Understanding Lumbar Spine Anatomy 101 David P Rouben

Understanding Lumbar Spine Anatomy 101 David P. Rouben, M. D. Norton Spine Specialists-Rouben & Casnellie Louisville, KY

REALITY CHECK � 8 out of 10 adults have back pain � 85% suffer recurrences � Back pain is the 2 nd most common reason people see their doctor

Back Disorders: A Widespread Problem Key Points $80 billion in lost work & productivity u 175 million working days are lost annually due to chronic back pain u Significant improvement in outcomes in past decade u Choose Fusion 12 Million Impaired by Back Pain 45 Million with Back Pain

Spine Anatomy Cervical = C 1 -C 7 Dura Dorsal/Thoracic = T 1 -T 12 Normal Disc Lumbar = L 1 -L 5 Sacral = S 1 -S 5 Spinous Process Body of Vertebra

Functions of the Spine � Arc of motion in six Spatial Planes Flexion and Extension Left and Right Side Bending Left and Right Rotation

Vertebral Structures (Axial View) Body Pedicle Transverse Process Vertebral Canal Lamina Spinous Process Articular Process

Structural Spinal Segment (Sagittal view) � � � Vertebrae body above Disc Vertebral body below

Vertebral Structural Columns (Axial View) Anterior Column l l l 2/3 of segment surface area Anterior 1/3 of Pedicle Anterior Longitudinal Ligament Posterior Longitudinal Ligament Disc Vertebral Body

Vertebral Structural Columns (Axial View) Posterior Column l l l l Posterior 1/3 of Segment Surface Area Posterior 2/3 pedicles Posterior Process Facet Joints Ligamentum Flavum Transverse Process Interspinous Ligament

Vertebral Structures (Posterior View) Pars Zygapophyseal Joint (Facet Joint) Superior Articular Process Inferior Articular Process

Intervertebral Disc � � � Fibrocartilaginous joint of the motion segment Makes up ¼ the length of the spinal column Present at levels C 2 C 3 to L 5 -S 1 Allows compressive, tensile, and rotational motion Largest avascular structures in the body

Intervertebral Disc � Annulus Fibrosus ◦ Outer portion of the disc l Made up of lamellae l Layers of collagen fibers l l Arranged obliquely 30° Reversed contiguous layers Great tensile strength Lamellae

Intervertebral Disc � Nucleus Pulposus l l Inner structure Gelatinous High water content Resists axial forces Nucleus Pulposus

Intervertebral Disc � � � Largest avascular structure Blood supply by diffusion through end plates Even partial damage to the blood supply leads to dessication (so called degeneration) of the disc

Spinal Ligaments � Protect the Spinal Segment from excessive excursion

Ligaments Posterior longitudinal ligament Anterior longitudinal ligament Ligamentum flavum

The Most Common Disorders Producing Pain Acute strains and sprains -Muscle, ligament, joint capsule Spinal Segment Osteoarthritis – Facet Joint Disc strain-Annular Tear -progressing to Disc Protrusion-Extrusion-Sequestration

Acute Strains and Sprains Cause � Improper lifting, twisting, falls or other injuries Pathology � Tearing, Stretching, and/or Separation of muscles or ligaments with commensurate Bleeding � ◦ ◦ Treatment If minor injury, no more than two days of rest If severe injury, Progress to Physical therapy

Disc Strain Pathology Annulus disruption/Chemical “itis” Pain will be often severe to the back and buttock as well as to the leg Treatment Restricted Activities for no more than 48 hours Anti-inflammatories, Muscle relaxants, analgesics Exercises- Physical Therapy Time and Patience-Usually Self-Limiting

Annular Disruption/Tears “Disc Bulge”

Disc Protrusion (Progressive Disc Strain) Annulus Tear becomes a Symmetric or Asymmetric Protrusion

Disc Extrusion Protrusions can Progress to become Disc Extrusions

Disc Sequestration Disc Extrusions can Progress to become Disc Sequestrations

Lumbar Spinal Stenosis Cause � A “Segmental” Problem (vertebrae/Disc/vertebrae) Narrowing of the Central or Lateral canal or Foramina with neural root compression Pathology � Thickening of the Ligamentum Flavum + Discal Compression+ Facet Arthropathy+ Intervertebral Collasp � ◦ ◦ Treatment Anti-inflammatory medications, steroid injections, physical therapy Surgery may be necessary due to pain, lifestyle compromise, motor loss

Spinal Stenosis

SURGICAL TREATMENT OPTIONS

Common Lumbar Surgical Techniques Laminectomy/Laminotomy (+ or –) Discectomy Decompression (+ or –) Discectomy Fusion Options. ALIF “ 2 in 1”- ALIF + (PLIF or TLIF or Posterior) Posterior or Transverse Process or Facet 360 Degree-PLIF/TLIF/DLIF

Laminotomy/ Laminectomy

Anterior Lumbar Interbody Fusion (ALIF) The ALIF operation is performed with the patient lying on his or her back. Incision The surgeon makes an incision in the patient's abdomen to access the spine. To have a clear view of the spine, the surgeon then retracts the abdominal and vascular structures. Disc Removal Once the spine is in view, the surgeon removes a portion of the degenerated disc from the affected disc space.