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Reconstruction of Post-Traumatic Orbital Defects and Deformities with Custom-Made Patient-Specific Implants: Evaluation of the Efficacy and Clinical Outcome

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The main purpose of this article is to evaluate the efficacy of patient-specific implants (PSI) in treatment of patients with post-traumatic orbital defects and deformities. Twenty-three patients with post-traumatic orbital defects and deformities, who underwent subsequent reconstructive procedures using PSI, were included in the study. All the patients were examined according to the standard algorithm involving the local status examination, vision assessment, and computed tomography before and after surgery. The study findings show neither postoperative infectious complications nor decreased visual acuity or loss of visual fields. Functional disorders resolved in 65.2% of cases 1 month after the surgical intervention and in 86.96% of patients within a 3-month term. Positive aesthetic outcomes were seen in 95.7% of cases. Reconstruction with computer-aided design/computer-aided manufactured PSI is an effective procedure that allows accurate restoring of the complex orbital anatomy.
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Reconstruction of Post-Traumatic Orbital Defects and
Deformities with Custom-Made Patient-Specic Implants:
Evaluation of the Efcacy and Clinical Outcome
Yurii Chepurnyi, DDS, PhD1Denis Chernogorskyi, DDS1Oksana Petrenko, MD, MScD2
Andrii Kopchak, DDS, MScD1
1Department of Stomatology, O.O. Bogomolets National Medical
University, Kyiv, Ukraine
2Department of Ophthalmology, Pl Shupik National Medical Academy
of Postgraduate Study, Kiev, Ukraine
Craniomaxillofac Trauma Reconstruction Open 2019;3:e9e17.
Address for correspondence Yurii Chepurnyi, DDS, PhD, Department
of Stomatology, O.O. Bogomolets National Medical University,
Zoologichna Street, 1 Kyiv 01601, Ukraine
(e-mail: 80667788837@ukr.net).
Despite the notable advances in reconstructive surgery techni-
ques,post-traumatic defects and deformities of theorbit remain
a majorchallengedue to the complex anatomy, variable trauma
patterns, and the need for an interdisciplinary approach. Inju-
ries of the orbital walls are associated with signicant facial
disguration because of the eyeball displacement, and they
cause functional decit (diplopia, restricted globe motility, and
a decrease or loss of vision). It complicates social adaptation of
the patients, and affects the psychological state.13
Traditional methodsfor restorationof the orbital volume and
anatomic shape include the usage of standard preformed
titanium plates and meshes available in different sizes, poly-
meric implants of thin polyethylene membranes, and autolo-
gous bone grafts.1,4 Bone grafts and standard titanium or
polymeric implants usually require prebending or intraopera-
tive bending and correction of the contours. It may be difcult
because of the lost anatomical landmarks and changes in
topographic anatomy of the orbit and its content. The proper
insertion and positioning of the implants or grafts inside the
orbit, especially in the region of the orbital ledge, remain
challenging.3,5 The problem could be solved with digital intrao-
perative navigation systems, but thehigh cost of the equipment
limitstheir use.Moreover, thesesystems donot ensurea precise
t of the bone graft or implant if their geometry does not match
the contours of the defect or individual orbital shape.1,6,7
In orbital reconstruction procedures, the location of
implants or bone grafts and their conformity to the individual
anatomy of the damaged structures in size and shape deter-
mine the surgical strategy and the integral success rate.
Recent developments of computer-aided design/computer-
aided manufacturing(CAD/CAM) technologies and evidence of
their effective clinical application in management of facial
bone defects and deformities have generated an increased
interest to their usage in reconstructive surgery of the orbit.
Keywords
orbital defects
patient-specic
implants
CAD/CAM
reconstruction
Abstract The main purpose of this article is to evaluate the efcacy of patient-specicimplants
(PSI) in treatment of patients with post-traumatic orbital defects and deformities.
Twenty-three patients with post-traumatic orbital defects and deformities, who under-
went subsequent reconstructive procedures using PSI, were included in the study. All
the patients were examined according to the standard algorithm involving the local
status examination, vision assessment, and computed tomography before and after
surgery. The study ndings show neither postoperative infectious complications nor
decreased visual acuity or loss of visual elds. Functional disorders resolved in 65.2%
of cases 1 month after the surgical intervention and in 86.96% of patients within a
3-month term. Positive aesthetic outcomes were seen in 95.7% of cases. Reconstruc-
tion with computer-aided design/computer-aided manufactured PSI is an effective
procedure that allows accurate restoring of the complex orbital anatomy.
received
September 22, 2018
accepted after revision
November 14, 2018
DOI https://doi.org/
10.1055/s-0039-1685505.
ISSN 2472-7512.
Copyright © 2019 by Thieme Medical
Publishers, Inc., 333 Seventh Avenue,
New York, NY 10001, USA.
Tel: +1(212) 584-4662.
THIEME
Original Article e9
The above technologies have contributed to improved diag-
nostics and initial assessment of the clinical case, facilitated
designing and manufacturing of orbital implants owing to the
virtual simulation of the surgical procedures, and ensured
highly predictable outcomes with signicantly improved con-
ditions postoperatively.1,3,6,8,9 Previously, there were reports
about successful experience of custom-made patient-specic
implants (PSI) manufactured from either titanium by selective
laser sintering (SLS) or polyether-ether-ketone (PEEK)for facial
or cranial reconstructions.13,1012 The authors noted the
complexityof conventional algorithms used for implant design
and manufacturing with increased probability of errors and
discrepancies.
One of the rst orbital reconstructions with PSI was
reported by Williams and Revington.11 Later, the rst series
of cases was presented by Gander et al.13 Several clinical
studies have documented the efcacy of orbital reconstruc-
tion with PSI since then. Most of the articles describe the
usage of titanium PSI. They differ in the number of patients
involved, the algorithms of the CAD procedures, the evalua-
tion criteria, a nd methods of implant manufactur ing. Despite
a considerable number of studies devoted to cranioplasty
and frontal bone reconstructions with PEEK implants, only
few reports present the outcomes of the orbital wall recon-
structions with PEEK PSI.14
It conditions the need for evidence-based improvement of
current approaches to the virtual simulation, manufacturing
and installation of PSI in reconstructive surgery of the orbit.
The aim of this study was to evaluate the clinical efcacy
of custom-made titanium and PEEK PSI in post-traumatic
orbital defects and deformations.
