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2. Vertebral type : Slightly mo"able

!. Limb type: ,reely mo"able

-) Degree of Freedom : Number of a#es at $hich the bone in a

%oint can mo&e'

*he structural classification is most commonly followed.

FAT)"S

A' Fibrous Joints

1. $ones are #oined by fibrous tissue.

2. Are either immo"able or permit slight degree of mo"ement.*ypes:a) Suture peculiar to s%ull and are immo"able.

b) Syndesmosis. *he bones are connected by interosseous

ligament. (/ample is the inferior tibiofibular #oint.

c) Gomphosis 'peg and soc%et #oint). (/ample : tooth in its

soc%et.

*' Cartilaginous Joints

1. $ones are #oined by cartilage.*wo types:

a) rimary Cartilaginous !oints 'synchondrosis or hyaline

cartilage #oints). *he bones are united by a plate of hyaline

cartilage. *he #oint is immo"able and strong and temporary in

nature. e.g. Joint between epiphysis and diaphysis of a growing

long bone costochondral chondrosternal and sphenooccipital.b) Se"ondary Cartilaginous !oints'symphyses or

fibrocartilaginous #oints). *he articular surfaces are co"ered by

a thin layer of hyaline cartilage and united by a disc of

fibrocartilage. *hese #oints are permanent and typically occur in

the median plane of the body and permit limited mo"ements.

(/amples : Symphysis pubis manubriosternal and

inter"enterbral #oints.

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C' Sno&ial Joint

1. 0ost common in the body.

2. 0ost mobile type of #oints.!. *he articular surfaces are co"ered with hyaline

'articular) cartilage.

. Joint ca"ity filled with syno"ial fluid. *he ca"ity may

be partially or completely subdi"ided by an articular disc or

meniscus.

. *he #oint is surrounded by an articular capsule.

3. Syno"ial membrane line whole of the interior of the#oint e/cept for the articular surfaces.

4. Syno"ial fluid or syno"ia secreted by the cells of the

syno"ial membrane.

5. &apsular or true ligaments representing thic%enings ofthe fibrous capsule.

6. Accessory ligaments which may be intra or e/tra

capsular. (/amples : plane hinge condylar pi"otellipsoid saddle and ballandsoc%et #oints.

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Stabilit of (sno&ial! %oints:

Factors maintaining stabilit at a %oint

1.#us"les.*he tone of different groups of muscles acting on the #oint

is the most important and indispensable factor e.g. 7nee shoulder

#oint.

2. 8igaments are important in pre"enting any o"ermo"ement and in

guarding against sudden accidental stresses.

!.$ones. elp in maintaining stability only in firm type of #oint li%ethe hip and an%le.

*lood su++l of sno&ial %oint:

*he articular and epiphysial branches gi"en off theneighbouring arteries form a periarticular arterial ple/us in the

deeper parts of syno"ial membrane. 'Arterial articular networ%s).

Articular "eins are communicating "eins.

Ner&e su++l of sno&ial %oint:

*he capsule and ligaments possess a rich ner"e supply which

ma%es them acutely sensiti"e to pain. Articular ner"es contain

sensory and autonomic fibres. Some of the sensory fibres are

propriocepti"e in nature. *hese are sensiti"e to position and

mo"ement and are concerned with the refle/ control of postureand locomotion. ilton9s 8aw states that a motor ner"e to the

muscle acting on #oint tends to gi"e a branch to that #oint 'capsule)

and another branch to the s%in co"ering the #oint.