Classification of human joints. Classification of joints by structure

Joints are called movable joints of various bones. A characteristic difference from other forms of combining different elements in the structure of the skeleton of the human body is the presence of a certain cavity filled with liquid. Each joint consists of several parts:

• Cartilaginous (hyaline, with the exception of the connection of the lower jaw with the temporal bone) surface;
• capsule;
• cavity;
• Synovial fluid.

General concept of human joints

The thickness of the cartilaginous layer can be different: from very thin, about 0.2 mm, to thick enough - about 6 mm. Such a significant difference is determined by the workload on the joint. The greater the pressure and its mobility, the thicker the hyaline surface.

Classification of human joints involves dividing them into several independent groups, identified by a similar feature. Conditionally it is possible to allocate:

• By the number of surfaces - simple, complex, combined, complex;
• Along the axes of rotation - uniaxial, biaxial, multiaxial;
• In shape - cylindrical, block-shaped, helical, ellipsoidal, condyle, saddle, spherical, flat;
• On the possible movement.

Variety of combinations

Different cartilaginous surfaces, which work interconnected, determine the simplicity or complexity of the structure of the joint. Classification of joints (table on anatomy) allows to divide them into simple, complex, combined, complex.

Simple - characterized by the presence of two cartilaginous surfaces, and they are formed can be two or more bones. As an example, you can bring joints of the upper limb: phalangeal and radiocarpal. The first of them is formed by two bones. The second one is more complicated. One of the surfaces of the wrist joint has a base of three bones of the proximal carpal series.

Complex - are formed from three or more surfaces placed in one capsule. In fact, these are a few simple joints that can work together or separately. For example, the elbow joint has as many as six surfaces. They form three separate compounds in one capsule.

Some joints, in addition to basic ones, have additional devices, such as disks or meniscuses. Classification of joints calls them complex. The disks divide the joint cavity into two parts, thus forming the "storey" of the joint. Menisci look like a half moon. Both adaptations ensure that the adjacent cartilage forms in the articular bag are aligned with each other.

The classification of joints in terms of structure distinguishes such a concept as combining. This means that two separate connections, being independent, can work exclusively together. A characteristic example of such synergism can be called right and left temporomandibular joints.

Possible rotation

Joint joints provide the character, amplitude and trajectory of movements of the human skeleton. Rotation occurs around biomechanical axes, which can be several. Among them there are vertical, sagittal and transverse. The classification of joints on this basis distinguishes several species.

• Uniaxial - have a single axis of rotation. For example, interphalangeal joints provide flexion and extension of the fingers, other movements are impossible.
• Biaxial - two axes of rotation. A typical example is the wrist joint.
• Three - axis - movement in all possible planes - humeral, hip joints.

Variety of forms

Classification of joints by forms is quite extensive. Each compound was evolutionarily adapted to reduce strain and increase labor.

• Cylindrical . Has a single axis of rotation - longitudinal. It is interesting that there are cylindrical joints with a fixed center, around which the ring rotates (atlant-axis), and vice versa, as in a radial -local articulation.
• Block - like - uniaxial joint. The name is directly determining its structure. One surface has the form of a comb, which is combined with a furrow of the second cartilage, forming a lock (interphalangeal joints).
• Screw-like . One of the types of block joint. It has one axis and an additional screw-like displacement. An example is the elbow joint.

• Ellipsoidal - rotates on two axes - vertical and sagittal. Movement in this joint provides flexion, extension, reduction and withdrawal (wrist connection).
• Ushchetkovy . The biaxial joint. Its shape is notable for a strongly convex cartilaginous surface on one side and flat on the other. On the latter, there may be a slight depression. The most striking example is the knee joint. Classification distinguishes and other condylar compounds. For example, the temporomandibular joint.
• Saddle-shaped . It is formed by two surfaces - concave and concave. The educated joint is able to move along two axes - frontal and sagittal. A vivid example can be a phalanx-pentad joint of the thumb.

One of the most massive in the body is the hip joint. The classification calls it globular. It has a characteristic shape. Movement is carried out on three possible axes. One of the varieties of the spherical form is the cup-shaped joint. It has a smaller amplitude of possible movements.

