An innovative surgical method to operate the zygomatico-maxillary-orbital complex in the absence of intraoperative computer tomography or intraoperative navigation using novel zygoma analysis and virtual surgical planning software

An innovative surgical method to operate the zygomatico-maxillary-orbital complex in the absence of intraoperative computer tomography or intraoperative navigation using novel zygoma analysis and virtual surgical planning software

Prem K Rathod, Rahul Yadav , Ongkila Bhutia, Ajoy Roychoudhury, Krushna Bhatt
All India Institute of Medical Sciences, New Delhi, India

Introduction:
Post-traumatic residual deformities of the Zygomaticomaxillary orbital complex (ZMOC) are challenging to operate on and may require intraoperative CT or navigation. Two major reasons for this are 1) Such devices costs crores of rupees, and 2) there is no method to quantify the amount of asymmetry of ZMOC. The purpose is to evaluate the surgical outcomes in the absence of intraoperative CT or Navigation using innovative zygoma analysis software planning and novel surgical protocol in operating these patients.

Methodology:
In this prospective study, a Zygoma analysis software planning was designed. Unilateral post-traumatic residual deformity of ZMOC (>10 weeks) was included. The uninjured side of the face was used to mirror, measure, and formulate the surgical plan after comparison with the injured side using this virtual surgical software planning. The primary objective was the symmetry and stability of ZMOC. Secondary outcome variables were changes in orbital volume, diplopia, ocular motility, mouth opening, and patient satisfaction. P < .05 was considered statistically significant. Measurements were assessed on affected and unaffected sides preoperatively, postoperatively, and six months postoperatively (Figure 1 shows measurements of zygoma analysis and virtual surgical planning). Paired t-test was used to compare the continuous variables. The continuous variable changes with time were evaluated using repeated measure ANOVA, followed by multiple comparisons using the Bonferroni test. The McNemar test assessed the changes within the categorical variable. P <.05 was considered statistically significant.

Results:
Thirteen patients were included (mean age = 28.38 ± 9.54 years; male:female = 5.5:1; left:right = 7:5). The mean duration of the residual deformity was 6.66±6.43 months. There was an improvement in the symmetry, and all parameters remained stable when measured at six months postoperatively. Patients reported a median satisfaction score of 4 out of 5. There was a significant improvement in orbital volume(P = .001) and mouth opening(P = .014).

Discussion:
The zygoma analysis virtual surgical planning software protocol results are comparable to those with intraoperative CT and navigation, thus proving a cost-effective innovation. These results proved to be stable over at least a 6-month follow-up period. Measuring the asymmetry of ZMOC and formulating a surgical plan becomes easy with zygoma analysis. This method is a solution in decision-making for treating bilateral residual deformities of the midface, aesthetic malar augmentation, aesthetic malar reduction cases, bilateral fractures of the zygomatico-maxillary-orbital complex, etc. It is now possible to operate and provide predictable outcomes in these cases when intraoperative CT or intraoperative navigation facilities may not be available.

Keywords: Zygomaticomaxillary complex, ZMC, orbital fractures, residual deformities, zygoma analysis, virtual surgical planning, symmetry, trauma, fracture