Isolated orbital floor fractures in the paediatric patient: case series and review of management

Abstract

Orbital injuries warranting surgical intervention are infrequent in the paediatric population, but ‘blowout, trap door’ fractures are unique in children and may constitute a relative surgical emergency. A retrospective review of isolated orbital floor fractures at the Royal Children’s Hospital of Melbourne over a 10-year period was undertaken to evaluate the outcome of those patients who required surgical exploration. Twenty-two patients with documented isolated orbital floor injuries were studied. Preoperative signs and symptoms including diplopia, ocular motility, paresthesia, enophthalmos, hypoglobus, and the presence of nausea and vomiting were recorded. Thirteen patients underwent non-surgical management and nine patients underwent surgical exploration of the orbital floor via a trans-subconjunctival approach to reduce any entrapped soft tissue. Postoperative follow-up of these patients varied between 1 month and 18 months and none had any visual disturbance or diplopia in central gaze; however, two patients experienced diplopia in upward gaze at follow-up, although this did not impair the quality of life. Due to the risk of permanent soft tissue damage from the entrapment of the periorbita with or without extraocular muscle tissue, it is recommended that exploration be undertaken as soon as possible to minimize the risk of persistent diplopia due to impaired ocular motility.

Orbital injuries warranting surgical intervention are infrequent in the paediatric population. Due to a higher cranial to facial ratio in this age group, trauma to the head more often manifests as a skull fracture with or without head injury, with the relatively smaller facial complex being less frequently involved. The most common bony facial injuries seen in children are nasal fractures, but the most frequent fracture requiring hospitalization is the mandible. A previously reported study of paediatric craniofacial trauma found that only 15% of all paediatric viscera-cranial injuries included orbit fractures, and of these, 40% involved the orbital floor.

Due to the thin dimension of the orbital floor, it is the most frequently fractured wall of the orbit. The term ‘blowout’ fracture was introduced over half a century ago to describe fractures of the orbital floor with an intact rim. The typical features associated with these fractures include pain in upward gaze, vertical diplopia, and infraorbital paresthesia. Enophthalmos or hypoglobus may be noted on examination, and if orbital tissues are trapped in the fracture, nausea and vomiting may be present.

A more specific clinical presentation, unique in the paediatric age group, is the ‘trapdoor fracture’ that can be observed on computed tomography (CT) imaging. Immediately following a ‘blowout’ fracture, it is postulated that the thin elastic bone of the orbital floor flexes inferiorly with displacement of soft tissue orbital contents, and then reduces to its pre-injury position thus entrapping the herniated tissues in the fracture line. Such fractures are not restricted to the orbital floor.

The aim of this investigation was to retrospectively review isolated orbital floor fractures in the paediatric population at the Royal Children’s Hospital of Melbourne over a 10-year period and to evaluate the outcome of those patients who underwent surgical exploration, to compare the results with previous studies, and to emphasize the principles of management.

Patients and methods

The database of the Oral and Maxillofacial Surgery Unit at the Royal Children’s Hospital of Melbourne was interrogated to identify patients with orbital fractures during the years 2002–2012 for a Unit audit. Orbital wall injuries with an associated adjacent fracture, such as the orbital rim, were excluded. A documented radiological diagnosis of an orbital wall fracture was a prerequisite for inclusion in the review. Thirty-one patients with isolated orbital fractures were identified, but two patients were excluded due to inadequate records. Seven of the patients had orbital roof fractures, one of which was in combination with an orbital floor fracture and one with a medial wall fracture. Two of these patients underwent surgical intervention due to fracture displacement into the periorbita. A total of 22 patients were recorded with isolated orbital floor injuries. Nine patients exhibiting clinical signs of suspected muscle entrapment underwent surgical intervention by one of three consultant surgeons using a standardized surgical approach.

At the time of presentation, the patient’s age, gender, and mechanism of injury were recorded. Preoperative signs and symptoms including diplopia, ocular motility, paresthesia, enophthalmos, hypoglobus, and the presence of nausea and vomiting were noted. The operative management, postoperative results, and duration of follow-up were also documented. All operative cases underwent preoperative and postoperative ophthalmological assessment.

Surgical technique

Following endotracheal intubation and infiltration of long-acting local anaesthesia and adrenaline, a trans-conjunctival incision enabled dissection to the orbital rim. The periosteum was then incised and a sub-periosteal dissection performed to identify the fracture and continued posteriorly to identify the intact posterior bony ledge. The incarcerated, prolapsed periorbital soft tissues were then reduced and the displaced ‘trapdoor’ bony segment further reduced where necessary. In seven cases, a thin resorbable implant (Gelfilm; Pharmacia & Upjohn, Kalamazoo, MI, USA) was inserted between the bony floor and soft tissues of the periorbita to maintain a barrier during healing. A routine coronal approach and dissection beneath the orbital rim was undertaken for orbital roof fracture reduction.

