ASOPRSFall Scientific SymposiumSyllabus
188
T33
UseofGoniometer inOrbital Reconstruction
GangadharaSundar
1
, ThiamChye Lim
2
, Raghuraj Hegde
1
,Michael Grant
3
.
1
Ophthalmology, National UniversityHospital,
Singapore, Singapore,
2
Plastic andAestheticSurgery, National UniversityHospital, Singapore, Singapore,
3
Ophthalmology, Johns
HopkinsSchool ofMedicine, Baltimore,MD, UnitedStates
Introduction:
Reconstruction of the inferomedial orbital strut is amajor challengeof orbital reconstruction as it is acurately
performedwith intraoperative judgement, image guided navigational surgerywith intraoperative verification, or postoperative CT
scan verification.AGoniometer is a device used tomeasure angles of rotation and adequacy of reduction of orthopedic (hand and
spinal) fractures.We herewith describe a technique of preoperative determination of theAngle of theOrbital Strut (AOS) based on the
contralateral orbit, prebending a ‘prefabricated anatomical orbital plate’ and intraoperative placement and fixation.
Methods:
Prospective study of 25 orbits of 25 patientswho sustained a complex blow out fracture (floor andmedial wall) or
extensive zygomatico-maxillary complex (ZMC) fracturewithmedial wall involvement. Operative team consisted of either anOrbital
team alone or with a Facial Plastic &Reconstructive Surgeon.All patients underwent surgery under General Anesthesia through a
swinging eyelid approach’ with fixation of the ‘ prefabricated anatomical (Synthes) implant to the inferior orbital rim.When necessary
a retrocaruncular incisionwas utilized to access themedial wall. Preoperative determination of the angle of the orbital strut (AOS)
at themidlevel of the coronal section of the orbit was performed on the contralateral side.AGoniometer was used to prebend the
prefabricated anatomical Titanium plate (Small (purple) and large (gold) plates. 12 of 25 patients had intraoperative verification of
the superior, posterior extent of the orbital implants usingNavigational Image guided technique (Brain Lab or Fusion system).
2 patients had a 3-Dmodel fabricated based on themirrored image of the unaffected side to be used as a template.All patients
had postoperative CT scan image to confirm accuracy of orbital content reduction and position of the orbital implant including the
angle of the orbital plate.
Results:
23 of 25 orbits had accurate correction of the inferomedial orbital strut with adequate coverage of bothwalls of the orbit.
2 of 25 patients had a suboptimal correction owing to varying contours of the extent of the floor andmedial wall of the orbit.All
patients had good postoperative recoverywith no diplopia in primary andwithin 30 degrees of primary gaze of fixation. None of the
patients required additional orbital plate repositioning or surgical intervention for diplopia or eyelidmalposition.Therewere no cases
of visual loss
Figure 1: Goniometer being used to Figure 2: Pre-operative assesment of the angle of the orbital strut
fashion a gold titanium implant
Conclusions:
Prebending a prefabricated titaniummesh, based on anglesmeasured on preoperative CT scans of the unaffected
orbit with the guidance of aGoniometer, helps both an accurate and fast reconstruction of the inferiomedial anglewith good
outcomes andminimizing complications.
References:
Kim JW, Goldberg RA, Shorr N.The inferomedial orbital strut: an anatomic and radiographic study.Ophthal Plast
Reconstr Surg. 2002 Sep;18(5):355-64.
DetailedProgram
—Thursday,October 16, 2014
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