Customised orbital implants
Reviewed by James Hsuan

This is a literature review of the outcomes of orbital fracture repairs using custom-made orbital implants. Customised implants were manufactured in one of three ways, all using a 3D printer; manual moulding of an implant based on a 3D-printed model of the fractured orbit, direct 3D printing of the implant, and 3D printing of a template which was then used as an intraoperative guide for a bone graft or to make a synthetic implant preoperatively. Fifteen articles were found which met the inclusion and exclusion criteria, reporting between five and 104 cases. Implant material included titanium alone, porous polyethylene with embedded titanium, porous polyethylene alone, polycaprolactone, and autologous bone. As this is a review of multiple studies there is little consistency between them, which prevents an accurate comparison of outcome measures. Two of the eight studies which described the manual moulding of an implant based on a 3D-printed model of the orbit were case-controlled comparing their outcomes with non-customised implants. Between them they had good numbers of over 100 patients in the customised and controlled groups, and found there was no difference in the postoperative diplopia rates. The overall rate of postoperative diplopia across all the studies varied between zero and 40%, which is comparable to the reported non-customised implant rate of 8-42%. Similarly, customised implants had a postoperative enophthalmos rate of 0-20%, compared with 7-27% for non-customised. The authors conclude that although customised implants can accurately and safely repair the fracture, at present the data does not show superior outcomes for them over conventional non-customised implants.

Patient-specific implants for orbital fractures: a systematic review.
Maher DI, Hall AJ, Gwini S, Artsi EB.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2022;38(5):417-24.