Eur Arch Otorhinolaryngol DOI 10.1007/s00405-014-2975-9
Otology
Ossiculoplasty with hydroxyapatite bone cement: our reconstruction philosophy Jean‑Marc Gérard · Gersende De Bie · Daniel Franceschi · Naima Deggouj · Michel Gersdorff
Received: 21 November 2013 / Accepted: 20 February 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract The main objective of this study is to analyze results obtained with hydroxyapatite bone cement (HABC) ossiculoplasties. This is a retrospective study of a case series. This study was conducted in an academic hospital and tertiary referral center. A total of 127 ossiculoplasties using HABC were evaluated. Ears were divided into three groups according to procedure: group 1 involved reinforcement of the incudostapedial joint with cement and reconstruction of an incus long process defect with cement. Group 2 involved partial ossicular reconstruction between the stapes and malleus handle with HABC. Group 3 was divided into two subgroups. Group 3B entailed reconstruction of the stapes with a mobile footplate (Austin–Kartush type B = group 3B) and group 3F with a fixed footplate (Austin–Kartush type F = group 3F) using a K-Helix piston (Grace Medical, Memphis, TN, USA) or a classical titanium piston (Kurz, Fuerth, Germany) glued to the incus remnant or malleus handle with cement. Anatomical and pre- and postoperative audiological results were assessed. The mean follow-up was 26 ± 14 months. Percentages of average postoperative air–bone gap ≤20 dB were 95, 82.5, 50 and 83.3 %, and for air–bone gap ≤10 dB, 80, 50.9, 16.6 and 50 % for groups 1, 2, 3B and 3F, respectively. No complications related to the cement or extrusion occurred. Hearing outcomes also remained stable over time. In
J.-M. Gérard (*) · G. De Bie · D. Franceschi · N. Deggouj Department of ENT and Head and Neck Surgery, Saint-Luc University Hospital, 1200 Brussels, Belgium e-mail: j‑[email protected] M. Gersdorff Department of ENT and Head and Neck Surgery, Saint-Elisabeth Hospital, 1180 Brussels, Belgium
our experience, ossiculoplasty with cement provides good and stable functional results, is safe, cost effective, and easy to use. HABC with or without biocompatible ossicular prostheses allows repair of different types of ossicular defects with preservation of the anatomical and physiological ossicular chain, as well as improved stability. Reconstruction of the incus long process or incudostapedial joint defect with cement is preferred over partial ossicular reconstruction. Keywords Cement · Ossiculoplasty · Tympanoplasty · Hydroxyapatite
Introduction Ossiculoplasty using bone cement is an alternative to classical prostheses to reconstruct the ossicular chain. It can also be used in stapedectomy, especially in revision surgery to reconstruct the long process of the incus or fix a stapes prosthesis to the incus remnant [1, 2]. Since its introduction to ear surgery in 1996, hydroxyapatite bone cement (HABC) has been successfully used to restore a functional ossicular chain. HABC is a calcium phosphate cement that sets to hydroxyapatite, the major component of human skeletal bone, and becomes like natural bone over time. This cement can be shaped before hardening, bonds directly to bone [3] and metal, does not require complete mucosal removal, is not sensitive to surrounding fluids like blood or water [4], can be easily removed or broken, and is not neurotoxic unlike glass ionomer cement [5]. Here, we report our audiological and anatomical results after reconstruction of the ossicular chain using HABC.
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Subjects and methods
Eur Arch Otorhinolaryngol
We conducted a retrospective study with the approval of the biomedical ethics committee for hospitals and the medical faculty of the University of Louvain. All ossiculoplasties using HABC (Otomimix, Olympus Corp., Tokyo, Japan), performed by an experienced senior surgeon (JMG) between August 2007 and January 2013 and having a minimum of 6-months postoperative follow-up, were evaluated. One hundred and twenty-seven ears were divided into three groups according to procedure. In group 1, the incudostapedial joint was reinforced and the incus long process defect reconstructed with HABC (Fig 1).
