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Endoscopic-Assisted Rigid Fixation of Condylar Fracture: A Technical Note
TECHNICAL NOTES J Oral Maxillofac Surg 64:1443-1446, 2006
Endoscopic-Assisted Rigid Fixation of Condylar Fracture: A Technical Note John Lo, BDS(HK), MDS(HK), MOSRCS(Edin), FCDSHK(OMFS), FHKAM(DS),* and Lim K. Cheung, BDS(Glas), PhD(HK), FFDRCS(Ire), FDSRCPS(Glas), FRACDS(Aust), FRACDS(OMS), FHKAM(DS), FCDSHK(OMS), FFGDP(UK), FDSRCS(Edin)† Endoscopic-assisted reduction and fixation has been commonly used in the management of maxillofacial trauma since 1995.1 This procedure is minimally invasive and yet able to provide greater visibility of the operating site without the need for a large incision, and hence reduces the extent of surgical scar and risk to the facial nerve. In cases of subcondylar or condylar neck fracture where the condyle fragment is displaced but without dislocation, it has been shown that the fractures could be reduced and fixed by intraoral approach assisted with an endoscope.1,2 In condylar neck fractures with medial dislocation, endoscopic assisted reduction has proven to be very difficult or impossible by intraoral approach alone. An extraoral approach using a submandibular incision alone or a combined extra- and intraoral approach has been advocated.2 The aim of this article is to report our technique of using endoscopic-assisted fixation with the use of some newly developed instruments for medially dislocated and nondislocated displaced condylar fractures.
gle illuminated by a xenon light source (7200B, Karl Storz, Tuttlingen, Germany) and a set of condylar fracture fixation system (Synthes, Paoli, PA) (Fig 1). The endoscope could be incorporated into a specially designed tissue dissector or a modified posterior border retractor (Fig 1). ENDOSCOPIC-ASSISTED FIXATION FOR NONDISLOCATED CONDYLAR FRACTURE
An intraoral mucosal incision is designed from the ascending ramus down to the vestibular mucosa lateral to the lower first molar region. Subperiosteal dissection exposes the lateral part of the mandibular ramus, posterior border, sigmoid notch and the gonial angle. A sigmoid notch retractor and a modified pos-
Methods SURGICAL ARMAMENTARIUM
The basic surgical armamentarium included a 4-mm diameter straight endoscope with 30° optical tip anReceived from the Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China. *Clinical Assistant Professor. †Chair Professor. This study received support in the form of a grant from the AO ASIF Research Commission, Dübendorf, Switzerland. Address correspondence and reprint requests to Dr Lo: Oral and Maxillofacial Surgery, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China; e-mail: [email protected] © 2006 American Association of Oral and Maxillofacial Surgeons
0278-2391/06/6409-0021$32.00/0 doi:10.1016/j.joms.2006.05.029
FIGURE 1. A, Straight endoscope inside a special design tissue dissector. B, Straight endoscope inserted anterior to a modified posterior border retractor. Lo and Cheung. Endoscopic-Assisted Fixation of Condylar Fracture. J Oral Maxillofac Surg 2006.
1443
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ENDOSCOPIC-ASSISTED FIXATION OF CONDYLAR FRACTURE
FIGURE 2. A 29-year-old man presented with fracture at the right parasymphysis and left subcondylar region. Reduction and fixation of subcondylar segment assisted by endoscope was via intraoral approach. A, Preoperative panoramic and B, preoperative postero-anterior cephalometric radiographs illustrating the fracture parasymphysis and left condyle. C, Postoperative panoramic, and D, postoperative postero-anterior cephalometric radiographs illustrating a good anatomical reduction and fixation with titanium plates. Lo and Cheung. Endoscopic-Assisted Fixation of Condylar Fracture. J Oral Maxillofac Surg 2006.
