Anatomy of the Hand

By Cesar Roman Negron, MS, ATC

Bones of the Hand 

In this article, we are going to the discuss the anatomy of the hand.  The hand is composed of 27 bones. These are divided in 3 major types of bones, including the:

• Phalanges.
• Metacarpals.
• Carpal bones.

Phalanges

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”.

Metacarpals

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).

Carpal Bones

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:

• Triquetrum.
• Lunate.
• Scaphoid.
• Pisiform.

Lower end of the wrist:

• Hamate.
• Capitate.
• Trapezoid.
• Trapezium.

To learn more about hand fractures, please read: Hairline Wrist or Hand Fractures and Hairline Fractures to the Arm.

There are also many structures that support the bones in the hand and help the hand to function properly and smoothly. Surfaces are lined with cartilage.  These are at the surface of bones and help them to glide smoothly.  The ligaments help to keep the bones in place and tendons help to enable the muscles to move the bones.

Common Injuries to the Bones of the Hand 

Bone Bruise 

Bone bruises can occur due to a direct blow or impact in sports related activities. They can also occur due to wear and tear on joints and bones. However, most bruises or hematoma’s are from trauma.

Dislocations 

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.

Fractures

Can occur whenever excessive force is applied.  The scaphoid bone, located near the base of the thumb and the 5^th 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.

Bone Disorders 

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.
• Deformity.
• Inability to move hand and/or fingers.
• Stiffness.
• Numbness or tingling.

Diagnosis 

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. Lastly, These tests may include: X-Rays, Bone Scans, and/or MRI’s.

Related Articles involving Hand Conditions:

• Dupuytren’s Contracture
• Carpal Tunnel Syndrome Video
• Hand Therapy

Anatomy of the Hand and Treatment 

The treatment for bone bruises, dislocations, and fractures may include a non-surgical approach or surgical approach.  So, it is best to be evaluated by a physician.

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.

Additionally, 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.  In other words, follow the instructions given by your MD during this healing process.

Surgical Treatment

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.
• Most importantly, surgery is an option when all other conservative treatment have failed.

Prevention of Injuries To The Hand

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.
• Stay active with exercise.

Although, these measures may not completely prevent an injury it may decrease the amount of damage or speed up recovery time.

In conclusion, we hope to have shown you how amazing the anatomy of the hand is and how it functions.

Related Articles: Joint and Bone Health and JOI Hand Therapy

Finally, to learn more about Direct Access to Physical Therapy without seeing an MD, please read this ARTICLE.

JOI and JOI Rehab

JOI Physicians continue to offer online new patient appointments. Make an appointment by calling (904) JOI-2000 or schedule online. This is a new option to make it more convenient to make new patient appointments.  Follow the link below to select your JOI MD and schedule online.

By: Cesar Roman Negron, MS, ATC