In group 2, partial ossicular reconstruction was carried out between the stapes and malleus handle with HABC (Fig 2). Group 3 was divided into two subgroups according to Austin’s classification of ossicular defects, as modified by Kartush [6]. In group 3B (Fig 3), with a mobile footplate (Austin–Kartush type B), the stapes reconstruction was done with a titanium prosthesis on the footplate fixed to the upper ossicular structure using HABC. In group 3F (Fig 4) with a fixed footplate (Austin–Kartush type F), the stapes reconstruction was done with a titanium prosthesis in a calibrated platinotomy fixed to the upper ossicular structure using HABC. In case of small or moderate erosion of the incus long process, a classical titanium piston (Kurz,
Fig. 1 Group 1: Reinforcement of the incudostapedial joint and reconstruction of an incus long process defect with HABC (in red)
Fig. 3 Group 3A: Reconstruction of the stapes with a mobile footplate using a titanium prosthesis attached to the malleus handle or incus long process remnant using HABC (in red)
Fig. 2 Group 2: Partial ossicular reconstruction between the stapes and malleus handle with HABC (in red)
Fig. 4 Group 3F: Reconstruction of the stapes with a fixed footplate using a titanium prosthesis attached to the incus long process remnant using HABC (in red)
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Eur Arch Otorhinolaryngol
Fuerth, Germany) was glued to the incus remnant with HABC. In case of extensive erosion of the long process of the incus, a K-Helix piston (Grace Medical, Memphis, TN, USA), a titanium piston with a conic helix allowing the cement to ‘flo’ around the coils slipped onto the incus remnant, was used. If the incus was absent, the K-Helix piston was glued to the malleus handle with HABC. Groups 1, 2, 3B and 3F included 40, 57, 18 and 12 cases, respectively. Audiological tests were performed using two audiometers (Madsen Otometrics, Tasstrup, Danemark: Orbiter 922-2 and Interacoustics, model AC40). Hearing results were reported at four frequencies, 0.5, 1, 2 and 4 kHz, and not at 3 kHz according to the guidelines of the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium [7]. Postoperative air and bone conduction were evaluated. Results retained for statistical purposes were last obtained during the follow-up period or prior to revision surgery for functional or pathological reasons. The mean postoperative air–bone gap (ABG) was calculated as the postoperative air conduction pure-tone average minus the postoperative bone conduction pure-tone average at the four respective frequencies. Statistical analysis was conducted with Excel 98 by Microsoft (Redmond, WA, USA). The statistical significance of pre- and postoperative differences in means (gains) of data was determined using Student’s t test. A probability value of p = 0.05 was the level of significance selected. Surgery was performed by a retroauricular or endaural approach. A transmastoid approach with removal of the disease from the middle ear was used when required. Ossiculoplasty was then carried out. A small quantity of calcium phosphate powder was mixed with the solvent according to the manufacturer’s specifications for 30–45 s before use, producing a minimal exothermic reaction. In group 1, a drop of cement was applied to repair the incudostapedial joint defect, or a drop-by-drop technique was used to restore the incus long process defect, in both cases using a needle. In group 2, a drop-by-drop cement bridge was reconstructed between the malleus handle (close to the malleus Table 1 Distribution of pathologies per group
neck) and capitulum with a needle. If the bridging distance was >2 mm, a small piece of cartilage or cortical bone, shaped like a match, was placed between the two structures. Finally, this solid link was fixed to the ossicles and coated with cement. In group 3, in case of moderate erosion, a classical Kurz titanium piston was glued to the incus remnant distal extremity using HABC. For extensive erosion, the conic helix of the K-Helix piston was slid onto the incus remnant before applying cement that ‘flows’ around the coil to connect the residual incus. If the incus was absent, the coil was placed as close as possible to the malleus neck and glued to it with HABC. There was no need to interpose cartilage between the cement and eardrum, and the HABC was readily removable with suction in case of leakage and could be easily broken or drilled. The cement hardened within 4–6 min. Grafting of the tympanic membrane was then performed if needed and the ear was closed using a standard technique. When required, tympanic membrane reconstruction was performed at the same time, after ossiculoplasty, using tragal cartilage with or without perichondrium, fascia temporalis or a Tutopatch (Tutogen Medical, Alachua, FL, USA).
Results We retrospectively evaluated 127 ossiculoplasties using HABC. Table 1 shows the distribution of pathologies (chronic otitis media with or without cholesteatoma, otosclerosis, trauma or congenital malformation of the ossicular chain) among the different groups. The mean follow-up was 26 ± 14 months, with a minimum of 6-month follow-up. Ninety-nine tympanic membrane reconstructions were performed. Six subjects presented with anatomical failure (recurrent perforation). Ten patients underwent revision surgery for uncontrolled pathology or functional failure. No extrusion was observed. We also noted stability of hearing outcomes over time, except in patients with a recurrent pathology.