terior border retractor are then placed in their respective locations to provide access for the endoscope and the subsequent plate fixation. The endoscope is inserted intraorally through the subperiosteal pocket of the lateral ramus to verify the fracture line. The occlusion is then wired together by intermaxillary fixation using arch bars. The nondislocated condylar segment is reduced using a combination of straight and angle periosteal elevators. A titanium compression miniplate (Catalog No. 443.460, Synthes) purposely designed for condylar fixation can be selected to adapt over the condylar segment and ramus. The transoral endoscope can provide good visibility of the fractured condylar segment and the lower part of the titanium plate. Under endoscopic guidance, fixation of the condylar segment is achieved with 2 or 3 titanium screws through a transbuccal route created by a 3-mm
stab incision made on the ear fold below the pinna. Precise anatomical reduction of the condylar segment over the mandibular ramus is achieved using a modified nerve hook and a long periosteal elevator (Synthes). Final fixation to the mandibular ramus is then achieved with 2 or 3 titanium screws to the lower part of the plate transbuccally as described above, or transorally using a right angle screwdriver drill. The intermaxillary fixation is removed to check for any occlusal shift. The wound is then closed primarily when a stable occlusion in retruded contact position is achieved (Fig 2). ENDOSCOPIC-ASSISTED FIXATION FOR DISLOCATED CONDYLAR FRACTURE
In cases of condylar fracture with medially dislocated condyle, an intraoral reduction is considered
LO AND CHEUNG
1445
FIGURE 3. A 16-year-old boy presented with left medially dislocated fracture condyle. Reduction and fixation assisted by endoscope was through a combined intraoral and preauricular approach. A, Preoperative panoramic and B, preoperative postero-anterior cephalometric radiographs showing a medial dislocated condyle. C, A modified preauricular approach for reduction of fracture. D, Fixation of condylar fragment with titanium plate and screws. E, Postoperative panoramic and F, postoperative postero-anterior cephalometric radiographs showing a good anatomical reduction and fixation with titanium plate. Lo and Cheung. Endoscopic-Assisted Fixation of Condylar Fracture. J Oral Maxillofac Surg 2006.
1446 very difficult or virtually impossible. A preauricular incision with temporal extension provides the best access for reducing the medially dislocated condyle. With the zygomatic arch and glenoid fossa exposed by subperiosteal dissection, the displaced condylar segment can be mobilized back to the glenoid fossa with a pair of manipulation forceps. Reduction of the fracture is facilitated by forceful mouth opening to allow the fractured condylar head to be relocated into the fossa. One titanium compression miniplate (Catalog No. 443.450, Synthes) is selected to adapt over the condylar segment and fixation is achieved with 2 or 3 titanium screws. The endoscope is inserted intraorally and manipulated to ascend cranially in order to visualize the fractured condylar neck and the lower part of the titanium plate. Precise anatomical reduction can be achieved by pulling down the plate attached to the condylar segment using a modified nerve hook (Synthes). Further stabilization is facilitated with a long periosteal elevator, angle elevator and modified posterior border retractor. A 3-mm stab incision is made on the skin fold below the ear pinna for access by a transbuccal trocar. Final fixation to the mandibular ramus is achieved with 2 titanium screws to the lower part of the plate through a transbuccal route. A right angle screwdriver drill can be used to apply these screws below the fracture line if available. The intermaxillary fixation is removed to check the occlusion (Fig 3).
