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Lumbar Spine Trauma Presented by M.A. Kaeser, DC Spring 2009 Compression Fractures M/C fracture of the lumbar spine Result from combined flexion and axial compression M/C level is T12-L1 Degree of compression and comminution depends on severity fo the force appliied and the strength of the vertebra Children – torus type fracture Incidence increases with age http://www.nature.com/sc/ journal/v42/n2/images/ 3101546f1.jpg http://www.eorthopod.com/images/ContentImages/spine/spine_ thoracic/compression_fx/thoracic_compression_fx_intro01.jpg Osteoporosis and Compression Fractures Precipitates spontaneous compression fractures during everyday activities Classified as insufficiency fractures (“grandma fracture”) Most commonly occur in women Up to 35% in female pts. Over the age of 45 years may be the result of early menopause and 30% to secondary osteopenia (corticosteroids 15%, hyperthyroidism 8%, malignancy >2%) http://api.ning.com/files/O9cKHJobD4EbaBjcqs2c2RwKwqc51mga V3nJ6kwGv5AnOKjq7OXspLL *FBSjq-RJdddXF432gr1MxZRI6Rn V8-sgh*y3Fy5/compression_fracture.jpg Symptoms/Treatment Acute symptoms of only 10-14 days duration, if no dislocation Treatment is based on the nature of the collapse and whether or not there is associated neurological symptomology Stability Post-fracture stability is determined based on the classification by Denis • Anterior column – from ALL to the mid vertebral body • Middle column – from the mid vertebral body to the PLL • Posterior column – from the PLL to the supraspinous ligament If two or more compartments are disrupted the fracture complex is unstable – neurological injury is high and interventional surgery is likely Radiographic Signs of Vertebral Compression Fracture Lateral radiographs best demonstrate fracture features Include: • Step defect • Wedge deformity • Linear zone of condensation • Displaced endplate • Paraspinal hematoma • Abdominal ileus The Step Defect Anterior aspect of the vertebral body is under the greatest stress, the first bony injury to occur is a buckling of the anterior cortex, usually near the superior vertebral endplate Seen as a sharp step off of the anterosuperior vertebral margin along the smooth concave edge of the vertebral body As the superior endplate is compressed in flexion, a sliding forward of the vertebral endplate occurs http://www.chiroweb.com/ content/images/ bassano02_1_2334.jpg Wedge Deformity Anterior depression of the vertebral body occurs, creating a triangular wedge shape The posterior vertebral height remains uncompromised, differentiating a traumatic fracture from a pathologic fracture May create angular kyphosis in the adjacent area Superior endplate is far more often involved than the inferior endplate Up to 30% or greater loss in anterior height may be required before the deformity is readily apparent on convention x-rays Normal variant anterior wedging of 10-15% or 13 mm is common thought the T/S and most marked at T11-L2. http://www.cascadewellness clinic.com/GRAPHICS/ 2ARTGFX/00ARTGFX/ COMPFRAC.GIF Linear White Band of Condensation (Zone of Impaction) Band of raadiopacity may be seen just below the vertebral endplate that has been fractured The band represents the early site of bone impaction following a forceful flexion injury where the bones are driven together Callus formation adds to the density of the radiopaque band later, in the healing stage of the fracture injury Band is not always apparent If present, denotes a fracture of recent origin (<2 months’ duration) http://www.theamerican chiropractor.com/ images/figure-1.jpg Disruption in the Vertebral Endplate A sharp disruption in the fractured vertebral endplate may be seen May be difficult to perceive on plain films and tomography CT provides the definitive means of identification The edges of the disruption are often jagged and irregular Superior is more commonly fractured http://download. imaging.consult.com /ic/images/S19330 33206711077/gr1midi.jpg Paraspinal Edema With extensive trauma, U/L or B/L paraspinal masses may occur – these represent hemorrhage Best seen in the thracic spine on the AP projection In L/S edema creates asymmetrical densities or bulges in the psoas margins http://download.imaging.consult.com/ic/images/ S1933033207730938/gr3-midi.jpg Abdominal Ileus An excessive amount of small or large bowel has in a slightly distended lumen Occurs as a result of disturbance to the visceral autonomic nerves or ganglia from pain, paraspinal soft tissue injury, edema or hematoma This sign warns that the trauma was severe and fracture is likely http://www.ganfyd.org/images/thumb/6/69/Axr_ileus.jpg/ 180px-Axr_ileus.jpg Old vs New Compression Fracture Signs of a