Influence of different postures under vertical impact load on thoracolumbar burst fracture

How does vertical laminar fracture impact the decision-making in thoracolumbar fractures? A systematic scoping review and meta-analysis

OBJECTIVE

Although vertical laminar fracture (VLF) is generally considered a severity marker for thoracolumbar fractures (TLFs), its exact role in decision-making has never been established. This scoping review aims to synthesize the research on VLF's role in the decision-making of TLFs.

METHODS

A systematic review was conducted following PRISMA guidelines. We searched PubMed, Scopus, and Web of Science from inception to  June 11, 2023, for studies examining the association of VLF in thoracolumbar fractures with dural lacerations, neurological deficits, radiographic parameters, or treatment outcomes. Additionally, experimental studies that analyze the biomechanics of burst fractures with VLF were included. The studies extracted key findings, objectives, and patient population. A meta-analysis was performed for the association of VLF with dural laceration and neurological deficit, and ORs were pooled with a 95% confidence interval (CI).

RESULTS

Twenty-eight studies were included in this systematic review, encompassing 2021 patients, and twelve were included in the meta-analysis. According to the main subject of the study, the association of VLF with a dural laceration (n = 14), neurological deficit (n = 4), radiographic parameters (n = 3), thoracolumbar fracture classification (n = 2), and treatment outcome (n = 2). Seven studies with a total of 1010 patients reported a significant association between VLF and neurological deficit (OR = 7.35, 95% CI [3.97, 14.25]; P < 0.001). The pooled OR estimates for VLF predicting dural lacerations were 7.75, 95% CI [2.41, 24.87]; P < 0.001).

CONCLUSION

VLF may have several important diagnostic and therapeutic implications in managing TLFs. VLF may help to distinguish AO type A3 from A4 fractures. VLF may help to predict preoperatively the occurrence of dural laceration, thereby choosing the optimal surgical strategy. Clinical and biomechanical data suggest VLF may be a valuable modifier to guide the decision-making in burst fractures; however, more studies are needed to confirm its prognostic importance regarding treatment outcomes.

Assessing the risk of re-fracture related to the percentage of partial union in scaphoid waist fractures

Aims

There is ambiguity surrounding the degree of scaphoid union required to safely allow mobilization following scaphoid waist fracture. Premature mobilization could lead to refracture, but late mobilization may cause stiffness and delay return to normal function. This study aims to explore the risk of refracture at different stages of scaphoid waist fracture union in three common fracture patterns, using a novel finite element method.

Methods

The most common anatomical variant of the scaphoid was modelled from a CT scan of a healthy hand and wrist using 3D Slicer freeware. This model was uploaded into COMSOL Multiphysics software to enable the application of physiological enhancements. Three common waist fracture patterns were produced following the Russe classification. Each fracture had differing stages of healing, ranging from 10% to 90% partial union, with increments of 10% union assessed. A physiological force of 100 N acting on the distal pole was applied, with the risk of refracture assessed using the Von Mises stress.

Results

Overall, 90% to 30% fracture unions demonstrated a small, gradual increase in the Von Mises stress of all fracture patterns (16.0 MPa to 240.5 MPa). All fracture patterns showed a greater increase in Von Mises stress from 30% to 10% partial union (680.8 MPa to 6,288.6 MPa).

Conclusion

Previous studies have suggested 25%, 50%, and 75% partial union as sufficient for resuming hand and wrist mobilization. This study shows that 30% union is sufficient to return to normal hand and wrist function in all three fracture patterns. Both 50% and 75% union are unnecessary and increase the risk of post-fracture stiffness. This study has also demonstrated the feasibility of finite element analysis (FEA) in scaphoid waist fracture research. FEA is a sustainable method which does not require the use of finite scaphoid cadavers, hence increasing accessibility into future scaphoid waist fracture-related research.

Spinal Fractures during Touristic Motorboat Sea Cruises: An Underestimated and Avoidable Phenomenon

PURPOSE

Each summer, many vacationers enjoy the Mediterranean Sea shores. Among the recreational nautical activities, motorboat cruise is a popular choice that leads to a significant number of thoracolumbar spine fractures at our clinic. This phenomenon seems to be underreported, and its injury mechanism remains unclear. Here, we aim to describe the fracture pattern and propose a possible mechanism of injury.

METHODS

We retrospectively reviewed the clinical, radiological, and contextual parameters of all motorboat-related spinal fracture cases during a 14-year period (2006-2020) in three French neurosurgical level I centers bordering the Mediterranean Sea. Fractures were classified according to the AOSpine thoracolumbar classification system.

RESULTS

A total of 79 patients presented 90 fractures altogether. Women presented more commonly than men (61/18). Most of the lesions occurred at the thoracolumbar transition region between T10 and L2 (88.9% of the levels fractured). Compression A type fractures were seen in all cases (100%). Only one case of posterior spinal element injury was observed. The occurrence of neurological deficit was rare (7.6%). The most commonly encountered context was a patient sitting at the boat's bow, without anticipating the trauma, when the ship's bow suddenly elevated while crossing another wave, resulting in a "deck-slap" mechanism hitting and propelling the patient in the air.

CONCLUSIONS

Thoracolumbar compression fractures are a frequent finding in nautical tourism. Passengers seated at the boat's bow are the typical victims. Some specific biomechanical patterns are involved with the boat's deck suddenly elevating across the waves. More data with biomechanical studies are necessary to understand the phenomenon. Prevention and safety recommendations should be given before motorboat use to fight against these avoidable fractures.