Management of Zygomaticomaxillary Complex Fractures Utilizing Intraoperative 3-Dimensional Imaging: The ZYGOMAS Protocol

Analysis of the implementation of a circuit for intra-operative superposition and comparison of the surgical outcomes using ICBCT in maxillofacial surgery

PURPOSE

This paper describes a novel circuit for intraoperative analysis with ICBCT in maxillofacial surgery. The aim is to establish guidelines, define indications, and conduct an analysis of the implementation of the circuit for intraoperative comparison of surgical outcomes in relation to 3D virtual planning in maxillofacial surgery.

METHODS

The study included 150 maxillofacial surgical procedures. Intraoperative actions involved fluoroscopy localization, intraoperative CBCT acquisition, segmentation, and superimposition, among other steps. Surgical times due to intraoperative superposition were measured, including time required for ICBCT positioning and acquisition, image segmentation, and comparison of 3D surfaces from the surgical planning.

RESULTS

Successful intraoperative comparison was achieved in all 150 cases, enabling surgeons to detect and address modifications before concluding the surgery. Out of the total, 26 patients (17.33%) required intraoperative revisions, with 11 cases (7.33%) needing major surgical revisions. On average, the additional surgical time with this circuit implementation was 10.66 ± 3.03 min (n = 22).

CONCLUSION

The results of our research demonstrate the potential for performing intraoperative surgical revision, allowing for immediate evaluation, enhancing surgical outcomes, and reducing the need for re-interventions.

Off-Label Use of an External Hand Fixator for Craniomaxillofacial Fractures-An Anatomical Feasibility Study

BACKGROUND

The lack of resources limits the treatment of craniomaxillofacial fractures (CMF) in low-income countries (LIC). Therefore, Barton bandages and/or interdental wiring are considered in these regions. Fracture reduction is maintained by permanent occlusion for 6 weeks, which often leads to limited compliance and dissatisfying results. The aim of this cadaver-based study is to evaluate the feasibility of the use of an external face fixator (EFF) for the treatment of CMF, its biomechanical values and to define the optimal pin insertion points and angles.

MATERIALS AND METHODS

An AO hand fixator was used. CMF of types Le Fort 1-3 with split fractures of the hard palate were treated with EFF on 13 anatomical specimens. Fractures were created using a chisel, and pins were placed in specific anatomical regions. The maximal pull-out force [N] of pins was analysed by a tensile force gauge, and Fmax of the mandibular pins was evaluated. Computer tomography scans were performed on the healthy, fractured and EFF-treated skulls.

RESULTS

The pull-out forces for the single pins were mandibular pins (n = 15, median 488.0 N), supraorbital pins (n = 15, median 455.0 N), zygomatic pins (n = 14, median 269.1 N), medial hard palate pins (n = 12, median 208.4 N) and lateral hard palate pins (n = 8, median 49.6 N).

CONCLUSIONS

The results indicate that the operation technique is feasible, and the stability of the EFF is sufficient for maintaining the reduction. The required pins can safely be inserted into the described areas with good reduction results. Using EFF offers a feasible alternative to the non-surgical treatment of CMF in LIC.

Predictors of Intraoperative Difficulty and Postoperative Examination Abnormalities in 164 Orbital Operations

BACKGROUND

Although orbital fractures are common, prediction of outcomes in orbital surgery can be quite challenging.

PURPOSE

We aim to identify predictors of intraoperative difficulty, operating time, and postoperative examination abnormalities in subjects undergoing post-traumatic orbital reconstructions.

STUDY DESIGN, SETTING, AND SAMPLE

This is a retrospective cohort study of all consecutive orbital operations performed at a private, Level 1 trauma center in Portland, Oregon, USA over an 82-month period. All subjects that underwent exploration of the internal orbit for traumatic indications during the study period were included in the cohort.

PREDICTOR VARIABLES

Four plating styles, surgical approach (transorbital vs transantral), days from injury to first surgery, fracture size (approximated as a rectangle using linear measurements from computed tomography scans), anteroposterior fracture position, and medial wall involvement were examined.

OUTCOME VARIABLES

The primary outcome variable was intraoperative difficulty (defined as requiring revision after intraoperative imaging or return to the operating room). Secondary outcome variables included operating time and postoperative examination abnormalities.