Group 1
Group 2
Group 3B
Group 3F
Total HABC
Austin/Kartush classification Chronic otitis media Cholesteatoma Otosclerosis Trauma Congenital ossicular malformation
A 33 5 0 1 1
A 22 27 0 6 2
B 4 14 0 0 0
F 0 0 12 0 0
59 46 12 7 3
Total
40
57
18
12
127
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Eur Arch Otorhinolaryngol
Fig. 5 Amsterdam hearing evaluation plots (AHEPs). Postoperative gain in air conduction plotted against the preoperative air–bone gap for each operated ear. The solid line indicates total closure of the gap between preoperative air conduction and bone conduction. An unsuccessful operative outcome in terms of air conduction was defined as a negative change in air conduction or a change in air conduction that was not enough to close the gap between postoperative air conduction and preoperative air–bone gap to 20 dB or less. This is indicated by the dotted line
Fig. 6 Amsterdam hearing evaluation plots (AHEPs). Preoperative bone conduction plotted gainst postoperative bone conduction for each operated ear. The two diagonal lines enclose area within bone conduction did not changed over more than 10 dB
Global hearing outcomes are presented in Figs. 5 and 6, following Amsterdam hearing evaluation plots (AHEPs) [8]. No significant bone conduction change was encountered.
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Average significant gains for groups 1, 2, 3B and 3F were 16.2, 13.8, 9.1 and 19.1 dB. Details per group are shown in Table 2.
Eur Arch Otorhinolaryngol Table 2 Preoperative (Preop) and postoperative (Postop) average (means) air–bone gap (ABG), average (means) gain and respective standard deviation (SD) per group at 0.5, 1, 2, and 4 kHz Groups
Preop ABG (dB)
SD (dB)
Postop ABG (dB)
SD (dB)
Average gain (dB)
SD (dB)
1 2 3B
23.4 28.7 32.5
7.4 14.9 23.4
34.0
±6.1 ±11.0 ±14.5
16.2* 13.8* 9.1*
3F
±12.4 ±14.2 ±13.3
±12.9 ±16.6 ±19.3
±11.8
14.9
±14.4
19.1*
±20.9
* Probability value ≤0.05
Percentages of postoperative ABG ≤20 dB were 95, 82.5, 50 and 83.3 % and for ABG ≤10 dB, 80, 50.9, 16.6 and 50 %, for groups 1, 2, 3B and 3F, respectively.
Discussion For many years, bone cements have been used in ear surgery for tegmen dehiscence or craniotomy reconstruction, mastoid or paratympanic space reconstruction, and ossiculoplasty. Since 1998, different types of cement have been described to reconstruct the incus long process with or without a stapes prosthesis, and to secure a partial or total ossicular prosthesis to an ossicle to avoid its migration or extrusion [1, 2, 9–11]. The original concept of using bone cement was to preserve incus remnants and mimic the normal anatomy, which could be beneficial for sound conduction [9]. In our department, we use HABC, a calcium phosphatebased material developed by dental research. HABC has demonstrated both biocompatibility and biostability. It bonds to adjacent bone and stimulates bony ingrowth, resulting in osteointegration. It does not cause foreign body giant cell formation. Moreover, HABC has not been shown to produce toxic reactions or elevated calcium, aluminum or phosphate elimination levels like other types of cements [5]. Glass ionomeric cement is an alternative to HABC. It is a hybrid composite material composed of inorganic aluminum fluorosilicate particles in a hydrogel matrix. This material must be used with caution around neural tissue because of the risk of severe neurological damage due to aluminum toxicity [5]. Side effects such as granulation formation have also been described with glass cements [12]. Moreover, glass ionomeric cements, unlike HABC, require the ossicles to be perfectly free of mucosa and need a very dry surgical field to avoid extrusion. HABC is well tolerated by the middle ear. As observed in ten revision cases for recurrent pathologies, functional or anatomical failures, at least 12 months after primary
surgery, the cement was ossified without any specific granulation tissue reaction and, so far, we have not encountered any extrusion. Important stability of the ossiculoplasty was noted. HABC is simple to use; small quantities of the two components should be mixed until the cement forms a paste that is easily manipulable. Hardening time is long enough to allow adequate application, without extending operating time. Cement removal is not dangerous or difficult to perform. In this study, favorable hearing results were obtained in all groups, without complications related to the HABC or extrusion. Babu et al. [9] also achieved statistically significant hearing improvement and reported no complications linked to reconstruction of incudostapedial disarticulation with HABC and Goebel et al. [11] described use of HABC in different types of ossicular reconstruction, without any extrusion. Elsheikh et al. [4] recommend use of HABC to reconstruct the ossicular chain over the placement of PORPs. Indeed, Babu et al. [9] reported that placement of PORPs runs the risk of prosthesis migration and resultant conductive hearing loss, while using bone cement to reconstruct the ossicular chain restores its integrity in the most natural way, with enduring results. From our previously published experience with 140 titanium prosthesis ossiculoplasties performed by the same surgeons [13], we retrospectively analyzed 36 PORPs (functional stapes and malleus handle, Austin–Kartush type A) and 33 TORPs (no stapes superstrucure and malleus handle, Austin–Kartush type B) using Kurz and Spiggle & Theis (Overath, Germany) prostheses. The prosthesis plate was slid under the malleus handle when possible, but not fixed with cement, and systematic cartilage interposition was carried out. This old group shows postoperative ABG of 16.8 and 16.6 dB, respectively. The percentage of postoperative ABG ≤20 dB was 69 % for PORPs and 70 % for TORPs. With a longer mean follow-up, this historical series of partial titanium prostheses appears to show a higher rate of prosthesis extrusion and worse functional results compared to the equivalent ossiculoplasty using cement (group 2). We
