Knee arthritis can be due to age related degeneration of joint or because of inflammatory arthritis such as Rheumatoid Arthritis, Psoriatic Arthropathy etc.
There may be a genetic predisposition to knee arthritis in some patients. Overweight per se may not lead to arthritis but can aggravate the degenerative process in apatient who is prone to develop it for other reasons. Also if arthritis does develop, obese patients are less likely to respond to non-operative treatment. It is therefore very important to keep one’s weight is check to prevent degenerative changes in knee.
Weight reduction can help avoid or delay knee replacement surgery in most cases but upto a point.If Arthritis becomes advanced with severe changes in knee joint causing continuous pain, difficulty in walking, Knee Replacement Surgery may be required. It could be Partial Knee Replacement or Total Knee Replacement depending on the type and extent of involvement as seen on x-rays.
There is no question that if a patient is thin, averageweight, surgery is easier to perform, post – operative rehabilitation is faster and chances of complications are less.
So what do we do if an obese patient with body mass index (BMI) of over 35 develops severe Arthritis which would merit knee replacement? Do we condemn an obese patient to pain or offer surgery?
Knee replacement in obese patients carries higher risk of infection, thrombosis, slower rehabilitation, increased length of stay in hospital and survival of the implants is relatively less. But research has shown that the difference in not so much as to deny knee replacement to grossly overweight or obese patient.
It would be very nice if one could lose weight by diet control or exercise before surgery. But it is easier said than done and chances of getting thinner by these means are very slim! What about weight reduction by Bariatric surgery?
Research has shown that patients develop Anaemia, Malabsorption, Osteoporosis and other changes in physiology following of Bariatric surgery.
It is controversial whether benefit of lower weight by Bariatric surgery is enough counter balance risks of complications due to altered metabolism.
However if Bariatric surgery is done, one must give a gap of at least six months before knee Replacement is done to prevent complications.
Patient often say that because of arthritis, they cannot lose weight as they cannot walk enough. Sometimes they presume or they are promised that following knee replacement, they will lose weight due to increased mobility.
That is contrary to the findings in the research conducted at various centres.
There is no change in BMI after knee Replacement compared to patients with arthritis who have not undergone surgery. In fact there may be increase in weight 2 years following surgery, because patients have much better quality of life following pain relief and tend to eat even better! This must be keeping in mind and step taken to avoid this tendency.
But the good news is, that overweight or obese patientshave excellent pain relief following knee replacement in case it is required because of advanced arthritis
Even though knee Replacement in obese patients is challenging, technology has come to surgeon’s aid. Availability of computer navigation like Gyroscope based navigation system makes getting the alignment easier, reduced bleeding and rehabilitation is faster.
A little more restrained or constrained type of knee prosthesis such as posteriorly stabilized knee implants are required in obese patients to guard against ligament laxity following surgery.
Obese patients deserve pain free life as much as thin ones. Research has proven that risks even though higher, far overweigh the disability and pain sufferedby patient due to advanced arthritis. In Nutshell, knee Replacement is a worthwhile endeavor in obese patients with advanced arthritis of knee.
DR YASH GULATI
MS. Dip Sports Medicine (Dublin)
MCh. (orth) England
PADMA SHRI National Award
DR. B.C. ROY National Award
Sr. Consultant Joint Replacement & Spine SurgeonApollo Hospital Delhi
Advisor Orthopaedics Apollo Group Of Hospitals