions. The small value of RD approximating zero demonstrates that the significant association is not very strong, and more data need to be collected to indicate a stronger association. We aim to statistically compare the adult auricular prosthesis skin reactions with the adult BAHA skin reactions when the results of the BAHA group become available. Tzortzis et al.: Skin Reactions in Auricular Prosthesis
1937
DISCUSSION Auricular prosthesis has revolutionized the rehabilitation of adults and children with no auricle. The aim of osseointegrated surgery is to achieve a stable integrated abutment surrounded by thin, hairless skin around the implant site that will allow for long survival of the implant. Implant skin reactions cause significant morbidity, such as infection and overgranulation. Causes of implant failure vary from primary failure to integrate to late failure, which are due to poor abutment hygiene and infection or direct trauma.5 Regardless of these failures, long-term follow-up studies have shown an overall long-term implant survival rate of greater than 90%.6 The location of the abutment and the surgical technique, such as the thinning of the soft tissue, has been thoroughly studied. There has been significant research to try and understand the pathophysiology of the tissues around an abutment. Recently, the shape of the abutment has been the center of attention and debate, particularly the angle between the skin and abutment. Currently, new techniques of linear incisions and punch biopsies are being trialed in various BAHA centers. Despite the different shape and position of the auricular abutment compared to the BAHA, skin reactions are still present. The placement of the BAHA is in areas of thicker skin and in hair-bearing areas with numerous pilosebaceous follicles secreting sebum, which would theoretically increase the risk of skin reactions. Several studies have reported long-term follow-up results of adult BAHAs. In the literature, implant loss caused by failed osseointegration ranged from 0.4% to 7%, whereas loss caused by infection ranged from 0.4% to 2.7%.7 In our study, adult auricular skin reactions were 7%, which coincides with those reported in the literature for adult BAHA skin complications (3.4%– 39.6%).7 An article by Faber et al. studied 248 adult patients receiving a BAHA implant and found no correlation between implant location and the frequency and severity of skin reactions.7 Skin reactions were observed in 130 patients (52.4%), and 46 patients (18.5%) had a skin reaction that required treatment (classified as Holgers grade 2–4), with an implant loss rate of 1.6% (four of the 248 implants).7 In another study by Goodyear et al. consisting of 80 BAHA patients, 56.6% had skin reactions.5 There were 12 implant failures (15% failure rate), of which 58% were due to poor hygiene and infection.5 In comparison with the above, our study shows a lower skin reaction rate of 7% in auricular implants, with an implant failure of 4% (4/95). There is a very limited number of studies examining BAHAs and auricular prosthesis skin reactions. Reyes et al. studied implant skin reactions in 149 BAHA patients and 65 auricular prosthesis patients over 8 years, with a total of 281 implants.2 Seventy percent of these patients had no skin reactions. These authors compared adverse skin reactions during the first 4 years with those during the next 4 years and found that the degree and frequency of adverse skin reactions showed a decreasing trend with time.2 The authors hypothesized that better patient education, with increased skin care Laryngoscope 125: August 2015
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and implant handling, might be the reason for this decreasing trend.2 Reyes et al. reports comparable skin reactions between the auricular and BAHA prosthesis group, which could be due to the similar pre-, peri-, and postoperative care for both groups. Literature on skin reactions around auricular prosthesis are sparse and cover a limited number of patients. Hamming et al. reported 33% (3/9) skin reactions around auricular prosthesis abutment, but the study was on a small series of nine patients.8 Wright et al. reported a series of 16 patients receiving 39 auricular implants. Three patients (18.75%) had grade 0, seven (43.75%) had grade 1, five (31.25%) had grade 2, and one (6.25%) had grade 3 soft tissue inflammation.9 The inflammation completely resolved in seven of the 13 patients (54%), with hygiene