Feasibility of Purely Endoscopic Intramedullary Fixation of Mandibular Condyle Fractures Paul C. Frake, MD, Joseph F. Goodman, MD, and Arjun S. Joshi, MD (J Craniofac Surg 2015;26: 91–93) Abstract: The investigators of this study hypothesized that fractures of the mandibular condyle can be repaired using short-segment intramedullary implants and purely endoscopic surgical technique, using a basic science, human cadaver model in an academic center. Endoscopic instrumentation was used through a transoral mucosal incision to place intramedullary implants of 2 cm in length into osteotomized mandibular condyles. The surgical maneuvers that required to insert these implants, including condyle positioning, reaming, implant insertion, and seating of the mandibular ramus, are described herein. Primary outcome was considered as successful completion of the procedure. Ten cadaveric mandibular condyles were successfully repaired with rigid intramedullary internal fixation without the use of external incisions. Both insertion of a pegtype implant and screwing a threaded implant into the condylar head were possible. The inferior portion of the implant remained exposed, and the ramus of the mandible was manipulated into position on the implant using retraction at the sigmoid notch. The results of this study suggest that purely endoscopic repair of fractures of the mandibular condyle is possible by using short-segment intramedullary titanium implants and a transoral endoscopic approach without the need for facial incisions or punctures. The biomechanical advantages of these intramedullary implants, including improved strength and resistance to mechanical failure compared with miniplates, have been recently established. The combination of improved implant design and purely endoscopic technique may allow for improved fixation and reduced surgical- and implantrelated morbidity in the treatment of condylar fractures. Key Words: Intramedullary fixation, internal fixation, mandible, mandible fracture, mandibular condyle, condyle, fracture, endoscope, endoscopic surgery From the Division of Otolaryngology–Head and Neck Surgery, The George Washington University Medical Center, Washington, DC. Received May 19, 2014. Accepted for publication July 31, 2014. Address correspondence and reprint requests to Arjun S. Joshi, MD, 2021 K St, NW, Suite 206, Washington, DC, 20006; E-mail: [email protected] Supported by a trauma research grant from AO North America. The funding source had no role in study design, conduct, data collection, analysis, interpretation, writing, or approval of this article. Disclosures: Paul Frake is the author of a United States patent that is related to the treatment principles described in this article. There is no financial or corporate relationship at this time. The other authors report no conflicts of interest. Presented at the Annual Meeting of the American Academy of Otolaryngology-Head & Neck Surgery, September 11–14, 2011, San Francisco, CA. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001252


he treatment of mandibular condyle fractures has been a topic of great debate and research over the last century. Because these fractures can cause significant morbidity if left untreated, facial trauma surgeons have attempted to apply many different operative techniques and implant designs to prevent these complications, which include malocclusion, facial asymmetry, and mandibular hypofunction or dysfunction.1 In their review of the biomechanical mechanisms of condylar function in the setting of a fracture, Ellis and Throckmorton2 described biomechanical adaptations to condylar fractures and discussed how, on the basis of the physiology of the individual fracture, certain fractures will functionally heal without intervention and others will not, despite the most careful surgical treatment. When we consider mandibular condyle fractures that do require surgical intervention, there is a continued debate over whether “open” or “closed” treatment is best.3–6 Closed treatments involve rigid or elastic maxillomandibular fixation with or without reduction of the fracture. Open treatments include a variety of surgical approaches using incisions through the face, neck, or oral mucosa. These open approaches improve anatomic reduction of condylar fractures, but they add a dimension of iatrogenic morbidity to the treatment of these complex patients.5 The most common iatrogenic complications of surgical treatment of mandibular condyle fractures include paresis or paralysis of the facial nerve or its branches. This has been reported to occur in approximately 12% to 17% of patients, although most recover function in the long term.7,8 Hypertrophic scars on the face or neck are another concern, occurring in 7.5% of cases, and rarely, salivary fistula is encountered.8 In an effort to reduce iatrogenic morbidity, surgeons have begun to use transoral endoscopic assistance to access condylar and subcondylar fractures. This allows for anatomic reduction of the fracture, but application of currently available plates and perpendicularly oriented bone screws is difficult and regularly requires the use of a transfacial puncture incision (which reintroduces the risk for injury to the facial nerve, hypertrophic scarring, and salivary fistula).9 Further problems regarding the strength and stability of miniplates in the treatment of condylar fractures have also been encountered. In a detailed biomechanical evaluation of the stresses on a miniplate applied to a condylar fracture, Wagner et al10 have demonstrated that bite force loading on a titanium miniplate can exceed the static yield limit of the plate, leading to mechanical failure (bending or breaking) of the implant. This phenomenon of miniplate mechanical failure has been encountered clinically in excess of 20% of cases.10,11 The optimal implant for use with a transoral endoscopic technique for fixation of these fractures would have greater mechanical strength than miniplates and would not require a transfacial puncture or incision for its application. In a recent biomechanical study, the strength, stiffness, and increased resistance to mechanical implant failure for short-segment titanium intramedullary condylar implants, compared with miniplates, has been demonstrated.12

