Not every case of knee osteoarthritis requires knee replacement surgery immediately.
Surgery is often the last resort, especially for younger patients.
Orthopaedic doctors stress that many factors might account for knee osteoarthritis, from the age, weight and limb alignment of a patient to the location, extent and severity of the arthritis.
"The (first) challenge is to treat any cartilage injuries in the patient before they progress to full-blown arthritis," said Associate Professor Denny Lie, senior consultant at the Singapore General Hospital's department of orthopaedic surgery.
Treatment can begin with lifestyle changes such as weight management and avoiding squatting or kneeling, as well as muscle strengthening and physiotherapy.
Treatment should be individualised, said Associate Professor Wilson Wang, head and senior consultant at National University Hospital's orthopaedic surgery department. "Swimming is a good low-impact exercise. But if the patellofemoral joint (the part of the knee joint under the kneecap) is severely affected, kicking during breaststroke will aggravate it. A different style of swimming may be recommended instead."
Hyaluronic acid injections that act as lubricants are frequently used to reduce inflammation in the knee, but they do not regenerate the damaged cartilage.
Arthroscopic procedures are effective for mild cases. In such "key-hole" procedures, the ulcer in the cartilage, a symptom of arthritis, is cleaned up and its edges are smoothened before small holes are made at the base of the ulcer.
This allows blood and stem cells from the bone marrow to be released and help in the healing of the cartilage ulcer. Over time, the blood clots and fibrocartilage, which is similar to the original cartilage, is formed.
For surgical options to replace the knee, the two main ones are partial and total replacements.
Partial knee replacement surgery preserves the bone tissue of the knee not affected by osteoarthritis. There are two ways it can be done - by the traditional manual method or with a robotic arm part of the makoplasty system.
This surgery results in earlier recovery and a more natural feeling in knee movements. But it is not suitable if the patient's arthritis affects the entire knee.
For optimal results, the organic tissue that remains in the knee, such as the anterior cruciate ligament (ACL), should be healthy.
"Results tend not to be so good if the ACL has been injured before or is not functioning normally," said Prof Wang. "In patients who have had an ACL reconstruction before, careful assessment will have to be made of the ACL graft function before this decision."