Material and Methods
Twenty-three patients with unilateral post-traumatic
defects and deformities of the orbit (15 males and 8 females,
aged 16 to 54 years, mean age 37.9 13.7 years), who
underwent orbital reconstruction procedures with PSI at
the Center for Maxillofacial Surgery and Stomatology, Kyiv
Regional Hospital, Ukraine from January 1, 2016 to Febru-
ary 28, 2018, were included to this study. In all cases, an
informed consent from patients for the treatment and parti-
cipation in the present study was obtained. The research was
approved by Bioethics Committee of Bogomolets National
Medical University, Kyiv, Ukraine (Protocol No. 104). The
exclusion criteria were the following: age under 16, bilateral
orbital trauma, endocrine orbitopathy, anophthalmia, one or
both side loss of vision, defects caused by gunshot injuries,
defects and deformities after tumor resections, radiation or
chemotherapy in anamnesis, mental illness, noncompliance
with medical recommendations and lack of interaction with
a doctor in the postoperative period, and refusal of the
patient to participate in the study.
The diagnostics and treatment of the above patients were
performed bya multidisciplinary team, whichincludedoral and
maxillofacial surgeons, ophthalmologists, and ENT surgeons.
All patients were examined preoperatively, rst day after
surgery, 1 and 3 months after surger y following the stan-
dardized algorithm, including local status examination
(facial symmetry, scars, and position of the eyeball) and
evaluation of vision (visual acuity, diplopia, and ocular
mobility). Visual elds were also recorded. All patients
underwent 64-slice computed tomography (CT; Philips Dia-
mond Select Brilliance CT 64, Koninklijke Philips N.V.; slice
thickness0.5 mm) before and after surgery (Table 1).
Efciency evaluation criteria included the duration of the
surgical intervention and the period of implant adaptation,
orbital volume measurements, early and long-term post-
operative complications, and changes in the aesthetics and
ophthalmologic status. Aesthetic outcomes of the treatment
were considered as unsatisfactory (where a residual cos-
metic defect was signicant, obvious to the patient, and
requiring a secondary surgical correction), satisfactory (sur-
gical repair of residual cosmetic defect was not necessary or
only a small intervention on the paraorbital soft tissues was
required), or good (where both the surgeon and patient were
satised with the obtained result).
Design and Manufacturing of the Implants
Virtual simulation of surgical procedures and PSI designing
were performed in close collaboration between surgeons and
biomedical engineers. Preoperative CT data (Digital Imaging
and Communications in Medicine [DICOM] les without com-
pression) were provided to the manufacturer of the implants
(Imatek-Esco Ltd., Kyiv, Ukraine 3D Systems [USA] reseller).
Then, biomedical engineers analyzed the clinical case, created
thedesignoftheimplantanddened its optimal position inside
the orbit with the participation and under control of surgeons.
Computer-aided design procedures were performed in the
software environment (SimPlant 10.03; Materialise Dental) by
segmentation of the CT data, creating virtual models of the
orbit and editing them. The models were edited in multiple
slice modes (slice-by-slice) considering the contour of the
mirrored healthy orbit after its superimposition on DICOM
data of the damaged orbit using manual reposition. The
purpose of the editing procedure was to restore the integrity
of the orbital wallsfor creation of a constant surfacein all slices
without triangular mesh defects. STL model of the orbit after
multiple slice editing was exported to design software (Geo-
magic Freeform Plus). Further processing of the model
included wrapping, smoothing, and xing procedures. The
design of the implant was obtained by creating the required
surface shape and its subsequent transformationinto an object
with dened thickness. Then, clearance of the object and holes
for xation were created using boolean operations.
The design of the implants was aimed at repairing the
orbital wall defects and deformities of the orbital rim, thus
restoring a true-to-original shape of the damaged structures.
In all cases, retention points for precise intraoperative posi-
tioning of the implants and their stable retention after the
installation as well as additional elements with holes for
screw xation to the orbital rim were modeled and created.
The diameter and shape of the holes corresponded to the
osteosynthesis system selected for xation. In three cases,
the design of the implant allowed correcting deformities of
Craniomaxillofacial Trauma & Reconstruction Open Vol. 3 No. 1/2019
Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al.e10
the orbital rims and defects of the bones adjacent to the orbit
(Fig. 1).
Virtual three-dimensional models of PSI in STL format
were reimported to the software (SimPlant 10.03 with
cranio-maxillo-facial module) for CT data analysis, where
the surgeons performed the preoperative evaluation of PSI
location inside the orbit in relation to the bone (orbital oor)
and soft tissues (the optic and infraorbital nerves and mus-
cles). After validation and correction by clinicians, STL le was
sent for manufacturing. The implantswere made by milling of
radiopaque PEEK blocks (Merz Dental; 18 cases) on the
machines with numerical control or by SLS of the titanium
(Ti6Al4V) powder (DIN: 3.7165) according to ISO 5832-3 (in 5
cases). We preferred PEEK in cases where only orbital wall
reconstruction was indicated. However, we considered tita-
nium PSI as a method ofchoice in cases where the reconstruc-
tion of the orbitozygomatic complex with stabile xation of
the orbital rim fragments was performed simultaneously with
orbital walls reconstruction. The implants were sterilized the
day before operation by autoclaving at 132°C.
Virtual orbital models of the damaged and intact sides
were generated for all cases before and after surgery. For this
purpose, a threshold value segmentation of the CT data was
performed with generation of the bony orbital model and
models of the soft tissue content (orbital models). These
orbital models were edited considering the contour of the
bony orbit and orbital margins. Their volumes were mea-
sured in the computer software and compared for each
individual case. Addit ionally, a superimpos ition of the virtual
models (mirrored intact and damaged) was performed after
trauma, after design of PSI, and after surgical treatment.15,16
Statistical analysis of the data included the calculation of
mean values, and standard deviation for each parameter
evaluated. Nonparametrical statistics was employed for
analysis of the data. The MannWhitney Utest was used
to compare the differences between these parameters in the
study group. The level of signicance was set at p<0.05.
Statistical calculations were performed in SPSS Statistics
software environment (IBM Inc.).
Results
Post-traumatic defects and deformities resulted from blow-
out orbital fractures (ve of them were combined with
orbitozygomatic fractures and two with fractures of the
orbital roof).
Table 1 Patient demographic and clinical features
Patient Age Sex Timing Material Aesthetic
outcomes
Post-traumatic
diplopia
Diplopia 3 months
after surgery
118M>1 month PEEK Good Yes No
246M>1 month Titanium Satisfactory No No
316F>1 month Titanium Satisfactory Yes Yes
427M>1 month Titanium Good No No
525M>2weeksto<1month PEEK Good Yes No
648M>2weeksto<1month PEEK Good Yes No
728F>1 month Titanium Satisfactory Yes No
829F<2 weeks PEEK Satisfactory Yes Yes
944F<2weeks PEEK Good Yes No
10 46 M >1 month PEEK Good Yes No
11 52 F >1 month PEEK Good Yes No
12 43 M >1 month PEEK Good Yes No
13 27 M >1month PEEK Satisfactory Yes No
14 53 F >1 month Titanium Good Yes No
15 48 F >1 month PEEK Satisfactory Yes Yes
16 42 M <2weeks PEEK Good Yes No
17 49 M >2weeksto<1month PEEK Good Yes No
18 59 F >1 month PEEK Good Yes No
19 47 M <2weeks PEEK Good No No
20 24 M >2weeksto<1month PEEK Good Yes No
21 27 M <2weeks PEEK Good Yes No
22 57 M <2weeks PEEK Good Yes No
23 16 M <2weeks PEEK Good Yes No
Abbreviation: PEEK, polyether-ether-ketone.