The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015

Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.


The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015

Frake et al

FIGURE 1. Endoscopic view (A) and schematic drawing (B) of the surgical position of the condyle placed lateral to the mandibular ramus.

FIGURE 3. Endoscopic view (A) and schematic drawing (B) of placement of the intramedullary implant.

It is in this setting that we examined the feasibility of the purely endoscopic surgical technique for application of short-segment intramedullary implants, which may eliminate some of the morbidity associated with transfacial incision and puncture approaches.6

space, and reduction is complete (Fig. 5A, B). The transoral incision is then sutured closed in the standard fashion.7


All steps of the surgical procedure were successfully applied in all of the cadaveric specimens. Zero- and 30- degree endoscopes provided excellent visualization of the fracture site. The free condylar fragment was readily positioned lateral to the ramus using endoscopic instrumentation. Gentle hand twisting of a drill bit was adequate to remove the contents of the medullary space without removal of the adjacent cortical bone. The implant was able to be inserted or screwed into position into the proximal condylar fragment. A retractor with a 90-degree bend followed by a right or left hook was needed to securely apply inferior retraction at the sigmoid notch. Once this retraction was applied and the mandible was displaced inferiorly below the implant, retraction was released and the implant was partially seated into the medullary space of the ramus. Depending on the tightness of fit within this medullary space, a varying degree of superiorly directed gentle pressure was applied at the angle of the mandible to complete the reduction and application of the implant.


Approval from the institutional review board of the George Washington University was not required because this study does not involve live human subjects, only cadaveric specimens. The cadaveric specimens were placed in the appropriate anatomic position for transoral endoscopic surgery. A saw was used to make a uniform osteotomy perpendicular to the posterior border of the ramus at the inferiormost level of the sigmoid notch in both cases. Access was gained to the condylar region using a small transfacial incision over the condyle, which was then closed with suture and not used for any surgical access during the procedure. An incision was made in the buccal mucosa at the level of the mandibular ramus with a scalpel. Blunt dissection was carried down to the mandibular ramus. A Freer elevator was used to dissect the soft tissue away from the fracture site and create the optical pocket, then the endoscope was introduced. It is not necessary to be in the subperiosteal plane for dissection (maintaining the integrity of any remaining periosteum may improve blood supply and viability of the adjacent bone); however, a subperiosteal plane of dissection may be used if desired. Once the fracture site was adequately exposed, the free end of the condylar fragment was visualized. If the condylar neck is displaced medially, it is manipulated into a position lateral to the mandibular ramus using a hooked probe instrument (Figs. 1A, B). Next, the medullary space of the condyle is reamed using gentle finger twisting of a free surgical drill bit (Figs. 2A, B). The implant is then introduced and can be either directly advanced or screwed (depending on the design of the implant) into the medullary space of the condyle (Figs. 3A, B). The condyle with the distal segment of the implant still exposed is placed lateral to the ramus (Fig. 4A, B). A retractor is then placed over the sigmoid notch, and an inferiorly directed retraction force is placed on the mandible. Once the ramus is below the level of the protruding implant, its medullary space is maneuvered over the implant, and the retraction at the sigmoid notch is released. Gentle superiorly directed pressure can be applied to the angle of the mandible externally using the surgeons' hand to further seat the implant within the distal medullary

