Pediatric orbital blowout fractures are often associated with residual diplopia if not treated emergently. Pediatric bones are more flexible than adult bones; thus, pediatric blowout fractures occasionally result in linear fractures entrapping orbital contents, called trapdoor fractures,1–5 which occasionally need urgent surgical reduction. Over the past decade, surgical results, which have varied across reports, include persistent diplopia in 0%–55% of patients with pediatric blowout fractures.1,3,6–27

The timing of surgery for urgent cases and the types of pathology requiring urgent surgery have been controversial. Previous studies have recommended surgery as soon as possible for urgent cases,9,10,16,20 within 24 h,1,7,13 within 48 h,2,4,28 or over 48 h from injury.11,12,17,18,23,29 Previous studies have not described any definite algorithm for surgical intervention.

Regarding patient age, it has been reported that younger pediatric patients are less likely to have improvements in ocular movement than older pediatric patients.30 Younger pediatric patients were reported to have a higher rate of urgent cases.6

In previous studies, ocular movement was evaluated based on the presence of diplopia3,7,8,10,12,14–17,19–22,24,27 or quantitative scales.9,11,13,18,26 On the other hand, Hess Area Ratio (HAR%)31 is a definitive objective scale, but no previous studies of the clinical results of pediatric orbital blowout fractures have used an objective scale.

Here we present an algorithm for surgical intervention to treat pediatric orbital blowout fractures. This study is the first in which ocular movement was described based on both HAR% and the presence of diplopia. Ocular movement results after treatment according to the algorithm were subjectively and objectively satisfactory. The purpose of this study is to retrospectively examine the validity of our proposed algorithm by analyzing our clinical results according to the algorithm and comparing the results with historical controls in previous reports.3,6,8,11,12,14,20,27,28,32

Table 1 shows the characteristics of the study patients.

We have shown that we had good outcomes for pediatric orbital blowout fractures based on the algorithm. This simple and effective algorithm will help specialists and non-specialists who refer pediatric orbital blowout fractures to specialists at the appropriate time.

Follow-up ocular movement was satisfactory among patients who underwent surgery, such as urgent release and repair, and patients who received conservative treatment in this study. Ocular movement was evaluated with HAR%, which is an objective measurement.31 Although follow-up HAR% was statistically significantly better for patients who received conservative treatment than for patients who underwent surgery, follow-up HAR% for patients who underwent surgery was markedly higher than 85%. If HAR% is more than 85%, diplopia is not recognized.31

The proportion of patients without postoperative diplopia in this study was also satisfactory compared with that of previous studies.3,6,8,11,12,14,20,27,28,32 It would be convenient and reasonable to select treatment according to the algorithm. According to our results, the desirable surgical timing for urgent cases might be within 12 h.

We divided the patients into 2 groups: age 0–12 years and age 13–18 years, similar to a previous report,6 in consideration of the growth of the paranasal sinuses.38 Regarding the clinical results of the 2 groups, there were statistically significantly more urgent cases in the age 0–12 years group than in the age 13–18 years group. On the other hand, follow-up HAR% was similar in both groups. Therefore, there were no differences in clinical results by age group after treatment according to the algorithm.

The first important feature of the algorithm that differs from previous reports3,6 is that the HESS screen test was not used to determine urgency. Pediatric patients, especially patients under 5 years of age, are often uncooperative with the examination.6 Therefore, we focused on objective signs to evaluate urgency, such as missing rectus9,33 and OCR causing nausea, vomiting, or adynamia.1,34–36 However, it was essential to confirm the presence of diplopia in order to judge a case as urgent because the symptoms of OCR are similar to those of concussion.

The second important feature of the algorithm is the distribution of surgical timing; urgent release was performed as urgent surgery and repair was performed as standby surgery. The urgent release group included patients who had serious injury of the orbital contents. The repair group included patients who had restricted ocular movement or enophthalmos, but surgery was not urgent. We decided to perform urgent release as soon as possible. Because entrapped orbital contents are severely affected by insufficient blood supply, fibrosis and muscle dysfunction could appear in 6–8 h after entrapment.7,9,10,33 Indications for standby surgery are the same as previous studies, such as > 2 mm enophthalmos, extraocular muscle restriction with symptomatic diplopia (within 30° fixation), and large orbital wall defect (>50%) on CT after improvement of orbital swelling.2,8,11,19,22,28,34 Although previous studies have recommended standby surgery within 2 weeks to avoid adhesions among orbital contents,3,7,8 standby surgery was performed after ocular movement improvement became stable in the current study. As a result, the timing of repair was within 2 weeks in this study.

The transorbital approach through a subciliary incision or transconjunctival incision is a suitable surgical approach for pediatric orbital blowout floor fractures because it is more convenient to release the incarcerated orbital contents with a transorbital approach in pediatric patients, in whom linear fractures are common.2,6 Reconstruction of the orbital floor is rarely needed, especially for linear fractures.39 In this study, all patients in the urgent release group except for 1 patient with medial rectus muscle entrapment underwent surgery via the transorbital approach without reconstruction.

Even in patients with limited ocular movement, attention should be paid to conditions such as extraocular muscle palsy, ruptured globe, or retinal detachment that require postponement or avoidance of surgical treatment.1,40 All the participants of this study were evaluated by an ophthalmologist to rule out those conditions.

CT is the most suitable modality for pediatric blowout fractures, especially for urgent conditions. The time for imaging is short and it can be performed in pediatric patients.34 In addition to the condition of the bone, the condition of the orbital contents can be evaluated in the soft tissue window. On the other hand, Magnetic Resonance Imaging (MRI) has several advantages compared with CT: no radiation, better evaluation of soft tissue, and functional evaluation of orbital contents.1,41 In the algorithm, CT, which has the characteristic of short imaging time, was adopted as the first imaging modality. In this study, all patients were able to undergo urgent CT evaluation of orbital conditions. MRI was performed subsequently as needed in non-urgent cases.

We have typically used a subciliary incision for the transorbital approach. However, a transconjunctival incision also could be used; transconjunctival incisions have been reported to result in fewer complications than subciliary incisions.42 In this study, the transnasal endoscopic approach was used for non-linear fractures. This approach is relatively common, and postoperative ocular movement are unlikely to differ substantially depending on the type of approach.

Our study has three limitations. First, this was a single-arm study in which delayed surgery in urgent cases was not evaluated. However, more importantly, the treatment of pediatric blowout fractures according to the current algorithm resulted in satisfactory outcomes. Second, this study was conducted at a single institution. Therefore, the number of cases was small. It is necessary to examine more cases in more institutions. Third, the superiority of the treatment was not statistically evaluated because it was not statistically compared to treatments in previous studies. In addition, it is possible that diplopia in special eye positions could not be evaluated due to diplopia.

Despite these limitations, we believe that this study is valuable because it clearly defines the symptom of patients with pediatric orbital blowout fractures who should be selected for urgent release and describes how soon surgery should be performed after trauma. The timing of surgery has been controversial in previous reports: as soon as possible,9,10,16,20 within 24 h,1,7,13 within 48 h,2,4,28 or over 48 h11,12,17,18,23,29 from injury.

This study has shown the validity of our algorithm. This simple algorithm might be helpful to physicians treating pediatric orbital blowout fractures.

The authors declare no conflicts of interest.