Discussion This Technical Note illustrates the 2 endoscopic approaches commonly used for the management of condylar fractures. With precise anatomical reduction, the temporomandibular joint function can be restored more easily. Postoperative intermaxillary fixation can be avoidable. A preliminary study confirmed that unrestricted joint movement without any dysfunction can be achieved after endoscopic-assisted rigid fixation of condylar fracture.3 In management of subcondylar fracture or low-level condylar neck fracture where the condylar fragment is dislocated laterally, an endoscope-assisted intraoral approach can be adequate; whereas a medially dislocated condylar fracture, a preauricular approach should be added to relocate the condyle and fixation of the screws on the condylar segment. It is noteworthy that the endoscope, after being incorporated into the modified posterior border retractor, can provide a good light source to the operation site for reduction
ENDOSCOPIC-ASSISTED FIXATION OF CONDYLAR FRACTURE
and fixation under direct vision. During fixation, a stab incision is normally required for the transbuccal fixation to the mandibular ramus region. This incision is avoidable if a right-angle screwdriver drill is used, further minimizing additional facial scars. Apart from the preauricular approach, surgical access of the medially dislocated condyle can be acheived via a submandibular or a retromandibular approach. The use of the submandibular approach alone for the application of an endoscope and subsequent reduction and fixation has been recommended.4 Apart from the presence of a lengthy submandibular scar, the risk to the marginal mandibular nerve needs to be considered. In reduction of a medially dislocated condylar fracture, submandibular access is extremely difficult because 1) the ramus fragment normally rises upward into the condylar fossa and obscures the view of the dislocated segment, and 2) the distance from the skin surface to the fracture site is long, hence visibility is naturally poor even with additional light from the endoscope. A retromandibular approach can offer relatively good access to the condylar region owing to the close proximity of the fracture site. However, some difficulties are expected, such as dissection of the marginal mandibular and the buccal branches of facial nerves from the enveloping parotid glandular tissues, which increases the risk of facial nerve damage subsequently.5 The disadvantage of a conventional preauricular approach is a more obvious exposed scar when compared with the scars from submandibular and retromandibular approaches. With the use of an endoscope, the length of the incision can be shortened. In our center, we have modified the preauricular incision medial to the tragus, resulting in a more camouflaged scar than the conventional preauricular scar.
References 1. Chen CT, Lai JP, Tung TC, et al: Endoscopically assisted mandibular subcondylar fracture repair. Plast Reconstr Surg 103:60, 1999 2. Schon R, Gutwald R, Schramm A, et al: Endoscopy-assisted open treatment of condylar fractures of the mandible: Extraoral vs intraoral approach. Int J Oral Maxillofac Surg 31:237, 2002 3. Schon R, Schramm A, Gellrich NC, et al: Follow-up of condylar fractures of the mandible in 8 patients at 18 months after transoral endoscopic-assisted open treatment. J Oral Maxillofac Surg 61:49, 2003 4. Troulis MJ, Kaban LB: Endoscopic approach to the ramus/condyle unit: Clinical applications. J Oral Maxillofac Surg 59:503, 2001 5. Ellis E, Dean J, el-Attar A: Rigid fixation of mandibular condyle fractures. Oral Surg Oral Med Oral Pathol 76:6, 1993
Endoscopic-Assisted Rigid Fixation of Condylar Fracture: A Technical Note John Lo, BDS(HK), MDS(HK), MOSRCS(Edin), FCDSHK(OMFS), FHKAM(DS),* and Lim K. Cheung, BDS(Glas), PhD(HK), FFDRCS(Ire), FDSRCPS(Glas), FRACDS(Aust), FRACDS(OMS), FHKAM(DS), FCDSHK(OMS), FFGDP(UK), FDSRCS(Edin)† Endoscopic-assisted reduction and fixation has been commonly used in the management of maxillofacial trauma since 1995.1 This procedure is minimally invasive and yet able to provide greater visibility of the operating site without the need for a large incision, and hence reduces the extent of surgical scar and risk to the facial nerve. In cases of subcondylar or condylar neck fracture where the condyle fragment is displaced but without dislocation, it has been shown that the fractures could be reduced and fixed by intraoral approach assisted with an endoscope.1,2 In condylar neck fractures with medial dislocation, endoscopic assisted reduction has proven to be very difficult or impossible by intraoral approach alone. An extraoral approach using a submandibular incision alone or a combined extra- and intraoral approach has been advocated.2 The aim of this article is to report our technique of using endoscopic-assisted fixation with the use of some newly developed instruments for medially dislocated and nondislocated displaced condylar fractures.