COVARIATES

Age and sex were included.

ANALYSES

χ2 and Regression analyses were performed using a significance level of P < .05.

RESULTS

One hundred and sixty four orbital operations were performed (90 isolated injuries and 74 combined orbital/midface injuries) on 155 subjects (73% male, mean age 39.8 years, standard deviation 16.7). In subjects with isolated orbital fractures, medial wall involvement was associated with intraoperative difficulty (P = .01). When using a transantral approach, intraoperative difficulty was more likely in more anterior fractures (P = .02). Plating style was associated with operating time (P = .03), with median times from 81 to 105 minutes (range 21 to 248 minutes). Postoperative examination abnormalities were more likely in the transorbital approach group (P = .01). Neither days to first surgery nor intraoperative difficulty were associated with postoperative examination abnormalities. Postoperative eyelid changes were seen in 13.6% of transorbital approaches and 0% of transantral approaches. Correction of gaze restriction and enophthalmos were more likely than correction of diplopia (P < .01).

CONCLUSIONS AND RELEVANCE

Medial wall involvement is associated with intraoperative difficulty in orbital surgery. Anteriorly positioned fractures are better treated transorbitally, while posterior fractures may be amenable to transantral repair, thus avoiding risk of lower eyelid changes.

The Value of Intraoperative Computed Tomography in the Treatment of Zygomatic Complex Fractures

BACKGROUND

Due to the complex anatomical morphology and lack of anatomic markers on the surface of zygomatic complex (ZMC), the treatment results of ZMC fractures are often suboptimal.

PURPOSE

The study aimed to evaluate the effectiveness of intraoperative computed tomography (ICT) in the treatment of unilateral ZMC fractures, and further study the feasibility of ICT to replace early postoperative Computed Tomography (CT).

STUDY DESIGN, SETTING, AND SAMPLE

The investigators designed a retrospective cohort study. Adult patients who underwent surgery with unilateral ZMC fractures were enrolled.

PREDICTOR VARIABLE

According to whether intraoperative CT was used, the subjects were divided into the ICT group and the control group (without ICT).

MAIN OUTCOME VARIABLES

Five distances and 3 angles representing bilateral ZMC symmetry were main outcome variables. The differences of outcome variables were compared between the 2 groups and the indices of ICT group were further compared with their postoperative indices.

COVARIATES

Demographics (eg age), etiology (eg traffic injury), dysfunction (eg diplopia), and surgical approach (eg vestibular incision) were collected as covariates while we conducted clinical investigation, examination, and implementation.

ANALYSES

The data were analyzed using independent-samples t test, paired-samples t test, Mann-Whitney U test, and χ2 test. P value < .05 was considered statistically significant.

RESULTS

A total of 60 patients (18 to 59 years) were enrolled in this study. All median values of the measurements in the ICT group were smaller than those in the control group, and the differences of horizontal displacement distance (0.56 vs 1.02 mm), anteroposterior displacement distance (1.69 vs 2.34 mm, 0.90 vs 2.35 mm), horizontal angle of bilateral zygomatic arch (2.31 vs 4.19°), and horizontal angle of bilateral zygomatic process (1.77 vs 2.94°) were significantly different between the 2 groups with P value < .05. Moreover, there was no statistically significant difference in all indices between the intraoperatively and postoperatively injured sides in the ICT group.

CONCLUSIONS

ICT can improve the treatment outcomes of ZMC fractures by evaluating the fracture reduction adequacy during surgery. Moreover, ICT can replace early postoperative CT.

Application Value of the CT Scan 3D Reconstruction Technique in Maxillofacial Fracture Patients

Purpose The aim of the study was to explore the application value of computerized tomography (CT) scan 3D reconstruction technology in maxillofacial fracture patients. Methods A total of 80 maxillofacial fracture patients who underwent surgical treatment in Shijiazhuang People's Hospital from January 2019 to January 2020 were enrolled. All of them received 128-slice spiral CT  scans before surgery, and the images were subjected to multiplanar reconstruction (MRP) and volume reconstruction (VR). Results A total of 181 fractures were found in 80 patients with maxillofacial fractures. The detection rates of axial CT, MRP, and VR were 77.90% (141/181), 93.92% (170/181), and 97.79% (177/181), respectively. The detection rates of the four inspection methods were statistically different. Taking the findings of surgical anatomy as the gold standard, the sensitivity of MRP and VR for the diagnosis of maxillofacial fractures was 90.06% (163/170) and 95.56% (174/177), with no significant difference. Conclusion CT scan 3D reconstruction technology has a high application value in the clinical diagnosis and treatment of maxillofacial fracture patients.

