Postoperative CT of the Orbital Skeleton After Trauma: Review of Normal Appearances and Common Complications

Abstract

The goal of surgery is to restore the preinjury orbital anatomy to improve function and prevent enophthalmos. Radiologists need to be cognizant of the more frequently encountered operative procedures used for orbital fracture repair, the desired goals of treatment, and common complications. This will permit accurate interpretation of postoperative CT and provide surgeons with clinically useful results.

Computed tomography based analysis of the lamina papyracea variations and morphology of the orbit concerning endoscopic surgical approaches

“…The notches in the LP, which can be identified on coronal CT image are a good reference for the position and orientation of the ethmoidal arteries. 1 , 10 , 14 For the removal of the pathologies in paranasal sinuses and reconstruction of normal orbital anatomy, CT imaging is the primary technique using to view LP variations or dehiscence and to localize the ethmoid air cells and hypoplastic maxillary sinus. 4 , 8 , 14 Also, MPR allows observation of craniofacial bones from various angles and an evaluation of the sinonasal pathologies and complex fractures with overlapping fragments or minimal displacement.…”

“…The significant discrepancy between the implant shape and the normal anatomic shape of the orbital wall in fractures including IMS can result in insufficient orbital volume reduction. 7 , 10 , 21 On the other hand, the AEF and PEF at the level of the frontoethmoid suture can serve as a vital anatomic reference to proper implant placement. As a result of inaccurate reduction and reconstruction of the orbital walls, residual complications such as enophthalmos, diplopia, retrobulbar hemorrhage from injury to the posterior ethmoidal artery and orbital emphysema can be seen.…”

“…As a result of inaccurate reduction and reconstruction of the orbital walls, residual complications such as enophthalmos, diplopia, retrobulbar hemorrhage from injury to the posterior ethmoidal artery and orbital emphysema can be seen. 7 , 10 , 11 Therefore, revision surgery to treat them is required before excess scarring occurs. To avoid these complications it is necessary to be aware of the linear and angular orbital morphometry including the IMS.…”

“…Also, these parameters can be used in confirmation of the posterior margin of the fracture, which is critical to prevent residual enophthalmos due to inadequate placement of the implant. 10 , 11 , 21 Using CT scans Song et al measured the anterior and posterior heights of the LP, the length of the LP and LP area as 15.32 mm, 11.04 mm, 30.50 mm and 4 cm 2 . 11 Using 3D CT images Kang et al reported the anterior and posterior heights of the LP and inferomedial angles as 17.73 mm, 12.76 mm, 132.118° and 136.88°, respectively.…”

“…In addition, an adequate surgical exposure and access as well as an implant with proper size and shape is essential to insure the success of surgical technique. 10 , 11 Also, the lack of malleability of thick implants, the close proximity of the implant to vital orbital structures, and incorrect estimation of the dimensions of the implant can cause significant postoperative complications such as enophthalmos, optic neuropathy secondary to implant impingement, orbital emphysema and hemorrhage. 7 , 10 , 11 …”