Craniomaxillofacial Trauma & Reconstruction Open Vol. 3 No. 1/2019
Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al. e11
The preoperative examination revealed diplopia in all
elds of view in 16 patients, diplopia in two elds of view
(when looking downward and upward, or downward and
inward) was found in 3 patients, and in one eld of view
(when looking downward) in 1 patient. In three cases, no
functional disorders were observed.
Facial asymmetry caused by post-traumatic enophthal-
mos was noted in 17 cases; in ve patients, it was associated
with eyeball vertical displacement. In two cases, the aes-
thetic deciency resulted from the deformity of the orbital
rims. Concomitant post-traumatic deformities of the eyelids,
lateral or medial telecanthus, in ve cases also contributed to
the worsening of the appearance and deterioration of the
aesthetic condition.
In our series, the orbital oor was broken in all cases; the
medial wall was damaged in 14 cases, orbital roof in
two cases. Post-traumatic deformities of the orbital rims
were recorded in ve cases. Orbital oor or medial wall
Fig. 1 Steps for patient-specic implant (PSI) design in orbital wall reconstruction. (A, B) Deformity of the orbital walls after blowout fracture:
computed tomography (CT) data; (C, D) mirroring of the intact orbit and its comparison with the model of the damaged orbit; (E) editing of the
CT-based three-dimensional vir tual model of the orbit with the creation of a constant surface; (FH) design and position of the PSI into the orbit;
(I) evaluation and comparison of orbital volumes; (JL) CT control after orbital reconstruction with PSI).
Craniomaxillofacial Trauma & Reconstruction Open Vol. 3 No. 1/2019
Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al.e12
reconstructions in all cases were performed via subciliary
approach. Further reposition of the orbital content, implant
insertion, and xation to the orbital rim were accomplished
by placing the eyeball to proper position. In three cases, we
employed a coronal approach for reconstruction of the
damaged orbitozygomatic complex and orbital roof.
Difculties in proper positioning of the implant inside the
orbit were seen only in two cases. They were associated with
incomplete reposition of orbital content. In one case, the
xation hole was in the projection of the bone defect (in an
area of incomplete osteogenesis).
In three cases, implants were us ed both for reconstruction
of the orbital walls and correct ion of the orbital rim anatomic
shape.
In this series, the average period of CAD procedures was
4.04 2.9 days. The average time spent on manufactur ing of
the PEEK PSI was 1.8 0.7 days vs. 23.7 4.9 days spent on
the manufacturing of the titanium PSI with delivery from the
United States or European Union. The average duration of the
surgical interventions was 58.8 17.3 minutes.
In this series, no inammatory complications, decreased
visual acuity, or loss of visual elds were observed within the
postoperative period. The average duration of hospital stay
was 4.2 1.6 days.
The aesthetic outcomes of the treatment were good in 17
cases and satisfactory in 6 cases. In ve patients with
satisfactory aesthetic outcomes, additional corrections of
paraorbital soft tissues were indicated. Depending on the
status, these patients underwent surgical repair of the eyelid
deformities or ptosis, and reshaping the scars.
Mobility disorders were totally absent in 22 cases (95.7%)
1 month after surgery, and in onlyone case they were partially
preserved; however, a signicant improvement was seen.
One monthafter surgery,diplopia waspresent in 8 cases, but
3 months after surgery it was absent in 20 patients. Another
three patients reported a signicant decrease in diplopia.
Mydriasis was noted in three cases with recovery after a
year follow-up. Sensory disturbances on the second branch
of the fth cranial nerve 3 months after surgery were present
in nine patients but after a 6-month follow-up they resolved.
In one case, aesthetic and functional outcomes were
unsatisfactory due to the restriction of the eyeball mobility,
caused by compression of the medial rectus muscle with the
edge of the implant. The patient underwent a secondary
surgery to eliminate the compression of the muscle. The nal
functional and aesthetic outcomes were satisfactory.
Thus, in our series, positive aesthetic results were
obtained in 95.7% of patients. Functional disorders resolved
in 65.2% of cases in a month term after surgery, in 86.96% of
patients within 3 months.
The measurements of the orbital volumes on the intact
side before and after surgery (actually, this volume did not
change) showed the minor differences in all cases, which can
be recognized as measurement error. On average, they con-
stituted 0.45 0.35 cm
3
and were statistically nonsigni-
cant (U¼262; Z¼0.055; p¼0.956).
The average volume of the orbit on the intact side was
25.6 2.5 cm
3
, whereas the average volume of the damaged
orbits in our study signicantly increased and constituted
29.8 4.3 cm
3
(U¼112; Z¼3.35; p¼0.001). The mean
difference was 4.2 3.0 cm
3
.
After reconstructive surgery in this series, the average
volume of the damaged orbits reduced to 25.8 2.6 cm
3
.
The average difference with intact orbits after the surgical
interventions was only 0.77 0.6 cm
3
and there were no
signicant differences between the mean volumes of the
damaged and intact orbits (U¼231; Z¼736; p¼0.462)
(Table 2). Analysis of the orbital virtual model superimposi-
tion found a high degree of congruence between the shape of
the mirrored intact and damaged orbits.
Discussion
Reconstruction of the orbit is always a challenge for surgeons
due to the complexity of the anatomy, small size, and excep-
tional importance of the eye for the human life.2The main
objectives to besolved in the treatment of orbital injuries are as
follows: (1) the repair of the orbital wall defects by restoration
of the orbital volume, (2) the reconstruction of the normal
orbital shape, taking into account the individual anatomic
features, and (3) the correction of the globe position.3The rst
objective is traditionally accomplished by the use of standard
preformed implants made of different materials (titanium,
polytetrauoroethylene, silicone, polyethylene, etc.) or auto-
logousgrafts (bone and cartilage).The main problem is that the
process of their adaptation to the parameters of the damaged
orbit is complex and time-consuming.3,4 The proper position-
ing of the standard implants or grafts inside the orbit is difcult
to achieve, and it is the main reason for unsatisfactory treat-
ment outcomes.6,7 However, according to Zieliński et al,17 the
use of standard titaniummeshes was not associatedwith worse
functional outcomes as compared with PSI, but it required
time-consuming intraoperative adaptation and demonstrated
higher blood loss during surgery.