reinforcement or soft tissue reduction. Both the above studies show higher rates of skin reactions than we have demonstrated in the Birmingham auricular prosthesis study, with a rate 7% (7/95), and both have significantly smaller numbers than the Birmingham auricular prosthesis study. In our study, children had higher rates of skin reactions and implant loss. It is believed that compared with the adult skull, a child’s skull is thinner and has less mineral content and more water, which results in a higher risk of failed osseointegration in the younger population.7 Children also theoretically experience more difficulties with maintaining a clean area. In addition, children also have more active and greater numbers of pilosebaceous glands, which could also increase the rate of skin reactions and infections. Papsin et al. reported a BAHA pediatric implant failure rate of five in a series of 32 patients (15%) due to loss of implant, trauma, or chronic skin problems.10 All procedures were two- stage, with a 3 mm implant.10 These results are similar to this study’s pediatric auricular implant failure rate at 3/36 (8%). The pediatric Birmingham BAHA group included 182 patients, and the adverse reactions were reported at 17%.4 In our study, the total auricular skin reactions were 36%, but only 3% were considered adverse or Holgers grade 3 or over. The pediatric auricular prosthesis skin reactions settled with conservative management. The pediatric auricular fixture failure rate in this study was 8% (3/36), lower than the pediatric Birmingham BAHA fixture failure rate, which is reported at 14%.4 The statistical analysis performed in our study shows that the pediatric BAHA prosthesis groups are statistically more likely to develop a skin reaction, but a larger series of the auricular group is required to prove a strong association. This study was a retrospective case analysis, which was limited by the detail of recording in the notes. A prospective study would be more effective and analytical. Photography would also complement the description in the notes. Long-term follow-up is also compromised, as many children and adults had been referred from other regions, and skin reactions may be dealt with locally and not recorded in the department notes. However, this study includes 10 years of data, which allows a comparison between the different implants. Tzortzis et al.: Skin Reactions in Auricular Prosthesis
A multidisciplinary approach is paramount for such a program to succeed and deal with the high proportion of medical conditions (67%) affecting the patients. Due to an anesthetic risk, a one-stage procedure maybe more appealing, but there is not enough evidence in this study to compare one- and two-stage procedures. In addition, many of these conditions may increase the risk of failure to osseointegrate by affecting the underlying bone. In Birmingham, the need for a multidisciplinary approach for BAHA and auricular prosthesis patients was acknowledged early on. This allowed for patients to be carefully selected and supported throughout their osseointegration journey.
CONCLUSION In this study, the incidence of soft tissue skin reactions around adult auricular prosthesis was 7%, which is comparable to BAHA skin reactions and is lower than the auricular prosthesis skin reactions published in the literature.6–8 Skin reactions around abutments for auricular prosthesis were found to be more common in children than adults. The statistical analysis suggests there are significantly more skin reactions in the pediatric Birmingham BAHA population than the pediatric auricular prosthesis group, which may be due differences in skin characteristics or the type of implants. Overall, despite the skin reactions and implant failures, an auricular prosthesis is an alternative to auricular reconstruction and is preferred by many patients. Osseointegration, in principle, has tremendous advantages in the use of osseointegrated implantable devices for skull vibration for BAHAs and stability for auricular prostheses. However, abutment-free devices would likely ameliorate skin
Laryngoscope 125: August 2015
reactions. Future research will most likely involve improvements in abutment design and hopefully abutment-free devices.
Acknowledgments The authors acknowledge Ms. Ann-Louise McDermott for allowing them to use her patients for this article, Mrs. Gill Currier for providing the patient photographs, and Ms. Margaret Price for providing images of the implants.
