1- Anatomy of cartilage
Cartilage is a form of thick connective tissue: sturdy and viscoelastic.
The ends of bones are covered with it, which creates a low-friction
environment and cushioning at the joint surface. When the joint cartilage
is healthy, it allows for smooth bending movements and protects the joint
from weight-bearing forces. The creation of some bodily components,
some of which are totally formed of cartilage, such as the outer portions
of the ear and the ends of long bones, cartilage in infants that eventually
transforms into bones.
Cartilage acts as a protective cushion between the bones, absorbing
the pressure applied to the joints during movement. It made of a complex
of specialized cells called chondrocytes; its function is to create
extracellular collagen, proteoglycans, and elastic fibers. The collagen
protein bundles which known as ‘sponge’, form a reticular network that
contains water, when a weight is applied to the cartilage, the water is
squeezed out and exits the network, and when the pressure is released, the
water returns. The proteoglycans bind water and serve as a foundation for
the absorption of strong compressive stresses. Providing elasticity and
resilience to the tissues is what elastic fibers do in cartilage.
It's worth mentioning that cartilage is completely devoid of blood
vessels and nerves.
It is distributed evenly throughout the body, including the spaces
between the vertebrae of the spine, bronchial tubes or airways, the ends
of the ribs, the ears, and the nose.
Cartilage is divided into three types:
firstly, elastic cartilage is the most flexible and adaptable form of cartilage
due to its high concentration of yellow elastin fibers, thus the name yellow
cartilage. The auricles, some portions of the nose, throat, and epiglottis
are mostly composed of elastic cartilage. Secondly, Fibrous cartilage is
the strongest form of cartilage, capable of supporting enormous loads in
addition to decreasing friction between the long bones in the joints.
Additionally, it is present between the spine's discs and vertebrae, as well
as between the hip and pelvic bones. Lastly, Hyaline cartilage which is a
tough, flexible, contractile, and stretchy kind of cartilage found between the ribs,
around the trachea, and in joints.
2- Cartilage diseases:
Osteoarthritis and Spondylolysis
Minor cartilage injuries may heal on their own within a few
weeks, but more serious cartilage damage may need surgery in
the future. It may be harmed as a consequence of a traumatic
injury, such as a sports injury, or as a result of progressive wear
and tear. Patients who have cartilage damage in a joint may suffer
the following symptoms:
• Inflammation the region expands, gets warmer than
surrounding areas, and becomes sensitive, sore, and painful.
• Stiffness, and Range restriction - as the injury worsens, the
injured limb loses its ability to move freely and effortlessly.
- Osteoarthritis
OA is a condition that is sometimes referred to as degenerative
joint disease. It is a degenerative disorder in which the protective
cartilage that cushions the tops of bones degrades or wears away.
This results in swelling and discomfort. Additionally, it may
result in the formation of osteophytes, or bone spurs.
Osteoarthritis of the spine is a degeneration of the cartilage in the
neck and lower back joints and discs. Occasionally, osteoarthritis
results in spurs that push on the nerves exiting the spinal column.
This might result in arm or leg weakness and discomfort.
Osteoarthritis is a progressive condition with five stages, from 0
to 4. The first stage (0) corresponds to a normal joint. Stage 4 is
the most advanced stage of OA. Not everyone with OA will go to
stage 4. Often, the illness stabilizes well before it reaches this
stage. Severe OA patients have substantial or total cartilage loss
in one or more joints. The resulting bone-on-bone friction may
result in severe symptoms such as:
o Inflammation and edema: the synovial fluid level may rise.
Ordinarily, this fluid aids in reducing movement friction. It
may induce joint swelling in excessive doses. Synovial fluid
contains broken-off cartilage fragments, enhancing
discomfort and edema.
o Pain intense: you may have discomfort when moving or
sitting. In case you utilized your joints a lot during the day,
Osteoarthritis
you may notice a rise in joint swelling or soreness as the day
goes on.
Limitation of movement: joint stiffness or soreness may
limit your ability to move. Difficulty in daily tasks might be
a result of chronic pain.
o Unstable joints: your joints may lose stability; as an
example, severe knee OA might cause locking (sudden lack
of movement). If your knee buckles, you risk falling and
being hurt.
It is a common occurrence as individuals age. Men are more likely
to get osteoarthritis than women under the age of 45. Women are
more likely to get osteoarthritis after the age of 45. Osteoarthritis
is more prevalent in obese individuals. Additionally, it happens
more commonly in persons who work in occupations or
participate in activities that place repeated stress on certain joints.
Osteoarthritis is a slow-developing illness that is difficult to
identify until it causes pain or disability. Early OA is commonly
detected after a fracture that necessitates an X-ray. Your doctor
may utilize an MRI scan to diagnose OA. The picture of bone and
soft tissue is created using radio waves and magnetic fields. A
blood test can rule out other illnesses that cause joint discomfort,
such as RA. An examination of joint fluid may also reveal if the
inflammation is due to gout or infection.
X-rays are the best approach to diagnose osteoarthritis. The
doctor will ask about your medical history and do a physical exam
to discover whether you have neck or lower back discomfort,
soreness, loss of mobility, or indications of nerve involvement
including weakening, reflex changes, or loss of feeling.
The majority of the time, therapy for spinal osteoarthritis
focuses on alleviating pain sensations and improving a person's
capacity to function. The objective is to maintain a healthy
lifestyle. Initial therapy may involve weight loss if necessary and
then maintaining a healthy weight for everyone. Additionally,
physical activity may be added. Apart from aiding in weight loss,
exercise may also aid in improving adaptability. Improve one's
attitude and mood, strengthen the heart's defenses, and boost
blood flow, and simplify routine tasks.