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do not see the same trend for total titanium prostheses and group 3B. Group 3 represents a useful alternative in the challenging situation of moderate or extensive erosion of the long process in stapes surgery, since we believe, like Van Rompaey et al. [2], that placement of a malleovestibular prosthesis is technically more difficult and poses a greater risk to the inner ear. Cement helps achieve solid proximal fixation of the prosthesis, allowing better stability on the footplate. From our experience, when possible, reconstruction of the long process of the incus or incudostapedial joint defect with cement is preferable to partial ossicular reconstruction with HABC. If not appropriate, partial ossicular reconstruction with HABC is favorable over a titanium PORP. In the literature, functional results for group 1 procedure are between 60 and 81 % of residual ABG ≤20 dB [14– 16], and from 64 to 87.5 % for group 2 [16, 17], comparable with our results. Results obtained in this study are promising and appear stable in the medium term, with a follow-up extending to over 60 months with some patients. More studies and series are needed to assess the use of HABC in the long term (power analysis reveals that 85 subjects would be needed in each group to achieve 80 % power). Our good functional results might be explained by the fact that ossicular reconstructions with cement are not limited by their length or axis. Another explanation may be the optimal biointegration potential of such material. Indeed, two revision surgeries have shown the HABC to be firmly attached to the ossicles and looking like natural bone. Moreover, in the tympanic retraction around the cement, there is no sign of inflammation or extrusion, confirming this biointegration. We also noted stability of hearing outcomes over time, except in patients with recurrent pathologies. On the practical and financial side, using HABC reduces the stock of various ossicular prostheses, while its cost is similar to standard prostheses. Twenty patients (16 %) did not obtain satisfactory results (ABG >20 dB). This may have resulted from several causes: suspected fracture of the cement bridge while closing the tympanomeatal flap or packing the external auditory canal, tympanic graft failure, or pathological recurrence and specific congenital ossicular chain malformations.
Conclusion Today, use of HABC could help us improve our functional results and also avoid extrusion. In our experience, ossiculoplasty with HABC provides good and stable functional results. HABC is safe, cost effective and easy to use. Use of cement with or without biocompatible ossicular prostheses allows us to repair
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Eur Arch Otorhinolaryngol
different types of ossicular defects, whilst preserving the anatomical and physiological ossicular chain. Reconstruction of the incus long process or incudostapedial joint defect with cement is favored over partial ossicular reconstruction. In partial ossicular reconstruction, we use HABC between the malleus handle and stapes head instead of the classical partial ossicular reconstruction with a titanium prosthesis or incus interposition. Acknowledgments No fund received for this work. Conflict of interest None of the authors or any relatives have any financial interest in Olympus. Olympus had no part in the writing or approving this manuscript.
References 1. Chen DA, Arriaga MA (2003) Technical refinements and precautions during ionomeric cement reconstruction of incus erosion during revision stapedectomy. Laryngoscope 113(5):848–852 2. Van Rompaey V, Claes G, Somers T et al (2011) Erosion of the long process of the incus in revision stapes surgery: malleovestibular prosthesis or incus reconstruction with hydroxyapatite bone cement. Otol Neurotol 32(6):914–918 3. Kveton JF, Coelho DH (2004) Hydroxyapatite cement in temporal bone surgery: a 10 year experience. Laryngoscope 114(1):33–37 4. Elsheikh MN, Elsherief H, Elsherief S (2006) Physiologic reestablishment of ossicular continuity during excision of retraction pockets: use of hydroxyapatite bone cement for rebridging the incus. Arch Otolaryngol Head Neck Surg 132(2):196–199 5. Hantson P, Mahieu P, Gersdorff M et al (1994) Encephalopathy with seizures after use of aluminium-containing bone cement. Lancet 344(8937):1647 6. Kartush JM (1994) Ossicular chain reconstruction. Capitulum to malleus. Otolaryngol Clin North Am 27:689–715 7. Gurgel RK, Popelka GR, Oghalai JS