BIBLIOGRAPHY 1. Branemark PI, Adell R, Breine U, Hansson BO, Lindstr€om J, Ohlsson A. Intra-osseous anchorage of dental prostheses, I: experimental studies. Scand J Plast Reconstr Surg 1969;3:81–100. 2. Reyes RA, Tjellstr€om A, Granstr€om G. Evaluation of implant losses and skin re- actions around extraoral bone-anchored implants: a 0- to 8-year follow-up. Otolaryngol Head Neck Surg 2000;122:272–276. 3. Holgers KM, Tjellstr€om A, Bjursten LM, Erlandsson BE. Soft tissue reactions around percutaneous implants: a clinical study of soft tissue conditions around skin-penetrating titanium implants for bone-anchored hearing aids. Am J Otol 1988;9:56–59. 4. McDermott AL, Williams J, Kuo M, Reid A, Proops D. The Birmingham pediatric bone-anchored hearing aid program: a 15-year experience. Otol Neurotol 2009;30:178–183. 5. Goodyear PAW, Raine CH, Firth AL, Tucker AG, Hawkins K. The Bradford bone-anchored hearing aid programme: impact of the multidisciplinary team. J Laryngol Otol 2006;120:543–552. 6. Dunn CA, de Wolf MJ, Hol MK, Wigren S, et al. Stability, survival, and tolerability of a novel BAHA implant system: six-month data from a multicenter clinical investigation. Otol Neurotol 2011;32:1001–1007. 7. Faber HT, Wolf MJF, Rooy WJ, Bone-anchored hearing aid implant location in relation to skin reactions. Arch Otolaryngol Head Neck Surg 2009;135:742–746. 8. Hamming KK, Lund TW, Lander TA, Sidman JD. Complications and satisfaction with pediatric osseointegrated external ear prostheses. Laryngoscope 2009;119:1270–1273. 9. Wright RF, Zemnick C, Wazen JJ, Asher E. Osseointegrated implants and auricular defects: a case series study. J Prosthodont 2008;17:468–475. 10. Papsin BC, Sirimanna TKS, Albert DM, Bailey M. Surgical experience with bone-anchored hearing aids in children. Laryngoscope 1997;107: 801–806.
Tzortzis et al.: Skin Reactions in Auricular Prosthesis
1939
Rhinological and Otological Society, Inc.
A Ten-Year Review of Soft Tissue Reactions Around Percutaneous Titanium Implants for Auricular Prosthesis Sevasti Tzortzis, MBChB, BMedSci, MSc; Konstantina Tzifa, MPhil, FRCS(ORL-HNS), DLO; Theofano Tikka, MD; Steve Worrollo, FIMPT; Joanne Williams, MSc, RGN, RSCN, DPSN, PgDip; Andrew P. Reid, FRCS(ORL-HNS), DLO; David Proops, BDS(Hons), MBChB, FRCS, FRCS Ed Objectives/Hypothesis: Soft tissue reactions around abutments are the most common complications of percutaneous osseointegrated implants. The main objective of this study was to review our series of osseointegrated implants, evaluate the degree of adverse skin reactions around the auricular abutments, and compare with skin reactions in the pediatric boneanchored hearing aid (BAHA) population. The reason for comparing these two groups was the difference in abutment shape and position in skin with different characteristics. Study Design: A retrospective case analysis of 131 patient notes. Methods: We retrospectively studied 131 pediatric and adult patients who underwent an osseointegrated auricular prosthesis over a 10-year period (1997–2007). Results: There were 95 adults and 36 children who had been implanted and fitted with an auricular prosthesis during the 10-year study period. All patients were followed up postoperatively for a 2-year minimum up to a 14-year maximum follow-up. Thirteen (13/36, 36%) children and seven adults (7/95, 7%) had a skin reaction around the ear prosthesis. Conclusions: The literature review has supported our study results and has shown that children have higher skin reactions in both BAHA and auricular prostheses than adults. Adverse skin reactions in the pediatric auricular group were significantly lower that the pediatric BAHA group. Key Words: Auricular implants, bone-anchored hearing aid, pediatric, skin reactions. Level of Evidence: 4 Laryngoscope, 125:1934–1939, 2015
INTRODUCTION Osseointegration in otolaryngology launched revolutionary and exciting applications with hearing amplification (bone-anchored hearing aid [BAHA]) and craniofacial rehabilitation prostheses. Bra˚nemark et al. first described the principle of osseointegrated implantation in the dental region.1 Reyes et al. reported the fitting of their first patient in 1977 with a BAHA using a Bra˚nemark implant.2 The implant in the skull enables sound vibrations to be transmitted to the cochlea (bone conduction) in patients with conductive, mixed hearing loss and single-sided sensorineural hearing loss and has been a well-established treatment for over 25 years. In 1979, the technique of osseointegration was also used to retain a craniofacial prosthesis.2