-Spondylolysis
Spondylolysis is a weakening or stress fracture in one of the bone
bridges connecting the vertebra's upper and lower facet joints. It is the
most prevalent cause of low back pain in children and adolescents who
participate in sports. Spondylolysis is a kind of stress fracture that occurs
when the pars interarticularis is subjected to mechanical stress. Stress
fractures are more likely to form as a result of recurrent load and stress
than as a result of a single traumatic incident. In extension and rotation
motions, the stress distribution in the pars interarticularis is greatest. Half
of all pediatric and teenage back pain in athletes is caused by different
posterior element abnormalities, including spondylolysis. Low back pain
is the most prevalent clinical manifestation of spondylolysis. This is
exacerbated by exercise and is usually accompanied with a lack of
physical findings or none at all. Pars stress fractures and early
spondylolysis are prevalent, and often misdiagnosed.
Historically, patients were often advised to minimize their activities
(particularly involvement in sports and physical exercise) in order to
prevent aggravating the spondylolysis. However, fresh information from
sophisticated imaging tests and current research shows that decreased
activity and/or rest may not always be essential to prevent the
spondylolysis from sliding. Rest is required only if the patient develops
symptoms. Rest may assist alleviate discomfort, and after the pain has
subsided, the patient can resume regular activities.
Spondylolysis occurs in 3-6% of the population. It often manifests in
the first or second decade of life; its prevalence rises with age up to 20
years. However, there is no change in occurrence as one ages from 20 to
80 years. Men are twice as likely to be impacted as women
There may be
Spondylolysis
a hereditary predisposition for individuals with reduced cortical bone
density in the pars interarticularis. Specific ethnic, sports, and familial
groupings have a higher occurrence. Spondylolysis is more prevalent in
young athletes. Gymnasts, football players, cricketers, swimmers, divers,
weight lifters, and wrestlers are at an elevated risk.
Spondylolysis develops most often at L5 (80%–95%) as a result of
repeated hyperextension, which increases contact between the caudal
edge of the inferior articular facet of L4 and the pars interarticularis of L5.
Spondylolysis is often associated with a weakening in the pars inter
articularis. This tiny bone fragment joins the facet joints, which connect
the vertebrae immediately above and below to create a functional unit that
allows the spine to move. The fissures are sometimes referred to as pars
fractures.
While we do not know why the deficiency arises, it is possible that your
genes have a part. You may be born with fragile vertebrae, increasing your
chance of pars fractures. Repetitive stress to the lower back — such as
hurting oneself repeatedly while participating in sports or other activities
— may also weaken the pars inter articularis.
Spondylolysis and spondylolisthesis are synonymous but distinct
conditions: spondylolisthesis occurs when one vertebra slides over the one
below but, spondylolysis is a frequent cause of spondylolisthesis, since
the bone may slide due to the break in the vertebra.
Surgery
Adolescents with lumbar spondylolysis may have surgery. A robust
titanium screw may heal the fracture. An incision of 2 to 3 inches is made
in the center of the lower back. The screw secures the two sides of the
fracture together, producing compression. Then a bone transplant (bone
from another part of the body) might help support the restoration.
The procedure takes three hours, and the recuperation takes two or three
days. Most teenagers require two to four weeks off school to heal at home.
Sports and strenuous exercise are prohibited for three months. This
operation effectively relieves spondylolysis-related back discomfort.
Most individuals can resume normal sports and activity without
discomfort. If spondylolysis has caused your vertebrae to move forward,
your doctor may propose a surgical surgery like spinal fusion.
Diagnose
The combination of SPECT and computed tomography is the gold
standard for diagnosing spondylolysis (CT). Computed tomography may
clearly reveal spondylolysis in the presence of a pars fracture. The neural
arch should be closed and continuous at the level of the pedicles on axial
CT images. When a pars defect occurs, a discontinuity occurs at this level.
Sagittal CT scans are more reliable at differentiating between a pars defect
and a facet joint and also in detecting partial fractures. While MRI has
shown promise in diagnosing spondylolysis, it may also be used to assess
the condition of the disc above and below the afflicted vertebra.
Frequently, teenagers are withdrawn from sports due to worries that
their spondylolysis would progress to spondylolisthesis (vertebral
slippage) and that the slippage may become severe enough to cause
irreversible injury or paralysis. Adults diagnosed with spondylolysis are
often advised to abstain from strenuous activity and/or physically
demanding professions. However, there are no cases in the published
medical literature of a patient in a work, industrial, or sports-related
context experiencing trauma that caused the spondylolisthesis to slide
further and result in neurological impairment or paralysis. Sophisticated
imaging methods such as single-photon emission computed tomography
(SPECT) bone scans and magnetic resonance imaging (MRI) spine scans
now enable the evaluation of spondylolysis-related physiological
alterations. This information is critical in determining the difference
between active and passive spondylolysis.
A SPECT scan demonstrates active spondylolysis, while an MRI
scan demonstrates bone marrow edema next to the pars defect. These data show that the pars defect is connected with activity/movement, which is
likely to result in low back pain complaints. Spondylolysis that is not
active. If there are no signs of activity associated with the pars defect, the
spondylolysis is deemed inactive and any low back pain the patient is
having is most likely incidental (meaning that the patient's lower back
discomfort is most likely due to another cause, such as a muscle strain).
While activity limitation is not always essential, it is usually prudent
to treat spondylolysis carefully. Acute (active) spondylolysis needs more
intense care, although chronic (inactive) spondylolysis symptoms may be
handled conservatively.