et al (1995) American Academy of Otolaryngology-Head and Neck Surgery Foundation, Inc Committee on hearing and equilibrium guidelines for the evaluation of results of treatment of conductive hearing loss. Otolaryngol Head Neck Surg 113:186–187 8. de Bruijn AJ, Tange RA, Dreschler WA (2001) Efficacy of evaluation of audiometric results after stapes surgery in otosclerosis. II. A method for reporting results from individual cases. Otolaryngol Head Neck Surg 124(1):84–89 9. Babu S, Seidman MD (2004) Ossicular reconstruction using bone cement. Otol Neurotol 25(2):98–101 10. Feghali JG, Barrs DM, Beatty CW et al (1998) Bone cement reconstruction of the ossicular chain: a preliminary report. Laryngoscope 108(6):829–836 11. Goebel JA, Jacob A (2005) Use of Mimix hydroxyapatite bone cement for difficult ossicular reconstruction. Otolaryngol Head Neck Surg 132(5):727–734 12. Kupperman D, Tange RA (1997) Long-term results of glass ionomer cement, Ionocem, in the middle ear of the rat. Acta Otorhinolaryngol Belg 51(1):27–30 13. De Vos C, Gersdorff M, Gérard JM (2007) Prognostic factors in ossiculoplasty. Otol Neurotol 28(1):61–67 14. Bayazit YA, Ozer E, Kanlikama M et al (2005) Bone cement ossiculoplasty: incus to stapes versus malleus to stapes cement bridge. Otol Neurotol 26(3):364–367
Eur Arch Otorhinolaryngol 15. Ozer E, Bayazit YA, Kanlikama M et al (2002) Incudostapedial rebridging ossiculoplasty with bone cement. Otol Neurotol 23(5):643–646 16. Baglam T, Karatas E, Durucu C et al (2009) Incudostapedial rebridging ossiculoplasty with bone cement. Otolaryngol Head Neck Surg 141(2):243–246
17. Kalcioglu MT, Tan M, Fleerakkers J (2013) The use of bone cement for ossicular chain defects. Eur Arch Otorhinolaryngol 270:2849–2855
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Otology
Ossiculoplasty with hydroxyapatite bone cement: our reconstruction philosophy Jean‑Marc Gérard · Gersende De Bie · Daniel Franceschi · Naima Deggouj · Michel Gersdorff
Received: 21 November 2013 / Accepted: 20 February 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract The main objective of this study is to analyze results obtained with hydroxyapatite bone cement (HABC) ossiculoplasties. This is a retrospective study of a case series. This study was conducted in an academic hospital and tertiary referral center. A total of 127 ossiculoplasties using HABC were evaluated. Ears were divided into three groups according to procedure: group 1 involved reinforcement of the incudostapedial joint with cement and reconstruction of an incus long process defect with cement. Group 2 involved partial ossicular reconstruction between the stapes and malleus handle with HABC. Group 3 was divided into two subgroups. Group 3B entailed reconstruction of the stapes with a mobile footplate (Austin–Kartush type B = group 3B) and group 3F with a fixed footplate (Austin–Kartush type F = group 3F) using a K-Helix piston (Grace Medical, Memphis, TN, USA) or a classical titanium piston (Kurz, Fuerth, Germany) glued to the incus remnant or malleus handle with cement. Anatomical and pre- and postoperative audiological results were assessed. The mean follow-up was 26 ± 14 months. Percentages of average postoperative air–bone gap ≤20 dB were 95, 82.5, 50 and 83.3 %, and for air–bone gap ≤10 dB, 80, 50.9, 16.6 and 50 % for groups 1, 2, 3B and 3F, respectively. No complications related to the cement or extrusion occurred. Hearing outcomes also remained stable over time. In
J.-M. Gérard (*) · G. De Bie · D. Franceschi · N. Deggouj Department of ENT and Head and Neck Surgery, Saint-Luc University Hospital, 1200 Brussels, Belgium e-mail: j‑[email protected] M. Gersdorff Department of ENT and Head and Neck Surgery, Saint-Elisabeth Hospital, 1180 Brussels, Belgium
our experience, ossiculoplasty with cement provides good and stable functional results, is safe, cost effective, and easy to use. HABC with or without biocompatible ossicular prostheses allows repair of different types of ossicular defects with preservation of the anatomical and physiological ossicular chain, as well as improved stability. Reconstruction of the incus long process or incudostapedial joint defect with cement is preferred over partial ossicular reconstruction. Keywords Cement · Ossiculoplasty · Tympanoplasty · Hydroxyapatite
Introduction Ossiculoplasty using bone cement is an alternative to classical prostheses to reconstruct the ossicular chain. It can also be used in stapedectomy, especially in revision surgery to reconstruct the long process of the incus or fix a stapes prosthesis to the incus remnant [1, 2]. Since its introduction to ear surgery in 1996, hydroxyapatite bone cement (HABC) has been successfully used to restore a functional ossicular chain. HABC is a calcium phosphate cement that sets to hydroxyapatite, the major component of human skeletal bone, and becomes like natural bone over time. This cement can be shaped before hardening, bonds directly to bone [3] and metal, does not require complete mucosal removal, is not sensitive to surrounding fluids like blood or water [4], can be easily removed or broken, and is not neurotoxic unlike glass ionomer cement [5]. Here, we report our audiological and anatomical results after reconstruction of the ossicular chain using HABC.
