Non-union of the scaphoid

The long term consequences of a failure of the scaphoid to unite are usually weakness and sometimes pain, but more importantly the high risk of developing arthritis. The scaphoid may stick together with fibrous tissue rather than bone and in this instance some stability may result which lessens the symptoms and reduces the risk of arthritis. However, if the fracture was displaced at the time of the original injury then it is unlikely to join at all, leading to eccentric movement of both broken ends. In this scenario arthritis is probably inevitable and it is just a matter of time before it presents, probably dependent on the level of physical requirements for the hand.

If we recognise a non-union early, especially if it is causing symptoms then generally surgery is recommended to attempt to establish bony union. There are many types of operations available to make this attempt at scaphoid union, but in my opinion no single operation is suitable for all scaphoid non-unions. The site of the fracture, the length of time since injury, whether there have been changes within the bone itself (cystic change or avascular necrosis) and whether it is displaced, undisplaced or collapsed, are all important factors to be taken into consideration planning surgery. Investigations such as CT scanning or MRI scanning are frequently used to make these assessments. An injection of gadolinium may be given at the time of the MRI scan to help determine the blood supply status (vascularity) of the proximal pole.

The different types of operations include the following:

  1. Vascularised bone graft with or without internal fixation
  2. Iliac crest bone graft with or without internal fixation.
  3. Percutaneous screw fixation and core bone grafting from the radius.
  4. Inlay graft either iliac crest or distal radial as described by Matte-Russe.

My practice is quite simple - if the fracture is virtually undisplaced and there has been no shortening or collapse then a vascularised graft is appropriate. The rationale for this technique is that it addresses the problem of the blood supply to the proximal pole. The operation involves raising a piece of bone from the side wall of the radius with its blood supply still attached to it and inserting that piece of bone into a trough created across the scaphoid fracture. Essentially this results in bridging the two scaphoid fragments with a piece of live bleeding bone. If possible I try to avoid inserting any metalwork relying on pushing the graft into the trough as a 'press fit'.

Scaphoid graft001

Comprehensive articles available for perusal include the following:

  • eMedicine
  • American Academy of Orthopaedic Surgeons
  • As already mentioned smoking reduces the chances of the graft taking but even in non-smokers there is no absolute guarantee of success in achieving union. I expect a 90% success rate in compliant patients.