Adult Spine Trauma
Anatomy & Science
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Neck & Upper Extremity Spine Exam
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Thoracic Spine Anatomy
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Spinal Cord Injuries
Incomplete Spinal Cord Injuries
Syrinx & Syringomyelia
Spinal Cord Tumors
Cauda Equina Syndrome
Cervical Spine Trauma Evaluation
Occipital Condyle FX
Occipitocervical Instability & Dislocation
Atlas Fracture & Transverse Ligament Injuries
Odontoid Fracture (Adult and Pediatric)
Traumatic Spondylolisthesis of Axis (Hangman's Fracture)
Cervical Facet Dislocations & FX
Cervical Lateral Mass Fracture Separation
Subaxial Cervical Vertebral Body FX
Closed Cervical Traction
Halo Orthosis Immobilization
Osteoporotic Vertebral Compression Fracture
Thoracolumbar Burst FX
Chance Fracture (flexion-distraction injury)
Adult Pyogenic Vertebral Osteomyelitis
Spinal Epidural Abscess
Ossification Posterior Longitudinal Ligament
Low Back Pain - Introduction
Discogenic Back Pain
Thoracic Disc Herniation
Lumbar Disc Herniation
Synovial Facet Cyst
Lumbar Spinal Stenosis
Adult Isthmic Spondylolisthesis
Adult Spinal Deformity
Rheumatoid Cervical Spondylitis
DISH (Diffuse Idiopathic Skeletal Hyperostosis)
Pediatric Cervical Spine
Pediatric Cervical Trauma Overview
Pseudosubluxation of the Cervical Spine
Pediatric Spinal Cord Injury
Atlantoaxial Rotatory Displacement (AARD)
Congenital Muscular Torticollis
Adolescent Idiopathic Scoliosis
King Classification of AIS
Lenke Classification of AIS
Juvenile Idiopathic Scoliosis
Infantile Idiopathic Scoliosis
Cerebral Palsy - Spinal Disorders
Pediatric Spondylolisthesis & Spondylolysis
Disk Space Infection - Pediatric
Thoracic Spine Anatomy
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Sagittal plane alignment
normal thoracic kyphosis
normal range is 20
the long prominent spinous process found at T1
articulation between ribs and vertebral segments
present on all vertebral bodies and transverse processes from T1 to T9
articulation with ribs leads to increased rigidity of thoracic spine (most rigid in axial skeleton)
Vertebral body size
progressively from T1 to T12
varies from T1 to T12
The orientation of the
determines the degree and plane of motion at that level
varies throughout the spine to meet physiologic function
sagittal (angled superio-medially)
allows flexion-extension, lateral flexion, rotation
sagittal (facets in coronal plane)
6 degrees of freedom
allows some rotation, minimal flexion-extension (also limited by ribs)
prevents downward flexion on heart and lungs
sagittal (facets in sagittal plane)
allows flexion-extension, minimal rotation
helps increase abdominal pressure
Thoracic Pedicle Anatomy
the pedicle wall is twice as thick medially as laterally
T4 has the narrowest pedicle diameter
T7 can be irregular and have a narrow diameter on the concave side in AIS
T12 usually has larger pedicle diameter than L1
pedicle length decreases from T1 to T4 and then increases again as you move distal in the thoracic spine
T4: 14mm (
T10: 20 mm
transverse pedicle angle
varies from 10deg (mid thoracic spine) to 30deg (L5)
sagittal pedicle angle
15-17deg cephalad for majority of thoracic spine
neutral (0deg) for lumbar spine except L5 (caudal)
Erector Spinae Muscles
located dorsal to vertebral column
innervated by dorsal rami of spinal nerves
Erector spinae muscles include
origin and insertion: spinous process to spinous process
origin and insertion: transverse process to transverse process
origin: ilium and ribs
insertion: ribs and transverse process
Surgical approaches for thoracic disc herniation
VATS (video assisted thoracoscopic surgery)
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Qbank (1 Questions)
In the adult spine, which of the following pedicles have the smallest average transverse diameter.
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PREFERRED RESPONSE ▶
Of the levels listed, T6 has the smallest pedicle diameter.
Knowledge of pedicle diameter is important when placing pedicle screws. On average, thoracic pedicle diameter is maximal at T1 and T12, and gradually "dips" to its smallest diameter at the T4 to T6 region.
Scoles et al. performed an anatomic study of 50 normal adult vertebral columns ranging in age from 20 to 40 years at the time of death. They found the average pedicle diameter was smallest at T6 and largest at L5.
Ofiram et al. is an anatomic study of 100 patients comparing the pedicle isthmic width from T10 to L1 using magnetic resonance imaging. In this area they found the smallest pedicle isthmic width was at L1, while T12 had the largest pedicle width in the thoracolumbar junction.
Illustration A shows the finding of pedicle diameter in the Scoles et al study, with the smallest diameter being at T6. Illustration B shows a composite average of multiple studies and depicts the average pedicle diameter from C1 to the sacrum. Notice the "dip" in thoracic diameter from T4 to T6. Notice and additional dip in the lumbar spine at L1, so the diameter of T12 is actually greater than that of L1.
Answer 1: T1 has the largest pedicle diameter in the upper cervicothoracic spine. It is an important fixation point in cervicothoracic fusions.
Answer 3: On average T12 has the largest diameter in the thoracolumbar region,.
Answer 4 & 5: Lumber pedicle diameter continues to increase in the caudal direction, making L5 the largest diameter in the lumbar spine.
Vertebral body and posterior element morphology: the normal spine in middle life.
Scoles PV, Linton AE, Latimer B, Levy ME, Digiovanni BF.
Spine (Phila Pa 1976). 1988 Oct;13(10):1082-6.
PMID: 3206263 (Link to Pubmed)
Is it safer to place pedicle screws in the lower thoracic spine than in the upper lumbar spine?
Ofiram E, Polly DW, Gilbert TJ, Choma TJ
Spine. 2007 Jan;32(1):49-54.
PMID: 17202892 (Link to Pubmed)
Derek Moore MD
John Badylak MD
Michael Hughes MD
Eric Shirley MD
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