Clinical Anatomy of Sciatica and femoral hernia Flashcards
1
Q
What is sciatica and what is the typical presentation of it
A
- A term used to describe the symptoms that present within the distribution of the sciatic nerve.
2
Q
What is sciatica most commonly presented as and what are some common symptoms
A
- Most commonly presents as pain radiating down the leg
- Pain
- Numbness
- Tingling
- Weakness of movement of the knee and ankle.
3
Q
What are the 5 causes sciatica
A
- Herniation of an IVD
- Entrapment
- Spinal pathology
- Malignancy
- Infection
4
Q
How does herniation of an IVD cause sciatica
A
- The herniated IVD will compress the roots that form the sciatic nerve. These are L4-S3 however L5 and S1 are the nerves that are most commonly compressed.
5
Q
What can cause sciatica by entrapping the sciatic nerve
A
- The piriformis muscle, when it is overused.
6
Q
What are some treatments for sciatica
A
- Physical therapy & pain relief
- NSAIDs (reduce inflammation)
- Steroid injections
- Surgical Repair
- Microdiscectomy (removing of IVD)
- Laminectomy (removing part of the lamina)
7
Q
Describe the categories of spinal nerves and how they leave the vertebral column
A
- Split into cranial nerves and spinal (cervical, thoracic, lumbar and sacral nerves)
- Spinal nerves C1-C7 exit the vertebral column above vertebrae
- Spinal nerves C8-S3 exit the vertebral column above the vertebrae
8
Q
What spinal levels make up the conus medullaris and cauda equina
A
- T12-L1
- L2- Sacrum
9
Q
What structures make up the anterior, posterior, inferior and superior boundaries of the intravertebral foramen
A
- Anterior - Posterior longitudinal ligament, body of 2 vertebrae and IVD
- Posterior - Ligamentum flavum and capsule of facet joint
- Superior - Pedicle of vertebrae above
- Inferior - Pedicle of vertebrae below
10
Q
What type of joint is an IVD
A
- Secondary Cartilaginous joint
11
Q
What makes an IVD a secondary cartilaginous joint
A
- It is made up of fibrocartilage and then covered by hyaline cartilage
12
Q
What are the 3 components of an IVD and what is each component made of
A
- Vertebral endplate (hyaline cartilage)
- Annulus fibrosis (alternating collagen fibre lamellae)
- Nucleus pulposus (hydrated gel)
13
Q
Nerve roots from what part of the spinal cord will pass several spinal levels before leaving the vertebral column
A
- Cauda Equina
14
Q
Which ramii form spinal plexuses
A
- Ventral (anterior) rami of mixed spinal nerves
15
Q
What spinal nerves form each of the plexus and trunks of the body and what do the spinal nerves that do not form plexuses form instead
A
- Cervical - C1-C5
- Brachial - C5-T1
- Intercostal Nerves - T2-T12
- Lumbar - L1-L4
- Lumbosacral trunk - L4-L5
- Sacral - L4-L5 & S1-S4
- Coccygeal Plexus - S5 and coccygeal nerve
16
Q
What are the 2 components of the lumbosacral plexus that make up the sciatic nerve
A
- Common Fibula nerve
- Tibial nerve
17
Q
What makes up the tibial nerve
A
- Anterior divisions of ventral rami L4, L5, S1, S2, S3
18
Q
What makes up the common fibula nerve
A
- Posterior divisions of ventral rami L4, L5, S1, S2
19
Q
Describe the course of the sciatic nerve down the lower limb
A
- Comes out below the piriformis muscle through the greater sciatic foramina.
- Down and past 4 muscles (obturator internus, 2 gemelli, quadratus femoris)
- Into the posterior aspect of the thigh behind the long head of the biceps in front of the adductor magnus,
- Separates into 2 terminal branches at the apex of the popliteal fossa.
- Tibial nerve goes straight down into the back of the leg
- Common (peroneal) fibular winds around the fibula and enters the anterolateral compartment
20
Q
What are the 3 occasions that would cause piriformis syndrom
A
- Sciatic nerve separating earlier and common fibula piercing piriformis.
- Sciatic nerve separating earlier and common fibula extending superiorly to piriformis muscle to enter greater sciatic foramen
- Sciatic nerve piercing piriformis.