Preliminary outcomes of the surgical navigation system combined with intraoperative three-dimensional C-arm computed tomography for zygomatico-orbital fracture reconstruction

This study analyzed the outcomes of zygomatico-orbital fracture reconstruction using the real-time navigation system with intraoperative three-dimensional (3D) C-arm computed tomography (CT). Fifteen patients with zygomatico-orbital or isolated orbital/zygoma fractures were enrolled in this prospective cohort. For zygoma reduction, the displacement at five key sutures and the differences between preoperative and intraoperative CT images were compared. For orbital reconstruction, the bilateral orbital volume differences in the anterior, middle, and posterior angles over the medial transitional buttress were measured. Two patients required implant adjustment once after the intraoperative 3D C-arm assessment. On comparing the preoperative and postoperative findings for the zygoma, the average sum of displacement was 19.48 (range, 5.1–34.65) vs. 1.96 (0–3.95) mm (P < 0.001) and the deviation index was 13.56 (10–24.35) vs. 2.44 (0.6–4.85) (P < 0.001). For the orbit, the mean preoperative to postoperative bilateral orbital volume difference was 3.93 (0.35–10.95) vs. 1.05 (0.12–3.61) mm³ (P < 0.001). The mean difference in the bilateral angles at the transition buttress was significantly decreased postoperatively at the middle and posterior one-third. There was no significant difference in orbital volume, angle of the transition zone, and the sum of five zygoma distances between post operative results and preoperative virtual planning. The surgical navigation system with the intraoperative 3D C-arm can effectively improve the accuracy of zygomatico-orbital fracture reconstruction and decrease implant adjustment times.

The application of augmented reality in craniofacial bone fracture reduction: study protocol for a randomized controlled trial

Background

Augmented reality (AR) is a new technology that increases users’ perception of the real world. The purpose of this study is to evaluate the efficacy and safety of augmented reality navigation system in treatment with craniofacial fracture reduction.

Methods

This will be a single-center prospective randomized controlled trial. Twenty-two patients will be assigned to two groups of 11, and those with zygomaticomaxillary complex fractures will undergo preoperative three-dimensional CT modeling and have operational plans designed. The control team will use traditional optical navigation to perform the surgery, and the experimental team will use an AR navigation system. The primary outcome measures will be the accuracy of the key points of surgical area between the preoperational surgical plan and post-operation. The secondary outcome measures will be the blood loss, operation time, bone reduction time, hospital time, and complication rate. The findings obtained through this study are expected to evaluate efficacy and safety of the augmented reality navigation system in the treatment of zygomaticomaxillary complex fractures.

Discussion

This controlled trial of augmented reality navigation system in treatment with zygomaticomaxillary complex fracture reduction will clarify the efficacy and safety of this technology by measuring the accuracy of the key points of surgical area and blood loss, operation and bone reduction times, hospital stay duration, and complication rates. This is a single-center study, and the results are expected to promote the application of augmented reality in craniofacial fracture reduction to improve surgery accuracy and efficacy.

Trial registration

Chinese Clinical Trial Registry ChiCTR1900022626. Registered on April 19, 2019.

Contemporary Management of Zygomaticomaxillary Complex Fractures

Zygomaticomaxillary complex fracture is one of the most commonly treated facial fractures. Accurate reduction and stable fixation of the zygoma are required to restore facial symmetry and projection and avoid functional sequalae from changes in orbital volume. Achieving optimal outcome is challenging due to the complex three-dimensional anatomy and limited visualization of all affected articulations of the zygoma. This article provides an updated overview of the evaluation and management of zygomaticomaxillary complex fractures based on available evidence and clinical experience at our center. The importance of soft tissue management is emphasized, and approaches to internal orbital reconstruction are discussed. While evidence remain limited, intraoperative imaging and navigation may prove to be useful adjuncts in the treatment of zygomaticomaxillary fractures.