The result of an untreated scaphoid fracture often leads to chronic instability due to the poor healing conditions in the carpal joints. The fractures often do not grow back together as is usual after a fracture, but scar tissue develops, offering no stability. This defective healing is named pseudoarthrose (false joint).
The consequence of permanent wrist joint instability is devastating. The moveable and often twisted bone fragments cause joint surfaces to rub against each other, which over the course of years leads to severe osteoarthritis of the wrist, in other words irreversible joint damage. In advanced stages, it is not only pain, but a stiffening of the wrist joint and loss of strength in the hand that results. Therefore, any discovered pseudoarthrosis, even if it is found by pure coincidence, should be operated on even if it does not present any symptoms at the time.
In reconstructive surgery, access to the wrist joint is gained through making an opening on either the front or back side of the wrist, depending on the actual position of the pseudoarthrosis. In order to have optimal sight of where the bone fragments lie, open operative techniques are used. The objective of the surgery is to connect and fix the bone fragments of the scaphoid in such a way that they naturally heal together with bone. To do this, scar tissue is removed and the arising gap filled with a bone graft from another part of the body (Matti-Russe technique – without screws). The bone graft is usually taken from the ilium. Today’s techniques usually then involve fixing the bone with wires or a special scaphoid screw called a “Herbert Screw”. However, sometimes it can occur that bone fragments or very small fragments do not have their own blood supply anymore. Then a vital replacement must be gained from the radius or taken in a micro-vascular procedure from the iliac crest or from the head of the shin. After the operation, a forearm cast is worn for 8-12 weeks to immobilize the wrist. This length of time is required namely because it takes so long until new and flexible bone has developed. X-rays will determine if longer immobilization is necessary in order to avoid risking the success of the operation.
Scaphoid pseudoarthrosis can be as a result of a scaphoid fracture.
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