Vertebral column
Column of 33 vertebrae (7 cervical, 12 thoracic, 5 lumbar, 5 fused sacral, about 4 coccygeal) with four curvatures. It supports the trunk, protects the spinal cord, and is the site of scoliosis, kyphosis and inflammatory back disease.
Core anatomy
- Location
Posterior midline of the neck and trunk, from the skull to the coccyx.
- Classification
Irregular bones joined by intervertebral discs and synovial facet joints.
- Key features & landmarks
- Regions: cervical (7), thoracic (12), lumbar (5), sacrum and coccyx (5 fused), coccyx (usually 4 fused, range 3–5)
- Typical vertebra: body (anterior, weight-bearing), vertebral arch (pedicles + laminae) enclosing the vertebral foramen, spinous process, two transverse processes, four articular processes; the pars interarticularis lies between the superior and inferior articular processes
- Curvatures: primary (kyphoses, concave anteriorly, present at birth) in the thoracic and sacral regions; secondary (lordoses) in the cervical (head control) and lumbar (walking) regions
- Joints: intervertebral discs between bodies; zygapophysial (facet) joints between articular processes; supported by the vertebral ligaments
- Relations
The spinal cord and meninges occupy the vertebral canal; spinal nerves exit through the intervertebral foramina. The erector spinae and deep back muscles lie in the grooves beside the spinous processes.
- Notes
Surface landmarks (patient standing, arms at sides): C7 (vertebra prominens) is the first clearly palpable spinous process at the base of the neck; the medial end of the scapular spine is at about T3; the inferior angle of the scapula at about T7; the line joining the top of the iliac crests (Tuffier/intercristal line) crosses the L4 spinous process or L4–L5 interspace; the dimples over the posterior superior iliac spines mark S2. verify
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Clinical correlations
Scoliosis PANCE
- Mechanism / lesion
Lateral curvature of the spine with vertebral rotation. Adolescent idiopathic scoliosis is most common and more likely to progress in girls, especially during growth spurts. Others are congenital, neuromuscular or degenerative.
- Classic presentation
Shoulder or scapular asymmetry, uneven waist, and a rib hump on forward bending (Adams test). Usually painless; significant pain or neurologic signs suggest another cause. Measured by the Cobb angle on standing X-ray (10° or more defines scoliosis). Bracing is used for moderate curves in growing children; large curves may need surgery. verify
Hyperkyphosis
- Mechanism / lesion
Scheuermann disease (wedging of adjacent thoracic vertebrae in adolescents) and osteoporotic compression fractures in older adults.
- Classic presentation
Rounded back that doesn't correct fully on extension (Scheuermann), or progressive height loss and "dowager's hump" (osteoporosis).
Ankylosing spondylitis PANCE
- Mechanism / lesion
HLA-B27–associated seronegative spondyloarthropathy, starting in the sacroiliac joints and ascending the spine.
- Classic presentation
Inflammatory back pain in a young adult (usually under 40): morning stiffness lasting more than 30 minutes, improves with exercise, not with rest; night pain. Reduced lumbar flexion (Schober test), reduced chest expansion, anterior uveitis. X-ray: sacroiliitis, later "bamboo spine" from syndesmophytes.
High-yield PANCE pearls
- Vertebral count: 7 C, 12 T, 5 L, 5 S (fused), ~4 Co.
- Scoliosis screen: Adams forward bend test; confirm and measure with Cobb angle on standing X-ray.
- Inflammatory back pain (young, morning stiffness, better with exercise) → ankylosing spondylitis (HLA-B27, bamboo spine).
- Landmarks: C7 prominens, scapular spine T3, inferior angle T7, iliac crests L4, PSIS S2.
Imaging anatomy
- X-ray
Standing PA and lateral full-spine films for scoliosis (Cobb angle) and sagittal balance. Lateral views show vertebral height loss, spondylolisthesis and syndesmophytes.
