GENERAL ANATOMY OF JOINTS

1. JOINTS
Dr. SOMESH M.S.MBBS, MD
Associate Professor

2. OVERVIEW
 Joints - definition
 Classification - Structural &Functional
 Different Varieties of Joints with Examples
 Synovial Joint - Classification with Examples
 Synovial Joint - Blood supply & Nerve supply
 Applied Aspects / Clinical Anatomy

3. JOINTS
 Definition:
 Junction between 2 or
more bones or
cartilages, a device to
permit movement
 Related terms:
Arthron(G),
Articulation(L),
Junctura(L),
Syndesmology(G)

4. STRUCTURAL CLASSIFICATION
 Presence of Space & Type of Connective tissue that
binds two bones:
1. FIBROUS JOINTS(solid joints) – Fibrous Tissue binds
two bones
2. Cartilaginous Joints(solid joints) - Pad of cartilage
between two bones
3. Synovial Joints (Cavitated joints) – synovial fluid with
Synovial cavity

5. FUNCTIONAL CLASSIFICATION
 Degree of Mobility -
 Synarthroses - Fibrous Joints
(IMMOVABLE & Fixed )
 Amphiarthroses - Cartilaginous Joints
 (Slightly Movable)
 Diarthroses - Synovial Joints
 ( Freely Movable)

6. FIBROUS JOINTS
SUTURES
A . Serrate - Sagittal
B. Denticulate –
Lambdoid
C. Squamous – Parietal
&Temporal
D . Plane – Maxillae
E . Wedge & Groove
(schindylesis)

7. SYNDESMOSIS
 Two Bones are united by-
INTEROSSEOUS
LIGAMENT ( Collagen
fibres)
 Persist throughout life
 Partially Movable
 Eg: Beween radius & ulna
 Inferior tibio-fibular joint

8. GOMPHOSIS
 PEG & SOCKET JOINT
 Roots of tooth fits into
Socket (alveolar) of jaw
 United by Fibrous
membrane

9. CARTILAGINOUS JOINTS
 PRIMARY CARTILAGINOUS
(Synchondrosis)
 Plate of hyaline cartilage
 Strong & Immovable &Temporary
 Eg: Epiphysis& Diaphysis
 Body of sphenoid* basilar of occipital
 SECONDARY CARTILAGINOUS
(Symphysis)
 Disc of Fibrocartilage
 Slightly Movable & Permanent
 Median Plane of body
 Eg: Intervertebral jts.,
 Pubic Symphysis, Manubriosternal Jt.

10. General Structure of Synovial Joints
1. Articular cartilage
 Hyaline
 Spongy cushions absorb
compression
 Protects ends of bones from
being crushed
2. Joint (synovial) cavity
 Potential space
 Small amount of synovial fluid

11. General structure of synovial joints (cont.)
3. Articular (or joint) capsule
 Two layers
 Outer*: fibrous capsule of
dense irregular connective
tissue continuous with
periosteum
 Inner*: synovial membrane
of loose connective tissue
(makes synovial fluid)
Lines all internal joint surfaces
not covered by cartilage*
*
*
*

12. General structure of synovial joints (cont.)
4. Synovial fluid
 Filtrate of blood
 Contains special glycoproteins
 Nourishes cartilage and
functions as slippery lubricant
 “Weeping” lubricatioin
5. Reinforcing ligaments (some
joints)
 Capsular (most) – thickened
parts of capsule
 Extracapsular
 Intracapsular

13. DIARTHROSIS (SYNOVIAL JOINTS)
 UNIAXIAL- only 1° freedom
1. Hinge joint- flexion & extension
2. – Transverse Axis
Eg: ELBOW JT. , Ankle Jt.
2. Pivot joint- rotation -
Vertical Axis
Eg: ATLANTO-AXIAL JT.,
Superior Radio-Ulnar Jt.

14.  BIAXIAL - 2° freedom, Two Axis
Condylar Jt- Transverse Axis & Rotation –
Flexion & Extension, Side-side & limited rotation
Eg: Knee Jt, Metacarpo Phalangeal Jt.
TemporoMandibular jt.
Ellipsoid Jt- Convex Elliptical - Concave Elliptical
Transverse Axis & Antero-Posterior Axis
Flexion, extension, abduction & adduction
Little rotation
Eg: Wrist Jt. ( Radiocarpal Jt.)

15.  MULTIAXIAL - 3° freedom, Three Axis
SADDLE Jt- Reciprocally Concavo – Convex
Transverse Axis & Antero-Posterior Axis & rotation
flexion, extension, rotation
abduction, adduction,
Eg: 1st Carpometacarpal jt
BALL & SOCKET Jt-
Above + circumduction
Eg: Hip Jt, Shoulder Jt.

16. PLANE SYNOVIAL JOINT
 PLANE Jt-
 gliding movement,
 One bone slips over
other bone
 Intercarpal
 Intertarsal
 acromioclavicular

17. CLASSIFICATION
other type
 SIMPLE - only 2bones - eg: Interphalangeal jt
 COMPOUND - More than 2 bones, but single capsule -
eg: Ankle jt
 COMPLEX - More than 2 bones & divided into 2
compartments by articular disc eg: Knee Jt

18.  Blood Supply:
 Articular &Epiphyseal br. From neighboring A form
Periarticular Arterial Plexus
 Br. From these – pierce fibrous capsule – Vascular plexus –
Supplies Synovial Membrane, Epiphysis
 Articular CARILAGE IS AVASCULAR
 Nerve Supply:
 Capsule&Ligaments – Rich Nerve supply– Pain Sensitive
 Synovial Membrane & Articular Cartilage – Poor nerve
Supply
 Hilton’s Law: Nerve that supplies the jt. Also supplies to
Muscles producing its movements & also to skin over the jt.