SYNOVIUM AND ASSOCIATED PATHOLOGIES
PRESENTER : Dr. ABHISHEK GAUTAM
MENTOR :DR RAJEEV GARG(SR)
MODERATOR :DR RAJENDRA(AP)

Synovial joint

SYNOVIUM:
• The synovium is a specialized
connective tissue that lines synovial
joints, forms the lining of bursae and
fat pads.
• In synovial joints, the synovium
membrane with outer fibrous layer
form joint capsule that seals the
synovial cavity and fluid from
surrounding tissues.
• The synovium membrane is
responsible for the maintenance of
synovial fluid volume and
composition, mainly by producing

• Through the synovial fluid, the synovium also
aids in articular cartilage has no intrinsic
vascular or lymphatic supply
• Histologically synovial tissue may be fatty,
fibrofatty or fibrous and contains type 1 and
type 3 collagen

LAYERS OF SYNOVIUM:
Synovium has normally have two layers
The inner layer intima lies next to the
joint cavity and consists of a layer of 1–4 cells only 20–
40 μm thick
The outer layer, or subintima, is up to 5 mm thick
and consists of multiple types of connective tissues:
Fibrous (dense collagenous type)
Adipose (found mainly in fat pads)
Areolar (loose collagenous type)
This layer is rich in type I collagen and microvascular
blood supply, accompanied by lymphatic vessels
and nerve fibres, but is relatively acellular

Cross section of joint capsule

COMPOSITION
• vascularized connective tissue is porous and lacks
basement membrane
• CELL TYPES:
• TYPE A cells -
• derived from macrophages
• non-fixed cells with antigen presenting ability
• located in superficial layer
• important in phagocytosis

• TYPE B cells
• fibroblast like cells
• rich rough endoplasmic reticulum and dendritic processes
that reach out to the joint surface
• located at various depths, frequently in deeper layer
• produce synovial fluid
• produce hyaluronic acid, fibronectin , collagen
• TYPE C cells
• intermediate cell type
• unknown function and origin
• may serve as multi-potent precursor to either type A or B
synovial cell

FUNCTIONS OF SYNOVIUM
• Secretion of synovial fluid for lubrication of
the joint
• Phagocytosis of waste material derived from
the various components of the joint
• Regulation of the movement of solutes ,
electrolytes and proteins from the capillaries
into the synovial fluid.

SYNOVIAL FLUID
• It is an ultra dialysate of plasma to which
proteoglycans have been added by local synthesis
from the joint tissue regulated by synovium
• Healthy knee contains-2ml of synovial fluid
• Consists of HYALURONIN and LUBRICIN
• Functions ????

• HYALURONIN: uridine diphosphoglucose
dehydrogenase enzyme critical for its
synthesis
• LUBRICIN: a key lubricating glycoprotien
reduces coefficient of friction within the joint
• Proteinase
• Collagenases
• prostaglandins

• BIOMECHANICS:
• Synovial fluid exhibits non-newtonian flow
characteristics
• The viscosity coefficient is not a constant
• The fluid is not linearly viscous
• Viscosity increases as the shear rate decreases

SYNOVIAL DISORDERS
• INFECTIVE: SEPTIC ARTHRITIS
Tuberculosis,
Syphilitic
• INFLAMMATORY: Rheumatoid arthritis
Gouty arthritis ,
Tenosynovitis.
• TRAUMATIC: Traumatic synovitis
• DEGENERATIVE: Synovial cyst,
Osteoarthritis
• TUMOURS: Pigmented villo nodular synovitis , synovial
chondromatosis , synovial haemangioma, hoffa’s disease and
synovioma.

SEPTIC ARTHRITIS
 Septic arthritis is the inflammation of a joint due to an infection usually
involving the synovial membrane.
 The infections occurs as the pathogens travel through the blood stream from
another part of the body.
 It can also occur through penetrating injuries
to the joint , During intraarticular injection ,iatrogenic
 A surrounding infection in the bone or tissue(from osteomyelitis, septic bursitis,
abscess)
 Knees are the most commonly affected joints followed by hip shoulder and
other joints
 Most common (50 %) in children less then 3 years

