Primary reconstruction of combined orbital and zygomatic complex fractures with patient-specific milled titanium implants - A retrospective study.

The aim of this retrospective study was to compare mid-facial symmetry and clinical outcomes between patients treated with patient-specific and standard implants in primary fracture reconstructions of combined orbital and zygomaticomaxillary complex fractures. Patients who underwent primary reconstruction of orbital and zygomaticomaxillary complex fractures during the study period were identified and background and clinical variables and computed tomography images were collected from patient records. Zygomaticomaxillary complex dislocation and orbital volume were measured from pre- and postoperative images and compared between groups. Out of 165 primary orbital reconstructions, eight patients treated with patient-specific and 12 patients treated with standard implants were identified with mean follow-up time of was 110 days and 121 days, respectively. Postoperative orbital volume difference was similar between groups (0.2 ml for patient-specific vs 0.3 ml for standard implants, p = 0.942) despite larger preoperative difference in patient-specific implant group (2.1 ml vs 1,5 ml, p = 0.428), although no statistical differences were obtained in symmetricity or accuracy between the reconstruction groups. Within the limitations of the study it seems that patient-specific implants are a viable option for primary reconstructions of combined zygomaticomaxillary complex and orbital fractures, because with patient-specific implants at least as symmetrical results as with standard implants can be obtained in a single surgery.

Computer-Aided Fracture Size Measurement in Orbital Fractures-An Alternative to Manual Evaluation.

OBJECTIVE: We aimed to present a novel semiautomated tool for orbital fracture size measurement and to compare the variability of the proposed method with traditional manual measurements. METHODS: Maximal anteroposterior (AP) and mediolateral (ML) dimensions of orbital fractures from computed tomography images were measured for 15 patients with unilateral orbital fractures by 2 surgeons manually and with a semiautomatic software. Variability was assessed with Bland-Altman limits of agreement plots and intra-class correlation coefficients (ICCs). RESULTS: The intra-observer ICCs in manual and automatic measurements were high, >0.9. The inter-observer ICCs in manual measurements were 0.926 (AP) and 0.631 (ML) and in automatic measurements 0.989 (AP) and 0.989 (ML). The ICCs for manual and semiautomated variability were 0.899 (AP) and 0.669 (ML). The differences were thus particularly pronounced in the ML dimensions. In addition, with the semiautomated technique, a total fracture area could be measured and compared with the total area of the bony orbit and a 3-dimensional reformatted image could be generated. CONCLUSIONS: Intra- and inter-observer variability proved to be very low for measuring fracture maximal AP length and ML width, making both the manual and the semiautomatic methods feasible clinically. The semiautomatic fracture size analysis allows better observer-independent repeatability for fracture size measurements and provides the possibility for total fracture area measurements at any orbital bony site, even in challenging nonplanar topography.

Three-Dimensional Computer-Aided Analysis of 293 Isolated Blowout Fractures - Which Radiological Findings Guide Treatment Decision?

PURPOSE: Our study purpose was to clarify the extent of isolated unilateral orbital blowout fracture in relation to surgical treatment and other factors behind the treatment decision. The specific aim was to determine which computer-aided measurements based on radiological images associate with treatment choice. METHODS: A retrospective cohort study was implemented on patients with an isolated unilateral orbital blowout fracture. Computer-aided measurement of fracture extent was performed. The study variables included treatment as primary outcome (surgical vs nonsurgical), post-traumatic orbital volume difference (mL) compared to contralateral orbit, fracture area (mm2), fracture depth (mm) as predictor variables, and age, sex, injury mechanism, side and site of orbital fracture and positions of recti muscles as explanatory variables. Postoperative outcomes were reported. Logistic regression analysis was used to determine the risk factors for surgery. The statistical significance level was set at P < .05. RESULTS: Of 293 patients, 28.0% received surgical and 72.0% nonsurgical treatment. Volume difference, fracture area and fracture depth predicted surgical outcome (P < .001). In adjusted univariate regression analyses, fractures with moderate and severe displacement of recti muscles were more likely to receive surgical treatment than fractures with mild or no displacement (OR 6.15 and 30.75, respectively, P < .001). Isolated medial wall fractures were significantly less often (OR 0.05, P = .006) and patients with older age (OR 0.97, P = .013) slightly less often treated with surgery. Patients with preoperative symptoms had more often persisting postoperative symptoms than patients without preoperative symptoms. CONCLUSIONS: Positions of the recti muscles are an independent radiological factor guiding orbital blowout fracture treatment decision. The bony fracture extent is a combination of volume difference, fracture area and fracture depth which are strongly correlated to each other. A computer-aided method significantly facilitates the systematic evaluation of bone fragments, and the extent of orbital fractures.

Zygomatico-Orbital Fracture-Dislocation in Surgical Treatment: Novel 3-Dimensional Software Automated Analysis.

PURPOSE: The human capability to detect the degree of zygomatico-orbital (ZMO) fracture-dislocation in surgical treatment is unknown. The aim of this study was to examine the association between ZMO fracture-dislocation and injury etiology and treatment. MATERIALS AND METHODS: We implemented a retrospective cross-sectional study, enrolled a sample composed of patients with an isolated unilateral ZMO fracture, and analyzed fracture-dislocation from computed tomography images with an automatic algorithm. The primary predictor variable was mean surface point-to-point dislocation (the mean distance of dislocation for all surface points in isolated ZMO fracture segments between the original position and after virtual repositioning). The primary outcome was the treatment choice (operative vs nonoperative). Other studied variables were gender, age group, injury mechanism, clinical asymmetry, and human-evaluated dislocation on computed tomography images. Descriptive and bivariate statistics were computed, and the threshold for statistical significance was set at P < .05. RESULTS: The sample consisted of 115 patients with a mean age of 66.3 years, 66.1% of whom were male patients, and the most common cause of injury was falling on the ground (49.6%). Operative treatment was required in 58 patients (50.4%). A significant association was found between mean dislocation and operative treatment. Mean dislocation of operatively versus nonoperatively treated fractures was 2.39 mm versus 1.05 mm (P < .001). Mean fracture-dislocation was greatest in injuries caused by assault (2.41 mm) and smallest in motor vehicle accidents (1.08 mm) and ground-level falls (1.25 mm). The threshold of human-eye detection for ZMO fracture-dislocation was 1.97 mm. CONCLUSIONS: The results of this study demonstrate that the threshold for operative treatment of ZMO fracture-dislocation is over 2 mm, which the human eye is able to detect. True dislocation is greater in younger patients than elderly patients and in injuries caused by assault compared with falling.