Download Bone and joint diseases

Manar Hajeer, MD, FRCPath
University of Jordan, school of medicine





Degeneration……..osteoarthritis
Immune-mediated injury……rheumatoid arthritis.
Metabolic derangements……gout and pseudogout.
Infections…….infectious arthritis
Neoplasms.





Degenerative joint disease.
Most common joint disorder.
Part of aging.
Physical disability over the age of 65.
Degeneration of articular cartilage; any structural
changes in the underlying bone are secondary.



Friction free movement along with the synovial fluid.
Spreads the load across the joint surface so underlying
bones can absorb shock and weight.
OA is not exclusively a wear-and-tear phenomenon, but
mechanical stresses and aging figure prominently.
Genetic factors also seem to contribute to osteoarthritis
susceptibility.




Insidiously with age, without initiating cause (primary
osteoarthritis).
In youger patients, predisposing conditions: previous
traumatic injury, developmental deformity, or systemic
disease such as diabetes, hemochromatosis, or marked
obesity (secondary osteoarthritis)
knees and hands are more commonly affected in
women.
Hips are more commonly affected in men.




Earliest changes :increasing water content of the
cartilage with decreasing elasticity.
Vertical and horizontal fibrillation and cracking occur in
the superficial layers of the cartilage
Full-thickness portions of the cartilage are lost.
Subchondral bone is exposed.

Small fractures can dislodge pieces of cartilage and
subchondral bone into the joint, forming loose bodies
(joint mice).

Mushroom-shaped osteophytes (bony outgrowths)
develop at the margins of the articular surface.

No fusion of bone.






Insidious disease
Predominantly 50s and 60s.
Deep, aching pain exacerbated by use, relieved by rest.
Morning stiffness, crepitus , and limited range of movement.
Osteophyte impingement on spinal foramina can cause nerve root
compression with radicular pain, muscle spasms, muscle atrophy,
and neurologic deficits.
Hips, knees, lower lumbar and cervical vertebrae, proximal and
distal interphalangeal joints of the fingers, first
carpometacarpal joints, and first tarsometatarsal joints of the
feet are commonly involved

Heberden nodes in the fingers: prominent osteophytes at the
distal interphalangeal joints, are characteristic in women.

No predicted way to prevent progression of primary
osteoarthritis.
Can stabilize for years but is generally slowly progressive.
With time, significant joint deformity can occur, but unlike
rheumatoid arthritis , fusion does not take place








Chronic autoimmune inflammatory disorder.
Primarily affecting small joints of the hands and feet.
Joints producing a proliferative synovitis that often
progresses to destruction of the articular cartilage.
3:1 to 5:1 , female to male ratio.
Peak incidence: second to fourth decades of life.
No age is immune.






Symmetric arthritis.
Small joints of the hands and feet, ankles, knees,
wrists, elbows, and shoulders.
Typically, the proximal interphalangeal and
metacarpophalangeal joints are affected.
Distal interphalangeal joints are spared.
Axial involvement limited to upper cervical spine;
similarly.
Hip joint involvement is extremely uncommon.



Chronic synovitis,
Periarticular soft tissue edema usually develops
(fusiform swelling of the proximal interphalangeal
joints).
With progression, the articular cartilage is eroded and, in
time, virtually destroyed.

Subarticular bone may be attacked and eroded.

XRAY hallmarks: joint effusions , juxta-articular osteopenia,
narrowing of the joint space and loss of articular cartilage.

Destruction of tendons, ligaments, and joint capsules>>>joint
deformities:

Radial deviation of the wrist.
Ulnar deviation of the fingers.
Flexion-hyperextension abnormalities of the fingers (swan-neck
deformity, boutonnière deformity).



Rheumatoid subcutaneous nodules: 25% of patients, along
extensor surface of the forearm or areas subjected to mechanical
pressure. Rarely in the lungs, spleen, heart, aorta.

Rheumatoid nodules are firm, non-tender, oval or rounded masses
as large as 2 cm in diameter.

80% of patients have serum autoantibodies, called rheumatoid
factor (RF).
1.
2.
3.
4.
5.
6.
7.

Severe joint pain and morning stiffness.
Arthritis in 3 or more joint areas.
Arthritis of small hand joints.
Symmetric arthritis.
Rheumatoid nodules.
Serum rheumatoid factor.
Typical radiographic changes
At least four features are needed for the diagnosis.



