Taber's Medical Dictionary
joint
(joynt)
[Fr. jointe, fr. L. junctio, a joining]
The place where two or more bones meet. Some joints are fixed or immobile attachments of bones; other joints allow the bones to move along each other. A joint usually has a thin, smooth articular cartilage on each bony surface and is enclosed by a joint capsule of fibrous connective tissue. A joint is classified as immovable (synarthrodial), slightly movable (amphiarthrodial), or freely movable (diarthrodial). A synarthrodial joint is one in which the two bones are separated only by an intervening membrane, such as the cranial sutures. An amphiarthrodial joint is one having a fibrocartilaginous disk between the bony surfaces (symphysis), such as the symphysis pubis; or one with a ligament uniting the two bones (syndesmosis), such as the tibiofibular articulation. A diarthrodial joint is one in which the adjoining bone ends are covered with a thin cartilaginous sheet and joined by a joint capsule lined by a synovial membrane, which secretes synovial fluid.
SYN: SEE: arthrosis (1)
TYPES OF JOINTS
MOVEMENT
Joints are also grouped according to their motion: ball-and-socket (enarthrodial); hinge (ginglymoid); condyloid; pivot (trochoid); gliding (arthrodial); and saddle.
Joints can move in four ways: gliding, in which one bony surface glides on another without angular or rotatory movement; angulation, occurring only between long bones, increasing or decreasing the angle between the bones; circumduction, occurring in joints composed of the head of a bone and an articular cavity, the long bone describing a series of circles, the whole forming a cone; and rotation, in which a bone moves about a central axis without moving from this axis. Angular movement, if it occurs forward, is called flexion; if backward, extension; if away from the body, abduction; and toward the median plane of the body, adduction.
Because of their location and constant use, joints are prone to stress, injury, and inflammation. The main diseases affecting the joints are rheumatic fever, rheumatoid arthritis, osteoarthritis, and gout. Injuries comprise contusions, sprains, dislocations, and penetrating wounds.
acromioclavicular joint
ABBR: AC joint A gliding or plane joint between the acromion and the acromial end of the clavicle.
ACROMIOCLAVICULAR JOINT The AC joint capsule AND ligaments
amphidiarthrodial joint
A joint that is both ginglymoid and arthrodial.
ankle joint
SEE: Ankle.
arthrodial joint
Diarthrosis permitting a gliding motion.
SYN: SEE: gliding joint
ball-and-socket joint
A joint in which the round end of one bone fits into the cavity of another bone.
SYN: SEE: enarthrodial joint; SEE: multiaxial joint; SEE: polyaxial joint
biaxial joint
A joint with two chief movement axes at right angles to each other.
bilocular joint
A joint separated into two sections by interarticular cartilage.
bleeders' joint
Hemorrhage into joint space in hemophiliacs.
SYN: SEE: hemophilic joint
Budin joint
SEE: Budin joint
cartilaginous joint
A joint with cartilage between the bones.
Charcot joint
SEE: Charcot, Jean M.
Chopart joint
SEE: Chopart, François
Clutton joint
SEE: Clutton joint
cochlear joint
A hinge joint permitting lateral motion.
SYN: SEE: spiral joint
compound joint
A joint made up of several bones.
condylar joint
SEE: Ellipsoid joint.
condyloid joint
A joint permitting all forms of angular movement except axial rotation.
cracking joint
The sound produced by forcible movement of a joint by contracting the muscles that contract or extend a joint, esp. the metacarpophalangeal joints. The cause is not known.
SEE: crepitation
craniomandibular joint
diarthrodial joint
A joint characterized by the presence of a cavity within the capsule separating the bones, permitting considerable freedom of movement.
dry joint
Arthritis of the chronic villous type.
elbow joint
The hinge joint between the humerus and the ulna and the radius of the forearm.
ellipsoid joint
A joint with two axes of motion through the same bone.
