PBL 4th Case (Musculoskeletal System)

1. Case #4
1. Anatomy of back in general?
a. lumbar spine (Lumbar vertebrae + intervertebral disc)?
• General description
The back consists of the posterior aspect of the body and provides the musculoskeletal axis
of support for the trunk. Bony elements consist mainly of the vertebrae. it gives protection
to the spinal cord, and this protection is mainly held by the vertebral column
• Support
The skeletal and muscular elements of the back support the body's weight, transmit forces
through the pelvis to the lower limbs.
• Movement
Muscles of the back consist of extrinsic and intrinsic groups:
• The extrinsic muscles of the back move the upper limbs and the ribs.
• The intrinsic muscles of the back maintain posture and move the vertebral column.

2. • Bones
The major bones of the back are the 33 vertebrae. There are seven cervical, twelve
thoracic, five lumbar, five sacral (Fused), and three to four coccygeal vertebrae. We’re
only going to focus on the Lumbar vertebrae.

3. • Lumbar Vertebrae
The five lumbar vertebrae are distinguished from vertebrae in other regions by their large
size. Also, they lack facets for articulation with ribs. The transverse processes are
generally thin and long The vertebral body of a typical lumbar vertebra is cylindrical and
the vertebral foramen is triangular in shape.
Intervertebral foramina are formed on each side between adjacent parts of vertebrae and
associated intervertebral discs. The foramina allow structures , such as spinal nerves and
blood vessels, to pass in and out of the vertebral canal.

4. • Intervertebral disc:
The intervertebral disc consists of an outer anulus fibrosus , which surrounds a central nucleus
pulposus
§ The anulus fibrosus consists of an outer ring of collagen of fibrocartilage
arranged in a circle like configuration. This arrangement of fibers limits rotation
between vertebrae.
§ The nucleus pulposus fills the center of the intervertebral disc, is gelatinous, and
absorbs compression forces between vertebrae.

5. 2. Determine the biomechanics of the lumbar spine?
• Lumbar flexion: More limited than extension, Increases diameter of intervertebral
foramina, generates compression forces on anterior side of disc tending to migrate
nucleus pulposus posteriorly
• Lumbar extension: Increase in lumbar lordosis, reduces the diameter of intervertebral
foramina, nucleus pulposus displaces anteriorly.

6. • Lumbar lateral flexion: Annulus fibrosus is compressed on concavity of curve and
stretched on convex side, Nucleus pulposus migrate slightly towards convex side of
bend.
• Spinal rotation: Limited due to shape of zygapophyseal joints, Amount of rotation
available at each vertebral level is affected by position of lumbar spine. The posterior
anulus fibrosus limits axial rotation when spine is flexed

7. 3. What are the reasons for the tremendous pain he feels?
• Muscular Problems: Most common lower back pain, due to heavy lifting, bending,
overusing back muscles.
• Herniated disk: WILL BE DISCUSSED IN THE NEXT OBJECTIVE!!!
• Degenerative disc disease: discs lose hydration and wear down. As the disc
loses hydration, it cannot resist forces.
• Spondylolisthesis: Spondylolisthesis occurs when one vertebra slips forward over the
one below it. The slip most commonly occurs in the lower lumbar vertebrae (e.g. L4 –L5 or
L5 – S1). If the slipped vertebra compresses the nerve root at that level, it can result in leg
pain and possibly foot pain.

8. 4. What are disc herniations?
A spinal disc herniation is a medical condition affecting the spine due to trauma, lifting injuries,
or idiopathic, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral
disc allows the soft, central portion (nucleus pulposus) to bulge out beyond the damaged
outer rings.
Lumbar disc herniations occur in the lower back, most often between the fourth and fifth
lumbar vertebral bodies or between the fifth and the sacrum. Symptoms can affect the lower
back, buttocks, thigh, anal/genital region (via the Perineal nerve), and may radiate into the foot
and/or toe. The sciatic nerve is the most commonly affected nerve, causing symptoms of
sciatica. The femoral nerve can also be affected and cause the patient to experience a numb,
tingling feeling throughout one or both legs and even feet or even a burning feeling in the hips
and legs.
• Diagnosis:
Diagnosis is based on the history, symptoms, and physical examination. tests may be
performed to confirm or rule out other causes of symptoms such as spondylolisthesis,
degeneration, tumors, metastases as well as to evaluate the efficacy of potential treatment
options.

9. 5. Radiology testing
Imaging of a herniated disc is mainly done by MRI, we can diagnose the herniated disc by
comparing it with the normal disc above it or below it, and we can see clearly that the
nucleus pulposus had penetrated the annulus fibrosus leading to compression of the
nerve.

10. 6 & 7. Management & Pharmacology and intervention?
• Rest : to relieve swelling and give the back time to heal.
• Physical Therapy :
A. stretching exercise to keep the muscle flexible
B. massage
C. Electrical muscle stimulation
• Medication :
1. Over the counter pain medicines : NSAIDs to relive the pain and bring down the
swelling
2. Muscle relaxants
3. Nerve pain medicines
• Injections : Epidural injection , steroid injection into the space around your spinal
nerve.
• Surgery:
A. You’re not getting relief from pain relievers, injections, and physical therapy.
B. Your symptoms keep getting worse.
C. You have trouble standing or walking.
D. You can't control your bowels or bladder.

11. § Types of surgery :
1. Lumbar laminotomy.
Sometimes your surgeon will also need to remove a small piece of bone called the lamina from
the vertebra. The lamina forms a protective cover over your spinal cord. Removing part or all of
it helps the surgeon access your herniated disk. It also can relieve pressure on your nerves and
eliminate leg pain and sciatica. The lamina can be removed during the discectomy. Or, you
might have it taken out in a separate surgery.
2. Spinal fusion
After a discectomy or laminotomy, your surgeon may fuse together the two vertebrae on either
side of the disk to stabilize your spine. This is called spinal fusion. Fusing the two disks will stop
the bones from moving and prevent you from having any more pain
3. Artificial disk surgery.
Only a few people are good candidates for artificial disk surgery because it only works on
certain disks in your lower back. But if your doctor thinks this is an option, he will replace your
damaged disk with one made of plastic or metal. The new disk will help keep your spine stable
and let you move more easily.