ASOPRSFall Scientific SymposiumSyllabus
109
Orbit Session II
Moderator: Suzanne K. Freitag,MD
1:00pm
Symmetryof theAngleof theOrbital Strut (AOS) –ARadiological Study
Raghuraj Hegde
1
, GangadharaSundar
1
, Eric Ting
2
, ThiamChye Lim
3
,Michael Grant
4
.
1
Ophthalmology, National UniversityHospital,
Singapore, Singapore,
2
Radiology, National UniversityHospital, Singapore, Singapore,
3
Plastic andAestheticSurgery, National
UniversityHospital, Singapore, Singapore,
4
Ophthalmology, JohnsHopkinsSchool ofMedicine, Baltimore,MD, UnitedStates
Introduction:
Introduction: Reconstruction and restoration of the orbital strut is an integral part of anatomical correction in complex
orbital fractures.The orbital strut plays an important role in globe position and extraocularmuscle function. In complex orbital trauma
the orbital strut is often poorly reconstructed or not even paid attention to, but just repairing an reconstructing the floor and the
medial wall alone.Awareness, recognition andmeasurement of theAngles of orbital strut preoperatively on the contralateral side is
a useful guide to intraoperative reconstruction., helps guide intraoperative reconstruction thereby translating into good postoperative
globe position and ocularmotility. Evenwhen prefabricated implants are available, refashioning the angles prior to insertion helps
restore this symmetry andmakes it easy by avoiding unnecessary or undesirable intraoperative intraorbital manipulation.Thismay be
a reasonable alternative especially IntraoperativeNavigation is not readily available, as inmost centres in theworld.
Methods:
Retrospective review of 162 consequtive CT scan orbits(max.3mm cuts) with intact bilateral orbitsmeasuring angle
between orbital floor andmedial wallAOSmeasured at 3 standard locations:
1. Rim-RimAOS(RAOS)
2. 9mm behind the RAOS-MiddleAOS(MAOS)
3. 18mm behind the RAOS-Posterior AOS(PAOS)
Statistical analysis(unpaired t-test andMann-Whitney U) was done taking race into account.
Figure 1: Symmetry at RimAngle of theOrbital Strut
Figure 2: Symmetry at MiddleAngle of theOrbital Strut
Figure 3: Symmetry at Posterior Angle of theOrbital Strut
Results:
324orbits (162 patients) studied.Analysis showed significant symmetry of AOS at all the above locations irrespective
of race(p>0.05).AverageAOS:East Asians-127.6°,SouthAsians 126.7°&Caucasians-127.3°
Conclusions:
Variations of AOS between the right and left orbits are small indicating real world applications in repair of
orbital fractures.
References:
Cho RI, Davies BW.Combined orbital floor andmedial wall fractures involving the inferomedial strut: repair technique
and case series using preshaped porous polyethylene/titanium implants.CraniomaxillofacTrauma Reconstr. 2013Sep;6(3):161-70.
DetailedProgram
—Friday,October 17, 2014