The most difcult task that cond itions functional recovery
and a high aesthetic outcome of treatment is the accurate
restoration of the orbital shape, taking into account indivi-
dual parameters of the anatomical structure. This is espe-
cially important for the lower and medial walls, which form a
ledge near the orbital apex area.3,5 Other important intraor-
bital structures which should be considered for proper
reconstruction are the inferior orbital ssure (IOF), intraor-
bital buttress (IOB), and posterior ledge (PL). Their safety or
damage is determined by the severity of trauma, surgical
strategy, shape of the orbit after reconstruction (due to
design and positioning of the implant or graft).3,5,18
Restoration of the orbital shape can be achieved by
individualization of the standard implants (giving them a
specic shape during or before operation, manually or with
the use of special equipment). CAD/CAM technologies are
one of the most effective approaches to solve these problems.
The above technologies demonstrated signicant benets in
reconstruction of facial and cranial bones. In orbital recon-
struction, CAD/CAM technologies are used for accurate eva-
luation of the injury pattern, exact measurements of the
orbital volume and its changes, designing and manufacturing
Craniomaxillofacial Trauma & Reconstruction Open Vol. 3 No. 1/2019
Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al. e13
of the implant for orbital shape restoration, considering the
anatomical landmarks of the damaged orbit, and the geo-
metry of the intact orbit. An implant designed in computer
software can be created with specic elements and indivi-
dually shaped to ensure xation and placement inside the
orbit only in one predetermined position. Thus, virtual
design of the implants and the rapid prototyping become
an effective alternative to traditional surgical methods of the
orbital reconstruction.3,19,20
Our series of patients showed high efciency of the offered
algorithms of PSI modeling and manufacturing. In our experi-
ence, mirroringof the intact bony orbit enablesvirtual repair of
bone defects of the damaged orbit only under the following
conditions: the proper safety of IOF, IOB, PL, high CTresolution,
sufcient thickness, and/or X-ray density of the bone walls of
the intact orbit. The important role of these anatomical land-
marks is to ensure an exact match between the mirrored
model and the model of the damaged orbit. From the surgical
and bioengineering points of view, PL assured the proper
support for the distal edge of the PSI; the IOF conditioned
the position of distal and lateral borders of the PSI. The IOB
supported the medial border of the PSI and provided an exact
reconstruction of the orbital shape.
In the absence of one or more of the above-mentioned
conditions, the virtual model of the damaged orbit needed to
be edited in automatic/semiautomaticor manual mode af ter the
mirroring of the intact orbital model. The complexity of editing
(virtual sculpturing) depended on the severity of the injury. If
the extent of the bony landmarks destruction was higher, the
time spent on manual editing increased as well as the need for
virtual sculpturing of such structures as IOB and PL. The
destruction of the IOB resulted in increased implant surface
due to the need to ensure its support in the area of the medial
orbital wall. The use of anatomic landmarks in combination with
mirroring of the contralateral orbit and virtual sculpturing
assured accurate reproduction of the orbital anatomicalshape in
the software environment. Thus, the design of the implant was
based on clinical status, geometry, and localization of the defect.
Some clinical trials report the outcomes of the PSI applica-
tion for orbital reconstruction by the use surgical navigation
and/or intraoperative CT to control the implant position inside
the orbit.14,21 However, in our study, the presence of specic
elements (curves and legs) provided in each case allowed
precise placement of the implants in the exact optimal/desired
position with due consideration of specicclinicalandanato-
mical conditions (Fig. 2). However, in some cases it required
Table 2 Injury patterns in patients included in the study
Patient Fracture Damaged zone
(according to AOCMF
classication system
for orbital fractures16)
Damaged
IOF
a
Damaged
IOB
b
Damaged
posterior
ledge
Volu me di ffe rence
before surgery
(damaged/intact)
mm
3
Volu me di fference
after surgery
(damaged/intact)
mm
3
1 Blowout W2 (im) A(i) Yes Yes Yes 8,913 440
2 Combined R(li)W1(im)2(im) Yes Yes Yes 5,148 935
3 Combined R(im)W1(im) 2(im) No Yes No 3,736 1,984
4 Combined R(il)W2(il) Yes No No 457 275
5 Blowout W1(i)2(i) No Yes No 3,708 48
6 Blowout W1(mi)2(1) A(i) Yes Yes Yes 7,605 625
7 Combined W1(i)2(iml) A(i) Yes Yes Yes 1,210 634
8 Blowout W1(i)2(i) No Yes No 1,553 1,385
9 Blowout W1(i)2(i) No No No 1,083 351
10 Blowout W1(im)2(im) A(m) No Yes No 9,737 909
11 Blowout W1(is)2(i) Yes Yes Yes 2,972 868
12 Blowout W1(im)2(im) No No Yes 2,294 174
13 Combined R(il)W1(sm)2(lim)A(im) Yes Yes Yes 9,838 2,408
14 Combined R(li)W1(i)2(lm) Yes No Yes 7,232 1,764
15 Blowout W1(im)2(im) No Yes Yes 1,830 428
16 Combined W1(mi)2(im) No Yes No 5,780 1,562
17 Blowout W1(im)2(im) No Yes No 5,463 654
18 Blowout W1(i)2(i) No No No 3,241 353
19 Blowout W1(i)2(i) No No No 1,145 240
20 Blowout W1(im)2(im) Yes Yes Yes 6,342 315
21 Blowout W1(im)2(im) No No No 429 280
22 Blowout W1(i)2(i) No No No 5,160 231
23 Blowout W1(i)W(mi) No Yes Yes 2,567 843
a
Inferior orbital ssure.
b
Intraorbital buttress.
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to increase the size of implants to t an orbital anatomy, which
demand more wide surgical approaches.
The use of different types of materials in treatment of
our patients was conditioned by the different clinical goals
and the limitations of manufacturing processes. Individua-
lized titanium PSI provided the possibility of both orbital
walls reconstruction and stabile xation of the orbital rim
fragments in cases of complex orbitozygomatic fractures.
We also took into consideration the manufacturersrecom-
mendations which made it possible to produce the
implants with the thickness of 0.6 mm by milling of PEEK
and of 0.9 to 1 mm (depending on geometry) by titanium
sintering (Fig. 3). For isolated orbital wall defects the
thinner plates from PEEK were more appropriate. Thus, the
shape and dimensions of the PSI inuenced the choice of
the material.
The only limitation in the production of PSI by milling was
the presence of a negativeanglein the region of the orbital rim
when it was necessary to reshape it, which made it impossible
to mill the inner surface of the implant. In such cases, we
preferred SLS titanium implants. With respect to SLS technol-
ogy, wall thickness conditioned the limitations for the manu-
facturing of thin sections of the implants (mostly retention
points and xing elements).
