A joint, also known as an articulation, is a type of bone attachment. They give the skeletal system stability while also allowing for specialised movement. 

There are two types of joints: structural and functional. If the neighbouring bones are tightly linked to each other by fibrous connective tissue or cartilage, or if the adjacent bones articulate with each other within a fluid-filled region called a joint cavity, structural classifications of joints are used. The degree of mobility allowed between the bones is described by functional categories, which range from static to slightly movable to freely moveable joints. The functional needs for a given joint are related to the amount of movement available at that joint. 

Classification of joints

  • On the basis of structure
  • On the basis of extent of their function (degree of movement)

Classification of joints on the basis of structure:

The existence or absence of a joint cavity, as well as the types of supporting tissue that holds two bones together, determine this categorization.

  1. Fibrous joints
  2. Cartilaginous joints
  3. Synovial joints

On the basis of extent of their function (degree of movement)

  1. Synarthrosis – immovable.
  2. Amphiarthrosis – slightly moveable.
  3. Diarthrosis – freely moveable.

Fibrous joints

Fibrous joints have no joint cavity and are linked by fibrous tissue, specifically thick fibrous connective tissue. The degree of movement permitted is determined by the length of connective tissue fibres that link the bones. The majority of fibrous joints are immovable, however a few can be moved somewhat.

  • Sutures- Sutures, syndesmoses, and gomphoses are the three forms of fibrous joints. Sutures are immovable joints found only between the head’s flat, plate-like bones.
  • Gomphoses- The immovable joints between the teeth and their sockets in the mandible and maxilla are known as gomphoses. The fibrous tissue that links the tooth to the socket is known as the periodontal ligament.
  • Syndesmoses – Syndesmoses are joints that can move slightly (amphiarthrosis). They’re made up of bones that are joined by an interosseous membrane. The middle radioulnar joint and the middle tibiofibular joint are syndesmosis joints.

Cartilaginous joints

Cartilaginous joints are those in which cartilage, either hyaline cartilage or fibrocartilage, completely connects the bones. These joints allow for greater movement than fibrous joints, but less than synovial joints. Synchondroses & symphyses are the two main forms.

  • Synchondrose – Hyaline cartilage connects the bones in a synchondrosis. These joints can’t be moved (synarthrosis). The joint between the diaphysis and epiphysis of a growing long bone is an example of a synchondrosis.
  • Symphyses – In a symphyseal joint, fibrocartilage links the bones. They can be moved gently (amphiarthrosis). The pubic symphysis and the junctions between vertebral bodies are two examples.

Synovial joints

The synovial joint’s main function is to keep the articulating bones of the joint cavity from rubbing together. While all synovial joints are diarthroses, the range of motion varies between subtypes and is frequently restricted by the ligaments that link the bones. This category includes nearly all limb joints as well as the majority of body joints.

Synovial joints are divided into various categories based on the form of their articular surfaces and the range of motion they allow:

  • Hinge – a hinge is a joint that allows movement in only one plane, commonly flexion and extension.

For example, the elbow, ankle, and knee joints.

  • Saddle – Due to its resemblance to a saddle on a horse’s back, it was given the name Saddle. Carpometacarpal joints, for example.
  • Condyloid -A convex surface articulates with a concave elliptical hollow in a condyloid. Ellipsoid joints are another name for them. Wrist, metacarpophalangeal, and metatarsophalangeal joints, for example.
  • Ball and Socket – when one rounded bone’s ball-shaped surface fits into the cup-like depression of another bone. It allows for unfettered movement along a number of axes. Hip and shoulder joints, for example.

How to treat ac joint injury

Sprains of the acromioclavicular joint are common, usually caused by a fall on the shoulder or, less frequently, an outstretched arm. The shoulder blade (scapula) meets the collarbone at the AC joint (clavicle). The acromion is the highest point on the shoulder blade. The AC joint is formed by strong ligaments connecting the acromion to the collarbone.

Treatment will be determined by the severity of the infection. It will also depend on if you have shoulder injuries in other areas. The following treatments may be used:

  • Rest. Your shoulder will be able to heal as a result of this. Activities that put a strain on the joint should be avoided. Reaching overhead or sleeping on your shoulder are examples of this.
  • Sling. This protects the shoulder and keeps it in a suitable healing position.
  • Packs of ice. These aid in the reduction of edema and pain.
  • Pain relievers, both prescription and over-the-counter. These aid in the reduction of pain and edema.

Conclusion

In this article, we study Joint Classifications. There are many different types of joints in our bodies. An articulation, often known as a joint, is a type of bone attachment. They provide stability to the skeletal structure while also allowing for specialised movement. Joints can be classified as synarthrosis, amphiarthrosis, or diarthrosis based on the type of tissue present (fibrous, cartilaginous, or synovial) or the degree of movement allowed.