13
Subjects and methods
Eur Arch Otorhinolaryngol
We conducted a retrospective study with the approval of the biomedical ethics committee for hospitals and the medical faculty of the University of Louvain. All ossiculoplasties using HABC (Otomimix, Olympus Corp., Tokyo, Japan), performed by an experienced senior surgeon (JMG) between August 2007 and January 2013 and having a minimum of 6-months postoperative follow-up, were evaluated. One hundred and twenty-seven ears were divided into three groups according to procedure. In group 1, the incudostapedial joint was reinforced and the incus long process defect reconstructed with HABC (Fig 1).
In group 2, partial ossicular reconstruction was carried out between the stapes and malleus handle with HABC (Fig 2). Group 3 was divided into two subgroups according to Austin’s classification of ossicular defects, as modified by Kartush [6]. In group 3B (Fig 3), with a mobile footplate (Austin–Kartush type B), the stapes reconstruction was done with a titanium prosthesis on the footplate fixed to the upper ossicular structure using HABC. In group 3F (Fig 4) with a fixed footplate (Austin–Kartush type F), the stapes reconstruction was done with a titanium prosthesis in a calibrated platinotomy fixed to the upper ossicular structure using HABC. In case of small or moderate erosion of the incus long process, a classical titanium piston (Kurz,
Fig. 1 Group 1: Reinforcement of the incudostapedial joint and reconstruction of an incus long process defect with HABC (in red)
Fig. 3 Group 3A: Reconstruction of the stapes with a mobile footplate using a titanium prosthesis attached to the malleus handle or incus long process remnant using HABC (in red)
Fig. 2 Group 2: Partial ossicular reconstruction between the stapes and malleus handle with HABC (in red)
Fig. 4 Group 3F: Reconstruction of the stapes with a fixed footplate using a titanium prosthesis attached to the incus long process remnant using HABC (in red)
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Fuerth, Germany) was glued to the incus remnant with HABC. In case of extensive erosion of the long process of the incus, a K-Helix piston (Grace Medical, Memphis, TN, USA), a titanium piston with a conic helix allowing the cement to ‘flo’ around the coils slipped onto the incus remnant, was used. If the incus was absent, the K-Helix piston was glued to the malleus handle with HABC. Groups 1, 2, 3B and 3F included 40, 57, 18 and 12 cases, respectively. Audiological tests were performed using two audiometers (Madsen Otometrics, Tasstrup, Danemark: Orbiter 922-2 and Interacoustics, model AC40). Hearing results were reported at four frequencies, 0.5, 1, 2 and 4 kHz, and not at 3 kHz according to the guidelines of the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium [7]. Postoperative air and bone conduction were evaluated. Results retained for statistical purposes were last obtained during the follow-up period or prior to revision surgery for functional or pathological reasons. The mean postoperative air–bone gap (ABG) was calculated as the postoperative air conduction pure-tone average minus the postoperative bone conduction pure-tone average at the four respective frequencies. Statistical analysis was conducted with Excel 98 by Microsoft (Redmond, WA, USA). The statistical significance of pre- and postoperative differences in means (gains) of data was determined using Student’s t test. A probability value of p = 0.05 was the level of significance selected. Surgery was performed by a retroauricular or endaural approach. A transmastoid approach with removal of the disease from the middle ear was used when required. Ossiculoplasty was then carried out. A small quantity of calcium phosphate powder was mixed with the solvent according to the manufacturer’s specifications for 30–45 s before use, producing a minimal exothermic reaction. In group 1, a drop of cement was applied to repair the incudostapedial joint defect, or a drop-by-drop technique was used to restore the incus long process defect, in both cases using a needle. In group 2, a drop-by-drop cement bridge was reconstructed between the malleus handle (close to the malleus Table 1 Distribution of pathologies per group
neck) and capitulum with a needle. If the bridging distance was >2 mm, a small piece of cartilage or cortical bone, shaped like a match, was placed between the two structures. Finally, this solid link was fixed to the ossicles and coated with cement. In group 3, in case of moderate erosion, a classical Kurz titanium piston was glued to the incus remnant distal extremity using HABC. For extensive erosion, the conic helix of the K-Helix piston was slid onto the incus remnant before applying cement that ‘flows’ around the coil to connect the residual incus. If the incus was absent, the coil was placed as close as possible to the malleus neck and glued to it with HABC. There was no need to interpose cartilage between the cement and eardrum, and the HABC was readily removable with suction in case of leakage and could be easily broken or drilled. The cement hardened within 4–6 min. Grafting of the tympanic membrane was then performed if needed and the ear was closed using a standard technique. When required, tympanic membrane reconstruction was performed at the same time, after ossiculoplasty, using tragal cartilage with or without perichondrium, fascia temporalis or a Tutopatch (Tutogen Medical, Alachua, FL, USA).