Our results did not allow us to give a comparative descrip-
tion of the titanium and PEEK PSI application due to the
presence of signicant individual variations in the trauma
patterns, as well as different indications for their use. At the
same time, we did not observe any complications or any
signicant differences in the accuracy of restoring the shape
and volume of the orbits. The principles of modeling and the
time spent on the CAD procedures were not different, as well
as inquiries in time of manufacturing were determined by
subjective factors. All this exclude the possibility to deter-
mine evidence-based recommendations of the material
selection for PSI manufacturing.
According to the literary data, PEEK is a widely used
biocompatible polymer with numerous physical character-
istics that are favorable for craniofacial reconstruction.2,12 It
is a semicrystalline and thermoplastic material with good
imaging properti es,stiffness, durability, light weight, fatigue,
and chemical resistance. PEEK implants can be repeatedly
sterilized without the degradation of their structure and
mechanical properties.
Fig. 2 Patient K with blowout fracture of the right orbit, 3 weeks after trauma (AC) computed tomography (CT) slices of the damaged orbital
walls; (D, E) virtual mode of the PSI, positioned into the orbit; (FH) control CT of the reconstructed orbit with patient-specicimplant.
Craniomaxillofacial Trauma & Reconstruction Open Vol. 3 No. 1/2019
Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al. e15
In addition, the modulus of elasticity of this material is close
to the cortical bone, thus avoiding stress shielding effect.
Allergic reactions to PEEK are extremely rare. PEEK implants
can be easilymodied using high-speedburs and it is easy to x
them with conventional screws to the bone edges. In our series,
neither clinical nor radiological manifestations of inamma-
tory complications, including sinusitis, caused by PEEK
implants were observed (a maximum follow-up of 2 years).
Design and the way of implant insertion conditioned the
choice of surgical approach. We used a subciliar y approach as
optimal one for mobilization of the orbital content, place-
ment of the eyeball in the proper position, and insertion of
the PSI into the orbit. According to our observations, the
presence of a scar in the subciliary area did not affect the
integral aesthetic outcomes of the treatment.
Virtual preoperative simulation was employed for the
estimation of the implant position inside the orbit, and its
interrelationships with bony structures, nerves, and oculomo-
tor muscles. In the cases where collisions between the implant
and anatomical structures were seen the design was changed.
Preoperative planning allows the precise measurement of
orbital volume and analysis of its changes caused by traumatic
injury and surgical interventions. The results of this study
demonstratedthe effectiveness of the offeredalgorithm for PSI
design and manufacturing. It enabled adequaterecovery of the
orbital volume and shape after reconstructive surgery so that
the differences between volume of damaged and intact orbits
became nonsignicant (Fig. 4).
Fig. 3 Patient D with post-traumatic deformity of the left orbitozygomatical complex (A) three-dimensional (3D) computed tomography before surgery,
(B) virtual model of the patient-specic implant (PSI) and surgical guide for zygoma reposition;(C) removed titanium þpolyethylene implant and titanium
PSI; (D) 3D after surgery).
Fig. 4 Superimposition of the virtual models after surgery: mirrored
intact and damaged orbits.
Craniomaxillofacial Trauma & Reconstruction Open Vol. 3 No. 1/2019
Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al.e16
The main advantage of the offered surgical approach was
accurate reconstruction of the orbital shape, especially in the
key area,according to Hammer,22 which ensured high aes-
thetic outcomes of treatment. Postoperative CT images of
patients, who were treated by the use of the offered algorithm,
showed the high accuracy of implants positioning inside the
orbit and the restoration of its anatomical structure in the vast
majority of observations. PSI location was almost similar to the
preoperative planning. The difcultiesin positioning were due
to scarring andpresence of small bone fragments that werenot
adequately reected on the CT slices.
The results obtained correlate with those reported by
other authors. Zieliński et al17 reported the presence of
motility disorders after CAD/CAM-assisted orbital recon-
structions in 29 and 13% of cases 1 and 6 months after
surgery, respectively. According to the multicenter study by
Zimmerer et al,21 there was a statistically signicant reduc-
tion in the time of surgical intervention when PSI were used.
An average time of surgery in this study was 60 minutes,
which correspond to the results obtained in present study.
Motility disorders after orbital reconstruc tion with the use of
PSI were in 15.8% of cases 1 month and in 3.3% 4 months after
surgery. Diplopia was found in 35.8% of cases 1 month after
surgery. The value decreased to 24.6% 4 m onths after surgery.
These results are almost similar to those obtained in our
study. However, our study had following limitation, such as
subjective evaluation of the facial asymmetry and diplopia,
absence of the control group with hand-bentimplants and
enophthalmos evaluation, as well as failure to determine the
relationship between clinical and radiological objective data,
absence of long-term follow-up, a relatively small number of
observations with various trauma patterns. Accordingly, all
these issues require further research and in-depth analysis.
Conclusion
The obtained results conrm the advantages of CAD/CAM
technology and PSI in treatment of orbital defects and
deformities. The use of anatomical landmarks in combina-
tion with mirroring of the contralateral orbit and virtual
sculpturingensured accurate reproduction of the anatomi-
cal shape of the orbit in the software environment. Both
titanium and PEEK can be effectively used for PSI manufac-
turing, depending on clinical situation, surgical purposes,
and geometry of the orbit.
Conict of Interest
None.
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Evaluation of the Efficacy and Clinical Outcome of PSI Chepurnyi et al. e17
... Таким образом, на сегодняшний день важным и актуальным вопросом является поиск новых возможностей для планирования и проведения хирургической декомпрессии орбиты с целью профилактики вышеуказанных осложнений. Среди современных тенденций развития медицины в аспекте планирования хирургических вмешательств и точной их реализации можно отметить использование Computer-Aided Design (CAD) / Computer-Aided Manufacturing (CAM) технологий, которые помогают решать наиболее сложные клинические задачи в разных отраслях медицины, в частности в челюстно-лицевой и офтальмопластической хирургии [9][10][11][12]. ...
