Anatomy of the Hand
By Cesar Roman Negron, MS, ATC
Bones of the Hand
The anatomy of the hand is composed of 27 bones. These are divided in 3 major types of bones, including the:
- Carpal bones.
14 bones are found in the fingers. Each finger has 3 phalanges which are divided in distal, middle, and proximal; the thumb only has two.
- Proximal Phalange: The longest of the three, this bone extends from the edge of the palm. It’s where your ring would rest.
- Middle Phalange: This bone is part of both finger joints.
- Distal Phalange: The smallest of the finger bones, this is what is commonly called the “fingertip”.
The 5 bones that compose the middle part (palm) of the hand. The metacarpal bones are long cylindrical bones and are labeled:
- I (thumb).
- II (index).
- III (middle).
- IV (index).
- V (pinky).
Or sometimes 1, 2, 3, 4, and 5. Each metacarpal consist of 3 main parts (base, shaft, and head). The base articulates with the carpal bones; the shaft which is the body; and the head that articulates with the fingers (phalanges).
The eight irregular shape bones that help create the wrist. The carpal bones are bound in two groups of four bones:
Upper end of the wrist:
Lower end of the wrist:
There are also many structures that support the bones in the hand and help the hand to function properly and smoothly such as: cartilage, which are at the surface of bones and help them to glide smoothly; the ligaments helps to keep the bones in place; and tendons that enable the muscles to move the bones.
Common Injuries to the Bones of the Hand
Occurs due to a direct blow or impact due to sports related activities, repeated wear and tear on joints and bones.
Hand dislocations occur when a force causes the bones in the hand to move out position. This common injury occurs often amongst athletes, motor vehicle accidents, and hard physical labor occupations. Two of the carpal bones are commonly dislocated the lunate and the capitate.
Can occur whenever excessive force is applied. The scaphoid bone, located near the base of the thumb and the 5th metacarpal bone (knuckle joint) are two of the most common bones fractured in the bones of the hand. Another fracture site is the Hook of the Hamate that is typically associated with athletes who hold a stick or club.
Different disorders of the bones may occur because of old age, an accident or by genetic factors. Some common bone disorders include the following:
- Kienbock’s Disease: A condition in which the lunate bone loses its blood supply, leading to death of the bone.
- Deformities of the joints: Due to destruction of joint cartilage or ligaments.
- Rheumatoid arthritis: Destroys the cartilage lining and ligaments of synovial joints.
- Osteoarthritis: Deformities cause by osteoarthritis result in pain and stiffness of the joints.
- Nerve Compression Syndromes: This condition occurs when a bone or connective tissue presses a nerve.
- Osteoporosis: It weakens bones and makes them more likely to break.
Anatomy of the Hand Signs and Symptoms of a Hand Injury
- Swelling ache.
- Bruising weakness.
- Tenderness or pain
- Decreased range of motion.
- Inability to move hand and/or fingers.
- Numbness or tingling.
Your doctor will take a history of the injury or disorder; examine the injury and other potential injuries that may occur. Additionally, they will also look for signs and symptoms and may order very specific tests to help them identify the injury, location, and extent of the injury. These tests may include: X-Rays, Bone Scans, and/or MRI’s.
Anatomy of the Hand and Treatment
The treatment for bone bruises, dislocations, and fractures may include a non-surgical approach or surgical approach.
Non-Surgical or Conservative Treatment
Non surgical options may include the following:
- Immobilized cast, functional splint or cast, close reduction to keep bones in acceptable alignment, close reduction, medication, and physical therapy.
Your doctor will probably order a second set of x-rays about 1 to 2 weeks later. This is done to ensure that the bones are healing in the proper position. If your bones move, you might then required surgery.
You may need surgery to implant pins, plates, rods or screws to keep your bones in place while they heal.
Some of the treatments for bone disorders are:
- Physical therapy through a Certified Hand Therapist.
- Anti-inflammatory medication or steroid injection to decrease pain.
- Surgery is considered when all other conservative treatment have failed.
You can protect bone health through certain guidelines, such as:
- Participating in weight-bearing and resistance training exercises, preferably daily.
- Preventing falls by improving balance.
- Consuming vitamin D, and a calcium rich diet.
Although these measures may not completely prevent an injury it may decrease the amount of damage or speed up recovery time.
JOI Fracture and Injury Care
JOI Physicians are currently offering ASAP Fracture care. Make an appointment by calling (904)JOI-2000. This is a new option for patients who would like to avoid the emergency room if they have suffered a fracture or soft tissue injury. To learn more about this service, read this article about fracture and injury care.