Compressed injuries

Peripheral neuropathies maybe widely disseminated or focal. Patients with disseminated polyneuropathy, whether demyelinative or axonal, usually demonstrate distal sensory and/or motor impairment. Multifocal neuropathy, also referred to as mononeuropathy multiplex, is often a consequence of lesions affecting the vasa nervorum, the blood vessels that supply peripheral nerves. The most common diseases to compromise the vasa nervorum and cause infarction of nerve fascicles are diabetes mellitus and periarteritis nodosa. Other frequent causes of mononeuropathy multiplex include infection (e.g. Lyme disease and leprosy) and multiple compression injury (e.g. bilateral carpal tunnel syndrome). When mononeuropathy... 

TIRILAZAD MESYLATE IN CAT SPINAL CORD COMPRESSION INJURY... 

Fig. 4. Dose-response correlation in cats of the effects of U-74006F on post-traumatic (compression injury) spinal cord lipid peroxidation (i.e., loss of reduced vitamin E) and on progressive white matter ischemia at 4 hours post-injury (data from ref. [24]) versus chronic (4-week) neurological recovery (data from ref. [46]). Doses indicated were administered at 30 minutes post-injury. Doses in parentheses under the chronic recovery dose-response curve indicate the total 48-hour dosing regimen that these cats received. All values are mean standard error. Numbers of animals are given in parentheses in each bar. Asterisks indicate p < 0.05 vs vehicle-injured animals by ANOVA.

Related to the post-traumatic microvascular damage is the pathophysiological process of vasogenic brain edema that represents a disruption of blood-brain barrier integrity, resulting in sodium and protein accumulation and osmotic fluid expansion of the brain extracellular space. Clinically, this is reflected by an increase in intracranial pressure which, if unchecked, can cause secondary compressive injury to vital brain structures. 

Anderson, D.K., Waters, T.R. and Means, E.D. (1988) Pretreatment with alpha tocopherol enhances neurologic recovery after spinal cord compression injury, J. Neurotrauma 6, 61-68. 

Acceleration Injury Force Injury Compression Injury ... 

Anterior wedging of the upper cervical bodies particularly C3 (Fig. 7.62) is a normal developmental variant and should not be confused with a compression injury. It may be the result of relative hypermobility of the spine during childhood and resolves with increasing maturity (Swischuk et al. 1993). Secondary ossification centres ( ring epiphyses or apophyses) appear at the superior and inferior aspects of all vertebral bodies and do not fuse with the vertebral body until early adulthood (Figs. 7.63, 7.64). These should not be mistaken for fractures, although they can be avulsed as a result of trauma (JOHNSSON et al. 1991). 

The iliac artery and its branches run through the pelvis creating a highly vascular area. These arteries may be disrupted by shearing forces or compression injuries and can be a cause of significant blood loss resulting in hypovolaemic shock. 

With lateral compression injuries, the forces are applied to the side of the pelvis. Lateral compression injuries are also subdivided to reflect the different degrees of severity. 

This is the least severe type of injury pattern with internal rotation of the innominate bone which pivots on the anterior margin of the sacroiliac joint. There may be compression fractures of the sacrum. Pubic rami fractures are common and typically have a known oblique orientation but can be comminuted, compared with the vertical fractures of AP compression injuries (Figs. 12.10,12.11). 

This is the so-called windswept pelvis. There is internal rotation of the pelvis on the side of impact but external rotation of the opposite side. As a consequence, there are lateral compression injuries on one side of the pelvis with AP compression fractures on the other. 

Fig. 12.8. AP Types compression injury. (Images courtesy of Dr.Hughes)...

This is usually the result of forces transmitted through the axial skeleton from an impact into the head and shoulders through to the lower limbs. There may be symphyseal diastasis, anterior arch fractures or posterior disruption of the sacroiliac joints with cephalic displacement. Vertical injuries are often severe with disruption of all the ligaments plus associated pelvic instability. Radiographs demonstrate ipsilateral or contralateral pubic rami fractures, with disruption of the sacroiliac joint. The major differentiating feature from compression injuries is the cephalic displacement of the pelvis on the side of the impact (Fig. 12.14). 

Complex injuries are a combination of lateral compression and anterior compression injuries. It is important to recognise the complexity in view of the need to apply the appropriate external fixation. 

Type B1 fractures are the open book type fracture with external rotation of both iliac wings and Type B2 fractures are lateral compression injuries. TypeB3 is the classical open book type fracture (Fig. 12.17). 

Fig. 12.23. The classification of triradiate cartridge injuries based upon the Salter-Harris classification. (i)Shear injury (ii) fracture (iii) compressive injury...

C6 and C7 are particularly susceptible to spinous process injuries. Traction injuries occur in flexion and compression injuries occur in extension. In extension the spinous processes impact against each other. Clay-shoveler s fracture is an oblique fracture of the spinous process of the C6-T3 vertebrae due to avulsion by supra-spinous ligament injury. The juvenile form is referred to as Schmitt s disease. The avulsion may not be visible on initial radiographs in children due to unossified centre here. However, follow-up radiographs will show callus formation and ossification along the supra spinous ligament. 

Marques, S. A., Almeida, F. M., Fernandes, A. M., Dos Santos Souza, C., Cadilhe, D. V., Rehen, S. K., and Martinez, A. M. 2010. Predifferentiated embryonic stem cells promote functional recovery after spinal cord compressive injury. Brain Res, 1349 115-28. 

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