PATHOPHYSIOLOGY

CLINICAL FEATURES

INVESTIGATION,MANAGMENT
InvestigaExplaination
Full blood count
ESR
CRP
Blood culture
Usg
Arthocentesis
MANAGEMENT
ANTIBIOTIC 6 WEEKS
JOINT DRAINAGE AND LAVAGE

TUBERCULAR SYNOVITIS
• SKELETAL TB ACCOUNTS FOR 10 TO 35 PERCENT OF CASES OF
EXTRAPULMONARY TUBERCULOSIS
• SKELETAL TB GENERALLY OCCURS DUE TO HEMATOGENOUS
SPREAD FROM A PRIMARY FOCUS
● COEXISTING PULMONARY TB IS SEEN IN APPR.50%
CASES
Most common involved spine ,hip ,knee
SPINE>HIP>KNEE

SYNOVIAL MEMBRANE(SM)
GETS CONGESTED,
EDEMATOUS & STUDDED WITH
TUBERCLES
NAKED EYE EXAMINATION: PINKISH
BLUE/GREY APPERANCE.
SM BECOMES HYPERTROPHIED &
THICKENED W GRANULATION
TISSUE
PATHOPHYSIOLOGY OF TUBERCULAR SYNOVITIS

CLINICAL TYPES
TWO CLINICAL TYPES:-
SYNOVIAL GRANULAR –IN CHILDREN JOINT IS
PREDOMINATELY INVOLVED AND DISEASE IS MILD
,NON DESTRUCTIVE AND FIBROSING
SYNOVIAL EXUDATIVE –ACUTE INTENSE
INFLAMMATORY ,DESTRUCTIVE AND ABSCESS
FORMING
INVESTIGATION –
CBC
TUBERCULIN TEST
CULTURE
BIOPSY
PCR
X RAY
USG

X-RAY FINDINGS

WHAT ARE RICE BODIES?
• INTRA-ARTICULAR RICE BODY FORMATION
CAN OCCUR IN CHRONIC INFLAMMATORY
DISEASES SUCH AS RA, TB ARTHRITIS,
CHRONIC FUNGAL INFECTIONS, SYNOVIAL
CHONDROMATOSIS, PIGMENTED
VILLONODULAR SYNOVITIS, GOUT, OR
SYSTEMIC LUPUS ERYTHEMATOSUS
• RICE BODIES ARE MAINLY FORMED OF
FIBRIN AND ARE SEEN IN RELATION TO
JOINTS, BURSA OR TENDON SHEATHS
• RICE BODIES ARE NON-SPECIFIC FINDINGS
IN CHRONIC INFLAMMATION THAT ARISE
FROM MICROINFARCTIONS WITH
SYNOVIAL SHEDDING ENCAPSULATED BY
FIBRIN

SYNOVIUM IN OSTEOARTHRITIS

2. SYNOVIUM IN RHEUMATIC ARTHRITIS
• RA IS CHRONIC INFLAMMATORY AUTOIMUUNE DISEASE THAT
AFFECT ALL JOINTS SYMETRICALLY,INITIALLY COUPLE OF
JOINTS THEN PROGRESS TO OTHER JOINTS
• COMMONLY IN WRIST,HAND,ELBOW,SHOULDER ,KNEE AND
ANKLE
• RA IS PRIMARILY A SYNOVITIS WHERE IMMUNOLOGICAL
RESPONSE TAKE PLACE IN SYNOVIAL TISSUE

CLINICAL FEATURES
Early stages of disease
⚫Pain
⚫Stiffness (mostly in morning lasts for
30 minutes to several hours)
⚫Swelling
In metacarpophalangeal joints of fingers
In proximal interphalangeal joints of
fingers
In interphalangeal joints of thumb
In metatarsophalangeal joints
In joints of wrist

Late stages of disease
⚫ Boutonniere deformity of thumb
⚫ Ulnar deviation of metacarpophalangeal joints
⚫ Swan-neck deformity of fingers
Other manifestations
⚫ Myalgia
⚫ Fatigue
⚫ Low grade fever
⚫ Weight loss
⚫ Depression
COCK UP TOE DEFORMITY
WALKING ON MARBLES
HALLUX VALGUS
HAMMER TOES
ACHILLES TENDINITIS
RHEUMATOID NODULES

