Pure orbital blowout fracture: new concepts and importance of medial orbital blowout fracture.

Pure orbital blowout fracture first occurs at the weakest point of the orbital wall. Although the medial orbital wall theoretically should be involved more frequently than the orbital floor, the orbital floor has been reported as the most common site of pure orbital blowout fractures. A total of 82 orbits in 76 patients with pure orbital blowout fracture were evaluated with computed tomographic scans taken on all patients with any suspicious clinical evidence, including nasal fracture. Isolated medial wall fracture was most common (55 percent), followed by medial and inferior wall fracture (27 percent). The most common facial fracture associated with medial wall fracture was nasal fracture (51 percent), not inferior wall fracture (33 percent). This finding suggests that the force causing nasal fracture is an important causative factor of pure medial wall fracture as the buckling force from the medial orbital rim. Of patients with medial wall fractures, 25 percent had diplopia and 40 percent had enophthalmos. On plain radiographs, diagnostic signs were found in 79 percent of medial wall fractures and in 95 percent of inferior wall fractures. On computed tomographic scans, late enophthalmos was expected in 76 percent of medial wall fractures. Therefore, the medial orbital blowout fracture may be an important cause of late enophthalmos, because it has a high incidence of occurrence, a low diagnostic rate, and a high severity of defect. Among the causes of limitation of ocular motility, muscle traction of the connective septa and direct muscle injury were found frequently, but true incarceration of the muscle was extremely rare in all fractures. The medial and inferior orbital walls are clearly demarcated by the bony buttress, which is an important structure supporting these orbital walls. Its buttress was closely correlated with the fracture of these orbital walls. Most orbital blowout fractures without collapse of the bony buttress had a trapdoor fracture with or without small fragments of punched-out fracture.     

Endoscopic endonasal reduction for blowout fracture of the medial orbital wall

Endoscopic endonasal reductions have been addressed in 63 patients with blowout fracture of the medial orbital wall since 1992. The operations were carried out under general anesthesia with a magnified operative space projected on a television monitor by a charge coupled device video camera attached to the endoscope. The middle nasal turbinate was fractured toward the nasal septum, the uncinate process was cut off, and the bulla was opened. The ethmoidal bony partition and the mucous membrane were removed; however, the fractured bone chips of the medial orbital wall were preserved. The herniated orbital contents were pressed back into the orbital cavity, and the medial wall was set with 2-mm-thick bent silicone plates placed in the ethmoidal sinus. The plates were removed in the outpatient clinic 2 months after the operation. The surgical results of 21 patients treated with endoscopic reduction were compared with those of four patients treated with transfacial reduction with an iliac bone graft. All of the patients had isolated medial wall fracture and became aware of diplopia within 15 degrees in any direction from the primary position (straight gaze) before the operation; the follow-up period covered 6 months. The patients were classified into two categories according to postoperative double vision: "good," indicating no double vision or diplopia of more than 45 degrees, and "poor," diplopia of less than 45 degrees. Improvement of diplopia was observed in all patients without any complication. Of the 21 patients who underwent endoscopic reductions, 17 were classified as "good" and four as "poor." On the other hand, of the four patients who underwent transfacial reductions, three were classified as "good" and one as "poor." Significant differences were not observed between the surgical results of our two methods. Endoscopic endonasal reduction showed greater aesthetic advantages and, moreover, required no grafting. This technique is suggested as one of the most reasonable treatments of medial orbital wall fractures.     

Endoscopic endonasal reconstruction of blowout fractures of the medial orbital walls

High-resolution endoscopes and the advent of endoscopic instruments for sinus surgery currently provide surgeons with excellent endonasal visualization and access to the medial orbital walls. The purpose of this study was to demonstrate the reduction of medial orbital wall fractures through an endonasal endoscopic approach that allows the repair of the medial orbital wall fractures without an external incision. This study was a retrospective analysis of 16 patients who underwent surgical repair of medial orbital wall fractures from March of 1997 to May of 1998. The 11 male and five female patients ranged in age from 16 to 54 years (mean, 30.5 years). These patients had undergone primary reduction of medial orbital wall fractures and were observed for at least 12 months after surgery. There were no intraoperative or postoperative complications. Fifteen of 16 patients showed a complete improvement of their symptoms. One patient showed persistent diplopia, which was well managed by prisms. Endoscopic reduction of medial orbital wall fracture using an endonasal approach seems to produce good results and definite cosmetic advantages.     

