Scaphoid fractures are common carpal injuries
Despite their prevalence, the imaging diagnosis in remains problematic.
Plain radiographs with dedicated views of the scaphoid bone are standard
Displaced scaphoid fractures are easy, undisplaced fractures may be occult.
Negative plain films are often treated as fracture with casting for a number of weeks.
Bone reabsorbtion around the fracture then makes it more obvious
Early clinical review may support the diagnosis, occasionally MRI is performed at this time to confirm.
More usually casting is continued until the fracture heals usually for approximately 6 to 8 weeks.
If there are still symptoms then, MRI helpful in deciding whether the cast can be removed or further treatment required.
Coronal orientated T1 and fat suppressed images are most helpful.
If the scaphoid is not fractured, the radial styloid, other carpal bones and base of the thumb should be scrutinised carefully
The principal complication of scaphoid fracture is avascular necrosis.
This arises because of the unique blood supply of the bone.
Fracture through the scaphoid waist may disrupt this blood supply and lead to AVN of the proximal pole.
Imaging may demonstrate
• Sclerosis on X Ray
• Preservation of normal bone density in the light of reducing bone density elsewhere.
• Loss of normal narrow signal on T1 weighted images in the proximal pole.
• If marrow signal is also low on T2, avascular necrosis is confirmed
• Contrast enhancement may assist with the diagnosis in some cases
• Dynamic enhancement curves difficult to usefully interpret
One of the commonest causes of radial side wrist pain is osteoarthritis of the scaphoid-tripezium-trapezoid (STT) and the first carpometacarpal joint.
Pain does not correlate well with radiographic abnormality
May correlate better with synovitis on ultrasound
Advanced disease is easily diagnosed on plain radiographs
although these do not distinguish between chronic inactive disease and patience with active synovitis or synovial cysts and
more advanced imaging is required using MR or ultrasound.
Ultrasound has one advantage over MRI in that diagnosis can be followed by a guided injection.
A palmar approach is useful for injecting the 1st CMC joint
In addition to the capsule, a strong ligament passes between the base of the 1st MC and tripezium
There are superficial and deep components
These can be traumatised
