Carpal subluxation - differential diagnosis
What's the clinical image of a carpal subluxation ?
The functional examination shows a slightly painful and limited active and passive extension. Passive flexion is not limited but after some time, it becomes painful because one or more of the dorsal ligaments get involved (due to the local overstretch because of the carpal subluxation).
Mostly the capitate bone is the subluxated one.
The treatment consists of manipulation first, to reduce the subluxed bone, and then, if indicated, the affected ligament(s) can be treated by deep transverse friction massage.
Manipulation can be done in a specific and in an non-specific way.
Carpal subluxation : differential diagnosis ?
Manipulation should give immediate result, if not then we have to consider various differential diagnostic options such as :
- dorsal ganglion : this is soft and can be punctured
- Kienböck's disease : an aseptic necrosis of the lunate bone. Occurs spontaneously or after trauma, in young patients ("twenties"), can cause constant pain, eventually weakness
- a non-union fracture
- an isolated osteoarthrosis.
In the last three cases medical imaging is called for.
Remark : a palmar carpal subluxation is a rare possibility too. Mostly the lunate bone subluxes causing a small limitation of flexion and perhaps partial compression on the median nerve.