In order to make it easier and clearer for you to read information about hand surgery, Medica experts have compiled a list of basic relevant terms:
Ligaments
Ligaments are constructs, made of strong connective tissue, and their purpose is to hold the bones close together. The purpose of the ligaments on either side of the joint is to prevent the finger from bending to the sides, and they are called collateral ligaments.
Tendons
The tendons are the continuity of the muscles, and they have a shape of ropes up until they reach the finger, where they appear as flat bands. This special structure allows the hands to be of a small size that they are. The tendons that cause the finger to straighten are called the straightening tendons. They begin in the muscles originating at the elbow and forearm, and become tendons that cover the wrist and palm.
Muscles
Many muscles of the hand begin in the forearm. Some muscles are responsible for straightening and bending the wrist only, and others – for straightening and bending the fingers. The function of many muscles is to stabilize the wrist and allow the fingers and the thumb to move. The small muscles of the hand that activate the thumb and the little finger originate from the bones in the wrist. These muscles allow the thumb to move across the palm in front of the fingers, a movement called opposition. In addition to these muscles, there are other small muscles that originate from the metacarpal bones, and are responsible for the gentle movement and coordination of the fingers.
Nerves
All the nerves in the upper limb originate from the spinal cord in the neck. The nerve fibers (referred to in this area of the body as the “nerve roots”) are attached together to a plexus that extends from the sides of the neck to the shoulder. Here start the nerves of the hand, including the main nerves: radialis, medianus and ulnaris. These nerves carry impulses (instructions) from the brain to the muscles that move the arm, forearm, hand and fingers. In the opposite direction they relay the sensations of pain, touch and temperature from the hand to the brain.
Bones and joints
The hand is made up of 27 bones. The wrist is made up of a connection between the two forearm bones (radius & ulna) and 8 small bones called carpal bones. The carpal bones connect to the five metacarpal bones that make up the palm. The phalanges are attached to each metacarpal bone – three on each finger and two on the thumb. The three cylinders in each finger are separated by joints called interphalangeal joints, which function as hinges on which bending and straightening movements of the fingers are performed. All the joints of the hand are covered with a shiny white cartilage, which has a slight springiness when pressured. Cartilage exists wherever there is movement between two bones.
Blood vessels
Alongside the nerves are the blood vessels (arteries and veins) which supply to and drain blood from the hand and the fingers. The largest artery is the radial artery which accompanies the radial nerve. The pulse in this artery can be felt in the wrist area on the side facing the thumb. The ulnar artery, ‘runs’ along the nerve of the same name and through the Guyon canal. The two arteries connect on the palm side of the hand and form arches where smaller vessels branch out from, supplying blood to the fingers. Additional arteries are located on the back of the hand, which also supply blood to the hand.
Paresthesia
Paresthesia is a spontaneous feeling where the person feels a prickly sensation in a certain area. It is a phenomenon of nerve stimulation. Judging by the location of the sensation, the doctor can determine which nerve is affected.
