Pathology
Common Wrist Injuries
- Carpal Fracture
- Breaking the bones of the wrist
- Dislocation the Wrist
- Wrist Fracture Dislocation
- Combination of both a carpal fracture and dislocation
Wrist Dislocation
A wrist dislocation is the separation of the bones at the level of the joint with disruption of the ligaments. Ligaments attach bones to other bones and normally keep them together, providing stability while the joint moves.
Perilunate Dislocations
The most frequent dislocations about the wrist involve the joints around the lunate wrist bone, and are called perilunate dislocations.
In a perilunate dislocation, the ligament disruption occurs sequentially. It starts initially at the scapholunate joint, then progresses in a clockwise direction around the lunate, through the lunocapitate joint and lunotriquetral joint before culminating in a complete lunate dislocation in the palmar side of the wrist.
Wrist Fracture Dislocations
Wrist fracture dislocations represent a spectrum of the perilunate wrist dislocation. As in the perilunate dislocations, they are the result of high energy trauma.
Transscaphoid Perilunate Dislocation (TSPLD)
- More frequent than a lunate dislocation
- TSPLD is a dislocation of the lunate
Instead of the ligament tearing, there is instead an associated fracture of the scaphoid and the proximal scaphoid fragment is carried along with the lunate dorsally towards the back of the wrist.
Treatment
When a TSPLD has occurred, it is necessary to attempt immediate reduction of the scahoid fracture. This is necessary to avoid progressive swelling and kinking of the remaining blood supply to the scaphoid, which can potentially result in necrosis of the scaphoid bone.
This is rarely achieved by closed manipulation in the emergency room and requires the patient to be brought to the operating room for treatment. The median nerve responsible for the commonly known carpal tunnel syndrome, is located in the same vicinity, is also assessed for acute traumatic compartment carpal tunnel syndrome and is decompressed if necessary.
If the bones are successfully repositioned at the emergency room, the patient can be splinted for comfort and final treatment scheduled within days once the swelling has subsided.
If surgery is required, the surgeon will fix the scaphoid fracture (open reduction and internal fixation) and the injured ligaments in combination with pins to maintain carpal bone alignment while the ligaments that are repaired can heal in good position.
Immobilization for 8 – 12 weeks is done to allow for ligamentous healing. During initial healing, the wrist should remain supported by a splint with minimal motion allowed; the pins can easily toggle, loosen and become infected. The pins are removed after 8-12 weeks when enough time has elapsed for the ligaments to heal.