What is the blood supply to the scaphoid?

What is the blood supply to the scaphoid?

The major blood supply to the scaphoid is via the radial artery. Seventy to eight percent of the intraosseous vascularity and the entire proximal pole is from branches of the radial artery entering through the dorsal ridge.

Does the scaphoid have poor blood supply?

Because portions of the scaphoid have a poor blood supply—and a fracture can further disrupt the flow of blood to the bone—complications with the healing process are common.

Why is scaphoid prone to avascular necrosis?

Avascular necrosis (AVN) is one complication of scaphoid fracture. Since the scaphoid receives its arterial supply in a retrograde fashion (i.e. from distal to proximal pole), the part proximal to the fracture is usually affected.

What is avascular necrosis of scaphoid?

Avascular necrosis: This is a complication in which cells of the scaphoid bone die due to lack of blood supply, causing bone collapse and arthritis. This usually happens in case of displaced fractures, as the displaced bone fails to get proper nutrients.

What does retrograde blood supply mean?

Blood flow to the scaphoid bone occurs via retrograde (‘backwards’) flow, meaning blood enters at the distal (top) portion of the bone and there is no direct blood supply to the proximal (bottom) portion of the bone. This retrograde blood supply is what can cause a fracture nonunion to go on to AVN (Picture 4).

What is the scapholunate joint?

The scapholunate joint is a small joint between two carpal bones at the wrist crease, namely the scaphoid and lunate bones. The scapholunate joint is very important for the stability of the wrist joint. It is often injured during sport, for example, if you fall heavily onto your hand.

What happens if the scaphoid bone dies?

Avascular necrosis occurs when part of the scaphoid bone dies because of the loss of blood flow. This can eventually result in fragmentation and the collapse of the bone. Its presence also makes repair of the scaphoid much more difficult.

What happens if scaphoid bone dies?

How common is avascular necrosis of scaphoid?

Posttraumatic avascular necrosis (AVN) of the scaphoid is a common complication probably due to the precarious blood supply [1]. The rate of incidence is about 13% to 40% and almost all are seen in the proximal fragment [2, 3].

What happens if avascular necrosis is left untreated?

Untreated, avascular necrosis worsens with time. Eventually, the bone can collapse. Avascular necrosis also causes bone to lose its smooth shape, potentially leading to severe arthritis.

Is scaphoid fracture serious?

A scaphoid fracture can lead to wrist osteoarthritis, especially if the fracture is untreated and does not heal correctly. This is called “nonunion.” Severe cases of this kind of osteoarthritis can lead to an incorrect alignment of wrist bones in what is called scaphoid nonunion advanced collapse (SNAC).