Radiomorphometric analysis of isolated zygomatic arch fractures: A comparison of classifications and reduction outcomes.

PURPOSE: Although different proposals have been made to categorize isolated zygomatic arch fractures (ZAF), an investigation about fracture type and clinical outcome has not been published. In this study, we analyzed the geometric fracture morphology in isolated ZAF and provide a survey of reduction outcomes in accordance with 4 independent classifications.

MATERIALS AND METHODS: Geometric measurements were performed in radiologic images of 94 patients with isolated ZAF, which were consecutively treated by closed reduction over transbuccal approach. Fracture types were allocated to the classifications of Rowe and Williams, Honig and Merten, Yamamoto et al., and Ozyazgan et al. The odds of achieving a satisfactory outcome were calculated for all categories.

RESULTS: Wide preoperative dislocation angles of more than 22° presented in M-type fractures (77.1%) more frequently compared to 2 fragments without the M-shape (33.3%) and one fragment (14.8%, p < 0.001). Favorable reduction outcome was significantly higher for M-shaped fractures than for differently configured fractures (83.3% vs. 30.4%, odds ratio 11.43, confidence interval 4.27-30.61). The rate of reduction in 100%-75% was most frequent for the Honig and Merten type I as well as Ozyazgan type IBV (both 85.4%, p < 0.001) and Yamamoto type II (84.2%, p < 0.001).

CONCLUSION: The classifications of Honig and Merten, Yamamoto et al., and Ozyazgan were quite applicable, and subgroups showed significant increments in reduction outcome. Our analysis emphasizes that the differentiation of two clinical relevant groups, M-shaped and variable arch fractures, is feasible to manage and efficient to determine the odds of reduction outcome.