Fracture Burst

When a force is applied to the posterosuperior quadrant of the head or when a crown impact is administered while the head is in flexion, the neck is subjected to a combined load of axial compression and forward bending. Anterior wedge frartures of vertebral bodies are commonly seen, but with increased load, burst fractures and fracture-dislocations of the facets can result. The latter two conditions are unstable and tend to disrupt or injure the spinal cord, and the extent of the injury depends on the penetration of the vertebral body or its fragments into the spinal canal. Recent experiments by Pin tar et al. [1989, 1990] indicate that burst fractures of lower cervical vertebrae can be reproduced in cadaveric specimens by a crown impact to a flexed cervical spine. A study by Nightingale et al. [1993] showed that fracture-dislocations of the cervical spine occur very early in the impact event (within the first 10 ms) and that the subsequent motion of the head or bending of the cervical spine cannot be used as a reliable indicator of the mechanism of injury. 

Marco, R.A.W., Kushwaha, V.P. 2009. Thoracolumbar burst fractures treated with posterior decompression and pedicle screw instrumentation supplemented with balloon-assisted vertebroplasty and calcium phosphate reconstruction. J Bone Joint Surg Am 91(1), 20-28. 

The lateral masses of Cl and C2 may be offset bilaterally in young children so that the lateral masses of Cl overhang those of C2 on the AP view, simulating a Jefferson burst fracture. This phenomenon is thought to be secondary to disparity in growth rate between the two vertebra and is most commonly... 

The intervertebral disc in the paediatric spine has greater resistance to herniation. Therefore, there is a tendency to compression fracture with flexion and axial loading. Simple compression fractures are stable and heal satisfactorily. With severe axial loading, burst fractures can occur. The posterior vertebral line is a useful sign to assess this injury. There is retropulsion into the spinal canal vfliich can be satisfactorily assessed on CT. MR imaging is optimal for the effects of the retropulsion on cord and nerve roots. Compression and burst fractures are discussed in detailed in Sections 20.7.1.2 and 20.7.1.4. 

Bulas DI, Fitz CR, Johnson DL (1993) Traumatic atlanto-oc-cipital dislocation in children. Radiology 188 155-158 Cammisa FP Jr, Eismont FJ, Green BA (1989) Dural laceration occurring with burst fractures and associated laminar fractures. J Bone Joint Surg Am 71 1044-1052 Chance G (1948) Note on a type of flexion fracture of the spine. Br J Radiol 21 452-453... 

McAfee PC, Yuan HA, Lasda NA (1982) The unstable burst fracture. Spine 7 365-373... 

Panjabi MM, Kifiine M, Wen L, et al. (1995) Dynamic canal encroachment during thoracolumbar burst fractures. J Spinal Disord 8 39-48... 

Vertebral bulge and vertebral axial displacement were used as a measure of stability. Vertebral bulge was defined as the maximum radial bulge of the vertebral body under load as a burst fracture predictor irrespective of endplate failure, and vertebral axial displacement represented the maximum axial displacement of the vertebral body under load as a predictor for burst fracture following endplate failure. 

The results indicated that vertebral bulge and axial displacement decreased with the addition of cement in aU scenarios, and therefore PV decreased the risk of burst fracture initiation. However, the magnitude of the increase in stabiUty depended on the location and geometry of the cement injected. Burst fracture risk appeared to be minimized when cement was injected near the posterior waU of the vertebral body. 

The location of cement injection relative to the tumor tissue is critical in attaining maximum vertebral stability following PV. Vertebrae with tumors located in the posterior region are at a higher risk for the occurrence of burst fractures due to their proximity to the posterior vertebral body wall (Tschirhart et al. 2004). Tschirhart et al. (2005) described that stabilization effects of PV on vertebrae with posterior tumors are not as positive as for tumors in other locations. 

Roth SE, Mousavi P, Finkelstein J, Chow E, Kreder H, Whyne CM Metastatic burst fracture risk prediction using bio-mechanically based equations. Clin Orthop Relat Res 2004 83-90. 

Whyne CM, Hu SS, Lotz JC Biomechanically derived guideline equations for burst fracture risk prediction in the metastatically involved spine. J Spinal Disord Tech 2003 16 180-5. 

Tschirhart CE, Nagpurkar A, Whyne CM. Effects of tumor location, shape and surface serration on burst fracture risk in the metastatic spine. J Biomech 2004 37 653-660. 

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