Accessibility Tools
  • Carpal Tunnel Syndrome

    Carpal Tunnel Syndrome

    Carpal tunnel syndrome is a common, painful, progressive condition that is caused by compression of the median nerve at the wrist area.

  • Dupuytren’s Contracture

    Dupuytren’s Contracture img

    Dupuytren’s contracture is a hand condition where thickening of the underlying fibrous tissues of the palm causes the fingers to bend inward. This makes it difficult to fully straighten the affected fingers. It commonly occurs in the ring finger and little finger. Occasionally, the middle finger is affected, but the thumb and index finger are rarely affected

  • Flexor Tendon Injuries

    Flexor Tendon Injuries img

    Deep cuts on the under surface of the wrist, hand or fingers can cut and injure the tendon, and make it unable to bend one or more joints in a finger. When a tendon gets cut, the cut ends gets pulled away from each other like a rubber band.

  • Arthritis of the Hand

    Arthritis of the Hand img

    Arthritis is an inflammatory condition of the joints. There are several types of arthritis and the most common type is osteoarthritis or wear-and-tear arthritis. Arthritis affects various joints in the body and the arthritis in the hand affects the joint at the base of the thumb. Arthritis may also affect the joints of other digits. 

  • Trigger finger

    Trigger finger img

    Inflammation in the tenosynovium leads to a condition called trigger finger, also known as stenosing tenosynovitis or flexor tendonitis, where one of the fingers or thumb of the hand is caught in a bent position. The affected digit may straighten with a quick snap, like pulling and releasing the trigger on a gun, hence the name trigger finger.

  • Fingertip Injuries/Amputations

    Fingertip Injuries/Amputations img

    A fingertip injury is a wound or damage caused to the most distal portion of the finger. It can be a crush, a sharp cut, a tear or a combination of these, and can result in damage to the skin, nail or nailbed, tendon, pulp, bone, and nerve endings. It is one of the most common injuries to the hand and may occur due to accidents at home, work, or play. 

  • Boutonnière Deformity

    Boutonnière Deformity img

    Tendons in your fingers connect the finger bones to finger muscles and help bend and straighten the finger at the joint when the muscles contract. Boutonnière deformity is a condition in which a tendon injury to the middle joint of the finger results in the inability to straighten the affected finger.

  • Hand Fractures

    Hand Fractures img

    A fracture is a break in the bone, which occurs when force greater than the bearable limit is applied against a bone. The most common symptoms of any fracture include severe pain, swelling, bruising or bleeding, deformity and discoloration of the skin and limited mobility of the hand.

  • Mallet Finger

    Mallet Finger img

    A mallet finger is a condition where the end of the finger is bent and does not straighten. Mallet finger occurs when the extensor tendon at the back of the finger is damaged.

  • Thumb Fractures

    Thumb Fractures img

    A break or a crack in the bones of the thumb is known as a thumb fracture. Fractures may occur anywhere on the thumb, but a fracture at the base of the thumb, near the wrist, is considered the most serious.

  • Arthritis of the Wrist

    Arthritis of the Wrist img

    Arthritis is an inflammatory condition of the joints. There are several types of arthritis and the most common type is osteoarthritis or wear-and-tear arthritis. Arthritis affects various joints in the body and the arthritis in the hand affects the joint at the base of the thumb. Arthritis may also affect the joints of other digits. 

  • Ganglion (Cyst) of the Wrist

    Ganglion (Cyst) of the Wrist img

    Ganglion cysts are swellings that most commonly develop along the tendons or joints of wrists or hands. They can be found either at the top of the wrist, palm side of the wrist, end joint of a finger or at the base of a finger. A ganglion cyst is not cancerous and will not spread to the other parts of the body.

  • Distal Radius Fracture

    Distal Radius Fracture img

    The forearm consists of two bones, the radius, and ulna. The radius is the larger of the two forearm bones. The region towards the wrist is called the distal end. Fractures in this end are most common.

  • Wrist Sprains

    Wrist Sprains img

    Injuries caused due to stretching or tearing of the ligaments in the wrist are called wrist sprains. Sprains can range from mild to severe, based on the extent of injury to the ligament. 

  • Wrist Arthroscopy

    Wrist Arthroscopy img

    Wrist arthroscopy is a minimally invasive surgical procedure performed to view, diagnose and treat problems of your wrist joint.

  • Wrist Joint Replacement

    Wrist Joint Replacement img

    Wrist joint replacement surgery, also referred to as total wrist arthroplasty, involves the replacement of a severe arthritic wrist joint with an artificial joint made of metal and plastic components. It relieves pain and restores function when conservative treatment fails to provide relief.