Results We retrospectively evaluated 127 ossiculoplasties using HABC. Table 1 shows the distribution of pathologies (chronic otitis media with or without cholesteatoma, otosclerosis, trauma or congenital malformation of the ossicular chain) among the different groups. The mean follow-up was 26 ± 14 months, with a minimum of 6-month follow-up. Ninety-nine tympanic membrane reconstructions were performed. Six subjects presented with anatomical failure (recurrent perforation). Ten patients underwent revision surgery for uncontrolled pathology or functional failure. No extrusion was observed. We also noted stability of hearing outcomes over time, except in patients with a recurrent pathology.
Group 1
Group 2
Group 3B
Group 3F
Total HABC
Austin/Kartush classification Chronic otitis media Cholesteatoma Otosclerosis Trauma Congenital ossicular malformation
A 33 5 0 1 1
A 22 27 0 6 2
B 4 14 0 0 0
F 0 0 12 0 0
59 46 12 7 3
Total
40
57
18
12
127
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Fig. 5 Amsterdam hearing evaluation plots (AHEPs). Postoperative gain in air conduction plotted against the preoperative air–bone gap for each operated ear. The solid line indicates total closure of the gap between preoperative air conduction and bone conduction. An unsuccessful operative outcome in terms of air conduction was defined as a negative change in air conduction or a change in air conduction that was not enough to close the gap between postoperative air conduction and preoperative air–bone gap to 20 dB or less. This is indicated by the dotted line
Fig. 6 Amsterdam hearing evaluation plots (AHEPs). Preoperative bone conduction plotted gainst postoperative bone conduction for each operated ear. The two diagonal lines enclose area within bone conduction did not changed over more than 10 dB
Global hearing outcomes are presented in Figs. 5 and 6, following Amsterdam hearing evaluation plots (AHEPs) [8]. No significant bone conduction change was encountered.
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Average significant gains for groups 1, 2, 3B and 3F were 16.2, 13.8, 9.1 and 19.1 dB. Details per group are shown in Table 2.
Eur Arch Otorhinolaryngol Table 2 Preoperative (Preop) and postoperative (Postop) average (means) air–bone gap (ABG), average (means) gain and respective standard deviation (SD) per group at 0.5, 1, 2, and 4 kHz Groups
Preop ABG (dB)
SD (dB)
Postop ABG (dB)
SD (dB)
Average gain (dB)
SD (dB)
1 2 3B
23.4 28.7 32.5
7.4 14.9 23.4
34.0
±6.1 ±11.0 ±14.5
16.2* 13.8* 9.1*
3F
±12.4 ±14.2 ±13.3
±12.9 ±16.6 ±19.3
±11.8
14.9
±14.4
19.1*
±20.9
* Probability value ≤0.05
Percentages of postoperative ABG ≤20 dB were 95, 82.5, 50 and 83.3 % and for ABG ≤10 dB, 80, 50.9, 16.6 and 50 %, for groups 1, 2, 3B and 3F, respectively.