gle illuminated by a xenon light source (7200B, Karl Storz, Tuttlingen, Germany) and a set of condylar fracture fixation system (Synthes, Paoli, PA) (Fig 1). The endoscope could be incorporated into a specially designed tissue dissector or a modified posterior border retractor (Fig 1). ENDOSCOPIC-ASSISTED FIXATION FOR NONDISLOCATED CONDYLAR FRACTURE
An intraoral mucosal incision is designed from the ascending ramus down to the vestibular mucosa lateral to the lower first molar region. Subperiosteal dissection exposes the lateral part of the mandibular ramus, posterior border, sigmoid notch and the gonial angle. A sigmoid notch retractor and a modified pos-
Methods SURGICAL ARMAMENTARIUM
The basic surgical armamentarium included a 4-mm diameter straight endoscope with 30° optical tip anReceived from the Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China. *Clinical Assistant Professor. †Chair Professor. This study received support in the form of a grant from the AO ASIF Research Commission, Dübendorf, Switzerland. Address correspondence and reprint requests to Dr Lo: Oral and Maxillofacial Surgery, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China; e-mail: [email protected] © 2006 American Association of Oral and Maxillofacial Surgeons
0278-2391/06/6409-0021$32.00/0 doi:10.1016/j.joms.2006.05.029
FIGURE 1. A, Straight endoscope inside a special design tissue dissector. B, Straight endoscope inserted anterior to a modified posterior border retractor. Lo and Cheung. Endoscopic-Assisted Fixation of Condylar Fracture. J Oral Maxillofac Surg 2006.
1443
1444
ENDOSCOPIC-ASSISTED FIXATION OF CONDYLAR FRACTURE
FIGURE 2. A 29-year-old man presented with fracture at the right parasymphysis and left subcondylar region. Reduction and fixation of subcondylar segment assisted by endoscope was via intraoral approach. A, Preoperative panoramic and B, preoperative postero-anterior cephalometric radiographs illustrating the fracture parasymphysis and left condyle. C, Postoperative panoramic, and D, postoperative postero-anterior cephalometric radiographs illustrating a good anatomical reduction and fixation with titanium plates. Lo and Cheung. Endoscopic-Assisted Fixation of Condylar Fracture. J Oral Maxillofac Surg 2006.
terior border retractor are then placed in their respective locations to provide access for the endoscope and the subsequent plate fixation. The endoscope is inserted intraorally through the subperiosteal pocket of the lateral ramus to verify the fracture line. The occlusion is then wired together by intermaxillary fixation using arch bars. The nondislocated condylar segment is reduced using a combination of straight and angle periosteal elevators. A titanium compression miniplate (Catalog No. 443.460, Synthes) purposely designed for condylar fixation can be selected to adapt over the condylar segment and ramus. The transoral endoscope can provide good visibility of the fractured condylar segment and the lower part of the titanium plate. Under endoscopic guidance, fixation of the condylar segment is achieved with 2 or 3 titanium screws through a transbuccal route created by a 3-mm
stab incision made on the ear fold below the pinna. Precise anatomical reduction of the condylar segment over the mandibular ramus is achieved using a modified nerve hook and a long periosteal elevator (Synthes). Final fixation to the mandibular ramus is then achieved with 2 or 3 titanium screws to the lower part of the plate transbuccally as described above, or transorally using a right angle screwdriver drill. The intermaxillary fixation is removed to check for any occlusal shift. The wound is then closed primarily when a stable occlusion in retruded contact position is achieved (Fig 2). ENDOSCOPIC-ASSISTED FIXATION FOR DISLOCATED CONDYLAR FRACTURE
In cases of condylar fracture with medially dislocated condyle, an intraoral reduction is considered
LO AND CHEUNG
1445
FIGURE 3. A 16-year-old boy presented with left medially dislocated fracture condyle. Reduction and fixation assisted by endoscope was through a combined intraoral and preauricular approach. A, Preoperative panoramic and B, preoperative postero-anterior cephalometric radiographs showing a medial dislocated condyle. C, A modified preauricular approach for reduction of fracture. D, Fixation of condylar fragment with titanium plate and screws. E, Postoperative panoramic and F, postoperative postero-anterior cephalometric radiographs showing a good anatomical reduction and fixation with titanium plate. Lo and Cheung. Endoscopic-Assisted Fixation of Condylar Fracture. J Oral Maxillofac Surg 2006.
