Joint mouse (ankle)
A joint mouse is a loose piece of bone or cartilage. It can occur due to a cartilage defect, but is also often caused by a bone fracture or serious accident to the joint, which causes a loose piece of bone to enter the joint.
What are the symptoms of a joint mouse?
The loose piece of bone or cartilage can cause pain and "lock" the joint.
Diagnosis
The final diagnosis is made by asking specific questions about the symptoms and an examination of the joint. An X-ray is also taken.
If this does not provide enough information, an additional NMR scan (MRI) or CT scan may be performed.
How is a joint mouse treated?
During keyhole surgery (arthroscopy) the loose fragment can be removed. During this the surgeon looks inside the joint and can also directly treat any abnormality.