- CT
Best for bony detail in trauma (fractures, alignment) and surgical planning.
- MRI
Best for discs, spinal cord, nerve roots, marrow (infection, metastases, acute vs old fractures), and early sacroiliitis.
- Key views & landmarks
- Standing full-spine PA and lateral (scoliosis)
- CT for trauma; MRI for neurologic symptoms, infection, malignancy
Physical exam
- Surface landmarks
C7 vertebra prominens, spinous processes, scapular landmarks (T3, T7), iliac crests (L4), PSIS dimples (S2).
- Palpation
Palpate spinous processes and paraspinal muscles for tenderness, step-offs and spasm; percuss for point tenderness (fracture, infection, malignancy).
- Strength / function testing
Range of motion (flexion, extension, lateral bending, rotation); gait; neurologic exam of the limbs.
Adams forward bend test
- Technique
The patient bends forward at the waist with arms hanging and knees straight; the examiner views the back from behind (and from the side).
- Positive test
A rib or lumbar prominence (hump) on one side.
- Significance
Structural scoliosis (the rotational component). A scoliometer quantifies the rotation.
Modified Schober test
- Technique
Mark the skin at the level of the PSIS dimples and 10 cm above in the midline (some versions add 5 cm below); the patient bends forward maximally and the distance is re-measured.
- Positive test
An increase of less than about 5 cm. verify
- Significance
Reduced lumbar flexion, e.g. ankylosing spondylitis.
Self-quiz
A 13-year-old girl has uneven shoulders noticed by her mother. When she bends forward, the right side of her back is higher than the left. She has no pain. What is the next step?
Correct answer: B
A positive Adams forward bend test suggests structural scoliosis. Standing full-spine radiographs measure the Cobb angle and skeletal maturity. MRI is reserved for atypical features (pain, neurologic signs, left thoracic curve).
Show answer
B
A positive Adams forward bend test suggests structural scoliosis. Standing full-spine radiographs measure the Cobb angle and skeletal maturity. MRI is reserved for atypical features (pain, neurologic signs, left thoracic curve).
A 24-year-old man has 6 months of low back pain and 1 hour of morning stiffness that improves with activity. He has reduced lumbar flexion and a history of red painful eye. Which finding is most likely on imaging?
Correct answer: B
Inflammatory back pain with uveitis suggests ankylosing spondylitis, which begins with sacroiliitis. Later films may show a bamboo spine.
Show answer
B
Inflammatory back pain with uveitis suggests ankylosing spondylitis, which begins with sacroiliitis. Later films may show a bamboo spine.
Which vertebral level corresponds to a line joining the highest points of the iliac crests?
Correct answer: D
The intercristal (Tuffier) line crosses the L4 spinous process or the L4–L5 interspace, the landmark for lumbar puncture below the end of the spinal cord.
Show answer
D
The intercristal (Tuffier) line crosses the L4 spinous process or the L4–L5 interspace, the landmark for lumbar puncture below the end of the spinal cord.
Which curvatures of the vertebral column are primary (present at birth)?
Correct answer: D
The thoracic and sacral kyphoses are primary curvatures, present in the fetus. The cervical (head control) and lumbar (walking) lordoses are secondary.
Show answer
D
The thoracic and sacral kyphoses are primary curvatures, present in the fetus. The cervical (head control) and lumbar (walking) lordoses are secondary.
A 15-year-old boy has a rounded upper back that doesn't correct fully when he extends his spine. Radiographs show wedging of several adjacent thoracic vertebrae. What is the most likely diagnosis?
Correct answer: E
Scheuermann disease is a structural hyperkyphosis in adolescents from wedging of adjacent thoracic vertebrae, so it doesn't fully correct on extension, unlike postural kyphosis.
Show answer
E
Scheuermann disease is a structural hyperkyphosis in adolescents from wedging of adjacent thoracic vertebrae, so it doesn't fully correct on extension, unlike postural kyphosis.