Article
Введение. При эндокринной орбитопатии (ЭО) средней и тяжелой степени тяжести, которая приводит к снижению качества жизни пациентов, применяют хирургическую декомпрессию, частота осложнений которой составляет от 9,3 до 35%. Поэтому поиск новых возможностей для профилактики послеоперационных осложнений является актуальной проблемой челюстно-лицевой хирургии и офтальмологии.Цель. Оценить результаты лечения и определить частоту осложнений при проведении декомпрессии орбиты с использованием хирургических навигационных шаблонов при лечении пациентов с эндокринной орбитопатией.Материалы и методы. Для достижения поставленной цели был проведен анализ результатов декомпрессии орбиты у 17 пациентов с ЭО, проходивших лечение на базе Киевской областной клинической больницы и Киевской городской клинической больницы № 1 в период с 2017 по 2021 г. Для проведения исследования нами был использован соответствующий цифровой протокол. Дизайн и изготовление навигационных хирургических шаблонов проводились по данным компьютерной томографии с помощью CAD/CAM-технологии после симуляции костной декомпрессии в пределах «безопасных зон» по отношению к анатомическим структурам орбиты и ее мягкотканному содержимому.Результаты. По данным предоперационной экзофтальмометрии средняя величина экзофтальма на правом и левом глазу составила 23,75±3,07 мм и 24,27±3,26 мм соответственно. В послеоперационном периоде средняя величина экзофтальма для правого глаза составила 18,88±2,18 мм, для левого – 19,47±3,01 мм; статистически достоверного различия в обследуемой группе также не было обнаружено (p=0,892). После проведения декомпрессии орбиты величина экзофтальма в среднем уменьшалась на 4,84±0,27 мм, достоверно отличаясь в исследуемой группе в сравнении с дооперационными показателями (р<0,001).Среди послеоперационных осложнений в сроки наблюдения 3 месяца у одного пациента нами отмечена диплопия, у трех пациентов сохранялась гипоэстезия в зоне иннервации II ветви тройничного нерва. При проведении декомпрессии 5 орбит было выявлено незначительное кровотечение, которое не нуждалось в дополнительных методах остановки. При этом ни в одном случае мы не наблюдали такого угрожающего послеоперационного осложнения, как ликворея. В то же время улучшение остроты зрения было выявлено при обследовании 8 глаз: среднее значение остроты зрения для обоих глаз перед лечением составляло 0,76±0,34, тогда как в послеоперационном периоде (3 месяца после лечения) – 0,82±0,30, хотя выявленная разница и не была статистически значимой (р>0,05).Выводы. Использование CAD/CAM-технологии при лечении пациентов с ЭО позволяет усовершенствовать этап планирования оперативного вмешательства за счет возможности виртуальной симуляции костной декомпрессии орбиты на предоперационном этапе. Применение навигационных хирургических шаблонов при проведении остеотомии позволяет достичь существенного уменьшения экзофтальма (в среднем на 4,84±0,27 мм) на фоне уменьшения площади костной резекции, что потенциально может уменьшить риск послеоперационных осложнений. Introduction. Orbital decompression still became the main method of treatment of moderate and severe endocrine orbitopathy (EO). The complication rate of orbital decompression EO, which leads to a dramatical decrease in the quality of life of patients, ranges from 9.3 to 35%. Therefore, the search for new opportunities for the prevention of postoperative complications is an actual problem of maxillofacial surgery and ophthalmology.Purpose. To evaluate the results of treatment and determine the frequency of complications during orbital decompression using surgical guides for management of EO. Materials and methods. To achieve this goal, the results of treatment of 17 patients with EOP, who underwent orbital decompression with cutting surgical guides at the Kyiv Regional Clinical Hospital and Kyiv City Clinical Hospital № 1 in the period from 2017 to 2021, were analised. The design and manufacture of surgical guides were carried out according to computed tomography data using CAD/CAM technology after simulating bone decompression within the "safe zones" in relation to the anatomical structures of the orbit and its soft tissue contents.Results. According to preoperative exophthalmometry, the average value of exophthalmosin the right and left eye was 23.75±3.07 mm and 24.27±3.26 mm, respectively. In the postoperative period the average value of exophthalmos for the right eye was 18.88±2.18 mm, for the left – 19.47±3.01 mm; statistically significant differences in the study group were also not detected (p=0.892). The average reduction in exophthalmos in the study group was 4.84±0.27 mm with significant difference between pre- and postoperative values (p<0.0001).Concerning the postoperative complications 3 months after surgery, diplopia were noted only in one patient, and hypoesthesia of the II branch of the trigeminal nerve were detected in tree cases. However, were no cases of such threatening postoperative complication as cerebrospinal fluid. At the same time, the improvement of visual acuity 8 eyes was noted after treatment: the average value of visual acuity before treatment was 0.74±0.35 increasing after surgery (observation period 3 months) to 0.82±0.27 (р>0.05). Conclusions. The use of CAD/CAM technology in the treatment of patients with endocrine orbitopathy allows to improve the planning stage of surgery due to the possibility of virtual simulation of bone decompression of the orbit in the preoperative stage.The use of surgical guides during osteotomy allows to achieve a significant reduction in exophthalmos (on average by 4.84±0.27 mm) against the background of reducing the area of bone resection, which can potentially reduce the risk of postoperative complications.
... Computer-assisted design/computer-aided fabrication (CAD/CAM) reconstruction of individual implants is an effective procedure that allows for very precise reconstruction of the complex orbital anatomy. CAD/CAM 3D planning and customized implants are now considered the gold standard in most centers (19)(20)(21). ...
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Advanced periorbital basal cell carcinomas may necessitate orbital exenteration and consequent vision loss, which significantly reduces patients’ life quality. Orbital reconstruction is a demanding surgical procedure due to the complex orbital anatomy and vital structures located in the orbit. In this report, we presented an 83-year-old patient with advanced basal cell carcinoma that had expanded into the orbit. An orbitotomy was performed to remove the tumor completely while preserving the eye function. Orbital reconstruction was performed by a standard surgical method using a titanium mesh modeled according to a natural phantom skull. This maintained the eye function and achieved satisfactory facial esthetics.
... Таким образом, на сегодняшний день важным и актуальным вопросом является поиск новых возможностей для планирования и проведения хирургической декомпрессии орбиты с целью профилактики вышеуказанных осложнений. Среди современных тенденций развития медицины в аспекте планирования хирургических вмешательств и точной их реализации можно отметить использование Computer-Aided Design (CAD) / Computer-Aided Manufacturing (CAM) технологий, которые помогают решать наиболее сложные клинические задачи в разных отраслях медицины, в частности в челюстно-лицевой и офтальмопластической хирургии [9][10][11][12]. ...
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Purpose Optimization of bone orbit decompression in patients with endocrine orbitopathy using Computer-Aided Design (CAD) / Computer-Aided Manufacturing (CAM) technologies with the manufacture of navigation templates. Methods To achieve this goal, the results of bone decompression of the orbit in 12 patients were analyzed. Each patient underwent a standard ophthalmological examination and assessment of binocular vision. Before and after surgery, patients underwent multislice computed tomography, the size of the exophthalmos was performed by the method of Ramli et al., 2015. With the help of CAD / CAM technologies, resection surgical templates were made for bone decompression of the orbit. Results The study included 12 patients (24 orbits) – 7 (58.3%) women and 5 (41.7%) men. All patients underwent combined bilateral orbital decompression. The average value of exophthalmos before surgery was 24.6 ± 3.5 mm on the left and 23.6 ± 2.9 mm on the right, and after surgery 21.4 ± 2.8 mm and 21.1 ± 2.9 mm, respectively, indicating a significant improvement in eye position (p > 0.05). In 2 patients (16.6%) diplopia was observed, in one patient (8.3%) - hypoesthesia of the second branch of the trigeminal nerve in the early postoperative period. Late postoperative complications (follow-up 3 months) were not observed. Conclusions Surgical decompression of the orbit using navigation templates can significantly reduce the degree of exophthalmos by an average of 3.2 mm, while reducing the area of bone resection, which reduces the risk of postoperative complications due to damage to the oculomotor muscles and the hyoid nerve. An individualized approach using CAD/CAM technologies is necessary to achieve optimal treatment results in patients with endocrine orbitopathy.