Volkmann's contracture of the extraocular muscles following blowout fracture

In the past decade there has been considerable controversy over the surgical indications for treatment of blowout fractures of the orbit. It has been well recognized that some fracture patients develop an ischemic contracture of the inferior rectus muscle. We have found that a Volkmann's type of contracture of the inferior rectus muscle does exist and is similar to that found in the distal extremities. A specific group of fracture patients is at greater risk for development of a contracture. Elderly patients, hypotensive patients, patients with small fractures, and those with high inferior rectus compartment pressures are more prone to developing a contracted extraocular muscle. We have measured compartment pressures in 18 patients who were surgical candidates following orbital fracture. Our conclusions indicate that surgical intervention following blowout fractures in these high-risk patients may be more prudent than medical management. Patients with persistent diplopia due to a contracted inferior rectus are extremely difficult to treat many months after fracture. We still believe it prudent to surgically repair orbital fractures in patients with diplopia, enophthalmos, and a risk for muscle contracture. The documentation of this additional sequela of unrepaired fractures lends more strength to this belief. There is no evidence to indicate that a Volkmann's contracture would be possible after early repair of a blowout fracture.     

Reconstruction of orbital floor fracture using solvent-preserved bone graft

The orbital floor is one of the most frequently damaged parts of the maxillofacial skeleton during facial trauma. Unfavorable aesthetic and functional outcomes are frequent when it is treated inadequately. The treatment consists of spanning the floor defect with a material that can provide structural support and restore the orbital volume. This material should also be biocompatible with the surrounding tissues and easily reshaped to fit the orbital floor. Although various autografts or synthetic materials have been used, there is still no consensus on the ideal reconstruction method of orbital floor defects. This study evaluated the applicability of solvent-preserved cadaveric cranial bone graft and its preliminary results in the reconstruction of the orbital floor fractures. Twenty-five orbital floor fractures of 21 patients who underwent surgical repair with cadaveric bone graft during a 2-year period were included in this study. Pure blowout fractures were determined in nine patients, whereas 12 patients had other accompanying maxillofacial fractures. Of the 21 patients, 14 had clinically evident diplopia (66.7 percent), 12 of them had enophthalmos (57.1 percent), and two of them had gaze restriction preoperatively. Reconstruction of the floor of the orbit was performed following either the subciliary or the transconjunctival approach. A cranial allograft was placed over the defect after sufficient exposure. The mean follow-up period was 9 months. Postoperative diplopia, enophthalmos, eye motility, cosmetic appearance, and complications were documented. None of the patients had any evidence of diplopia, limited eye movement, inflammatory reactions in soft tissues, infection, or graft extrusion in the postoperative period. Providing sufficient orbital volume, no graft resorption was detected in computed tomography scan controls. None of the implants required removal for any reason. Enophthalmos was seen in one patient, and temporary scleral show lasting up to 3 to 6 weeks was detected in another three patients. Satisfactory cosmetic results were obtained in all patients. This study showed that solvent-preserved bone, which is a nonsynthetic, human-originated, processed bioimplant, can be safely used in orbital floor repair and can be considered as another reliable treatment alternative.     

Direct local approach through a W-shaped incision in moderate or severe blowout fractures of the medial orbital wall

For moderate or severe blowout fractures of the medial orbital wall, the goals of treatment are complete reduction of the herniated soft tissue and anatomic reconstruction of the wall without surgical complications. Various surgical approaches have been used, depending on the anatomic location and the extent of medial wall fracture. However, there is no consistent method to achieve the treatment goals with minimal morbidity because of one or more problems of limitation of entire medial wall exposure, limitation of large implant or bone graft insertion, surgical damage of important periorbital or intraorbital structures, or postoperative scar deformities. In this study, a direct local approach through a 3-cm, W-shaped incision on the superior medial orbital area was used as a consistent method to reconstruct medial orbital blowout fractures. The angle of the W-limbs is 110 to 120 degrees. Four limbs of the W were placed parallel or oblique to the relaxed skin tension lines. This technique was applied to 39 orbits of 37 patients with moderate or severe blowout fractures of the medial orbital wall. This approach provided exposure of the entire medial orbital wall, adequate placement of a large implant, short operation time within 2 hours, and no damage of important internal structures. Postoperative computed tomographic scans showed complete reduction of the herniated orbital tissues and anatomic reconstruction of the medial orbital wall without complication related to the surgical approach in all cases. During the follow-up period of 6 to 14 months, excellent functional and cosmetic results were observed with an inconspicuous scar without secondary scar deformities. Therefore, a direct local approach through a W-shaped incision on the superior medial orbit may be a consistent method to gain the surgical goal in treatment of moderate or severe blowout fractures of the medial orbital wall.