Biomechanics of Spine PDF

# Anatomy of Spine Dr Pankaj N Surange MBBS, MD, FIPP Interventional Pain and Spine specialist ## Anatomical Planes The CORONAL PLANE, also called the FRONTAL PLANE, is a vertical cut that divides the body into front and back sections. Physicians look at the coronal plane when they view an A-P (a...

# Anatomy of Spine Dr Pankaj N Surange MBBS, MD, FIPP Interventional Pain and Spine specialist ## Anatomical Planes The CORONAL PLANE, also called the FRONTAL PLANE, is a vertical cut that divides the body into front and back sections. Physicians look at the coronal plane when they view an A-P (anterior-posterior) x-ray of the spine to evaluate scoliosis. - A-P X-ray of a scoliotic spine in the coronal plane. ## Functions of the Spine - Protection of - spinal cord and nerve roots - internal organs - Flexibility of motion in six degrees of freedom - Flexion and Extension - Left and Right Side Bending - Left and Right Rotation - Structural support and balance for upright posture - The spine is the axle bearing the load of the head, shoulders and thorax. The upper body weight is then distributed to the lower extremities through the sacrum and pelvis. - This reduces the amount of work required by the spinal muscles and can eliminate muscle fatigue and back pain. - To achieve these functions, the spine must have: - Resistance to axial loading forces, accomplished by: - Kyphotic and lordotic sagittal plane curves - Increased mass of each vertebra from C1 to the sacrum - Elasticity accomplished by: - Alternating lordotic and kyphotic curves - Multiple MOTION SEGMENTS ## The Motion Segment - The FUNCTIONAL UNIT of the spine - Composed of: - Two adjacent vertebrae - The intervertebral disc - Connecting ligaments - Two facet joints and capsules ## Regions of the Spine - Cervical - Upper cervical: C1-C2 - Lower cervical: C3-C7 - Thoracic: T1-T12 - Lumbar: L1-L5 - Sacrococcygeal: 9 fused vertebrae in the sacrum and coccyx ## Basic Vertebral Structures - Cervical - Thoracic - Lumbar ## Vertebral Structures - Vertebral Body - Pedicle - Transverse Process - Lamina - Spinous Process - Superior Articular Process - Vertebral Foramen - Pars - Zygapophyseal Joint (Facet Joint) - Inferior Articular Process - Pedicle notches - INTERVERTEBRAL FORAMEN through which the spinal nerve roots leave the spinal cord - Intervertebral Foramen - Deep Notch - Slight Notch ## The Atlas (C1) - Transverse Process - Transverse Foramen - Anterior Tubercle - Articular Facet for Dens - Superior Articular Facet - Lateral Mass - Posterior Tubercle - Lamina - Superior View ## The Axis (C2) - Body - Odontoid Process (Dens) - Superior Articular Facet - Transverse Process - Inferior Articular Facet - Anterior View - Lateral Mass - Spinous Process - Posterior View ## Lower Cervical Vertebrae - C3 to C7 - May be referred to as the subaxial region. - Disc at every level. - Vertebral structures are similar. - Lower Cervical - C3 - C4 - C5 - C6 - C7 - Sulcus for Spinal Nerve - Body - Transverse Process - Pedicle - Lateral Mass - Lamina - Transverse Foramen - Superior Articular Facet - Vertebral Foramen - Bifid Spinous Process - Axial View - The vertebral bodies of the subaxial cervical spine have upward projections on the lateral margins called UNCINATE PROCESSES. - These processes articulate with the level above to form the UNCOVERTEBRAL JOINT. These are also called JOINTS OF LUSCHKA. - Uncinate Process - Uncovertebral Joint (Joint of Luschka) - Anterior View - Sulcus for Spinal Nerve ## Vertebra Prominens (C#) - C7 is referred to as the VERTEBRA PROMINENS because it has a longer and larger spinous process than the other cervical vertebrae. - This spinous process is not usually bifid. - Spinous Process - Axial View ## Thoracic Vertebrae - Body - progressive increase in mass from T1 to T12 - Pedicles - small diameter - Laminae - vertical, with “roof tile” arrangement - Spinous processes - long, overlapping, projected downward - Intervertebral foramen - larger, less incidence of nerve compression ## Thoracic Vertebrae, T1-T12 - Body - heart shaped when viewed superiorly. - Vertebral foramen - round - Pedicles - small in diameter - Spinous processes - long and projected downwards - Articular processes - Superior Articular Process - Inferior Articular Process