... In addition, PEEK onlay implants have been utilized in zygoma contour augmentation [31,32] and mandibular angle reconstructive surgeries [59]. While the use of CAD/CAM milled PEEK orbital implants have been documented in the literature [60,61], the production of porous, meshlike orbital implants by FFF is relatively new. With improvement in AM systems, the potential for customized FFF 3D printed PEEK implants has surfaced, boosting interest in POC manufacturing [25,26,30]. ...
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Pure orbital blowout fractures occur within the confines of the internal orbital wall. Restoration of orbital form and volume is paramount to prevent functional and esthetic impairment. The anatomical peculiarity of the orbit has encouraged surgeons to develop implants with customized features to restore its architecture. This has resulted in worldwide clinical demand for patient-specific implants (PSIs) designed to fit precisely in the patient's unique anatomy. Material extrusion or Fused filament fabrication (FFF) three-dimensional (3D) printing technology has enabled the fabrication of implant-grade polymers such as Polyetheretherketone (PEEK), paving the way for a more sophisticated generation of biomaterials. This study evaluates the FFF 3D printed PEEK orbital mesh customized implants with a metric considering the relevant design, biomechanical, and morphological parameters. The performance of the implants is studied as a function of varying thicknesses and porous design constructs through a finite element (FE) based computational model and a decision matrix based statistical approach. The maximum stress values achieved in our results predict the high durability of the implants, and the maximum deformation values were under one-tenth of a millimeter (mm) domain in all the implant profile configurations. The circular patterned implant (0.9 mm) had the best performance score. The study demonstrates that compounding multi-design computational analysis with 3D printing can be beneficial for the optimal restoration of the orbital floor.
... The advanced capabilities of 3D CAD modeling and printing technology are changing a wide range of medical specialties, with craniomaxillofacial surgery being one of the most significant benefactors. While the use of CAD/computer-aided manufactured (CAM) milled PEEK orbital implants has been documented in the literature [43][44][45], the production of porous, mesh-like orbital implants by FFF is relatively new. With improvement in AM systems, the potential for customized FFF 3D printed PEEK implants has surfaced, boosting interest in POC manufacturing [16,17,21]. ...
Preprint
Full-text available
Pure orbital blowout fractures occur within the confines of the internal orbital wall. Restoration of orbital form and volume is paramount to prevent functional and esthetic impairment. The anatomical peculiarity of the orbit has encouraged surgeons to develop implants with customized features to restore its architecture. This has resulted in worldwide clinical demand for patient-specific implants (PSIs) designed to fit precisely in the patient's unique anatomy. Fused filament fabrication (FFF) three-dimensional (3D) printing technology has enabled the fabrication of implant-grade polymers such as Polyetheretherketone (PEEK), paving the way for a more sophisticated generation of biomaterials. This study evaluates the FFF 3D printed PEEK orbital mesh customized implants with a metric considering the relevant design, biomechanical, and morphological parameters. The performance of the implants is studied as a function of varying thicknesses and porous design constructs through a finite element (FE) based computational model and a decision matrix based statistical approach. The maximum stress values achieved in our results predict the high durability of the implants, and the maximum deformation values were under one-tenth of a millimeter (mm) domain in all the implant profile configurations. The circular patterned implant (0.9 mm) had the best performance score. The study demonstrates that compounding multi-design computational analysis with 3D printing can be beneficial for the optimal restoration of the orbital floor.
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The aim of this retrospective study was to compare mid-facial symmetry and clinical outcomes between patients treated with patient-specific and standard implants in primary fracture reconstructions of combined orbital and zygomaticomaxillary complex fractures. Patients who underwent primary reconstruction of orbital and zygomaticomaxillary complex fractures during the study period were identified and background and clinical variables and computed tomography images were collected from patient records. Zygomaticomaxillary complex dislocation and orbital volume were measured from pre- and postoperative images and compared between groups. Out of 165 primary orbital reconstructions, eight patients treated with patient-specific and 12 patients treated with standard implants were identified with mean follow-up time of was 110 days and 121 days, respectively. Postoperative orbital volume difference was similar between groups (0.2 ml for patient-specific vs 0.3 ml for standard implants, p = 0.942) despite larger preoperative difference in patient-specific implant group (2.1 ml vs 1,5 ml, p = 0.428), although no statistical differences were obtained in symmetricity or accuracy between the reconstruction groups. Patient-specific implants are a viable option for primary reconstructions of combined zygomaticomaxillary complex and orbital fractures. With patient-specific implants at least as symmetrical results as with standard implants can be obtained in a single surgery.
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Purpose: A variety of implants are available for orbital reconstruction. Titanium orbital mesh plates are available either as standard preformed implants or able to be individualized for the patient. The aim of this study was to analyze whether individualized orbital implants allow a more precise reconstruction of the orbit than standard preformed implants. Materials and methods: A total of 195 patients treated between 2010 and 2014 were followed up to 12 weeks after surgery. Of the patients, 100 had received standardized preformed and 95 individualized implants. The precision of orbital reconstruction with the different implants was determined by comparing the variances in the volume difference between the reconstructed and the contralateral orbit on the postoperative computed tomographic scans. Clinical volume-related parameters including globe position, vision, motility, and diplopia and surgical details including approach, timing and technique of implant modification, use of navigation, duration of surgery, as well as adverse events were documented. Results: Orbital reconstruction was significantly more precise when individualized implants were used. The same was seen with intraoperative navigation. An overlap in the use of individualized implants and navigation makes it difficult to attribute the improved precision to a single factor. Conclusion: This study demonstrated that individualization and navigation provide clinical benefit.
Article
Purpose: Nowadays, in orbital wall reconstruction, maxillofacial surgeons have the possibility to treat patients in modern ways such as with individual implants. Nevertheless, conventional treatment including standard titanium mesh shaped during the surgical procedure is also widely used. The aim of this study was to compare the above methods of orbital wall reconstructions. Materials and methods: In the first group (39 cases), patients were treated by means of computer-aided design/computer-aided manufacturing (CAD/CAM) milled individual implants made of ultra-high-molecular-weight polyethylene, dioxide zirconium and rapid prototyping titanium mesh pre-bent on an ABS model made by a three-dimensional (3D) printer. In the second group (54 cases), intraoperative bending of titanium mesh was implemented. Results: Ophthalmologic outcomes were the same in both groups. In patients who had greater destruction of the orbit, surgical procedures were longer regardless of the material used for individual implants (p < 0.05). Time of surgery was shorter in patients in whom individual implants were used. Intraoperative bleeding was higher in patients who were treated using intraoperative bending titanium mesh (p < 0.01). Conclusion: Application of CAD/CAM techniques do not give better ophthalmologic results in reference center but improve patient condition postoperatively. For this reason, CAD/CAM is a safer treatment method for patients.