PATHOLOGY
EXOGENEOUS ANTIGEN INTERECTS WITH LYMPHOCYTE
TRANSFORM INTO PLASMA CELL
PLASMA CELL PRODUCE ANTIBODIES
ANTIBODIES ,ANTIGEN AND COMPLEMENT COMPLEX IS FORMED
PHAGOCYTIC CELL ENGULF THESE COMPLEX AND LYSOSYMAL ENZYMES
DESTROY THESE COMPLEX
IN RA LYSOSYMES ESCAPE FROM PHAGOCYTIC CELL AND CAUSE PROTEASE
MEDIATED DISTRUCTION OF HYLINE CARTILAGE AND SYNOVIUM
MEMBRANE
THE INFLAMMED SYNOVIUM FORM PANNUS THAT GROW OVER AND
DESTROY CARTILAGE TENDON AND LIGAMENTS AND REPLACE WITH
FIBROUS TISSUE,IN RESPONSE TO IgG AUTOANTIBODIES IS SYNTHESIZED IN
RHEUMATOID SYNOVIAL TISSUE A/C/A RHEUMATOID FACTOR

• PERIARTICULAR
OSTEOPENIA
• MARGINAL EROSIONS
• SYMMETRICAL JOINT
NARROWING IN LARGE
JOINTS

3.GOUT
Metabolic disease characterized by Monosodium urate crystal deposition
within or around joints which results in inflammation in joints and
surrounding tissue.
• Clinical appearance:
• Acute inflammatory arthritis
• Hyperuricemea
• Uric acid nephrolithiasis
Commonly mono-articular (primarily affects metatarso-phalangeal joint (MTP)
of big toe)
• Other locations for urate crystal deposition
• Elbows
• Knees
• Feets
• Ear pinna (helix of the ear)
• Etiology: Hyperuricemia (blood uric acid level > 6.8 mg/dl)
• Hyperuricemia is a condition when blood serum uric acid level gets
increased
• Normal plasma uric acid level
• male: 3-7 mg/dl, Female: 2-6 mg/dl

• Uric acid is product of purine metabolism
• Gout is of two types –
• Primary gout
• Secondary gout-
• Pernicious anemia
• Hemolyic anemia
• Polycythemia
• LEUKEMIA
• ANTICANCER THERAPY
• STAGES
• Stage 1: Asymtomatic hyperuricemia
• Stage 2: Acute gout attacks
• Stage 3 : Intercritical period
• Stage 4: Chronic tophaceous gout

Pathology
• Sodium urate is deposited as crystals on the surface of
articular cartilage.
• Then articular cartilage is eroded
• The subchondral bone is replaced by crystaline
deposit.(tophii)
• A pannus of granulation tissue grows over the
articular surface, invades and replaces the cartilage .
• Then granulation tissue bridges the joint to the opposite
articular surface and producing fibrous ankylosis

RADIOLOGY

5.SYNOVIAL CYST
• SYNOVIAL CYST FORMATION OCCUR MAINLY IN
DEGENERATIVE LUMBAR JOINTS
• OTHER SITES KNEE SHOULDER AND HIP JOINT
• IN SPINE EXTRA SPINAL OR INTRASPINAL
• INVESTIGATION OF CHOICE –MRI ENHANCED WITH
GADOLINIUM CONTRAST –OUTLINE THE RIM OF CYST

6.PIGMENTED VILLONODULAR SYNOVITIS
⚫ Pigmented Villonodular Synovitis (PVNS) is a slow growing
tumor lesion of uncertain etiology arising from the synovial
membrane, characterized by pigmented villous and nodular
outgrowths of the synovial membrane of the bursae or
tendon sheath. Yellow brown pigment is due to deposition
of hemosiderin and cholesterol
⚫ Since bursae and tendon sheaths are related to synovium in
origin, they too are sites of xanthomatous growth
⚫ It is a reactive condition, and not a true neoplasm
⚫ Recurrentatraumatic hemarthrosis is a characteristic
feature
⚫ Often aggressive, with marked extra-articular extension

TYPES:- INTRA AND EXTRA-ARTICULAR
INTRAARTICULAR
⚫ Monoarticularinvolvement( mostcommon),
mimicking arthritis
⚫Localized form
⚫ Focal involvement of the synovium
⚫ Nodular/ sessile or pedunculated well circumscribed
masses common in hands
⚫Diffuse form
⚫ More common and in large joints
⚫ Affect virtually the entire synovium
⚫ knee > hip > shoulder