Hand Anatomy

The human hand is made up of the wrist, palm, and fingers and consists of 27 bones, 27 joints, 34 muscles, over 100 ligaments and tendons, and many blood vessels and nerves. 

The hands enable us to perform many of our daily activities such as driving, writing and cooking. It is important to understand the normal anatomy of the hand to learn more about diseases and conditions that can affect our hands.

Bones of the Hand

The wrist is comprised of 8 carpal bones. These wrist bones are attached to the radius and ulna of the forearm to form the wrist joint. They connect to 5 metacarpal bones that form the palm of the hand. Each metacarpal bone connects to one finger at a joint called the metacarpophalangeal joint (MCP joint). This joint is commonly referred to as the knuckle joint. 

The bones in our fingers and thumb are called phalanges. Each finger has 3 phalanges separated by two interphalangeal joints, except for the thumb, which has only 2 phalanges and one interphalangeal joint.

The first joint close to the knuckle joint is called the proximal interphalangeal joint (PIP joint). The joint closest to the end of the finger is called the distal interphalangeal joint (DIP joint).

The MCP and PIP joint act like hinges when the fingers bend and straighten.

Soft Tissues of the Hand

Our hand bones are held in place and supported by various soft tissues. These include: articular cartilage, ligaments, muscles and tendons.

Articular cartilages are smooth material that act as shock absorbers and cushion the ends of bones at each of the 27 joints, allowing smooth movement of the hand.

Muscles and ligaments function to control the movement of the hand.

Ligaments are tough rope-like tissues that connect bones to other bones, holding them in place and providing stability to the joints. Each finger joint has two collateral ligaments on either side, which prevents the abnormal sideways bending of the joints. The volar plate is the strongest ligament in the hand. It joins the proximal and middle phalanx on the palm side of the joint and prevents backward bending of the PIP joint (hyperextension).

Muscles of the Hand

Muscles are fibrous tissues that help produce movement. They work by contracting. 

There are two types of muscles in the hand:

  • Intrinsic muscles are small muscles that originate in the wrist and hand. They are responsible for fine motor movements of the fingers during activities such as writing or playing the piano.
  • Extrinsic muscles that originate in the forearm or elbow control the movement of the wrist and hand. These muscles are responsible for gross hand movements. They position the wrist and hand while the fingers perform fine motor movements. 

Each finger has six muscles controlling its movement: three extrinsic and three intrinsic muscles. The index and little finger each have an extra extrinsic extensor.

Tendons of the Hand

Tendons are soft tissues that connect muscles to bones. When muscles contract, tendons pull the bones, causing the finger to move. The extrinsic muscles are attached to finger bones through long tendons that extend from the forearm through the wrist. Tendons located on the palm side help in bending the fingers and are called flexor tendons, while tendons on top of the hand called extensor tendons help in straightening the fingers.

Nerves of the Hand

Nerves of the hand carry electrical signals from the brain to the muscles in the forearm and hand, enabling movement. They also carry the senses of touch, pain and temperature back from the hands to the brain.

The three main nerves of the hand and wrist include: 

  • Ulnar nerve: The ulnar nerve crosses the wrist through an area called Guyon’s canal and branches to provide sensation to the little finger and half of the ring finger. 
  • Median nerve: The median nerve crosses the wrist through a tunnel called the carpal tunnel. The median nerve provides sensation to the palm, thumb, index finger, middle finger and part of the ring finger. 
  • Radial nerve: The radial nerve runs down the thumb side of the forearm and provides sensation to the back of the hand from the thumb to the middle finger. 

All three nerves originate at the shoulder and travel down the arm to the hand. Each of these nerves has sensory and motor components.

Blood Vessels of the Hand

Blood vessels travel beside the nerves to supply blood to the hand. The main arteries are the ulnar and radial arteries, which supply blood to the front of the hand, fingers, and thumb. The ulnar artery travels next to the ulnar nerve through the Guyon’s canal in the wrist. The radial artery is the largest artery of the hand, traveling across the front of the wrist, near the thumb. Pulse is measured at the radial artery. 

Other blood vessels travel across the back of the wrist to supply blood to the back of the hand, fingers and thumb.

Bursae of the Hand

Bursae are small fluid-filled sacs that decrease friction between tendons and bone or skin. They contain special cells called synovial cells that secrete a lubricating fluid. 

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    Burbank, CA 91505

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