Intraoperative imaging in orbital reconstruction: how does it affect the position of the implant?

Current Guidelines and Opinions in the Management of Orbital Floor Fractures

Orbital floor fractures are a common manifestation of facial trauma that is encountered by ophthalmology, otolaryngology, and oral maxillofacial specialists. Surgical intervention is required emergently in cases of tissue entrapment and less urgently in cases of presenting with persistent diplopia, enophthalmos greater than 2 mm, and/or fractures involving greater than 50% of the orbital floor. Surgical management is a debated topic with differing opinions among surgeons regarding timing of repair, type of implant, and surgical approach.

Comparison of Anatomical Preformed Titanium Implants and Patient-Specific CAD/CAM Implants in the Primary Reconstruction of Isolated Orbital Fractures-A Retrospective Study

BACKGROUND/AIM

Reconstruction of the fractured orbit remains a challenge. The aim of this study was to compare anatomical preformed titanium orbital implants with patient-specific CAD/CAM implants for precision and intraoperative applicability.

MATERIAL AND METHODS

A total of 75 orbital reconstructions from 2012 to 2022 were retrospectively assessed for their precision of implant position and intra- and postoperative revision rates. For this purpose, the implant position after digital orbital reconstruction was checked for deviations by mirroring the healthy orbit at 5 defined points, and the medical records of the patients were checked for revisions.

RESULTS

The evaluation of the 45 anatomical preformed orbital implant cases showed significantly higher deviations and an implant inaccuracy of 66.6% than the 30 CAD/CAM cases with only 10% inaccuracy. In particular, the CAD/CAM implants were significantly more precise in medial and posterior positioning. In addition, the intraoperative revision rates of 26.6% vs. 11% after 3D intraoperative imaging and the postoperative revision rates of 13% vs. 0 for the anatomical preformed implants were significantly higher than for patient-specific implants.

CONCLUSION

We conclude that patient-specific CAD/CAM orbital implants are highly suitable for primary orbital reconstruction. These seem to be preferable to anatomical preformed implants in terms of precision and revision rates.

Is the Pre-Shaping of an Orbital Implant on a Patient-Specific 3D-Printed Model Advantageous Compared to Conventional Free-Hand Shaping? A Systematic Review and Meta-Analysis

This study aimed to perform a systematic review and meta-analysis to compare pre-shaped implants on a patient-specific 3D-printed (3DP) model to manual free-hand shaping (MFS) for orbital wall reconstruction. The PRISMA protocol was followed in this study, and the review was registered in the PROSPERO database (CRD42021261594). A search was conducted in MEDLINE (PubMed), Embase, Cochrane Library, Clinicaltrials.gov, Google Scholar, and the grey literature. Ten articles were included, and six outcomes were analyzed. In total, 281 patients were in the 3DP group and 283 were in the MFS group. The studies had an overall high risk of bias. 3DP models resulted in a better accuracy of fit, anatomical angle reproduction, and defect area coverage. The correction of orbital volume was also superior with statistical significance. There was a higher percentage of the correction of enophthalmos and diplopia in the 3DP group. Intraoperative bleeding and hospital stay were reduced in the 3DP group. The meta-analysis of operative time showed a reduction in the average operative time by 23.58 min (95% CI: -43.98 to -3.19), which was statistically significant (t(6) = -2.8299, p = 0.0300). The 3DP models appear advantageous for an accurate orbital wall reconstruction, with fewer complications than those for conventional free-hand-shaped implants.

Justifying the implementation of intraoperative computed tomography for midface fracture treatment in improving outcomes

Intraoperative CT scanning is the international standard for treating midface fractures as it allows intraoperative assessment of reduction and fixation. To our knowledge, no NHS hospital in the UK has this facility yet due to the financial and logistical burden of its implementation. The aim of this study was to determine if complications including the requirement for a return to theatre (RTT) could have been predicted from the post-fixation CT scan. All treated midface fractures that had presented to a regionalised major trauma centre within two years (01 January 2020 - 31 December 2021) were identified. Those developing complications including RTT were determined. All postoperative CT scans (including those without complication or RTT) were re-analysed with the clinicians blinded to the outcomes to determine the positive predictive value (PPV) and negative predictive value (NPV) of requiring RTT to alter plate position intraoperatively based on CT scan alone. In all, there were eight episodes of unplanned return to theatre, resulting in an overall RTT rate of 8/119 (6.7%). When only analysing patients treated for orbital fractures this RTT rises to 8/40 (20%). Of those eight patients who had a postoperative CT and required RTT, this could have been predicted in 7/8 (87.5%). A total of 16/44 (36.4%) patients that did not have RTT would have additionally been recommended to have the plate position altered based on CT alone. Based upon those that had a CT, the PPV of CT alone being able to predict those requiring RTT was 40.6% and the NPV 96.2%. Our results would suggest intraoperative CT would likely have prevented eight patients requiring RTT in two years and could have improved outcomes in 16 cases. In preventing RTT as well as potentially improving the outcomes of a further 16 cases in maxillofacial surgery, the purchase of an intraoperative CT scanner could yield net savings of £75534-£114990 over two years.