From the Ear, Nose, and Throat Department (T.T., J.W.), Prosthetics Department (S.W.), and Department of Otolaryngology (S.T., D.P.); and the Department of Paediatric ENT (K.T., A.R.), Birmingham Children’s Hospital, University Hospital Birmingham, Birmingham, United Kingdom. Editor’s Note: This Manuscript was accepted for publication January 20, 2015. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Sevasti Tzortzis, Department of Otolaryngology, Birmingham Children’s Hospital, Steelhouse Lane, B4 6NH Birmingham, United Kingdom. E-mail: [email protected] DOI: 10.1002/lary.25211
Laryngoscope 125: August 2015
1934
Soft tissue reactions around abutments are the most common complication of percutaneous osseointegrated implants. The main objective of this study was to review our series of osseointegrated implants, evaluate the degree of adverse skin reactions around the auricular abutments, and compare with skin reactions in the BAHA population. The reason for comparing these two groups was that the abutments have different shapes, and the skin characteristics where the abutments are positioned are different. The auricular and BAHA implant/abutment device are made of titanium. The BAHA implant system has a flange fixture with a diameter of 3.75 mm, and the abutment has a conical design, which became more rounded in 2007 (Fig. 1). The auricular prosthesis has a hexagonal connection, and there is a crestal flange enhancing the loading area. The shape of the abutment is cylindrical and has a larger neck that connects to the implant compared to the BAHA design (Fig. 2). A bar construction with clips acts as retention for the auricular prosthesis. During the prosthetic work, a gold bar is attached to the gold cylinders and the clips are incorporated into the prosthesis. Auricular prosthesis position varies greatly among cases. The position of the auricular implant/abutment is generally through a non–hair bearing area in contrast to the abutment for BAHA. One implant is required for BAHA prosthesis, whereas in auricular prostheses, two implants are necessary. In addition, unlike the BAHA, Tzortzis et al.: Skin Reactions in Auricular Prosthesis
Fig. 1. Self-tapping implant with hex lock and snap abutment and gold screw to connect. (Left) BAHA 2004. (Right) BAHA 2007. Pictures courtesy of Cochlear. BAHA 5 bone-anchored hearing aid.
there are no vibrations transmitted in auricular prosthesis. The technique to insert the BAHA prosthesis involves a raised flap with a dermatome and subcutaneous tissue reduction around the position of the implant. To insert an auricular prosthesis, a curved incision is made over the mastoid to raise a flap, and subcutaneous tissue thinning is performed. Often there is an existing scar that needs to be incorporated in the surgical planning. All of the surgeons in this study used the same technique to insert the BAHA implants and the same technique to insert the auricular implants. The differences between the two techniques are that a dermatome is used for the BAHA prosthesis and a U-shaped incision is made, unlike the auricular where a curved C-shaped incision is made.
Fig. 2. Self-tapping abutment. Titanium and gold screw for abutment and with hex lock (Vistafix 2004). Pictures courtesy of Cochlear.
with a range of 3 to 12 months. The postoperative follow up period was between 2 and 14 years, with the surgical team, prosthetics team, and specialist nurse.
Postoperative Instructions Post-BAHA or Auricular Prosthesis A head bandage is left on for 24 hours postoperatively, and the patient may return to work 48 hours after the operation. An appointment is made 5 to 6 days following surgery with a specialist nurse, and the white disc and healing cap stays on until then. If possible, we recommend avoiding washing the hair until the day of the appointment with the nurse. Teaching is then given to the patient and caregiver on how to clean and care for the operation site.
MATERIALS AND METHODS This was a retrospective case analysis of 131 pediatric and adult patients who underwent an osseointegrated auricular prosthesis over a 10-year period (1997–2007). The study was conducted in 2009 to allow for a minimum 2-year follow-up. Data collected included indication for prosthesis, radiotherapy exposure, skin reactions, implant/fixture failures, BAHA surgery, and complications. Holgers classification 0 to 4 was used to scale the skin reactions around the prosthesis (Holgers 0 5 1 mm redness, reddish discoloration around skin surrounding the implant; Holgers 2 5 moist surface around the skin surrounding the implant; Holgers 3 5 formation of granulation tissue around implant; Holgers 4 5 extensive soft tissue reaction requiring removal of implant).3 A previous study conducted in the department studied the rates of BAHA abutments skin reactions in our pediatric population, and the results were compared with the auricular prosthesis rates from this study (Figs. 3 and 4).