Classification of bones and joints distinguishes their division into departments. For example, the belt of the lower or upper extremities, the skull, the spine. The latter consists of small bones - vertebrae. Joints between them are flat, inactive, but capable of movement along three axes.

Joint joint of the temporal bone and lower jaw

This joint is combined and complex. Movement occurs simultaneously from the right and from the left. Any axis is possible. This is ensured by the adaptation of the lower jaw to chewing and talking. The cavity of the joint is divided in half by a cartilaginous fibrous disc, which is spliced with the joint capsule.

Are joints aching?

Joints in the human body perform an important function - movement. When they are healthy, the amplitude of the action is not disturbed. Life without pain and discomfort is much more pleasant than with them.

There are various diseases of the joints. The classification divides them into groups according to specific symptomatology, the complexity of the process and the nature of the current (acute, subacute, chronic). Pathologically distinguish:

• Arthralgia (joint pain of a fixed or volatile nature);
• Arthritis (inflammatory processes);
• Arthrosis (degenerative irreversible changes);
• Congenital diseases.

Arthritis

A large number of diseases affect the support apparatus, causing a disruption in the function of the joints. Classification of arthritis distinguishes infectious, non-infectious, traumatic and accompanying (with other diseases). A detailed list was approved in 1958 at the Congress of Rheumatologists.

Infectious arthritis, which constitute a large group of diseases, are specific, which are caused by the damaging effect of known types of pathogens, for example, a tubercle bacillus, or evolutionary ones. Particularly distinguish joint diseases according to the authors: Sokolsky-Buyo, Bechterew, Still.

Non-infectious arthritis is also called dystrophic. They occur quite often, etiology is the most diverse. Among the causes may be age-related changes, negative effects of environmental factors (hypothermia, excessive stress), hormonal and metabolic disorders (gout, thyroid disease, hemophilia, etc.).

Traumatic arthritis develops with blunt injuries, joint injuries. In addition, they can occur due to prolonged exposure to vibration.

A large number of arthritis is accompanied by other diseases that are not associated with the musculoskeletal system. Chronic forms of psoriasis, systemic lupus erythematosus, dermatoses - all can involve joints in the process. In addition, arthritis causes leukemia, some lung diseases (sarcoidosis) and the nervous system. Lead intoxication also often provokes a degenerative process in the joints.

Arthralgia

Pain syndrome, associated with the work of the joints, is called arthralgia. The nature of its manifestation can be superficial or deep, permanent or temporary, affecting one or several cartilaginous joints. The disease most often affects the largest joints in the human body: knee, elbow, hip. The smaller ones are much less affected.

Arthralgia often become an accompanying symptom in a variety of infectious diseases, especially those with febrile conditions. In the diagnosis used different methods of examination with mandatory collection of anamnesis. Laboratory tests involve counting the number of platelets in the blood, as well as other tests and samples.

Osteoarthritis

Classification of joints affected by arthrosis, can not be limited to their identity or a certain group. In itself, this disease is quite severe, since it is associated with the destruction of cartilage. This leads to deformation of the joints. It is proved that the genetic predisposition - heredity - plays an essential role in the development of arthrosis. In the risk group for this disease are people whose occupations are directly related to the constant stress on the joints: hairdressers, athletes, drivers, etc. The cause may be long-term hormonal disorders in the body.

Congenital malformations of the joints

The severity of congenital malformations of the joints varies from mild to severe. There are many diseases of newborns. These include: arthrogryposis, pseudoarthrosis of the lower leg, congenital dislocation of the thigh or patella, hip dysplasia, Marfan syndrome (autosomal disease).

Prevention of joint diseases

In recent years, diseases of the musculoskeletal system have become much younger. If earlier the average age of the patients was at the level of 55 years, now it is fixed at the level of 40.

To avoid serious complications and live a long life without limiting their movements, it is important to monitor overall health and conduct timely prevention. It consists in controlling body weight, proper nutrition, elimination of bad habits and moderate physical activity.