Evaluation of Injury Recidivism Using the Electronic Medical Record

Mandibular Titanium Miniplates Change the Biomechanical Behaviour of the Mandible in the Case of Facial Trauma: A Three-Dimensional Finite Element Analysis

Our study aimed to compare the biomechanical behaviour of mandibles with or without titanium miniplates when subjected to an impact after bone healing using a finite element model (FEM) of the human mandible. We simulated mandibular trauma on an FEM of a human mandible carrying or not two parasymphyseal miniplates and applying a concentrated force of 2000 N to four different areas, including the insertion area, the area straddling the edge of the miniplates and the adjacent bone, at a distance from the miniplates on the symphysis, and on the basilar border of the mandible below the miniplates. Then, we compared the Von Mises stress distributions between the two models. In the case of an impact on the miniplates, the maximum Von Mises stress occurred in two specific areas, on the cortical bone at the posterior border of the two miniplates at a distance from the impact, while in the model without miniplates, the Von Mises stresses were homogenously distributed in the impact area. The presence of titanium miniplates in the case of trauma affects the biomechanical behaviour of the mandible and could cause more complex fractures. We recommend informing patients of this potential risk.

Recidivism after orthopaedic trauma has diminished over time

PURPOSE

The purpose was to analyze our trauma population during two periods to assess for predictors of recidivism.

METHODS

Prior (2007-2011, n = 879) and recent (2014-2019, n = 954) orthopaedic trauma patients were reviewed. Recidivists were those returning with an unrelated injury. Recidivism rates were compared, and factors associated with recidivism were identified.

RESULTS

Recidivism decreased: 18.7% to 14.3% (p = 0.01). Mean age and sex of the two cohorts were not different. Recent recidivists were more likely to sustain gunshot wound (GSW) injuries (22.1% vs 18.9%, p = 0.09), and mental illness was more common (56.6% vs 28.1%, p < 0.0001). The recent recidivist population was less often married (12.9% vs 23.8%, p = 0.03), and both recidivist groups were often underinsured (Medicaid or uninsured: (60.6% vs 67.0%)).

CONCLUSION

Recidivism diminished, although more GSW and mental illness were seen. Recidivists are likely to be underinsured. The changing profile of recidivists may be attributed to socioeconomic trends and new programs to improve outcomes after trauma.

Do mandibular titanium miniplates affect the biomechanical behaviour of the mandible? A preliminary experimental study

INTRODUCTION

Whether to conserve or remove titanium miniplates after rigid internal fixation of mandibular fractures still remains controversial. Miniplates could affect the biomechanical behaviour of the mandible in case of trauma, and therefore cause more complex fractures.

MATERIALS AND METHODS

An experimental study, consisting in simulating a mandibular trauma, was designed in order to compare the fractures caused by an impact on the mandible in the presence or absence of an internal fixation. We simulated an impact on the right parasymphysis region in 10 post-mortem human subjects, according to the Charpy impact test method at an impact speed of 7.4 m/s, using a 5 kg test impactor.

RESULTS

In the control group, the fracture lines were vertical and straight, without comminution. In the miniplate group, the fractures occurred close to the miniplates (4 cases) and under the miniplates (one case). The fracture lines were more complex, even comminuted in 2 cases. Thus, miniplates impacted the biomechanical behavior of the mandible, resulting in more complex fractures.

CONCLUSION

Our experimental study highlighted the impact of the presence of miniplates on the mandible in case of trauma, and the risk of causing more complex fractures. We therefore recommend further investigations to determine if titanium miniplates should be systematically removed after bone healing, in patients with a higher risk of trauma in relation with previous assault injuries, alcohol or substance abuse, the practice of fighting or contact sport/activities, and soldiers.