RESULTS There were 95 adults and 36 children who were implanted and fitted with an auricular prosthesis during the 10-year study period. There were 79 male and 52 female patients, of whom 67 were right sided, 47 left sided, and 17 bilateral. Of the 36 children, 14 children had a BAHA and auricular prosthesis. The mean time between the first and second stage was 3 to 4 months, Laryngoscope 125: August 2015
Fig. 3. Skin reaction around the bone-anchored hearing aid abutment. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
Tzortzis et al.: Skin Reactions in Auricular Prosthesis
1935
TABLE II. Skin Reactions in Children With an Auricular Prosthesis. Holgers Grade
Children (n 5 36)
Percentage %
0 1
23 3
64 8
2
9
25
3 4
1 0
3 0
Skin Reactions Holgers classification of skin reactions is widely recognized for classification of skin reactions postimplantation. The documentation of postoperative skin reactions was a subjective record prior to 2002, and this was translated into Holgers classification for the purpose of this study. Holgers classification is now a standard method of documenting skin reactions in BAHA and auricular prostheses. Fig. 4. Skin reaction around auricular abutment. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
Children
We instruct the patients to ensure their hands have been thoroughly washed prior to cleaning the BAHA site with cooled water that had previously been boiled. We advise to moisten a cotton bud or use a baby wipe to clean around the affected area and within the abutment removing any debris/crusting. We recommend tearing off a strip from the baby wipes to use as a dental floss around the abutment using the remainder of the wipe to clean the skin around the abutment. The patients are supplied with a special brush to clean around the abutment and instructed to always dry the area thoroughly. The patients and their caregivers are aware that if they have any concerns to contact the specialist nurse.
There were 36 children included in the study. Thirteen (36%) had a skin reaction around the ear prosthesis. Three children had stage 1 Holgers skin reactions, nine had stage 2 Holgers, and one child had stage 3 Holgers (Table II). There were four skin reductions due to skin overgrowth and three keloid scar formations. Fourteen children had a unilateral or bilateral BAHA fitted in addition to the auricular prosthesis. Six children required a change of BAHA abutment. Four children with auricular abutment skin reactions had simultaneous BAHA reactions. One patient had BAHA Holgers 1 and 2 without ear prosthesis skin reactions. There was one BAHA fixture failure and three (3/36, 8%) children had loss of their auricular prosthesis fixture (Table III).
Indications
Adults
One hundred two (67%) patients had a congenital anomaly of their auricle due to isolated ear atresia or syndromes including Treacher Collins syndrome, Goldenhar syndrome, trisomy 21, Okihiro syndrome, Moebius syndrome, and hemifacial microsomia. Twenty-seven (26 adults and one child) sustained trauma resulting from burns, traffic accidents, and human and dog bites, and two adult patients had an arteriovenous malformation (Table I).
Congenital. The main indication for an auricular prosthesis in the adult population was a congenital deformity, which included 67 patients. There were five skin reactions around the auricular prosthesis. One
Cleaning Regime Daily/Alternate Days
TABLE I. Indication for Prosthesis. Indications (n 5 131)
Adults (n 5 95)
Children (n 5 36)
Congenital
67
35
Trauma
26
1
Arteriovenous malformation
2
–
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TABLE III. Fixture Failures in the Children Population. Fixture Failure
Holgers Grade
Percentage
BAHA patient
2
Auricular prosthesis patient
2
1/14 (7%) children with a BAHA 3/36 (8%) children with an auricular prosthesis
Auricular prosthesis patient
2
Auricular prosthesis patient
3
BAHA 5 bone-anchored hearing aid.
Tzortzis et al.: Skin Reactions in Auricular Prosthesis
TABLE IV. Skin Reactions in Adults. Holgers Grade
Adults (n 5 95)
Percentage
0 1
88 4
93 4
2
2
2
3 4
1 0
1 0
patient had a keloid scar formation, one developed a sinus, and one had a sebaceous cyst next to the wound. There were four implant fixture failures, and four (4/67, 6%) patients required skin reduction (Table IV). Trauma. Twenty-six patients required an auricular prosthesis secondary to trauma. In this group, two patients had a skin reaction.