Intramedullary fixation is a treatment concept that was popularized by orthopedic surgeons for the treatment of tubular long bone fractures in the early and mid-20th century. In orthopedic practice, it was noted that intramedullary fixation allowed for healing with greater ease of application and less muscular damage and periosteal stripping compared with plates and screws.13 Several years later, facial trauma surgeons began to describe the application of K-wire internal fixation of mandible fractures, including that for fractures of the condyle.14 Early condylar intramedullary fixation required insertion of the K-wire at the mandibular angle. The implant would then traverse the medullary space of the ramus and continue up to the condyle.14 Lag screw fixation has also been attempted in this manner and has shown favorable mechanical characteristics in comparison with traditional miniplates.15 However, this full-length intramedullary technique requires 1 or more transcervical or transfacial incisions, along with a fully patent and linear medullary canal, and is not widely used in clinical practice today.

FIGURE 2. Endoscopic view (A) and schematic drawing (B) of reaming of the proximal medullary space.

FIGURE 4. Endoscopic view (A) and schematic drawing (B) of the exposed distal segment of the implant during inferior retraction at the sigmoid notch.



© 2014 Mutaz B. Habal, MD

Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.

The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015

Mandibular Condyle Fracture Fixation

condylar implants are applied in the axis of the condylar bone through a transoral incision. No facial or cervical incisions or punctures are required for this technique.11


FIGURE 5. Endoscopic view (A) and schematic drawing (B) of the fracture after reduction using an intramedullary implant.

Attempts were made to reduce the surgical morbidity associated with transcervical approaches through the introduction of endoscopically assisted techniques to facial trauma surgery. Although this technique avoids larger neck incisions, the nature of the application of screws perpendicular to the axis of the bone has complicated its use. To use a miniplate that requires perpendicular screws for fixation, surgeons may use a transfacial puncture incision to apply the screws. This sacrifices some of the purported benefits of approaching the condyle transorally and results in a hybrid endoscopic-assisted technique. Facial nerve morbidity continues to be reported in recent literature studying these endoscopic-assisted techniques.16,17 To eliminate risk to the facial nerve, the surgical approach cannot traverse the course of the nerve or its branches in the neck, parotid gland, or face.9 This can be accomplished with the combination of axial application of intramedullary implants and purely endoscopic transoral technique. Beyond the potential reductions in morbidity of the surgical approach, reexamination of structural implant design has also demonstrated that short-segment intramedullary implants provide improved strength in the repair of mandibular condyle fractures. This may serve to eliminate many of the mechanical implant failures that can occur after a successful surgery. In addition, intramedullary implant design can broaden the scope of fractures that are endoscopically treatable. Most of the current studies evaluating endoscopic-assisted technique continue to focus on the subset of patients with subcondylar fractures.17,18 When compared with condylar neck fractures, subcondylar fractures have a larger amount of bone available for plate adaptation and screw insertion and the site of the fracture is closer to the surgeon, thereby facilitating surgical manipulation. Endoscopic application of an intramedullary implant is not dependent on these factors because the implant may be inserted into a shorter condylar neck fragment in the axis of the medullary canal at any distance from the operator, as was accomplished in these cadaveric specimens. Further clinical investigation will be needed to determine whether the marriage of mechanical and procedural benefits of short-segment intramedullary implants observed in biomechanical testing and these cadaveric specimens will help advance the surgical treatment of mandibular condyle fractures.10

