Although removing part of the lateral meniscus in the knee (partial meniscectomy) has an excellent result in most people, there are exceptions. About one-third of these surgeries result in symptoms like those you describe. There may be limping, difficulty climbing stairs, and trouble squatting. The knee can also lock up in one position.
Sometimes these problems occur in older adults who have the surgery. Problems of this sort are also more common in people who are overweight. Losing weight can help take pressure off the joint. Sometimes an exercise program to strengthen the knee can improve the function of the knee while decreasing pain and swelling. Talk to your doctor about these possibilities.