Article
Correction of orbito-frontal defects involves a multitude of surgical challenges, and requires careful and detailed planning. In the trauma setting, one must be prepared to deal with injuries to adjacent structures and be able to incorporate their repair into the surgical plan to maximize the functional and esthetic reconstruction for the benefit of the patient. Victims who have sustained trauma of the cranial complex in combination with mid-facial trauma, particularly involving the orbit, present a difficult scenario, especially when future ocular prosthetic rehabilitation is a concern. The authors present a patient of virtual surgical planning-guided planning of mid-facial osteotomies and custom implant creation for the secondary reconstruction of a patient who sustained extensive orbito-frontal trauma, requiring not only cranial vault recontouring, but also reconstruction of the mid-facial and orbital complex to accommodate an ocular prosthesis that would demonstrate proper anatomical relationships to maximize esthetics and function.
Article
Objective: Enophthalmos is a severe complication of primary reconstruction of orbital floor fractures. The goal of secondary reconstruction procedures is to restore symmetrical globe positions to recover function and aesthetics. The authors propose a new method of orbital floor reconstruction using a mirroring technique and a customized titanium mesh, printed using a direct metal laser-sintering method. Methods: This reconstructive protocol involves 4 steps: mirroring of the healthy orbit at the affected site, virtual design of a patient-specific orbital floor mesh, CAM procedures for direct laser-sintering of the customized titanium mesh, and surgical insertion of the device. Using a computed tomography data set, the normal, uninjured side of the craniofacial skeleton was reflected onto the contralateral injured side, and a reconstructive orbital floor mesh was designed virtually on the mirrored orbital bone surface. The solid-to-layer files of the mesh were then manufactured using direct metal laser sintering, which resolves the shaping and bending biases inherent in the indirect method. An intraoperative navigation system ensured accuracy of the entire procedure. Results: Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography data in 7 treated patients. Conclusion: The technique described here appears to be a viable method to correct complex orbital floor defects needing delayed reconstruction. This study represents the first step in the development of a wider experimental protocol for orbital floor reconstruction using computer-assisted design-computer-assisted manufacturing technology.
Article
Purpose Reconstruction of orbital deformities is a challenging task. Virtual 3-dimensional (3D) planning and the use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in the orbital region. Materials and Methods A retrospective study was performed of patients who underwent late orbital reconstruction from 2009 to 2013. To be included in the study, patients had a unilateral orbital deformity by involvement of at least 2 orbital wall defects. No orbital osteotomies could be used to correct the deformity. All patients underwent 3D virtual treatment planning. The unaffected orbit was mirrored onto the affected orbit. The PSI was fabricated according to this plan. Navigation was used to check the implant position. Results Six patients were included in this study. All patients had diplopia or motility limitations and enophthalmos. The ophthalmic parameters showed improvement in all patients. Enophthalmos was corrected adequately by the PSI. Four patients received a poly-ether-ether-ketone PSI. Two patients received a titanium mesh PSI. The position of the PSI was controlled by intraoperative navigation. Superimposition of the planned and postoperative positions of the PSI showed good correlation. Conclusion PSIs placed with intraoperative navigation facilitate late or secondary correction of orbital deformities.
Article
Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more predictable than traditional orbital reconstruction for optimal implant placement. Pre-injury computed tomography scans were obtained for 10 cadaver heads (20 orbits). Complex orbital fractures (Class III–IV) were created in all orbits, which were reconstructed using a transconjunctival approach with and without navigation. The best possible fit of the stereolithographic file of a preformed orbital mesh plate was used as the optimal position for reconstruction. The accuracy of the implant positions was evaluated using iPlan software. The consistency of orbital reconstruction was lower in the traditional reconstructions than in the navigation group in the parameters of translation and rotation. Implant position also differed significantly in the parameters of translation (p = 0.002) and rotation (pitch: p = 0.77; yaw: p <0.001; roll: p = 0.001). Compared with traditional orbital reconstruction, navigation-assisted reconstruction provides more predictable anatomical reconstruction of complex orbital defects and significantly improves orbital implant position.
Article
In the treatment of orbital defects, surgeon errors may lead to incorrect positioning of orbital implants and, consequently, poor clinical outcomes. Endoscopy can provide additional visualization of the orbit through the transantral approach. We aimed to evaluate whether endoscopic guidance during orbital reconstruction facilitates optimal implant placement and can serve as a convenient alternative for navigation and intra-operative imaging. Ten human cadaveric heads were subjected to thin-slice computed tomography (CT). Complex orbital fractures (Class III/IV) were created in all eligible orbits (n = 19), which were then reconstructed using the conventional transconjunctival approach with or without endoscopic guidance. The ideal implant location was digitally determined using pre-operative CT images, and the accuracy of implant placement was evaluated by comparing the planned implant location with the postoperative location. There were no statistically significant differences (p >0.05) in the degree of implant dislocation (translation and rotation) between the transconjunctival orbital reconstruction and the endoscopic-assisted orbital reconstruction groups. Endoscopic-assisted orbital reconstruction may facilitate the visualization of orbital defects and is particularly useful for training purposes; however, it offers no additional benefits in terms of accurate implant positioning during the anatomical reconstruction of complex orbital defects.
Article
Navigation-assisted orbital reconstruction remains a challenge, because the surgeon focuses on a two-dimensional multiplanar view in relation to the preoperative planning. This study explored the addition of navigation markers in the implant design for three-dimensional (3D) orientation of the actual implant position relative to the preoperative planning for more fail-safe and consistent results. Pre-injury computed tomography (CT) was performed for 10 orbits in human cadavers, and complex orbital fractures (Class III/IV) were created. The orbits were reconstructed using preformed orbital mesh through a transconjunctival approach under image-guided navigation and navigation by referencing orientating markers in the implant design. Ideal implant positions were planned using preoperative CT scans. Implant placement accuracy was evaluated by comparing the planned and realized implant positions. Significantly better translation (3.53 mm vs. 1.44 mm, p = 0.001) and rotation (pitch: −1.7° vs. −2.2°, P = 0.52; yaw: 10.9° vs. 5.9°, P = 0.02; roll: −2.2° vs. −0.5°, P = 0.16) of the placed implant relative to the planned position were obtained by implant-oriented navigation. Navigation-assisted surgery can be improved by using navigational markers on the orbital implant for orientation, resulting in fail-safe reconstruction of complex orbital defects and consistent implant positioning.