Final answer:
Wrist extension weakness with radial deviation could indicate an injury to the extensor carpi radialis brevis muscle, which assists in extending and abducting the wrist. Damage to this muscle could affect wrist stability and motion. Injuries involving the radiocarpal joint could require surgical intervention.
Step-by-step explanation:
Wrist extension weakness with radial deviation might suggest the diagnosis of an injury involving the extensor carpi radialis brevis muscle. This muscle assists the extensor radialis longus in extending and abducting the wrist; it also helps to stabilize the hand during finger flexion.
If this muscle is strained, torn, or otherwise impaired, it could result in wrist extension weakness specific to that muscle and a consequential radial deviation due to the imbalance of muscle actions.
Injuries to the wrist can be complicated if they involve the joint surfaces, such as a fracture of the distal radius. If the fracture involves the radiocarpal joint surface of the wrist, it may lead to significant pain, a decrease in the range of motion, and potential long-term functional impairment of the wrist joint.
In severe cases related to joint surface damage or where conservative treatments fail, surgical intervention might be necessary.