There are three types of joints –
These include the ball-and-socket
joints (e.g. hip) and the
hinge joints (e.g.
They possess a cavity and permit
the opposed cartilaginous
articular surfaces to move
painlessly over each other.
Movement is restricted to a
required range, and stability is
maintained during use. The load
is distributed across the
surface, thus preventing damage
by overloading or disuse.
Synovium and synovial fluid . The joint capsule, which is
to the periosteum, is lined with synovium which is a
few cells thick and vascular. Its surface is smooth and nonadherent
and is permeable to proteins and crystalloids. As
there are no macroscopic gaps, it is able to retain normal
joint fluid even under pressure. Macrophages and fibroblastlike
synoviocytes form the synovial layer by cell-to-cell interactions
mediated by cadherin-II. The synoviocytes release
hyaluronan into the joint space, which helps to retain fluid in
the joint. Synovial fluid is a highly viscous fluid secreted by
the synovial cells and has a similar consistency to plasma.
Glycoproteins ensure a low coefficient of friction between the
cartilaginous surfaces. Tendon sheaths and bursae are also
lined by synovium.
• Rheumatoid Arthritis (RA) is a chronic, autoimmune,
inflammatory systemic disease of unknown etiology
characterized by persistent joint
inflammation(chronic symmetrical polyarthritis) that
results in progressive joint destruction, joint
deformity, and physical disability. RA may affect other
organs and may also result in an increased risk for
premature death. The average life expectancy of RA
patients is decreased by 3 to 18 years compared to age
and gender matched controls. Because it can affect
multiple organs of the body, rheumatoid arthritis is
referred to as a systemic illness and is sometimes called
Rheumatoid arthritis is a chronic
disease, characterized by periods
of disease flares and remissions.
The cause of rheumatoid
arthritis is not known.
In rheumatoid arthritis, multiple
joints are usually, but not always,
affected in a symmetrical pattern.
Rheumatoid arthritis can affect
people of all ages.
Damage to joints can occur
early and does not correlate with
the severity of symptoms.
The "rheumatoid factor" is an
antibody that can be found in the
blood of 80% of people with
A joint is where two bones meet to allow movement of body parts. Arthritis
means joint inflammation. The joint inflammation of rheumatoid arthritis
causes swelling, pain, stiffness, and redness in the joints. The inflammation
of rheumatoid disease can also occur in tissues around the joints, such as
the tendons, ligaments, and muscles.
In some people with rheumatoid arthritis, chronic inflammation leads to the
destruction of the cartilage, bone, and ligaments, causing deformity of the
joints. Damage to the joints can occur early in the disease and be
progressive. Moreover, studies have shown that the progressive damage to
the joints does not necessarily correlate with the degree of pain, stiffness, or
swelling present in the joints.
Rheumatoid arthritis is a common rheumatic
disease, affecting approximately 1.3 million
people in the United States, according to
current census data. The disease is three
times more common in women as in men. The
high in the Pima Indian population and low
in black Africans
and Chinese people. The disease can begin at
any age, but it most often starts after age 40
and before 60. In some families, multiple
members can be affected, suggesting a genetic
basis for the disorder.
The cause of rheumatoid arthritis is
unknown.. It is believed that the tendency
to develop rheumatoid arthritis may be
genetically inherited (hereditary). It is
suspected that certain infections or factors
in the environment might trigger the
immune system to attack the body's own
tissues; resulting in inflammation in various
organs of the body such as the lungs or eyes.
Environmental factors also seem to play
some role in causing rheumatoid arthritis.
For example, scientists have reported that
smoking tobacco increases the risk of
developing rheumatoid arthritis.
Genetic and environmental factors play a part.
Gender. Women before the menopause are affected
three times more often than men. After the menopause
the frequency of onset is similar between the sexes,
suggesting an etiological role for sex hormones. The use
of the oral contraceptive pill
has shown no affect on RA overall, as previously
thought, but it may delay the onset of disease.
Familial. The disease is familial with an increased
incidence in first degree relatives and a high
concordance amongst monozygotic twins (up to 15%)
and dizygotic twins (3.5%). In occasional families it
affects several generations.
Genetic factors are estimated to account for up to 60%
of disease susceptibility.
There is a strong association
between susceptibility to RA and certain HLA
haplotypes. HLA-DR4, which occurs in 50–75% of
patients, correlates with a poor prognosis, as does
Individuals with HLA-DRB1 combined with a positive
factor are13 times greater risk
for developing bone erosions in early disease.
