1) Scoliosis is a lateral curvature of the spine that can be structural, caused by conditions like idiopathic scoliosis, or non-structural/postural. Structural scoliosis involves rotation and tilting of vertebrae. 2) The normal spine has four curvatures - thoracic and sacral kyphosis which are primary, and cervical and lumbar lordosis which are secondary. Lordosis bends backward and kyphosis bends forward. 3) Disc prolapse occurs when the nucleus pulposus herniates through weak spots in the annulus fibrosus, potentially compressing spinal nerves. Advanced aging decreases nutrition to discs.

1. Anatomical basis of scoliosis,
lordosis, disc prolapse ,
spondylolistheis and spina
bidfida
Dr Siddhartha Sinha
Assistant Professor, Department of Orthopaedics
HIMSR & HAHC

4. Scoliosis
• Scoliosis is an apparent lateral (sideways) curvature of the
spine
• 2 curves- primary and secondary/compensatory curve.
• Classification:
• Structural: permanent- rotation and tilt of the vertebra
• Idiopathic
• Congenital
• Paralytic
• Other causes
• Non structrural: transient- mobile, transient scoliosis
• Postural (Most common)
• Compensatrory
• Sciatic

5. • Postural scoliosis (correctable
deformity, improves with patient sits)
• Short leg
• Pelvic tilt
• Hip contracture
• Structural Scoliosis (non correctable
deformity)
• Spinous processes swing round
towards the concavity of the curve
• Transverse processes on the
convexity rotate posteriorly.
• thoracic region the ribs on the convex
side stand out prominently, producing
the rib hump (characteristic)

7. Curvatures of the spinal column
• 4 curvatures in adult
• Primary curvatures
• Thoracic and sacral kyphosis
• Secondary curvature
• Cervical and lumbar lordosis
• Lordosis: spine curvature concave posteriorly
• Kyphosis: spine curvature concave anteriorly

8. Lordosis
• Cervical and lumbar lordoses
• Appear during the late fetal period but do not become
obvious until infancy due to extension from the flexed fetal
position
• Secondary curvatures -primarily by differences in thickness
between the anterior and the posterior parts of the IV discs.
• The cervical lordosis
• when infant begins to raise (extend) the head while prone and to hold
the head erect while sitting.
• The lumbar lordosis becomes
• when toddlers begin to assume the upright posture, standing and
walking.
• This curvature, generally more pronounced in females,
ends at the lumbosacral angle formed at the junction of L5
vertebra with the sacrum

9. Exaggerated lumbar lordosis (hollow back/
sway back)
• Anterior tilting of pelvis
• Increased extension of lumbar vertebrae
• Weak musculature of anterolateral abdominal
muscles
• Pregnancy, obseity

10. Kyphosis
• Thoracic and sacral kyphoses are primary
curvatures
• Develop due to the (flexed) fetal position.
• The primary curvatures are in the same
direction as the main curvatures of the fetal
vertebral column.
• The primary curvatures are retained
throughout life as a consequence of
differences in height between the anterior and
posterior parts of the vertebrae.
• Vertebral developmental defects

11. Excessive throcacic kyphosis (hunchback/
humpback)
• Vertebral column curves posteriorly
• Erosion of anterior part of vertebrae
• Osteoporosis – horizontal trabeculae
affected- failure in compression-
compression fractures
• Multiple compression fractures
• loss of height
• Increased AP dm of chest wall- decreased
dynamic pulmonary capacity

13. Disc prolapse
• 3 components
• Cartilage end-plates
• Nucleus pulposus (NP)
• Annulus fibrosus (AP)
• Ageing decreases nutrition and number of chondrocytes in NP
decrease- decreased proteoglycans & increase in proportion of
collagen to water in NP leading to stiffness of NP and less distribution
of load- facets bear more load (back pain)
• Eventually annulus fails causing disc herniation and radiculopathy

16. • After disc extrusion – disc
compress one or more spinal
roots in extrathecal course
• Often exiting nerve root

18. Spodylolistheisis
• Forward displacement of one
vertebra over another
• Normal:
• Forward displacement of
vertebral body prevented by
articular process with the
vertebra below it
• Disc, intervertebral ligaments to
a small extent

22. Spina bifida
• Neural arches fail to develop
normally and and fuse posterior
to the vertebral canal resulting in
an "open" vertebral canal
1. Spina bifida occulta
• Relatively common in population
(upto 24%)
• L5-S1 most commonly affected
2. Spina bifida cystica
• One or more vertebral arch fail to
develop completely
• Herniation
• Meninges (meningocoele)
• Meninges and Spinal cord
(meningomyelocoele)
3. Neural tube defects- failure of
closure of neural tube at 4th week of
embryonic development