Patient-Specific Orbital Implants Vs. Pre-Formed Implants for Internal Orbital Reconstruction

Purpose: To compare the outcome of orbital blowout fracture repair by means of pre-formed porous-polyethylene titanium implants (PFI) vs patient-specific porous-polyethylene implants (PSI). Methods: Retrospective cohort study. Baseline characteristics, ophthalmic examination results, ocular motility, fracture type, the timing of surgery, implant type, and final relative enophthalmos of all patients operated on for blow-out fractures in a single center were collected and analyzed. Results: Twenty-seven patients (mean age 39 years, 9 females) were enrolled. Sixteen underwent fracture repair with PFI and 11 with PSI at 11 months (median) post-trauma. Mean follow-up duration was 1.1 years. Both groups showed significant postoperative improvement in primary or vertical gaze diplopia (P = .03, χ²). Relative enophthalmos improved from −3.2 preoperative PFI to −1.7 mm postoperative PFI, and from −3.0 mm preoperative PSI to −1.1 mm postoperative PSI (P= .1). PSI patients had non-significantly less postoperative enophthalmos and globe asymmetry than PFI patients. The outcome was not influenced by previous surgery, age, sex, number of orbital walls involved in the initial trauma, or medial wall involvement (linear regression). Both groups sustained complications unrelated to implant choice. Conclusion: Both PSI and PFI yielded good outcomes in this study. PSI may be a good alternative to PFI in primary or secondary orbital blowout fracture repair with less enophthalmos and globe asymmetry, in spite of the possible disadvantages of production time, a relatively larger design, and challenging insertion. Since it is a mirror image of the uninjured orbit, it may be beneficial in extensive fractures.