Restoration of the inferomedial orbital strut using a standardized three‐dimensional printing implant

Abstract

The inferomedial orbital strut (IOS) is the thin bony junction of the orbital medial wall and floor. Its fracture is common and leads to serious complications, including enophthalmos, globe dystopia and diplopia. However, anatomical restoration of the IOS is challenging owing to reduced structural support; sound anatomical background and accurate implants are therefore essential. The aim of the present study was to incorporate data from cadaveric orbit anatomy into three-dimensional (3D) printing technology and to reconstruct the complex orbital fracture elaborately. After averaging the data from computed tomography (CT) images of 100 adult cadavers, the dimensions of the IOS were extracted, and a tangent sphere was created using a computeraided design program. The curves were compared with the CT data of 10 adult patients from the simulation test. Based on these data, a standardized 3D implant, 1.15 mm thick, was designed using polycaprolactone. The implant was placed in five patients with complex orbital fractures. The radius of the sphere in contact with the orbit, measuring 33.54 mm, was confirmed to be appropriate. A comparison between the normal side volume (V0) and the postoperative volume (V post ) showed that they were statistically similar. Furthermore, a comparison between V0 and the preoperative volume (V pre ), and V post compared with V pre also showed a statistically significant difference (P < 0.05). On follow-up, the preoperative ocular symptoms were resolved. The orbital data obtained from 100 cadavers provided standardized orbital anatomy, and 3D printed implants were created. The implants were anatomically accurate with regard to the orbital cavity and adequately covered the simulation model. The implant also showed satisfactory results when applied clinically in actual patients.

Tongue-in-Groove: A Novel Implant Design for a Blow-Out Fracture

“…In recent years, patient-specific implants have shown good surgical results [ 20 ]. Most customized implants are based on the shape of the orbital floor on the normal side and the mirroring technology is used to reconstruct the orbital floor on the fracture side [ 34 ]. However, sometimes the orbital volume is undercorrected or overcorrected after surgery, which may be due to the fact that the patient customizing plate is not corrected as planned, or because the shape of the orbits on both sides is different [ 5 , 35 ].…”

Correction of facial asymmetry using a patient-specific three-dimensional printed polycarprolactone/beta tricalcium phosphate scaffold: a case report

“…Various clinical applications of 3D-printed PCL implant have been reported in the management of cleft alveoli, augmentation rhinoplasty, nasal septal deformity, orbital wall reconstruction, and complex maxillary defect [11,[19][20][21][22][23]. In the case of a cleft alveolus, the PCL scaffold with human bone marrow cells was found to have a newly regenerated bone volume that was approximately 45% of the total defect volume at 6 months after implantation [11].…”

“…In cases of nasal septal deformities, a multicenter clinical trial of 20 patients with septal deviations that were managed using 3D-printed PCL implant, it was found that PCL implant provided proper mechanical support and had excellent biocompatibility and surgical manipulability [20]. In an inferomedial orbit implant, five implants showed no extrusions and structural stabilities during the mean follow-up period of 20.8 (18)(19)(20)(21)(22)(23)(24)(25)(26)(27) months [21]. In the cases of three complex maxillary defects, the PCL scaffold was stable in the maxillary defect and promoted regeneration of the deficient tissues in 2 years [22].…”

3D Printing in Eye Care

“…Combined inferior and medial wall fractures pose a particular challenge given destruction of the inferomedial orbital strut. Kim et al used 100 cadaver skulls to create a digital model of a standardized inferomedial orbital strut used in 3D printing of polycaprolactone implants [ 83 ]. Interlocking puzzle-piece implants can be used to bridge two or more implants across missing landmarks in cases of adjacent wall fractures; doing so may reduce incisional burden by enabling piece-by-piece placement through the same incision [ 84 – 87 ].…”