Discal Injuries Flashcards
How does it occur?
Common levels?
Disc herniation occur often as a result of age-related degeneration of the annulus fibrosis. However trauma, straining, torsion and lifting injury are also involved. Disc herniation are asymptomatic most of the time, and 75% of the intervertebral disc herniation recover spontaneously within 6 months. It can occur in any disc in the spine, but lumbar disc herniation and cervical disc herniation are the two most common forms.
In a study using provocative discography for symptom mapping, Slipman et al showed that unilateral symptoms were found just as often as bilateral symptoms.
Tears are most frequent postero-lateral because of the absence of the anterior/posterior longitudinal ligament, where the annulus fibrosis is thin. Previously existing disc protrusion are often prior to disc herniation. The outermost layers of the fibrous ring are still intact and none of the central portion escapes beyond the outer layers. But with the amount of pressure rising on the disc, bulging is possible.
In 95% of the lumbar disc herniation the L4-L5 and L5-S1 discs are affected. This causes lower back pain (lumbago) and possibly leg pain as well, in which case it is commonly referred to as sciatica. Lumbar disc herniation occurs 15 times more than cervical disc herniation, and is an important cause of lower back pain. The prevalence of a symptomatic herniated lumbar disc is about 1% to 3% with the highest prevalence among people aged 30 to 50 years, with a male to female ratio of 2:1. In individuals aged 25 to 55 years, about 95% of herniated discs occur at the lower lumbar spine (L4/5 and L5/S1 level); disc herniation above this level is more common in people aged over 55 years. Recurrent lumbar disc herniation (rLDH) is a common complication following primary discectomy.
C spine herniation, most common levels?
The cervical disc herniation is most affected 8% of the time and most often at level C5-C6 and C6-C7. Intervertebral disc-related pain can be caused by structural abnormalities, such as disc degeneration or disc herniation; correspondingly, biochemical effects such as inflammation can also be the cause
Herniation of the nucleus pulposus is responsible for radiculopathy in approximately 20-25% of cases. Disc herniation can result from degeneration or are precipitated by traumatic incidents such as lifting, etc.
The thoracic discs are affected only 1 - 2% of the time The upper two cervical intervertebral spaces, the sacrum, and the coccyx have no discs and therefore excluded for the risk of disc herniation.
Lateral VS medial disc herniation
Jung Hwan Lee etal. describes how lateral disc herniation (foraminal and extra foraminal) has clinical characteristics that are different from those of medial disc herniation (central and subarticular), including older age, more frequent radicular pain, and neurologic deficits. This is supposedly because lateral disc herniation mechanically irritates or compresses the exiting nerve root or dorsal root ganglion inside of a narrow canal more directly than medial disc herniation. The lateral group showed significantly larger proportion of patients with radiating leg pain and multiple levels of disc herniations than the medial group.
No significant differences were found in terms of gender proportions, duration of pain, pre-treatment NRS, severity of disc herniation, and presence of leg muscles’ weakness. The proportion of patients who underwent surgery was not significantly different between both groups. However, the proportion of patients who accomplished successful pain reduction after treatment was significantly smaller in the lateral than the medial group
Diagnostic Procedures
Straight Leg Raise Test: The SLR test is a test done during the physical examination. This test is a very accurate predictor of a disc herniation in patients under the age of 35. In patients older than 60 a suppression in the positivity of the tests can be found
Sensory loss: can be tested with light touch or a pin prick followed by classification on a three-point scale[34][35].
Anesthesia linked to dermatomes
Muscle weakness: testing of muscle groups and rating them om a five-point scale. Examples: testing of dorsiflexion ankle, hip abductors, flexion knee
Knee tendon reflex
Achilles tendon reflex
Finger-ground distance in centimeter
Scoliosis: this is a mechanism developed by patients to avoid pain. In patients with a disc herniation the same scoliosis pattern can be found, starting with a short curve at the lumbosacral region and a long curve in the thoracic or thoracolumbar region in the other direction. The herniation can be found in most cases in the direction of the first curve and on the other side of the accompanying trunk shift.
To differentiate between a structural scoliosis and a scoliotic posture, the Adams forward bend test can be used
Femoral nerve stretch test: found to be positive if the patient experienced radiating pain