Discussion For many years, bone cements have been used in ear surgery for tegmen dehiscence or craniotomy reconstruction, mastoid or paratympanic space reconstruction, and ossiculoplasty. Since 1998, different types of cement have been described to reconstruct the incus long process with or without a stapes prosthesis, and to secure a partial or total ossicular prosthesis to an ossicle to avoid its migration or extrusion [1, 2, 9–11]. The original concept of using bone cement was to preserve incus remnants and mimic the normal anatomy, which could be beneficial for sound conduction [9]. In our department, we use HABC, a calcium phosphatebased material developed by dental research. HABC has demonstrated both biocompatibility and biostability. It bonds to adjacent bone and stimulates bony ingrowth, resulting in osteointegration. It does not cause foreign body giant cell formation. Moreover, HABC has not been shown to produce toxic reactions or elevated calcium, aluminum or phosphate elimination levels like other types of cements [5]. Glass ionomeric cement is an alternative to HABC. It is a hybrid composite material composed of inorganic aluminum fluorosilicate particles in a hydrogel matrix. This material must be used with caution around neural tissue because of the risk of severe neurological damage due to aluminum toxicity [5]. Side effects such as granulation formation have also been described with glass cements [12]. Moreover, glass ionomeric cements, unlike HABC, require the ossicles to be perfectly free of mucosa and need a very dry surgical field to avoid extrusion. HABC is well tolerated by the middle ear. As observed in ten revision cases for recurrent pathologies, functional or anatomical failures, at least 12 months after primary
surgery, the cement was ossified without any specific granulation tissue reaction and, so far, we have not encountered any extrusion. Important stability of the ossiculoplasty was noted. HABC is simple to use; small quantities of the two components should be mixed until the cement forms a paste that is easily manipulable. Hardening time is long enough to allow adequate application, without extending operating time. Cement removal is not dangerous or difficult to perform. In this study, favorable hearing results were obtained in all groups, without complications related to the HABC or extrusion. Babu et al. [9] also achieved statistically significant hearing improvement and reported no complications linked to reconstruction of incudostapedial disarticulation with HABC and Goebel et al. [11] described use of HABC in different types of ossicular reconstruction, without any extrusion. Elsheikh et al. [4] recommend use of HABC to reconstruct the ossicular chain over the placement of PORPs. Indeed, Babu et al. [9] reported that placement of PORPs runs the risk of prosthesis migration and resultant conductive hearing loss, while using bone cement to reconstruct the ossicular chain restores its integrity in the most natural way, with enduring results. From our previously published experience with 140 titanium prosthesis ossiculoplasties performed by the same surgeons [13], we retrospectively analyzed 36 PORPs (functional stapes and malleus handle, Austin–Kartush type A) and 33 TORPs (no stapes superstrucure and malleus handle, Austin–Kartush type B) using Kurz and Spiggle & Theis (Overath, Germany) prostheses. The prosthesis plate was slid under the malleus handle when possible, but not fixed with cement, and systematic cartilage interposition was carried out. This old group shows postoperative ABG of 16.8 and 16.6 dB, respectively. The percentage of postoperative ABG ≤20 dB was 69 % for PORPs and 70 % for TORPs. With a longer mean follow-up, this historical series of partial titanium prostheses appears to show a higher rate of prosthesis extrusion and worse functional results compared to the equivalent ossiculoplasty using cement (group 2). We
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do not see the same trend for total titanium prostheses and group 3B. Group 3 represents a useful alternative in the challenging situation of moderate or extensive erosion of the long process in stapes surgery, since we believe, like Van Rompaey et al. [2], that placement of a malleovestibular prosthesis is technically more difficult and poses a greater risk to the inner ear. Cement helps achieve solid proximal fixation of the prosthesis, allowing better stability on the footplate. From our experience, when possible, reconstruction of the long process of the incus or incudostapedial joint defect with cement is preferable to partial ossicular reconstruction with HABC. If not appropriate, partial ossicular reconstruction with HABC is favorable over a titanium PORP. In the literature, functional results for group 1 procedure are between 60 and 81 % of residual ABG ≤20 dB [14– 16], and from 64 to 87.5 % for group 2 [16, 17], comparable with our results. Results obtained in this study are promising and appear stable in the medium term, with a follow-up extending to over 60 months with some patients. More studies and series are needed to assess the use of HABC in the long term (power analysis reveals that 85 subjects would be needed in each group to achieve 80 % power). Our good functional results might be explained by the fact that ossicular reconstructions with cement are not limited by their length or axis. Another explanation may be the optimal biointegration potential of such material. Indeed, two revision surgeries have shown the HABC to be firmly attached to the ossicles and looking like natural bone. Moreover, in the tympanic retraction around the cement, there is no sign of inflammation or extrusion, confirming this biointegration. We also noted stability of hearing outcomes over time, except in patients with recurrent pathologies. On the practical and financial side, using HABC reduces the stock of various ossicular prostheses, while its cost is similar to standard prostheses. Twenty patients (16 %) did not obtain satisfactory results (ABG >20 dB). This may have resulted from several causes: suspected fracture of the cement bridge while closing the tympanomeatal flap or packing the external auditory canal, tympanic graft failure, or pathological recurrence and specific congenital ossicular chain malformations.
Conclusion Today, use of HABC could help us improve our functional results and also avoid extrusion. In our experience, ossiculoplasty with HABC provides good and stable functional results. HABC is safe, cost effective and easy to use. Use of cement with or without biocompatible ossicular prostheses allows us to repair
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Eur Arch Otorhinolaryngol
different types of ossicular defects, whilst preserving the anatomical and physiological ossicular chain. Reconstruction of the incus long process or incudostapedial joint defect with cement is favored over partial ossicular reconstruction. In partial ossicular reconstruction, we use HABC between the malleus handle and stapes head instead of the classical partial ossicular reconstruction with a titanium prosthesis or incus interposition. Acknowledgments No fund received for this work. Conflict of interest None of the authors or any relatives have any financial interest in Olympus. Olympus had no part in the writing or approving this manuscript.
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