fracture <2 months old = soft tissue hemorrhage, step defect and white band of condensation Healing of compression fracture can take up to 3 months in the adult spine Presence of contiguous disc degeneration is common in old compression fractures owing to altered discovertebral mechanics MRI reveals bone marrow edema with recent fracture Bone scan shows increased uptake with recent fractures undergoing repair (they may remain active for up to 18-24 months after injury, which diminishes its usefulness) Burst Fractures Specific form of a compression fracture Posterosuperior fragment is displaced into the spinal canal Neurological injury may result in up to 50% of cases (best demonstrated by MRI or CT) Most burst fractures are stable and can be treated adequately with conservative measures AP film – a vertical fracture line is often seen, Widening of the interpediculate distance signifies a fracture within the neural arch Acquired coronal cleft vertebra – coronally oriented fracture the separates the vertebral body into anterior and posterior halves Central depression of the superior and inferior endplates occurs with comminution of the vertebral body http://www. http://www.spine spineuniverse. com/displaygraphic. php/2240/Fig-1c-BB.jpg Posterior Apophyseal Ring Fractures Separation of the posterior vertebral body ring apophysis (posterior limbus bone) is a relatively uncommon abnormality More common in adolescents and young adults Clinical features include stiffness and spasm, numbness, weakness, neurogenic claudication and occasionally cauda equina syndrome Most common levels are L4/5 and L5/S1 50% are caused by trauma (ie. weightlifting, MVAs, gymnastics) Surgery may be warranted Between 15% and 20% are visible on lateral radiographs CT is definitive method of diagnosis http://www.scielo.br/ img/revistas/aob/ v10n1/a04fig05.gif Kummel’s Disease Delayed post-traumatic vertebral collapse Occurs months after an episode of spinal trauma Caused by complicating avascular necrosis resulting in progressive compression deformity Intravertebral vacuum phenomenon may be evident on radiographs http://download.imaging. consult.com/ic/images/ S1933033206702300/gr10midi.jpg Fractures of the Neural Arch TP fractures – 2nd M/C fracture of the L/S Occur from avulsion of the paraspinal muscles, usually secondary to a severe hyperextension and lateral flexion blow to the L/S Large forces are usually involved M/C segments are L2/3 Frequently missed on initial examination Usually occurring close to its point of origin from the vertebra Frequently displaced inferiorly If the fracture is horizontal, check for transverse or Chance fracture Fractures often occur at multiple levels Fractures of the L5 TP are frequently found in association with pelvic fractures Loss of the psoas shadow may occur secondary to hemorrhage Always check for abdominal organ injuries Associated renal damage may be associated with hematuria CT exam is recommended to check for fracture and integrity of the abdominal contents http://www.medscape.com/ content/2004/00/48/35/ Pars Interarticularis Fractures True fractures, not stress fractures, are uncommon MOI – violent hyperextension of the L/S – usually at the L4 or L5 level Not to be confused with spondylolysis of the pars, which is usually the result of a stress fracture Acute fractures are U/L, spondylolysis is B/L Acute fractures heal without residual defects or anterior displacement http://www.wheelessonline. com/image9/spdy1.jpg http://www.sportsinjuryclinic.net/galle Chance or Lap Seat Belt Fracture Horizontal splitting of the spine and neural arch Use of lap-type seat belts in the ’50s and ’60s coincided with an increasing occurrence of Chance fractures Severe abrasions can be seen on the lower anterior abdominal wall, outlining the position of the seat belt Internal visceral damage may occur – rupture of the spleen or pancreas and tears of the small bowel and mesentery Neurological deficits in 15% of cases M/C location is upper L/S (L1-L3) http://www.ajronline.org/cgi/contentnw/full/183/4/959/FIG6 http://www.e-radiography.net/radpath/f/chance%20fracture/ Fracture-Dislocation M/C in the T/L area afer a vilent flexion injury Avulsion fractures (teardrop) are commonly found associated with dislocation of the L/S Most dislocations are anterior in position, without lateral displacement Shearing injuries with disc and ligament rupture and fractures of the posterior arch are common Naked facet sign – absence of apposed http://www.ispub.com/ispub/ijns/volume_ 5_number_2_36/effect_of_pathology_ and_gestational_age_on_the_ management_of_neurosurgical_ References Yokum TR, Rowe LJ. Essentials of Skeletal Radiology. Baltimore: Williams & Wilkins, 1996: 373–545.