Constitutional symptoms: weakness, malaise, and low-grade fever.
Joints enlarged, motion limited, complete deformities may appear.
Sterile, turbid synovial fluid.




Microorganisms of any type can lodge in joints during :
(1)hematogenous dissemination.
(2)contiguous spread from osteomyelitis or a soft tissue
abscess.
Infectious arthritis is serious because it can cause rapid
joint destruction and permanent deformities.
Acute Suppurative Arthritis
 Bacterial in origin:
 Haemophilus influenzae predominates in children
under age 2 years.
 S. aureus is the main causative agent in older children
and adults.
 gonococcus is prevalent during late adolescence and
young adulthood.
 Individuals with sickle cell disease are prone to
infection with Salmonella at any age




Sudden onset of pain, redness, and swelling of the
joint with restricted range of motion.
Fever, leukocytosis, and elevated ESR.
In 90% of nongonococcal suppurative arthritis, the
infection involves only a single joint-usually the kneefollowed in order by hip, shoulder, elbow, wrist, and
sternoclavicular joints.
Joint aspiration is typically purulent, and allows
identification of the causal agent.



Acquired diseases of bone (osteoporosis and
osteomalacia).
Osteomyelitis.
Bone tumors.




Acquired condition.
Reduced bone mass, leading to bone fragility and
susceptibility to fractures.
Osteoporosis occurs when the dynamic balance
between bone formation by osteoblasts and bone
resorption by osteoclasts tilts in favor of resorption.
Primary versus secondary forms.

Primary osteoporosis: most common and may be
associated with aging (senile osteoporosis) or the
postmenopausal state in women.

The drop in estrogen following menopause tends to
exacerbate the loss of bone that occurs with aging,
placing older women at high risk of osteoporosis
relative to men.




Bone mass peaks during young adulthood.
The greater the peak bone mass, the greater the
delay in onset of osteoporosis.
The bone loss, averaging 0.5% per year, is a seemingly
inevitable consequence of aging and is most prominent
in the spine and femoral neck.
Increase in the risk of fractures.




Hallmark is a loss of bone.
Osteoclastic activity is present but is not dramatically
increased.
Mineral content of the bone tissue is normal.
In senile osteoporosis, cortical bone loss is prominent,
predisposing to fractures in weight-bearing bones, such
as the femoral neck.



vitamin D deficiency.
Impairment of mineralization and a resultant
accumulation of unmineralized matrix.
Contrasts with osteoporosis, in which the mineral
content of the bone is normal and the total bone mass is
decreased.

Rickets :vitamin D defficiency in children, in which it
interferes with the deposition of bone in the growth
plates.

Osteomalacia: the adult counterpart, bone formed
during remodeling is undermineralized, resulting in
predisposition to fractures.



Osteomyelitis is defined as inflammation and
infection of bone and marrow.
Osteomyelitis can be secondary to systemic infection
but more frequently occurs as a primary isolated focus
of disease; it can be an acute process or a chronic
debilitating illness.
Any microorganism can cause osteomyelitis, the most
common etiologic agents are pyogenic bacteria and
Mycobacterium tuberculosis.





Acute osteomyelitis
Routes:
(1) hematogenous dissemination (most common);
(2) extension from an infection in adjacent joint or
soft tissue;
(3) traumatic implantation after compound fractures
or orthopedic procedures.



Staphylococcus aureus is the most frequent causative
organism;
Escherichia coli and group B streptococci are
important causes in neonates,
Salmonella is an common pathogen in persons with
sickle cell disease.



Osteomyelitis classically manifests as an acute
systemic illness, with malaise, fever, leukocytosis,
and throbbing pain over the affected region.
Symptoms also can be subtle, with only unexplained
fever, particularly in infants, or only localized pain in
the adult.
A combination of antibiotics and surgical drainage
usually is curative, but up to a quarter of cases do not
resolve and persist as chronic infections





In infants epiphyseal infection can spread into the
adjoining joint to produce suppurative arthritis,
Pathologic fracture,
Sepsis and endocarditis,
Rarely development of squamous cell carcinoma if the
infection creates a sinus tract,
Rarely osteosarcoma.