Recent advances in Total Knee replacementDr.A.K.Venkatachalam

Consultant orthopaedic surgeon, ChennaiE mail akvenkat@gmail.com

Osteoarthritis of knees affects predominantly the senior citizen age group. Increasingly large numbers of these elderly people in our towns and cities are electing to have a total knee replacement to end their agony and lead a better quality of life. They survey the market and hope to get the best deals in terms of functional outcome, surgical and post surgical care and costs. Many a time they are dissuaded by skeptical relatives or friends to have the surgery. Since cultural, social and religious requirements of Indians are different from the West, the operation has to be tailored to the specific needs of our countrymen. In this article I shall discuss some recent advances and the implications of these on the outcome of the surgery.The main factors that deter people from having any major operation for a non life threatening condition are fear and perceived high cost. Fear may stem from the thought of postoperative pain the risks of anesthesia, surgery itself. Specifically the fear of infection is a big bugbear. Ideally a major replacement should be done by well trained and qualified surgeons. Experience of joint replacement is gained by overseas or Indian fellowship training. Infrastructure of the hospital is vitally important. The operating theatres should provide “Ultra clean air” with ideal parameters. Exponential Laminar airflow is ideal where air is changed 25 times per hour. The delivered air is treated by special HEPA (High efficiency particulate air filters) with 99.99 % efficiency so that the chance of infection is reduced to the level of < 1 %. No colony forming units of bacteria should be present. It would be correct to say that facilities are limited for these standards. Costs are not exorbitant when compared to the west and only amount to one tenth of the cost in the West. A price range of 1.75 lakhs to 2.5 lakhs rupees is quoted by surgeons and hospitals for standard prosthesis designed and manufactured in the west. Increasingly large numbers of UK and USA citizens are being lured to undergo this surgery because of these low costs. The quality of care in selected hospitals matches that in the west.Let us look at some of the recent advances in a total knee replacement.

1) Minimally invasive surgery- If you ask your friend who has undergone a knee replacement, about the worst thing about the surgery, he or she is likely to blame the amount of post operative pain. Some amount of Post op pain is inevitable from any operation. The amount of tissue dissection in normal knee replacements causes iatrogenic damage to the lining of the joint and results in pain postoperatively. A minimally invasive knee replacement is carried out through a smaller incision and produces less amount of pain. In this procedure the same prosthesis is implanted using smaller incisions and specially designed instrumentation. Duration of hospitalization will be lesser, there is no need of transfusions, pain is lesser and the cosmetic effect is better. Rehabilitation will also occur faster, a return to normal activity may be possible in 6 weeks.

Fig.1.Knee replacement scar measures 5 inches only

Chronological Bilateral knee replacements done spinal anesthesia

2. Alternative modes of anesthesia- Many anesthetists and surgeons prefer regional and local modes of abolishing operative pain. Spinal, Epidural and local nerve blocks may be administered by skilled anesthetists. The benefits are increased safety as there is less stress upon the body. Diabetics, Hypertensives, and people with ischemic heart disease can undergo safe surgery. As the patient is not unconscious and is only sedated, he is unlikely to feel postoperative nausea and vomiting. A drink or light meal can be given soon after surgery as tolerated and this comes as a big boon to many elderly who are unable to tolerate overnight starvation and thirst. 3. Multi modal pain relief- Instead of relying on opioids, multimodal analgesia employs a battery of pain relief methods and drugs. Pain relief is near total and the patient will not regret that he experience at all. Ice packs, oral drugs, pain pumps, epidural anesthesia are all used to make your experience as pleasant as possible.4. High flexion knee prosthesis-Special knee implants are available which provide more flexion or bending at the knee to suit Indian, and South Asian habits of kneeling for prayer, or sitting cross legged on the ground for meals or social purposes. Muslims in particular need this to offer prayers. Even westerners have begun to appreciate the benefits of high flexion knee prosthesis as they can pursue hobbies like gardening and are

also gratified for the ability to do recreational acts. The design features of such knees incorporate cut outs at the front, rotating platform or mobile bearings, increased bony

resection at the back amongst others. Fig 4.Patient squatting after knee replacement with high flexion prosthesis.

5. Navigational surgery- In this age of computers, navigational surgery has some benefits to offer. Not only can the trained surgeon perform the operation through smaller incisions, the seating of the implants could be more accurate. Perfectly positioned implants are less likely to loosen over time. Only selected prosthesis and not all types of knee prosthesis can be implanted through less sophisticated systems and this could be a disadvantage. Costs could be slightly higher in such centres.

A knee replacement offers permanent pain relief from osteoarthritis and could be made more attractive by doctors who have embraced the latest techniques and advances.The author is a Knee specialist in Chennai and can be contacted by e mail at akvenkat@gmail.com or mobile 9282165002. More information on knee and shoulder problems is available on websites www.kneeindia.com, www.shoulderindia.com