Following fracture reduction, a forced duction test was performed routinely to ensure freedom of the soft tissues, as indicated by a normal range of upward rotation of the globe. The periosteum and conjunctiva were then closed with 4–0 and 6–0 resorbable sutures, respectively. Prophylactic amoxicillin 250 mg was administered together with 8-hourly dexamethasone 4 mg for 2 days. Eye observations were conducted 4-hourly for the first 24 h.

Results

The age range of the 22 patients with orbital floor fractures was 3–17 years (mean age 10.5 years). For those patients undergoing surgery, the mean age was 9 years, whereas the mean age of patients managed non-surgically was 13 years. The mechanisms of injury were varied ( Table 1 ). Thirteen patients had right-sided orbital fractures and nine patients had left-sided injuries. Four patients, who were all managed non-surgically, had head injuries; two of these patients had radiological evidence of frontal sinus fractures and two had minor intracranial haemorrhage.

Table 1
Aetiology of orbital floor fracture.
Mechanism Number
Sport 5
Bicycle/scooter 5
‘Play fighting’ 4
Collision (on foot) 3
Fall 3
MVA 2
Total 22
MVA, motor vehicle accident.

Nine of the 22 cases (41%) underwent surgical exploration ( Table 2 ). One patient, at the request of ophthalmology, underwent a second procedure at 6 weeks due to marked diplopia suggesting a residual soft tissue incarceration, but no persistent entrapment was found and there was no further resolution in the immediate postoperative period. On presentation, six of the nine patients who underwent exploration experienced nausea and vomiting, whereas only four of the 13 patients treated non-surgically had these symptoms. Recurrent vomiting in one case, after the first dose of morphine, was attributed to opiate analgesia.

Table 2
Demographics, presentation, and follow-up of patients undergoing surgical exploration.
Patient Age, years Side Diplopia Extraocular movement Nausea/vomiting CT of fracture Time to surgery Diplopia Clinical enophthalmos
1 3 L Moderate Normal Nil Blowout displaced <24 h Resolved 7 days Nil
2 6 L Mild Fixed globe Yes Blowout displaced <24 h Resolved 8 weeks Nil
3 7 R Severe Reduced upward gaze Yes Blowout displaced 4 days Resolved 6 weeks Nil
4 7 R Severe Reduced upward gaze Yes Linear ‘trapdoor’ <24 h Residual upward at 18 months Minimal
5 8 R Vertical only Reduced upward gaze Yes Linear ‘trapdoor’ <24 h Resolved 7 days Nil
6 9 L Vertical only Reduced upward gaze Yes Blowout displaced <24 h Residual extreme upward Nil
7 10 R Vertical only Reduced upward gaze Yes Blowout displaced <24 h Resolved 4 weeks Minimal
8 12 L Severe Reduced upward gaze Nil Blowout displaced 10 days Residual extreme upward Minimal
9 13 R Vertical only Reduced upward gaze Nil Linear ‘trapdoor’ <24 h Resolved 12 weeks Nil
CT, computed tomography; L, left; R, right.

With respect to operative timing, seven of the nine cases were taken to theatre within 24 h. Two cases were explored on the same day as their injury and five patients on the first day post-injury. One patient underwent surgery at 4 days post-injury and the last patient underwent surgery on the tenth postoperative day due to evolving enophthalmos and no resolution of diplopia after initial non-surgical management.

Follow-up of the patients varied between 1 month and 18 months in our operative cases and none had any visual disturbance or diplopia in central gaze. Four patients (57%) had a full range of ocular movements and complete resolution of diplopia between 1 week and 3 months postoperatively. Ocular motility in the other three patients who underwent orbital floor exploration at under 24 h (43%) did not return to the normal pre-injury levels. One patient (age 9 years) had asymptomatic diplopia at extreme upward gaze at the 8 months review and the other (age 7 years) also had asymptomatic diplopia with a minor upward gaze restriction at 18 months. Neither patient required any further intervention and both were discharged from follow-up. The third patient (age 6 years) underwent a second exploration with no motility improvement but had no diplopia in primary gaze. The non-surgically managed cases received a shorter duration of follow-up, ranging from 2 weeks to 2 months.

With regard to the seven patients with orbital roof fractures, the age range was 5.3–14.5 years, with a mean of 9.75 years. There were two ‘blow-in’ fractures that were openly reduced; the remainder were minimally displaced or undisplaced and were treated non-surgically.

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Jan 17, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Isolated orbital floor fractures in the paediatric patient: case series and review of management
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