There are a number of potential causes of Hornerâs syndrome, each affecting a different place in the sympathetic chain: 1  First order neuron lesion: brainstem stroke. 2  Second order neuron lesion: apical lung tumor, neck trauma, other. 3  Third order neuron lesion: orbital trauma or inflammation, carotid dissection, other.
In very severe cases where the patella keeps dislocating, the attachment of the patellar tendon may also have to be moved. Once the surgery heals, the patella will track up and down in the patellar groove, reducing pressure on the articular cartilage. 1  Knee Pain: Symptoms, Causes, and Treatments.
This injury is caused by a forceful blow to the lower leg while the foot is planted, causing the knee to move in an unnatural direction. Symptoms of the unhappy triad include: 1  A popping or tearing sound at the time of the injury. 2  Extreme pain immediately following the collision. 3  Rapid swelling of the area. 4  Difficulty moving the knee, even days after injuring it. 5  Instability, especially when trying to walk.