Rheumatoid arthritis is typified by widespread persisting
synovitis (inflammation of the synovial lining of joints, tendon
sheaths or bursae). The cause of this is unclear, but the
production of rheumatoid factors (RFs) by plasma
cells in the synovium and the local formation of immune
complexes play a part. The synoviocytes play a central role
in synovial inflammation. In RA the synovium becomes
greatly thickened to the extent that it is palpable as a ‘boggy’
swelling around the joints and tendons. There is proliferation
of the synovium into folds and fronds, and it is infiltrated by
a variety of inflammatory cells, including polymorphs,
and lymphocytes and plasma cells. There are disorganized
lymphoid follicles. The normally sparse surface layer of lining
cells becomes hyperplastic and thickened. There is marked
vascular proliferation. Increased permeability of blood vessels
and the synovial lining layer leads to joint effusions that contain
lymphocytes and dying polymorphs.
Typically :symmetrical swollen , painful, and stiffness of
small joint of hands & feet that worse in the morning. This
can fluctuate ,and large joint may become involve.
Less common : sudden onset ,widespread arthritis
.Systemic illness with extra -articular symptom; fatigue,
low-grade fever, wight loss, lack of appetite , pericarditis
and pleurisy, recurrent soft tissue problem ,polymyalgia
onset-vague limb aches.
When only one joint is involved, the arthritis can mimic
the joint inflammation caused by other forms of
arthritis, such as gout or joint infection. Chronic
inflammation can cause damage to body tissues,
including cartilage and bone. This leads to a loss of
cartilage and erosion and weakness of the bones as well
as the muscles, resulting in joint deformity, destruction,
and loss of function. Rarely, rheumatoid arthritis can
affect the cricoarytenoid joint. When this joint is
inflamed, it can cause hoarseness of the voice.
•intrinsic plus deformity
•swan neck deformity
•ulnar deviation (towards the little finger) of the fingers
•Type 1 is a boutonniere deformity; it is most common
•Type 2 is a flexion deformity of metacarpo-phalangeal with
extension of inter-phalangeal joint
•Type 3 is a swan neck deformity; second most common
•Type 4 is abduction of the proximal-phalanx and adduction
of the metacarpal.
•dorsal (backward) dislocation of the ulna bone
•ulnar shifting of the wrist bones
•radial shifting (towards the index finger) of the metacarpals
Caused by the tightness of
the intrinsic muscles
(interossei and lumbrical
muscles) of the hand. When
joint is extended it is not
possible to flex the
proximal inter- phalangeal
Swan neck deformity is a
condition in which the distal
joint (behind the nail) of the
finger goes into flexion and the
proximal joint goes into
Is caused by the stretching of the collateral ligaments of
the metacarpo-phalangeal joints
stretching of the accessory ligaments causing the ulnar
drifting of the flexor tendons
contracture of the intrinsic muscles of hand
ulnar deviation or rupture of the extensor tendons.
Boutonniere deformity is a condition in which the
proximal joint (away from the knuckle joint) of the
finger goes into flexion and the distal joint goes into
Since rheumatoid arthritis is a systemic disease, its inflammation can
affect organs and areas of the body other than the joints. Examples of
other areas that may be affected include:
Sjogren's syndrome is
inflammation of the glands of the
eyes and mouth and causes dryness
of these areas.
Rheumatoid inflammation of the
lung lining (pleuritis) causes chest
pain with deep breathing or
Tissue inflammation surrounding
the heart, called pericarditis, can
cause chest pain that typically
changes in intensity when lying
down or leaning forward.
Rheumatoid disease can reduce the
number of red blood cells (anemia) and
white blood cells.
Decreased white cells can be
associated with an enlarged spleen
(Felty's syndrome) and can increase the
risk of infections.
Firm lumps under the skin
(rheumatoid nodules) can occur around
the elbows and fingers where there is
A rare and serious complication is
blood-vessel inflammation (vasculitis).
Vasculitis can impair blood supply to
tissues and lead to tissue death. This is
most often initially visible as tiny black
areas around the nail beds or as leg
Complications of the condition
oRuptured joints (Baker’s cysts)
oSpinal cord compression (atlantoaxial or upper cervical
oSide-effects of therapy
This is a serious complication with significant morbidity and
mortality. Affected joints are hot and inflamed with accompanying
fever and a neutrophil leucocytosis in the blood.
However, these signs are often absent, and any effusion,
particularly of sudden onset, should be aspirated. Staphylococcus
aureus is the most common organism. Blood cultures
are often positive. Treatment is with systemic antibiotics and drainage.
Complications of the condition
Amyloidosis is found in a very small number of people with
severe rheumatoid arthritis. RA is the most common cause
of secondary AA amyloidosis. AL amyloidosis causes a polyarthritis
that resembles RA in distribution and is also often
associated with carpal tunnel syndrome and subcutaneous
AA amyloidosis is secondary amyloidosis
AL amyloidosis primary amyloidosis
ATTR amyloidosis the most common form of familial amyloidosis,
associated with mutations of the gene encoding transthyretin.