Vascular Ear Anomalies Two patients with a history of auricular vascular anomalies required an auricular prosthesis. One patient developed an ulcer from the prosthesis. There were no skin reactions.
BAHA and Auricular Prosthesis Twenty-nine adult patients had BAHA and auricular prosthesis on the same side. In this group, seven (24%) patients had a skin reaction around the auricular prosthesis and six (20%) around the BAHA abutment.
Auricular Prosthesis Fixture Failures In this study, there were a total of four (4%) adult patient fixture failures in 112 ears (3.5%) and three (8%) fixture failures in the pediatric population.
Prosthesis Use Two children became nonusers of their prosthesis (2/36). One child had previous fixture failure and Holgers 3 skin reactions. It is unclear why the other child became a nonuser.
Statistical Analysis The percentage of adverse skin reactions reported in the pediatric Birmingham BAHA paper was 17%, whereas the total percentage of auricular skin reactions in our study was 36%, but from these only 3% would be considered adverse or Holgers 3 and above (Fig. 5).4 From the above, there appears to be an association between the type of prosthesis and the patients having an adverse skin reaction, because raw percentages are different between the auricular and BAHA subgroups (3% and 17%, respectively). To test this association, we assessed whether the percentages of patients developing adverse skin reactions after the auricular implantation (3%) was significantly different to the percentage of patients who underwent BAHA placement and develLaryngoscope 125: August 2015
Fig. 5. Comparison of adverse skin reactions in the pediatric Birmingham bone-anchored hearing aid (BAHA) and auricular implants. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
oped adverse skin reactions (17%). A v2 test was used to examine whether there was an association between the two categorized variables. Our null hypothesis was that there is no statistically significant difference in the number of patients developing adverse skin reactions for the BAHA and auricular implant, with an alternative hypothesis of a statistically significant difference between the numbers of adverse reactions between the two implants. The P value for the Pearson v2 statistic was .026, with .05 as the level of significance, so we can reject the null hypothesis. We can conclude that there is statistically significant evidence of an association between the number of adverse skin reactions and type of operation. The patients in the BAHA group were more likely to develop an adverse skin reaction compared to the patients who had an auricular implant. Although we determined that there is a significant association, we needed to find out the strength of the observed association. The Cramer’s V statistic (0.145) indicated that the association was relatively weak (Cramer’s V statistic near the zero value). This suggested that even though there was a statistically significant association, it was probably detected due to the small sample size in the auricular implant subgroup. Thus, we needed to continue recording skin reactions in the auricular subgroup to demonstrate a stronger significant association. The risk difference (RD) for adverse skin reactions for an auricular prosthesis versus a BAHA prosthesis was calculated to be 20.14 (P 5.0002 in the .05 level of significance, with a 95% confidence interval of 20.22 to 20.07). This suggests once again that there is a statistically significant association between type of operation and adverse skin reaction, with patients in the auricular subgroup less prone to develop adverse reactions. The small value of RD approximating zero demonstrates that the significant association is not very strong, and more data need to be collected to indicate a stronger association. We aim to statistically compare the adult auricular prosthesis skin reactions with the adult BAHA skin reactions when the results of the BAHA group become available. Tzortzis et al.: Skin Reactions in Auricular Prosthesis
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DISCUSSION Auricular prosthesis has revolutionized the rehabilitation of adults and children with no auricle. The aim of osseointegrated surgery is to achieve a stable integrated abutment surrounded by thin, hairless skin around the implant site that will allow for long survival of the implant. Implant skin reactions cause significant morbidity, such as infection and overgranulation. Causes of implant failure vary from primary failure to integrate to late failure, which are due to poor abutment hygiene and infection or direct trauma.5 Regardless of these failures, long-term follow-up studies have shown an overall long-term implant survival rate of greater than 90%.6 The location of the abutment and the surgical technique, such as the thinning of the soft tissue, has been thoroughly studied. There has been significant research to try and understand the pathophysiology of the tissues around an abutment. Recently, the shape of the abutment has been the center of attention and debate, particularly the angle between the skin and abutment. Currently, new techniques of linear incisions and punch biopsies are being trialed in various BAHA centers. Despite the different shape and position of the auricular abutment compared to the BAHA, skin reactions are still present. The placement of the BAHA is in areas of thicker skin and in hair-bearing areas with numerous pilosebaceous follicles secreting sebum, which would theoretically increase the risk of skin reactions. Several studies have reported long-term follow-up results of