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Scaphoid Non-Union

The scaphoid bone is one of the small bones in the wrist, situated on the thumb side of the hand. It is one of the eight carpal bones that sit between the bones of the fingers and thumb. It gets its name from the Greek word for 'boat' due to its boat-like shape. It is approximately the size of a cashew nut. Although the scaphoid can fracture in sports injuries and other accidents (e.g. car accidents), many fractures of the scaphoid bone occur when you fall on an outstretched hand to break the fall. This type of 'fall on outstretched hand' - often abbreviated to FOOSH - where the bulk of the fall is broken by the palm, generally fractures the scaphoid in the middle (called a waist fracture), but fractures can occur elsewhere in the bone.

A fractured scaphoid can be painful, generally with pain and tenderness felt just below the thumb, but it does not feel as serious as fractures in other larger bones and so is often overlooked. Partially due to relatively poor blood supply to the scaphoid, which is often made worse by a fracture, scaphoid fractures sometimes do not heal naturally, resulting in a condition called 'scaphoid non union' where the scaphoid remains in two pieces.

Scaphoid non-union can result in pain or a lack of strength in the affected wrist - for example an inability to do press ups (if you could before!). In young individuals, scaphoid non-union often results in a very predictable progression to further damage to carpal (wrist) joints and advanced arthritis – the SNAC (Scaphoid non-union advanced collapse) wrist.

Such a condition requires fixation of the scaphoid bone with screws as well as bone grafting to stimulate and facilitate healing. The bone graft would be harvested through a small 2-3 cm incision from the iliac crest or the distal radius bone.


CT scan image of a scaphoid non-union.