CONCLUSIONS The results of this study suggest that purely endoscopic repair of condylar fractures is possible when short-segment intramedullary

1. Ellis E. Complications of mandibular condyle fractures. Int J Oral Maxillofac Surg 1998;27:255–257 2. Ellis E, Throckmorton GS. Treatment of mandibular condylar process fractures: biological considerations. J Oral Maxillofac Surg 2005;63:115–134 3. Zide MF, Kent JN. Indications for open reduction of mandibular condyle fractures. J Oral Maxillofac Surg 1983;41:89–98 4. Nussbaum ML, Laskin DM, Best AM. Closed versus open reduction of mandibular condylar fractures in adults: a meta-analysis. J Oral Maxillofac Surg 2008;66:1087–1092 5. Danda AK, Muthusekhar MR, Narayanan V, et al. Open versus closed treatment of unilateral subcondylar and condylar neck fractures: a prospective, randomized clinical study. J Oral Maxillofac Surg 2010;68:1238–1241 6. Lee J, Lee Y, Kuo Y. Reappraisal of the surgical strategy in treatment of mandibular condylar fractures. Plast Reconstr Surg 2010;125:609–619 7. Gerbino G, Boffano P, Tosco P, et al. Long-term clinical and radiological outcomes for the surgical treatment of mandibular condyle fractures. J Oral Maxillofac Surg 2009;67:1009–1014 8. Ellis E, McFadden D, Simon P, et al. Surgical complications with open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg 2000;58:950–958 9. Schoen R, Fakler O, Metzger MC, et al. Preliminary functional results of endoscope-assisted transoral treatment of displaced bilateral condylar mandible fractures. Int J Oral Maxillofac Surg 2008;37:111–116 10. Wagner A, Krach W, Schicho K, et al. A 3-dimensional finite-element analysis investigating the biomechanical behavior of the mandible and plate osteosynthesis in cases of fractures of the condylar process. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:678–686 11. Hammer B, Schier P, Prein J. Osteosynthesis of condylar neck fractures: a review of 30 patients. Br J Oral Maxillofac Surg 1997;35:288–291 12. Frake PC, Howell RJ, Joshi AS. Strength of titanium intramedullary implant versus miniplate fixation of mandibular condyle fractures. Otolaryngol Head Neck Surg 2012;147:33–39 13. Küntscher G. The intramedullary nailing of fractures. Clin Orthop 1968;60:5–12 14. Stephenson KI, Graham WC. The use of the Kirschner pin in fractures of the mandibular condyle. Plast Reconstr Surg 1952;10:19–22 15. Tominaga K, Habu M, Khanal A, et al. Biomechanical evaluation of different types of rigid internal fixation techniques for subcondylar fractures. J Oral Maxillofac Surg 2006;6:1510–1516 16. Schmelzeisen R, Cienfuegos-Monroy R, Schön R, et al. Patient benefit from endoscopically assisted fixation of condylar neck fractures—a randomized controlled trial. J Oral Maxillofac Surg 2009;67:147–158 17. Arcuri F, Brucoli M, Baragiotta N, et al. Analysis of complications following endoscopically assisted treatment of mandibular condylar fractures. J Craniofac Surg 2012;23:e196–e198 18. Gonzalez-Garcia R, Sanroman J, Goizueta-Adame C, et al. Transoral endoscopic-assisted management of subcondylar fractures in 17 patients: an alternative to open reduction with rigid internal fixation and closed reduction with maxillomandibular fixation. Int J Oral Maxillofac Surg 2009;38:19–25

© 2014 Mutaz B. Habal, MD

Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.


Feasibility of purely endoscopic intramedullary fixation of mandibular condyle fractures.

The investigators of this study hypothesized that fractures of the mandibular condyle can be repaired using short-segment intramedullary implants and ...
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