The knee is a remarkable creation. It is both durable and vulnerable at the same time. The way the knee is assembled, with the patella (kneecap) virtually "floating" in front of the joint with relatively large spaces between the related bones, the knee depends on surrounding muscle and ligaments to keep it stable and strong. Damage to the knee is common in athletes, and is generally thought to be associated with the bones though that is not the case. Knee injuries are most often associated with the ligaments, muscles and cartilage that holds it together.
Actual kneecap injuries are not the usual source of knee problems. The cartilage and ligaments are. Consequently patella surgery is not performed as a first line treatment of most knee injuries. Most knee problems are minor and can be effectively dealt with by simple home treatments such as rest and ice. Others may require advanced physical therapy under the care of a licensed therapist. And finally others may have to be dealt with by surgery or other major interventions. But in every case there will be eventual exercise to retain or restore the normal range of motion of the knee joint.
Patella surgery is most often performed after a severe trauma to the knee such as kneecap dislocation from a hard twist to the leg. I've seen people in martial arts tournaments dislocate their knees while free sparring. It causes horrendous pain and is immediately disabling. It is generally from these type situations, if less invasive methods do not work, that surgery will be performed to realign and strengthen the kneecap.
Another issue that regularly results in surgery is Chondromalacia patella which is the softening or degeneration of the cartilage underneath the patella. In young people the condition is generally thought to be related to injury or excessive force on the knee joint. In older people it may be a sign of arthritis. People who have had a dislocation of the knee or other previous injury are most likely to develop this condition. In either case the condition inhibits the correct alignment of the kneecap. My mother has the condition in both knees and the cartilage is virtually gone between the bones of the knees leaving her in chronic pain and with very limited use of both knees.
Initial treatment of Chondromalacia patella may include anti inflammatory medications and rest to relieve pain combined with physical therapy to keep the knee's range of motion. If therapy does not work to realign the kneecap then patella surgery may be required. This is normally a last resort after all the other therapeutic methods. And doctors will not perform the surgery if it is determined that in very elderly individuals the surgery would not alleviate the problem.
Finally, as a preventive measure, be sure to exercise using full range of motion with the knees. Strengthening the muscles around the knee is the best protection you have against knee injury and deterioration. This, along with good walking posture and good nutrition will go a long way in getting a full life's use from your knees.
In any case, be sure to check with your physician if you experience any pain, problems walking straight, or injury to the knee. Problems left untreated can take what could be corrected, and turn them into chronic lifelong issues.