SYN: SEE: condylar joint
enarthrodial joint
facet joint
Any of the zygapophyseal joints of the vertebral column between the articulating facets of each pair of vertebrae.
false joint
SEE: Nonunion.
fibrous joint
Any of the joints connected by fibrous tissue.
flail joint
A joint that is extremely relaxed, the distal portion of the limb being almost beyond voluntary control.
ginglymoid joint
A synovial joint having only forward and backward motion, as a hinge.
SYN: SEE: ginglymus
SEE: hinge joint
gliding joint
SEE: Arthrodial joint.
hemophilic joint
SEE: Bleeders' joint.
hinge joint
A synovial joint in which two bones flex and extend in only one plane, usually because collateral (side) ligaments limit the direction of motion, as in the elbow joint.
hip joint
A synovial ball-and-socket joint in which the head of the femur fits into the acetabulum of the hip bone. More than seven separate ligaments hold the joint together and restrict its movements.
immovable joint
SEE: Synarthrosis.
intercarpal joint
Any of the articulations formed by the carpal bones in relation to one another.
irritable joint
A recurrent joint inflammation of unknown cause.
knee joint
The joint formed by the femur, patella, and tibia.
midcarpal joint
A combined joint between the navicular, lunate, and triquetrum bones proximally and the distal row of the carpal bones.
midtarsal joint
The calcaneocuboid joint plus the talocalcaneonavicular joint.
SYN: SEE: Chopart joint; SEE: transverse tarsal joint
movable joint
A slightly movable or freely movable joint, amphiarthrodial and diarthrodial, respectively.
multiaxial joint
native joint
A natural joint present in the body without surgical modification as opposed to a prosthetic joint.
pivot joint
A joint that permits rotation of a bone, the joint being formed by a pivot-like process that turns within a ring, or by a ringlike structure that turns on a pivot.
SYN: SEE: rotary joint; SEE: trochoid joint
plane joint
A synovial joint between bone surfaces, in which only gliding movements are possible.
polyaxial joint
prosthetic joint
An artificial joint. In the U.S., prosthetic joints are most often inserted into the knee or the hip.
receptive joint
SEE: Saddle joint.
rotary joint
SEE: Pivot joint.
sacroiliac joint
The articulation between the sacrum and the ilium of the hip bone. Joint movement is limited because of interlocking of the articular surfaces.
saddle joint
A joint in which the opposing surfaces are reciprocally concavoconvex.
SYN: SEE: receptive joint
shoulder joint
The ball-and-socket joint between the head of the humerus and the glenoid cavity of the scapula.
simple joint
A joint composed of two bones.
spheroid joint
A multiaxial joint with spheroid surfaces.
spiral joint
SEE: Cochlear joint.
sternoclavicular joint
The joint space between the sternum and the medial extremity of the clavicle.
stiff joint
A joint with reduced mobility.
subtalar joint
Any of the three articular surfaces on the inferior surface of the talus.
sutural joint
An articulation between two cranial or facial bones.
synarthrodial joint
SEE: Synarthrosis.
synovial joint
A joint in which the articulating surfaces are separated by synovial fluid.
SEE: joint for illus
SYNOVIAL JOINT
talocrural joint
SEE: Ankle.
tarsometatarsal joint
A joint composed of three arthrodial joints whose bones articulate with the bases of the metatarsal bones.
temporomandibular joint
Either of the encapsulated double synovial joints between the condylar processes of the mandible and the temporal bones of the cranium. These joints are separated by an articular disk and function as an upper gliding joint and a lower modified hinge or ginglymoid joint.
transverse tarsal joint
SEE: Midtarsal joint
trochoid joint
SEE: Pivot joint.
ulnomeniscal-triquetral joint
The functional articulation of the distal ulna, articular disk, and triquetrum. The disk may subluxate following injury or with arthritis and block supination of the forearm.
uniaxial joint
A joint moving on a single axis.
unilocular joint
A joint with a single cavity.