adult BAHAs. In the literature, implant loss caused by failed osseointegration ranged from 0.4% to 7%, whereas loss caused by infection ranged from 0.4% to 2.7%.7 In our study, adult auricular skin reactions were 7%, which coincides with those reported in the literature for adult BAHA skin complications (3.4%– 39.6%).7 An article by Faber et al. studied 248 adult patients receiving a BAHA implant and found no correlation between implant location and the frequency and severity of skin reactions.7 Skin reactions were observed in 130 patients (52.4%), and 46 patients (18.5%) had a skin reaction that required treatment (classified as Holgers grade 2–4), with an implant loss rate of 1.6% (four of the 248 implants).7 In another study by Goodyear et al. consisting of 80 BAHA patients, 56.6% had skin reactions.5 There were 12 implant failures (15% failure rate), of which 58% were due to poor hygiene and infection.5 In comparison with the above, our study shows a lower skin reaction rate of 7% in auricular implants, with an implant failure of 4% (4/95). There is a very limited number of studies examining BAHAs and auricular prosthesis skin reactions. Reyes et al. studied implant skin reactions in 149 BAHA patients and 65 auricular prosthesis patients over 8 years, with a total of 281 implants.2 Seventy percent of these patients had no skin reactions. These authors compared adverse skin reactions during the first 4 years with those during the next 4 years and found that the degree and frequency of adverse skin reactions showed a decreasing trend with time.2 The authors hypothesized that better patient education, with increased skin care Laryngoscope 125: August 2015
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and implant handling, might be the reason for this decreasing trend.2 Reyes et al. reports comparable skin reactions between the auricular and BAHA prosthesis group, which could be due to the similar pre-, peri-, and postoperative care for both groups. Literature on skin reactions around auricular prosthesis are sparse and cover a limited number of patients. Hamming et al. reported 33% (3/9) skin reactions around auricular prosthesis abutment, but the study was on a small series of nine patients.8 Wright et al. reported a series of 16 patients receiving 39 auricular implants. Three patients (18.75%) had grade 0, seven (43.75%) had grade 1, five (31.25%) had grade 2, and one (6.25%) had grade 3 soft tissue inflammation.9 The inflammation completely resolved in seven of the 13 patients (54%), with hygiene reinforcement or soft tissue reduction. Both the above studies show higher rates of skin reactions than we have demonstrated in the Birmingham auricular prosthesis study, with a rate 7% (7/95), and both have significantly smaller numbers than the Birmingham auricular prosthesis study. In our study, children had higher rates of skin reactions and implant loss. It is believed that compared with the adult skull, a child’s skull is thinner and has less mineral content and more water, which results in a higher risk of failed osseointegration in the younger population.7 Children also theoretically experience more difficulties with maintaining a clean area. In addition, children also have more active and greater numbers of pilosebaceous glands, which could also increase the rate of skin reactions and infections. Papsin et al. reported a BAHA pediatric implant failure rate of five in a series of 32 patients (15%) due to loss of implant, trauma, or chronic skin problems.10 All procedures were two- stage, with a 3 mm implant.10 These results are similar to this study’s pediatric auricular implant failure rate at 3/36 (8%). The pediatric Birmingham BAHA group included 182 patients, and the adverse reactions were reported at 17%.4 In our study, the total auricular skin reactions were 36%, but only 3% were considered adverse or Holgers grade 3 or over. The pediatric auricular prosthesis skin reactions settled with conservative management. The pediatric auricular fixture failure rate in this study was 8% (3/36), lower than the pediatric Birmingham BAHA fixture failure rate, which is reported at 14%.4 The statistical analysis performed in our study shows that the pediatric BAHA prosthesis groups are statistically more likely to develop a skin reaction, but a larger series of the auricular group is required to prove a strong association. This study was a retrospective case analysis, which was limited by the detail of recording in the notes. A prospective study would be more effective and analytical. Photography would also complement the description in the notes. Long-term follow-up is also compromised, as many children and adults had been referred from other regions, and skin reactions may be dealt with locally and not recorded in the department notes. However, this study includes 10 years of data, which allows a comparison between the different implants. Tzortzis et al.: Skin Reactions in Auricular Prosthesis
A multidisciplinary approach is paramount for such a program to succeed and deal with the high proportion of medical conditions (67%) affecting the patients. Due to an anesthetic risk, a one-stage procedure maybe more appealing, but there is not enough evidence in this study to compare one- and two-stage procedures. In addition, many of these conditions may increase the risk of failure to osseointegrate by affecting the underlying bone. In Birmingham, the need for a multidisciplinary approach for BAHA and auricular prosthesis patients was acknowledged early on. This allowed for patients to be carefully selected and supported throughout their osseointegration journey.
