28-06-2013, 12:46 PM
JOINTS
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INTRODUCTION
Human skeleton consists of about 206 bones.
It is divided two parts as axial skeleton and appendicular skeleton.
Axial skeleton includes skull bones, hyoid, auditory ossicles, vertebral column, thorax.
Appendicular skeleton includes pectoral girdle, upper limbs, pelvic(hip) girdle, lower limbs.
The bones are in such a way that a large variety of coordinated movements are possible.
These movement is mainly due to muscles called as skeletal muscles.
Bones act as levers, cartilage reduces friction and ligaments(bone-bone) prevents dislocation and mainly due to movable joints.
The site of connection of 2 or more bones of the skeleton is called a joint or articulation
Classification of joints
It is mainly dependent on the structure and function performed by them.
Functional classification of joints:
Based on the movement allowed it is classified into 3 types:
Synarthroses
Immovable joints are called synarthroses. It includes joints in which surfaces of the bones are almost direct contact as in the joints between the bones of the skull, except mandible.
Ex: sutures of skull.
Diarthroses:
The joints in the adult body are diarthroses. It is also called as freely movable joints.
In this joints the ends of the opposing bone are covered with hyaline cartilage and separated by a space called joint cavity.
The components of joints re enclosed in a joint capsule. The outer layer of the of capsule consists of ligaments and the inner layer is synovial membrane which secretes synovial fluid into the cavity for lubrication.
Fractures
A bone fracture is a medical condition in which a bone becomes cracked or bisected due physical trauma or due any medical conditions that weakens the bones, such as osteoporosis or any cancer.
Fracture takes place in more than one way as follows:
A complete fracture is when the bone has broken into two pieces.
A greenstick fracture is when the bone cracks on only one side.
A single fracture is when the bone is broken in one place.
Classification of fractures
Fractures are classified as closed, open(compound), simple and multi-fragmentary(comminuted).
If the bone breaks in such a way that the bone fragments stick out through the skin or wound penetrates down to the broken bone, it is called as open fracture.
In Closed fracture the skin is intact, while open fracture involves wounds and exposes bone to contamination.
Open injuries carry an elevated risk of infection, they require antibiotic and surgical treatment to remove all dirt and dead tissue.
TYPES OF TREATMENT
The following treatments are used for various types of fractures
Cast immobilization:- A plaster or fiberglass cast is the most common type of fracture treatment, since most of the broken bones can heal successfully once they have been repositioned and while healing, cast is applied to keep the broken ends in proper position.
Functional cast or brace:-This treatment is desirable for some but not all fractures.
Traction:-It is usually used to align a bone or bones by gentle, steady pulling action. The pulling force is transmitted to the bone through the skin tapes. It is a preliminary treatment before other treatments.