Associated Ophthalmic Injuries in Patients With Fractures of the Midface

Delayed Orbital Floor Reconstruction Using Mirroring Technique and Patient-Specific Implants: Proof of Concept

Enophthalmos is a severe complication of primary reconstruction following orbital floor fractures, oncological resections, or maxillo-facial syndromes. The goal of secondary orbital reconstruction is to regain a symmetrical globe position to restore function and aesthetics. In this article, we present a method of computer-assisted orbital floor reconstruction using a mirroring technique and a custom-made titanium or high-density polyethylene mesh printed using computer-aided manufacturing techniques. This reconstructive protocol involves four steps: mirroring of the healthy orbit computer tomography files at the contralateral affected site, virtual design of a customized implant, computer-assisted manufacturing (CAM) of the implant using Direct Metal Laser Sintering (DMLS) or Computer Numerical Control (CNC) methods, and surgical insertion of the device. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography measures in 13 treated patients and compared to a control group treated with stock implants. An improvement of 3.04 mm (range 0.3-6 mm) in globe protrusion was obtained for the patients treated with patient-specific implants (PSI), and no major complications have been registered. The technique described here appears to be a viable method for correcting complex orbital floor defects needing delayed reconstruction.

A retrospective comparison between one-stage and two-stage orbital reconstruction in patients suffering from combined injuries of the midface

Reconstruction of the bony orbit in patients with combined midface injuries is frequently discussed in the current literature. Two main concepts can be distinguished: single-stage reconstruction, usually with a hand-bent titanium orbital mesh, and two-stage reconstruction, in which osteosynthesis of the zygomaticomaxillary complex (ZMC) is followed by orbital reconstruction with a virtually-planned, patient-specific titanium implant in a second surgery. This study aimed to compare one-stage and two-stage surgical approaches on combined midface fractures regarding postoperative diplopia. A total of 58 patients treated with one-stage (n = 29) or two-stage (n = 29) reconstruction of the ZMC and orbit were included, and their postoperative course over five months was retrospectively analysed. A descriptive quantitative analysis of the course of occurrence of diplopia was recorded to calculate the success of orbital repair in complex midface fractures including the orbit. The two workflows differed in the prevalence of postoperative clinical diplopia and eyelid complications. Multiple factors affect the decision whether or not to reconstruct the orbit first, and in the same intervention as the associated midface fracture. Thorough evaluation of each individual patient with a patient-specific choice of surgical concept is crucial, and includes multiple factors.

Surgical Outcomes of Orbital Fracture Reconstruction Using Patient-Specific Implants

PURPOSE

Patient-specific implants (PSIs) are known to yield reliable outcomes in orbital wall fracture reconstruction (high precision, smoother operating techniques, and shorter surgical duration). This study analyzed the surgical error and clinical and esthetic outcomes of orbital reconstructions with PSIs.

METHODS

This ambispective cohort study enrolled patients who underwent orbital reconstruction using PSIs between October 2016 and January 2018. The study end points were surgical error, indication and duration of surgery, long-term sequelae, revision surgeries, and surgical complications. Surgical error was analyzed by superimposing the postoperative implant position onto the preoperative virtual plan. Both qualitative (heat map) and quantitative (distance) measurements were obtained.

RESULTS

Three patients were enrolled prospectively, and 23 were enrolled retrospectively. Indications for surgery were defect size (25 patients), diplopia (10 patients), impaired eye motility (4 patients), and significant enophthalmos (6 patients). At the last patient visit, there were 5 cases of diplopia, 1 case of exophthalmos, and 6 cases of slight enophthalmos of incremental degree. In terms of surgical error, a mean distance of 0.6 mm (95% confidence interval, 0.49 to 0.76), with a mean maximal distance of 3.4 mm (95% confidence interval, 2.79 to 4.02), was noted. No revision surgery was necessary. Lid malposition complications were not observed. However, 1 case each of symblepharon and scleral show were observed. No time-saving component was observed.

CONCLUSIONS

PSI use in orbital reconstruction guarantees a preplanned 3-dimensional anatomical shape with a mean surgical error of just 0.6 mm. Our clinical results were similar to those of other protocols; however, warranting a complex 3-dimensional anatomical shape also in large orbital fractures with a low mean surgical error is feasible by using PSIs.