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Anatomy of the Wrist and Hand: An Overview

The wrist and hand are intricate and vital areas of the body, responsible for a wide range of movements, including gripping, lifting, and manipulating objects. They are composed of numerous bones, tendons, ligaments, and soft tissue structures that work together to provide strength, stability, and dexterity. One key structure within the wrist is the triangular fibrocartilage complex (TFCC), which plays a crucial role in stabilising the wrist, particularly during rotational movements.

The wrist is comprised of two forearm bones: the ulna (on the little finger side) and the radius (on the thumb side). These bones connect to eight small hand (carpal) bones that form the wrist joint.

The Carpal Bones

The carpal bones are divided into two rows: the distal row (closer to the fingers) and the proximal row (closer to the forearm). These bones articulate with each other and the forearm bones, allowing the wrist its wide range of motion.

Image: X-Ray Displaying Carpal (hand) bones

  • Distal Row:
    • Trapezium (E)
    • Trapezoid (F)
    • Capitate (G)
    • Hamate (H)
  • Proximal Row:
    • Scaphoid (A)
    • Lunate (B)
    • Triquetral (C)
    • Pisiform (D)

These bones form the foundation of the wrist joint and contribute to its strength and flexibility.

The TFCC

The triangular fibrocartilage complex (TFCC) is a load-bearing structure located on the ulnar side of the wrist (the side of the little finger). It consists of cartilage and ligaments that provide crucial support to the wrist, stabilising it during rotational movements, such as turning a doorknob or using a screwdriver. It also helps in weight-bearing activities involving the wrist. The TFCC acts as a cushion between the end of the ulna and the carpal bones, protecting them from excessive friction and impact.

Causes

Tears to the TFCC can occur due to degenerative (wear and tear) or acute (sudden injury) causes.

Degenerative Causes

Over time, repeated stress or pressure on the ulnar side of the wrist can lead to wear and tear of the TFCC. Degenerative tears are more common in older individuals or in people who perform repetitive wrist movements. Some examples include:

  • Repeated compression or impact through the ulnar side of the wrist, common in sports like gymnastics or weightlifting
  • Repetitive twisting movements such as in tennis or racquet sports

Acute Causes

Acute injuries to the TFCC typically occur as a result of trauma or sudden movements, including:

  • Falling onto an outstretched hand (FOOSH), a common cause of wrist injuries
  • Twisting injuries involving rapid wrist rotation
  • Fractures of the distal radius or ulna (the lower end of the forearm bones)
  • Sudden traction forces applied to the wrist, such as pulling or jerking movements

Signs and Symptoms

The symptoms of a TFCC injury can vary depending on the severity of the tear and whether it is degenerative or acute. Some common signs and symptoms include:

  • Wrist pain on the ulnar side (the little finger side)
  • Pain that worsens with activity, particularly gripping or twisting movements
  • A clicking or clunking sensation during wrist movement
  • Weakness or discomfort when gripping objects
  • Pain or discomfort when tilting the wrist from side to side (ulnar and radial deviation)

In more severe cases, people may also experience swelling, decreased range of motion, and instability in the wrist.

Diagnosis

Diagnosing a TFCC injury involves a combination of clinical examination and imaging tests. A physiotherapist or doctor will perform a subjective examination by asking about the onset of symptoms, history of injury, and any activities that may have caused the injury. This is followed by an objective examination, which involves assessing wrist movement, grip strength, and performing specific tests to detect TFCC damage, such as the TFCC compression test.

Imaging techniques are often used to confirm the diagnosis and rule out other conditions:

  • X-rays are typically taken to rule out fractures or bone abnormalities.
  • Magnetic Resonance Imaging (MRI) is the gold standard for diagnosing TFCC tears, as it provides detailed images of the soft tissues.
  • Wrist arthroscopy, a minimally invasive surgical procedure, may be used to examine the TFCC directly and can provide more definitive information.

Management

Most TFCC injuries are initially managed conservatively (non-surgically), with physiotherapy playing a key role in the recovery process. The goals of treatment are to reduce pain, restore function, and prevent further injury.

Acute Phase: Managing Pain and Inflammation

In the early stages after an injury, the focus is on minimising pain and inflammation. Treatment options may include:

  • Activity modification: Avoiding activities that aggravate the wrist, such as lifting, gripping, or sports that require twisting movements.
  • Immobilisation: Using a wrist splint or brace to immobilise the wrist temporarily, allowing the TFCC to heal and preventing further damage.
  • Non-steroidal anti-inflammatory drugs (NSAIDs): Medications like ibuprofen may be recommended to reduce pain and swelling.
  • Corticosteroid injections: In cases of severe pain, a corticosteroid injection may be administered to reduce inflammation.

Rehabilitation: Restoring Motion and Strength

Once the initial pain and inflammation have subsided, the focus shifts to rehabilitation through physiotherapy. A typical rehabilitation program includes:

  • Range of motion exercises: Gentle exercises to restore flexibility and mobility to the wrist joint.
  • Strengthening exercises: Gradual strengthening of the muscles surrounding the wrist to improve stability and support the healing TFCC. Exercises targeting the forearm, wrist, and hand muscles help reduce strain on the TFCC during daily activities.
  • Proprioceptive exercises: These exercises help improve wrist stability and coordination, enhancing the ability to sense and control wrist movements.

Surgical Management

If conservative treatment fails to provide relief, or if the tear is large or associated with significant instability, surgical intervention may be necessary. Surgical options include:

  • Arthroscopic debridement: Removing damaged tissue and smoothing the torn edges of the TFCC.
  • TFCC repair: Suturing the torn TFCC back together in cases of more significant tears.
  • Ulnar shortening osteotomy: A surgical procedure to shorten the ulna if a structural imbalance between the ulna and radius is contributing to TFCC tears.

Post-surgery rehabilitation is essential for restoring function and includes physiotherapy to gradually regain strength and mobility in the wrist.

Information is provided for education purposes only. Always consult your physiotherapist or other health professional.