CONCLUSION In this study, the incidence of soft tissue skin reactions around adult auricular prosthesis was 7%, which is comparable to BAHA skin reactions and is lower than the auricular prosthesis skin reactions published in the literature.6–8 Skin reactions around abutments for auricular prosthesis were found to be more common in children than adults. The statistical analysis suggests there are significantly more skin reactions in the pediatric Birmingham BAHA population than the pediatric auricular prosthesis group, which may be due differences in skin characteristics or the type of implants. Overall, despite the skin reactions and implant failures, an auricular prosthesis is an alternative to auricular reconstruction and is preferred by many patients. Osseointegration, in principle, has tremendous advantages in the use of osseointegrated implantable devices for skull vibration for BAHAs and stability for auricular prostheses. However, abutment-free devices would likely ameliorate skin
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reactions. Future research will most likely involve improvements in abutment design and hopefully abutment-free devices.
Acknowledgments The authors acknowledge Ms. Ann-Louise McDermott for allowing them to use her patients for this article, Mrs. Gill Currier for providing the patient photographs, and Ms. Margaret Price for providing images of the implants.
BIBLIOGRAPHY 1. Branemark PI, Adell R, Breine U, Hansson BO, Lindstr€om J, Ohlsson A. Intra-osseous anchorage of dental prostheses, I: experimental studies. Scand J Plast Reconstr Surg 1969;3:81–100. 2. Reyes RA, Tjellstr€om A, Granstr€om G. Evaluation of implant losses and skin re- actions around extraoral bone-anchored implants: a 0- to 8-year follow-up. Otolaryngol Head Neck Surg 2000;122:272–276. 3. Holgers KM, Tjellstr€om A, Bjursten LM, Erlandsson BE. Soft tissue reactions around percutaneous implants: a clinical study of soft tissue conditions around skin-penetrating titanium implants for bone-anchored hearing aids. Am J Otol 1988;9:56–59. 4. McDermott AL, Williams J, Kuo M, Reid A, Proops D. The Birmingham pediatric bone-anchored hearing aid program: a 15-year experience. Otol Neurotol 2009;30:178–183. 5. Goodyear PAW, Raine CH, Firth AL, Tucker AG, Hawkins K. The Bradford bone-anchored hearing aid programme: impact of the multidisciplinary team. J Laryngol Otol 2006;120:543–552. 6. Dunn CA, de Wolf MJ, Hol MK, Wigren S, et al. Stability, survival, and tolerability of a novel BAHA implant system: six-month data from a multicenter clinical investigation. Otol Neurotol 2011;32:1001–1007. 7. Faber HT, Wolf MJF, Rooy WJ, Bone-anchored hearing aid implant location in relation to skin reactions. Arch Otolaryngol Head Neck Surg 2009;135:742–746. 8. Hamming KK, Lund TW, Lander TA, Sidman JD. Complications and satisfaction with pediatric osseointegrated external ear prostheses. Laryngoscope 2009;119:1270–1273. 9. Wright RF, Zemnick C, Wazen JJ, Asher E. Osseointegrated implants and auricular defects: a case series study. J Prosthodont 2008;17:468–475. 10. Papsin BC, Sirimanna TKS, Albert DM, Bailey M. Surgical experience with bone-anchored hearing aids in children. Laryngoscope 1997;107: 801–806.
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