Scaphoid nonunion means failure of the scaphoid bone to heal after a fracture.
The scaphoid is one of the 8 carpal bones that form the wrist on the hand side of the joint.
Unfortunately, the scaphoid is one of the more common fractures that fail to heal.
I feel that delay in initial treatment is an important cause for this, apart from its precarious blood supply. This delay is usually due to late presentation on the part of the patient, as there may be no signs externally of this fracture after an injury except a bit of pain. The other reason is also the difficulty in picking up these fractures on initial x rays.
It is good to have a high index of suspicion for this fracture and over treat it rather than under treat it.
As seen in the picture above there is a fracture of the scaphoid missed initially, and unfortunately failed to unite.
What happens next??
In my opinion, once the non union develops, it requires a surgery. I always perform a CT scan to clearly define the fracture.
Figure 2 CT scan showing a 1 year old nonunion with cavities and ‘hump back’ deformity.
I perform the surgery depending on the site of the fracture. Most fractures in the middle of the scaphoid (waist) can be approached from the volar(less hairy part of the wrist!)Side.
The fracture is exposed; surfaces are made raw and bleeding and hard ends are removed. Idea is to remove the areas which contain the cysts. This creates a rather large void that I prefer to fill with a bone piece (graft) taken from the pelvic bone (Iliac crest).
Fixation is done with pins or screws.
Figure 3 . Operative picture showing the exposed fracture
Figure 4 shows fracture site with ‘freshened ends’
Figure 5 bone graft from the pelvis
Figure 6 bone graft wedged in the fracture site
Figure 7 graft fixed with pins
Figure 8 post op x rays showing healed fracture
Figure 9 final clinical result
Figure 10 final scar
How successful is the surgery?
Success is defined as obtaining union. This depends on the site of the fracture and size of the fragments as well as the preservation of blood supply. If the blood supply is preserved, in my practice I have been able to achieve union in the vast majority of the patients. If the blood supply is hampered, one may need to go for a special graft with its blood vessels taken as well.(Vascularized bone graft) .