Entrapment of the inferior oblique and inferior rectus muscles in orbital trapdoor fracture

Lateral Rectus Muscle Entrapment in Complex Orbital Fracture in a Child

A 6-year-old boy presented with a lateral rectus muscle entrapment in a complex orbital fracture sustained during bicycle riding. He was diagnosed with a skull-base fracture with pneumocephalus and zygomatic and inferior orbital wall fractures at another hospital. The zygomatic fracture and pneumocephalus were treated conservatively. Although a detailed ocular motility examination could not be performed due to pain and inability to open the eyelid, the inferior wall fracture was surgically repaired. Postoperatively, persistent extraocular movement limitation prompted a referral to our clinic. Orbital CT imaging demonstrated a fracture at the greater wing of the sphenoid with a hypoattenuated area in the adjacent middle cranial fossa. Orbital MRI taken thereafter revealed lateral rectus and orbital fat prolapse into the middle cranial fossa, indicating entrapment of these structures through the lateral wall fracture. The incarcerated lateral rectus was released using an endoscopic transorbital approach via an upper lid crease, resulting in the recovery of extraocular movement.

A Comparative Analysis of the Incidence of Pediatric Orbital Fractures Before and During the COVID-19 Pandemic in the Japanese Population

INTRODUCTION

 The aim of this study is to compare data on the incidence of pediatric orbital fractures before the onset of the coronavirus disease 2019 (COVID-19) pandemic and during the period of the pandemic in the Japanese population.

METHODS

This retrospective, single-center, observational study including 225 patients (226 sides) aged ≤ 18 years old diagnosed with orbital fracture was conducted in our institution from March 2017 to April 2023. The study compared the incidence of pediatric orbital fractures in the pre-pandemic period from March 2017 to March 2020 and during the pandemic from April 2020 to April 2023.

RESULTS

The most common cause of injury was sports in both groups (137 sides, 60.6%), and the ratio of causes of injury (P = 0.610) or between outdoor and indoor sports (P = 1.000) was not statistically different between the groups. Although the daily rate of patient consults was lowest during the country's state of emergency with priority preventative measures, the difference between pre-pandemic and pandemic was not statistically significant (P = 0.911).

CONCLUSION

Despite the restrictions mandated by the Japanese government during the COVID-19 pandemic, the physical activities of children did not significantly decline. Hence, the risk of pediatric orbital fractures remained the same.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

'Frozen eye' - Post blowout fracture surgical correction - A case report

The Rationale

"Frozen Eye" is a very uncommon sequel after treatment of orbital blowout fractures requiring implant placement.

Patient Concerns

The implant may faultily impinge on the ocular and extra-ocular muscle(s), causing the abnormality in the movement of the eye.

Diagnosis

We present a 56-year-old male whose ocular implant impinged on muscle, causing "frozen eye" and had an infected implant.

Treatment Outcomes

The same was removed and surgically corrected. The manuscript describes the details and discusses the possible mechanism that led to the "Frozen Eye".

Anatomical implication of less occurrence of inferior oblique muscle entrapment in orbital floor trapdoor fracture

PURPOSE

To examine the anatomy of the inferior oblique (IO) muscle and its surrounding structures to clarify why IO muscle entrapment develops less in orbital floor trapdoor fractures.

METHODS

Computed tomographic (CT) images on the unaffected sides were obtained from 64 patients with unilateral orbital fractures. On coronal planes, presence or absence of an infraorbital groove below the IO muscle was confirmed. At the level of the medial margin of the infraorbital groove/canal, the distance from the orbital floor to the IO muscle (IO-floor distance), the thickness of the orbital floor, and the shortest distance from the inferior rectus (IR) muscle to the orbital floor (shortest IR-floor distance) were measured. On quasi-sagittal planes, the distances from the inferior orbital rim to the inferior margin of the IO muscle (IO-rim distance) and the most anterior point of the infraorbital groove (groove-rim distance) were measured.

RESULTS

The infraorbital groove was found below the IO muscle in eight patients (12.5%), and the IO-rim and IO-floor distances were significantly longer than the groove-rim and shortest IR-floor distances, respectively (p < 0.001). The orbital floor below the IO muscle was significantly thicker than that below the IR muscle (p < 0.001).

CONCLUSION

Although the medial margin of the infraorbital groove is the most common fracture site, the IO muscle was not located above the groove in most cases. A longer IO-floor distance and thicker orbital floor below the IO muscle may also contribute to less occurrence of IO muscle entrapment in orbital floor trapdoor fractures.