1446 very difficult or virtually impossible. A preauricular incision with temporal extension provides the best access for reducing the medially dislocated condyle. With the zygomatic arch and glenoid fossa exposed by subperiosteal dissection, the displaced condylar segment can be mobilized back to the glenoid fossa with a pair of manipulation forceps. Reduction of the fracture is facilitated by forceful mouth opening to allow the fractured condylar head to be relocated into the fossa. One titanium compression miniplate (Catalog No. 443.450, Synthes) is selected to adapt over the condylar segment and fixation is achieved with 2 or 3 titanium screws. The endoscope is inserted intraorally and manipulated to ascend cranially in order to visualize the fractured condylar neck and the lower part of the titanium plate. Precise anatomical reduction can be achieved by pulling down the plate attached to the condylar segment using a modified nerve hook (Synthes). Further stabilization is facilitated with a long periosteal elevator, angle elevator and modified posterior border retractor. A 3-mm stab incision is made on the skin fold below the ear pinna for access by a transbuccal trocar. Final fixation to the mandibular ramus is achieved with 2 titanium screws to the lower part of the plate through a transbuccal route. A right angle screwdriver drill can be used to apply these screws below the fracture line if available. The intermaxillary fixation is removed to check the occlusion (Fig 3).
Discussion This Technical Note illustrates the 2 endoscopic approaches commonly used for the management of condylar fractures. With precise anatomical reduction, the temporomandibular joint function can be restored more easily. Postoperative intermaxillary fixation can be avoidable. A preliminary study confirmed that unrestricted joint movement without any dysfunction can be achieved after endoscopic-assisted rigid fixation of condylar fracture.3 In management of subcondylar fracture or low-level condylar neck fracture where the condylar fragment is dislocated laterally, an endoscope-assisted intraoral approach can be adequate; whereas a medially dislocated condylar fracture, a preauricular approach should be added to relocate the condyle and fixation of the screws on the condylar segment. It is noteworthy that the endoscope, after being incorporated into the modified posterior border retractor, can provide a good light source to the operation site for reduction
ENDOSCOPIC-ASSISTED FIXATION OF CONDYLAR FRACTURE
and fixation under direct vision. During fixation, a stab incision is normally required for the transbuccal fixation to the mandibular ramus region. This incision is avoidable if a right-angle screwdriver drill is used, further minimizing additional facial scars. Apart from the preauricular approach, surgical access of the medially dislocated condyle can be acheived via a submandibular or a retromandibular approach. The use of the submandibular approach alone for the application of an endoscope and subsequent reduction and fixation has been recommended.4 Apart from the presence of a lengthy submandibular scar, the risk to the marginal mandibular nerve needs to be considered. In reduction of a medially dislocated condylar fracture, submandibular access is extremely difficult because 1) the ramus fragment normally rises upward into the condylar fossa and obscures the view of the dislocated segment, and 2) the distance from the skin surface to the fracture site is long, hence visibility is naturally poor even with additional light from the endoscope. A retromandibular approach can offer relatively good access to the condylar region owing to the close proximity of the fracture site. However, some difficulties are expected, such as dissection of the marginal mandibular and the buccal branches of facial nerves from the enveloping parotid glandular tissues, which increases the risk of facial nerve damage subsequently.5 The disadvantage of a conventional preauricular approach is a more obvious exposed scar when compared with the scars from submandibular and retromandibular approaches. With the use of an endoscope, the length of the incision can be shortened. In our center, we have modified the preauricular incision medial to the tragus, resulting in a more camouflaged scar than the conventional preauricular scar.
References 1. Chen CT, Lai JP, Tung TC, et al: Endoscopically assisted mandibular subcondylar fracture repair. Plast Reconstr Surg 103:60, 1999 2. Schon R, Gutwald R, Schramm A, et al: Endoscopy-assisted open treatment of condylar fractures of the mandible: Extraoral vs intraoral approach. Int J Oral Maxillofac Surg 31:237, 2002 3. Schon R, Schramm A, Gellrich NC, et al: Follow-up of condylar fractures of the mandible in 8 patients at 18 months after transoral endoscopic-assisted open treatment. J Oral Maxillofac Surg 61:49, 2003 4. Troulis MJ, Kaban LB: Endoscopic approach to the ramus/condyle unit: Clinical applications. J Oral Maxillofac Surg 59:503, 2001 5. Ellis E, Dean J, el-Attar A: Rigid fixation of mandibular condyle fractures. Oral Surg Oral Med Oral Pathol 76:6, 1993