Low-cost three-dimensional printed orbital template-assisted patient-specific implants for the correction of spherical orbital implant migration

Abstract

Purpose: To describe the outcomes of a patient-specific implant (PSI), fabricated using a three-dimensional (3D) printed orbital template and placed in the basin of the inferior orbital fissure to correct inferotemporally migrated spherical orbital implant.

Methods: This is a single-center, prospective, consecutive, interventional, case series of six patients, with non-porous, spherical, orbital implant migration that underwent implant recentration surgically with a novel technique. Migration was subclassified either as decentration that did not affect the prosthetic retention or as displacement that affected the prosthetic retention in the eye socket. Only implant displacements were treated. The primary outcome measure was centration of the implant clinically and radiologically, with ability to retain the prosthesis.

Results: At a mean follow-up of 21 months, all six orbital spherical implants remained centered. There were no cases of extrusion, exposure, or migration of either implants. There were no cases of PSI displacement. Additional procedures to optimize the aesthetic outcome of the customized ocular prosthesis (COP) required were simultaneous fornix formation suture in three patients, subsequent fornix formation with mucus membrane graft in two patients, and levator resection and sulcus hyaluronic acid gel injection in one patient each. The mean PSI implant weight was 2.66 ± 0.53 g. The mean COP weight was 2.2 ± 0.88 g postoperatively. The median patient satisfaction with the procedure was 9 on 10.

Conclusion: A 3D printing-assisted PSI placed in the basin of the inferior orbital fissure allows recentration of the migrated implant over a follow-up of 21 months without complications.

Keywords: Anophthalmic socket; complication; implant migration; orbital implant; three-dimensional printing.

Figure 1

Conversion of the patient's computed tomography scan to a three-dimensional (3D) model. (a) Exporting the patient's two-dimensional computed tomography scans and converting it to a 3D model, (b) cropping the 3D model to the region of interest, in this case the left orbit, and (c) removing the implant from the orbit and exporting STL file to 3D printer

Figure 2

Deciding the height of patient-specific implant (PSI). (a) Placing the migrated orbital implant (diameter known from radiography) into the orbit in the migrated position, (b) four PSIs fabricated for this patient with diameters of 7, 8, 9, and 10 mm each, (c) 10-mm height PSI producing an excessive migration of the spherical implant toward the roof, (d) thickness of the 10-mm PSI being demonstrated with a caliper, (e) 9-mm height PSI producing an excessive migration of the spherical implant toward the roof, (f) thickness of the 9-mm PSI being demonstrated with a caliper, (g) 8-mm height PSI producing an excessive migration of the spherical implant toward the roof, (h) thickness of the 8-mm PSI being demonstrated with a caliper, (i) 7-mm height PSI producing an adequate migration of the spherical implant toward the roof, and (j) thickness of the 7-mm PSI being demonstrated with a caliper

Figure 3

Pre- and postoperative pictures of case 1 treated with patient-specific implant. (a–c) Preoperative photographs, (d and e) postoperative photographs. (a) Preoperative appearance of the right side with an unstable prosthesis, (b) preoperative appearance of the right socket with an inferotemporal implant migration, (c) preoperative computed tomography scan with spherical implant migrated outside the intraconal space into the inferotemporal orbit, (d) postoperative appearance of the right side with a well-fitting prosthesis and a reduction in pretarsal shown on the right side following ptosis correction, (e) postoperative socket photograph showing a central implant, and (f) postoperative computed tomography scan showing a patient-specific implant pushing the migrated implant centrally

Figure 4

Motility of the prosthesis following patient-specific implant placement in patient 2. (a) Motility in upgaze, (b) motility in downgaze, (c) motility in right gaze, and (d) motility in left gaze

Figure 5

The direction of centration of the spherical implant in the orbit with placement of patient-specific implant in patient 3. (a and b) Preoperative computed tomography scan, (c and d) postoperative computed tomography scan, (a) preoperative computed tomography scan in the coronal cut showing an inferotemporal migration of the implant, and (b) preoperative computed tomography scan in the saggital cut. Note the position of the implant along the floor with relationship to inferior orbital rim, (c) postoperative computed tomography scan in the coronal view showing a centration of the implant in the xy-axis and (d) postoperative computed tomography scan in the saggital view. Note the posterior shift of the spherical implant in the orbit away from the inferior orbital rim due to the push by patient-specific implant