Loco typico distal radius fractures
This question is asking about fractures of the distal radius, to answer this we should consider some of the basic anatomy of the wrist joint. The wrist has a proximal and distal wrist joint. The proximal wrist joint is a condyloid joint between the bones of the forearm with the carpal bones. The distal wrist joint, also functions as a condyloid joint, joints the proximal carpal bones with the distal carpal bones.
The overall range of movement offered by these two joints is:
- Adduction - Abduction - 30-0-30
- Dorsal extension - plantar flexion - 100-0-80
The distal part of the radius (which we are most interested in) has a number of anatomical features that are noteworthy. It articulates directly with the scaphoid and lunate inferiorly, along with having a medial ulnar notch, where the ulna articulates. Furthermore, the radius has a styloid process on its lateral portion, and three grooves for tendons, the extensor digitorum groove, extensor carpi radialis (longs and brevis) groove) and area for extensor pollicis brevis and abductor pollicis longus muscles.
Fractures of the distal radius are very common, often caused by falling on an outstretched hand. We divide the fractures up as follows:
- Colles fracture
- Smith fracture
- Barton fracture
- Radial styloid fracture
Below we consider each one.
Colles fracture
Colles fracture requires three clinical features:
- The fracture is within one inch of the wrist
- Has a dorsal angulation of the distal fragment
- Has dorsal displacement of the fragment
- Is associated with a fracture of the ulnar styloid
There is a clear deformity in Colles fracture where there is a ‘dinner fork’ of backward angulation with five separate elements:
- Backward angulation
- Backward displacement
- Radial deviation
- Supination
- Proximal impaction
Complications following Colles fracture are not uncommon, they include:
- Sudeck's atrophy
- The hand becomes stiff and blue with reflex sympathetic dystrophy caused by disturbance of sensory and autonomic supply of bone and vessels
- More common if the patient does not move their fingers - it is vital patients do this to avoid this complication
- Median nerve damage
- The median nerve runs along the site of the colles fracture and can become compressed. This usually decompresses after time
- Rupture of extensor pollicis longus tendon
- The pollicis longus tendon runs across the fracture site, look out for thumb drooping
- Malunion
- Due to the instability of the bone malunion is common