Diarthrosis (Synovial) Joint
Characteristics
- Fluid‐filled joint cavity between bones.
- “Synovial Joints” – presence of synovial membrane.
- Designed for movement!
Examples:
- Majority of Upper and Lower extremity joints.
7 Features
- Synovial Fluid
- Articular cartilage
- Articular capsule
- Synovial membrane
- Capsular ligaments
- Blood vessels
- Sensory nerves
Possible Features
Synovial joints may contain:
- Intraarticular discs / menisci
- Peripheral labrum
- Fat Pads
- Synovial Plicae
Intraarticular discs / menisci
- Fibrocartilage between surfaces
- Increase congruency & improve force dispersion
Peripheral labrum
- Fibrocartilage
- Deepen concave surface & support capsule
Fat Pads
- Occupy space within capsular tissue
- Reduce synovial volume
Synovial Plicae
- “Pleats” / slack in the synovial membrane.
- Increase surface area of joint capsule to allow more motion
- Joints with large capsular surface areas.
Mechanical Classifications
Hinge
- Flex/Ext
- Door Hinge
Examples:
- Humeroulnar
- IP joints
Pivot
- Spin
- Door Knob
Examples:
- Proximal RU
- AA joint
Ellipsoid
- Flex/Ext + Abd/Add
- Ellipsoid & trough
Examples:
- Radiocarpal
Ball-and-socket
- Triplanar
- Sphere & cup
Examples:
- GH
- Hip
Plane
- Slide, ± Rotation
- Book on a table
Examples:
- Intercarpal
- Intertarsal
Saddle
- Biplanar
- Horse rider & saddle
Examples:
- CMC thumb
- SC joint
Condyloid
- Biplanar
- Abstract parallel: Knuckle & cup
Examples:
- MCP
- Tibiofemoral
Citation
For attribution, please cite this work as:
Yomogida N, Kerstein C. Diarthrosis (Synovial)
Joint. https://yomokerst.com/The
Archive/Anatomy/Joints/Joint Types/Synovial
Joint/synovial_joint.html