21
Q
What are the muscles supplied by the tibial component of the sciatic nerve
A
- Posterior thigh muscles - (Except for short head of biceps femoris)
22
Q
What are the posterior muscles of the thigh also known as in lay terms and what are the names of the muscles in this category
A
- Hamstrings
- Biceps Femoris
- Semimembranosus
- Semitendinosus
- Adductor magnus
23
Q
What are the muscles supplied by the common fibial component of the sciatic nerve
A
- Short head of the biceps femoris
24
Q
What are the muscles that are innervated by the tibial nerve
A
- Posterior muscles of the leg
25
What are the names of the posterior muscles of the leg
- Plantaris
- Gastrocnemius
- Popliteus
- Soleus
- Tibialis posterior
- Flexor digitorum longus
- Flexor hallucis longus
26
What are the muscles that are innervated by the common fibula nerve
- Anterior muscles of the leg
- Lateral muscles of the leg
27
What are the names of the anterior muscles of the leg
IDK
28
What are the names of the lateral muscles of the leg
IDK
29
What muscles in the foot does the tibial nerve innervate
- Abductor hallucis
- Flexor digitorum brevis
- Flexor hallucis brevis
- Lumbricals
30
What muscles in the foot does the common fibula nerve innervate
- Extensor digitorum brevis
31
Why are dermatomes important in the clinic
- Can be used to localise neurological levels in radiculopathies.
- Viral infections pain along dermatomes
32
What is the difference between dermatomes and myotomes
Dermatomes - area of skin innervated by a single pair of spinal nerves.
Myotomes - Group of muscles innervated by a single pair of spinal nerves.
33
What happens of the pair of spinal nerves of a myotome are damaged and how can the damage of these nerves be assessed
- They cause weakness of the muscles of that myotome, doctors can test for the function of muscles to assess damage to spinal nerves.
34
What are the movements that can assess for damage of the L4, L5 and S1 spinal nerves
- Extension of the knee - L4
- Plantar flexion - S1
- Dorsi flexion - L5
35
What is the effect of a disc hernia occurring in the central zone
- Will compress medial traversing nerves, symptoms will occur at multiple levels
36
What is the effect of a disc hernia occurring in the paracentral zone
- Will compress medial traversing nerves and maybe exiting nerves, symptoms will occur at multiple levels
37
What is the effect of a disc hernia occurring in the far lateral zone
- Will only effect exiting nerves, symptoms will occur at only that level.
38
What is an abdominal hernia
- Abdominal protrusion of abdominal viscera or part of the viscera through potentially weak areas.
39
Give some examples of rare abdominal hernias
- Hernia of Linea alba
- Post operative (incisional) hernia
- Hernia at Linea semilunaris
40
Give some examples of common abdominal hernias
- Inguinal hernia
- Umbilical hernia
- Femoral hernia
41
What are the 3 stages of an abdominal hernia
- Reducible - Contents of hernia return spontaneously to the abdominal cavity after increase in intraabdominal pressure (can be pushed back easily by patient)
- Incarcerated - Irreducible. May cause bowel obstruction. Should not attempt to reduce it forcibly
- Strangulated - Reduced blood supply due to compression. Requires emergency surgical intervention to avoid necrosis of the contents of the hernia.
42
What is a Ritcher's hernia
- When only a part of the bowel wall is herniated
43
What are the boundaries of the femoral triangle
- Superiorly - inguinal ligament
- Laterally - Sartorius
- Medially - medial border of abductor longus
44
What is the contents of the femoral triangle and how do you remember them
- NAVEL - (Laterally to medially)
- Femoral Nerve
- Femoral Artery
- Femoral Vein
- Empty space
- Lymph nodes
45
What structures in the femoral triangle are within the femoral sheath
- Femoral Artery
- Femoral Vein
- Empty space
46
What 2 fascia make up the femoral sheath
- Fascia transversalis anteriorly
- Fascia liliaceous posteriorly
47
What are the 3 compartments of the femoral sheath and what do each of them contain
- Lateral - Femoral Artery
- Intermediate - Femoral Vein
- Medial - Empty space known as femoral canal (site for femoral hernia, and continuous with abdominal cavity)
48
Why are abdominal hernias more common in women
- Wider pelvis
