One point fixation of zygomatic tripod fractures in the zygomatic buttress through Keen's intraoral approach: A review of 30 cases

Abstract

For decades, facial beauty and esthetics have been one of the most important quests of the human race. The lateral prominence and convexity of the zygomatic bone makes it the most important bone for providing the aesthetic facial look and sets up the facial width but at the same time this prominence and convexity makes this bone more vulnerable to injury. Zygomatic complex fractures or tripod fractures are the second most common fractures after nasal fractures among facial injuries. Several studies have been undertaken regarding the reduction and fixation of zygomatic fractures with mini plates and screws. In 2002 Fujioka et al in vivo studies successfully proved that one point fixation at the zygomaticomaxillary complex gives three point alignment and sufficient rigidity when the fractures are not comminuted. In this article, 30 cases have been reviewed with one point fixation of zygomatic complex tripod fractures at the zygomatic buttress through Keen's intraoral approach along with advantages and disadvantages.

Zygomatic complex fractures or tripod fractures are the second most common fractures after nasal fractures among facial injuries. The lateral prominence and convexity of the zygomatic bone makes it the most important bone for providing the aesthetic facial look and sets up the facial width but at the same time this prominence and convexity makes this bone more vulnerable to injury. About 45% of all midfacial fractures are zygomatic complex fractures.[1] zygomatic complex fractures are also known as tripod fractures and are most commonly treated by open reduction internal fixation through several incisions.[2] Several approaches are used namely lateral eyebrow, sub cilliary, temporal or intraoral incisions for one or two or three point fixation of zygomatic complex fractures. However, lateral eyebrow incisions have been placed previously for one point fixation at the frontozygomatic region.[3,4] The lateral eyebrow incision leaves an unsightly scar postoperatively and there may be a risk of palpability or intracranial penetration.[5] In 1909, Keen was the first to describe intra oral gingivobuccal sulcus incision to reduce the depressed zygomatic arch. The author have followed the intraoral Keen's approach for one point fixation in the zygomatic buttress region. This reduces the risk of palpability, extraoral scars or any intracranial penetrations. This article reviews 30 cases of zygomatic complex fractures treated effectively with one point fixation at the zygomatic buttress through intraoral approach and patients reviewed 6 months postoperatively. However, the selected cases excluded comminuted zygomatic complex fractures or comminuted lateral orbital fractures.

Procedure

Thirty patients with zygomatic complex fractures were treated with one point fixation [Figures 1–3]. Patients with comminuted zygomatic complex fractures and comminuted lateral orbital wall fractures are excluded.

Figure 1.

Preoperative

Figure 3.

Preoperative computed tomography scan

Figure 2.

Preoperative peripheral nerve stimulation X-ray

Under general anesthesia, nasoendotracheal intubation was done. Extraoral and intraoral preparation done with povidone iodine. Local anesthesia 1:80,000 is infiltrated intraorally in the zygomatic buttress region. Incision is placed in the mucobuccal fold (approximately 1–2 cm). The incision can be made from anterior to posterior or from medial to lateral and should extend through mucosa, submucosa, and any buccinators muscle fibers [Figure 4].

Figure 4.

Intraoral incision and fracture site exposed

Mucoperiosteal flap was elevated. Rowe's zygomatic elevator was then inserted behind the infra temporal surface of the zygoma, and bone was reduced into its correct anatomical position using superior, lateral and anterior force. An audible click and fullness of the cheek together with palpation for normal contour of the zygomatic bone and orbital rim gave an idea about the adequacy of the reduction. One hand over the side of the face was used to assist in the reduction.

A four hole plate with a gap was fixed with 4 mm × 2.5 mm screws on the zygomatic buttress [Figure 5]. Wound irrigated with metrogyl and saline solution. Wound closure done with 3–0 vicryl [Figures 6–9]. Patients were reviewed in immediate postoperative period and 6 months postoperative period.

Figure 5.

One point fixation

Figure 6.

Suturing done

Figure 9.

Six months postoperative and peripheral nerve stimulation X-ray

Figure 7.

Immediate post operative

Figure 8.

Immediate peripheral nerve stimulation X-ray

Results

For all the patients, immediate postoperative and 6 months postoperative peripheral nerve stimulation X-rays were taken, and the X-rays review successful reduction. None of the patients complained of any paresthesia, bony movements or pain in the frontozygomatic or zygomatic buttress region. Since intraoral approach was used, all the patients had an aesthetic facial profile without any unsightly scars.

Discussion

The integrity of the zygoma bone is critical in maintaining normal facial width and prominence of the cheek. It serves as the buttress between the face and the skull. The zygomatic bone is a major contributor to the orbit and plays an important role in protecting the eyes. Zygomatic bone alone is rarely involved in fractures; usually its articulating surfaces which are maxilla, temporal, frontal and sphenoid bones are also involved. The fractured fragments of a tripod or tetrapod zygomatic complex fracture near these suture lines needs to be restabilized by open reduction followed by fixation. Studies suggest that two point gives a considerable stabilization, and three point fixation gives the maximum stabilization.[6,7] However other studies suggest that one point fixation for zymatic complex fractures gives an excellent results considering the esthetics and stabilization[3,4,8,9] For simple tripod fractures without any comminution of the zygomatic bone or the lateral orbital wall one point fixation with a single mini plate in the frontozygomatic area through the lateral eyebrow incision have been suggested by many authors.[10,11,12] I n these cases it was found that when a tripod fracture without any comminution or mild or no displacement can be stabilized very well with a single point fixation in the frontozygomatic area without any complications of diplopia or enopthalmos. However, zygoma provides the attachment point for muscles of mastication and facial animation, but amongst these, it is the masseter that provides the most significant intrinsic deforming force on the zygomatic body and arch. The integrity of zygomatic buttress is necessary for withstanding the contraction force of the masseter muscle.[13] In 2002 Fujioka et al. in vivo studies successfully proved that one point fixation at the zygomaticomaxillary complex gives three point alignment and sufficient rigidity when the fractures are not comminuted.[14] In 2011 Kim et al. found out that lateral eyebrow incision for mini plate fixation at the frontozygomatic area led to unaesthetic scar and few patients underwent plate removal through a second surgical re-entry through the existing scar of the lateral eyebrow incision which further enhanced the unsightly scars and compromised facial esthetics.[15] Since the skin over the lateral eyebrow region is thin there are more chances of palapation of the mini plates after fixation, and it may lead to pain. As early as in 1994 Tarabichi et al. proved that in vitro studies are misleading regarding the mini plate fixation along the orbital margins and successfully applied transsinus reduction through anterior comminuted sinus wall.[16] In 2012 Kim et al. successfully reduced the zygomatic complex fractured fragments through intraoral approach and gained sufficient rigidity and excellent esthetics with one point fixation at the zygomatic buttress region.[17] They even used ultrasonography to substantiate their results. We also found that one point fixation with a single mini plate at the zygomatic buttress through intraoral incision provided excellent stability and esthetics in the selected cases of simple zygomatic complex fractures without any comminution of the zygoma or the lateral orbital rim without or with minimal displacement and none of our patient complained of pain or palpation or bony movements in the postoperative study period of 6 months rather they were happy to get operated without any unaesthetic facial scars.