An analysis of the pattern of orbital fractures at two referral teaching institutions in Nairobi

Abstract

Background of the study Orbital fracture is a common injury accompanying mid-face trauma. The incidence of isolated orbital fractures ranges from 4 to 16% of facial fractures. Combined with other injuries including those of the zygomatico-maxillary-complex (ZMC) and those of the naso-orbito-ethmoidal (NOE) complex, they account for 30 to 55% of all facial fractures. Orbital trauma can result in significant functional and cosmetic defects and hence can be significantly disabling. The modal age of 20-40 years leads to reduced productivity and loss of manpower. Patients with fractures involving the orbit often present with concomitant injuries of the eyeball and/or the surrounding extra-ocular structures. Misdiagnosis or delayed diagnosis may result in debilitating complications such as blindness, diplopia, permanent paresthesia, malocclusion and facial disfigurement. Material and Methods A descriptive prospective hospital-based study was carried out to determine the demographics, aetiology, clinico-radiological features and management modalities among patients presenting with orbital fractures (n=60) at the University of Nairobi Dental Hospital (UNDH) and Kenyatta National Referral Hospital (KNH) in Nairobi, Kenya. A specially designed data collection tool which was tested and calibrated was completed for all patients with confirmed orbital fractures. All data were coded and entered into the statistical package for social sciences (SPSS) software version 20 for analysis. Results Sixty patients (52 male, 8 females; p<0.05) with confirmed orbital fractures on CT scan were recruited into the study. Orbital fractures occurred most frequently in the 21-40-year old age group (80%, p<0.05). The self-employed group was the most affected occupational group (40%) whilst the least affected was the formally employed group (3.3%). The distribution of orbital fractures according to occupation was statistically significant (X2=23.500, p=0.000).The principal aetiological factor was motor cycle crashes (MCCs) at 30 % particularly riders (21.6%) followed by interpersonal violence (IPV) at 23.3%, public vehicle crushes (PVCs) at 20%, private vehicle crushes (PVCs) at 10%, injury from flying objects at 10% and falls at 8.3%. All the cases of IPV were male (n=14, p=0.071) particularly of the 20-30-yr old age (n=8) group. Clinical features noted included peri-orbital oedema, subconjuctival haemorrhage (SCH), step deformity on the rim, peri-orbital ecchymosis, trismus, eyelid laceration and avulsion, paresthesia, malar collapse and telecanthus, blindness, diplopia and entrapment of extra-ocular muscles, enophthalmos, vertical dystopia, exophthalmos and eyelid ptosis. The most commonly affected anatomical site was the floor (75%) followed by the lateral wall (71.7%), infra-orbital rim (66.7%), zygomatico-frontal suture (63.3%), medial wall (46.7%) and orbital roof (25%). Notably, 65% had zygomatic arch fractures whilst 51.7% had ZMC fractures. In this study 5 patients had pure blow-out orbital fractures whilst 55 patients had impure fractures. There were more fractures involving the left orbit (n=28) than the right (n=14). Bilateral orbital fractures were seen in 18 patients. Indirect CT scan findings included haemosinus (air-fluid level) in 47 patients, tissue emphysema, teardrop and pneumocephalus. The relationship between haemosinus and orbital fractures was statistically significant (p<0.05). More of the patients were managed conservatively (60%). Conclusion The present study has reaffirmed that RTCs, especially motor cycle crashes and IPV are the leading cause of orbital injuries most commonly in the young males in their third and fourth decades of life. Evidently, haemosinus as demonstrated on CT scanning together with peri-orbital oedema and SCH constitute the clinical features most consistent with orbital fractures, most of which were the impure variants. The left side was more affected than the right whilst the floor and the lateral wall being the commonest sites of orbital fractures. Impure variants particularly zygomaticomaxillary- complex fractures are by far more common than the pure variant. Depending on the severity of the injury, orbital fractures can be managed either surgically or conservatively.