Pathophysiology
• Chocolate colored mass with yellowish red colored pigment over a
base of fibrous tissue
• The mass is spongy in consistency
• Thickened synovium with either nodular or villous proliferation
• Villi is coarse (carpet like ) or fine (firn like )
• Nodular form is seen in extra-articular lesions /tendinous lesions
which can be sessile or pedunculated
• Pvns invade local tissue ,invade subchondral bone with resultant
cyst formation
HISTOPATHOLOGY
⚫ Synovium looks like a “shaggy carpet”
⚫ Histiocytes
⚫ lipid laden macrophages
⚫ hemosiderin containing cells
⚫ frequent giant cells
⚫ Subsynovial nodular proliferation of large round, polyhedral
or spindle cells with prominent cytoplasm and pale nuclei

CLINICAL FEATURES
Symptoms
⚫ Pain: 80%
⚫ Swelling: 75%
⚫ Stiffness
⚫ Locking
⚫ catching
⚫ Instability
⚫ Palpable mass: 12 %
Signs
⚫ Effusion – floating
patella
⚫ Tenderness
⚫ Decreased ROM
⚫ Usuallynot palpable; In
localised variety, can show a
joint mouse

INVESTIGATION
XRAY –NOT SPECIFIC
MRI- INVESTIGATION OF CHOICE
CT SCAN
ARTHROSCOPY
TREATMENT
SURGICAL /ARTHROSCOPIC EXCISION
ARTHROSCOPIC SYNOVECTOMY
RADIATION BEAM THERAPY AND RADIO ISPTOPE
SYNOVECTOMY
ADVANCE CASES TOTAL KNEE REPLACEMENT
The synovial surface of the knee joint (intraoperative photograph) is
diffusely nodular, tan-gold, and thickened, the typical appearance of
pigmented villonodular synovitis

SYNOVIAL OSTEOCHONDROMATOSIS
BENIGN CONDITION CHARACTERISED BY SYNOVIAL
MEMBRANE PROLIFERATION AND METAPLASIA OF
SYNOVIAL AND SUB-SYNOVIAL CONNECTIVE TISSUE
NODULAR PROLIFERATION OF SYNOVIAL LINING IN JOINT ,BURSA AND
TENDON SHEATH AND THAT NODULAR FRAGMENTS BREAK OFF INTO
THE JOINT AND IS NOURISHED BY SYNOVIAL FLUID
THE FRAGMENT MAY GROW ,CALCIFY OR OSSIFY AND VARY IN SIZE
MONOARTICULAR DISEASE
INVESTIGATION –XRAY,CTSCAN,MRI
FOR TRUE EXTENT OF DISEASE
TRAETMENT-SURGICAL REMOVAL
KNEE-ANTERIOR SYNOVECTOMY
DEPENDING ON LOOSE BODY POSITION
DIFFERENT TYPE OF INCISION GIVEN

HOFFA DISEASE
• INFRAPATELLAR FAT PAD SYNDROME
• POST TRAUMATIC REACTIVE CONDITION OF SYNOVIUM
• ANY JOINT CAN BE AFFECTED ARKED PAPILLARY YELLOW FAT
• GROSS APPEARANCE- MARKED PAPILLARY YELLOW FATTY
• MICROSCOPICALLY-MILD SYNOVIUM HYPER PLASIA WITH
ABUDENT FAT CELL
• TREATMENT –SURGICAL REDUCTION OF VOLUMEEE

SYNOVIOMA
• SYNOVIAL SARCOMA,SYNOVIAL SARCOMESOTHELIOMA
• ACCOUNT FOR 8 % OF ALL SOFT TISSUE SARCOMA
• TUMOR CAN ARISE FROM INTIMA OR SUBINTIMA LAYER
• GROSSLY TUMOR IS ROUNDED LOBULATED AND GROWS
EXPANSIVELY
• MICROSCOPIC –THREE PATTERN
• 1 FORMATION OF TISSUE SPACE
2 FORMATION OF CELL TUFT
3 EPITHELIAL LIKE CELL ON SUPPORTING
STROMA
CLASSIFICATION ON MORPHOLOGICAL APPEARANCE
BIPHASIC(SPINDLE+EPITHELIAL)
MONOPHASIC (SPINDLE ONLY)

THANK YOU