A total knee replacement (TKR) is a common surgical treatment for knee arthritis, and surgeons have been performing total knee replacements since 1968, and in that time, technology and procedures continue to evolve and improve.This surgery is safe and an effective treatment for knee pain. Improvement in surgical techniques and the knee implants over the years has helped in increasing the success of this surgery.
Over a period of time the surgical techniques have become more refined, leading on to good healing of surgical scar and early mobilization of the patient. Now the muscle cut in surgery is less and some surgeons perform the surgery without cutting any muscle, thus patient has better control of the knee and increased range of motion post knee replacement surgery.
Management of Blood Loss
The management of blood loss has been a big factor in reducing swelling and stiffness in the post-operative period and improving limb function in the longer term. The use of Tranexamic acid has reduced the need for blood transfusion by 90%, which has significantly improved patient outcomes. In a study conducted on 125 knee replacement patients at our hospital, we found that only 11 patients required blood transfusion.
Management of Pain
In early days, the pain used to be so severe after knee replacement that some patients would refuse physiotherapy or walking for days together and some would not even undergo surgery. However, now we have the advent of multimodal analgesia, which takes care of this pain. Anaesthetists give certain types of blocks and put catheters through which pain medicine is given regularly for days. Surgeons to inject the surgical areas with certain cocktail of medicines that control the postoperative pain. At our hospital, these protocols are routinely being followed. Thus the patient can start early movement of the knee and walks early.
For better alignment of the knee prosthesis, newer technologies are being developed. These include navigation based or personalized knee systems so that the fit of the implant is perfect. Robotics are also being tested. This in turn, theoretically, would lead to longer implant life, more range of motion, and a quicker operation. The drawbacks of these new technologies are the costs involved and because the technologies are new, there is no long-term proof that these offer improved function or longevity.
Over the last 30 years, manufacturing and processing methods of joint replacement parts have improved, resulting in longer-lasting joint replacements.
A new kind of plastic, called highly cross-linked polyethylene, has greatly slowed the wearing out of the implants. This is now being blended with Vitamin E. The new plastic virtually eliminates osteolysis and lasts longer. Metal used for knee implants has evolved and we now have the use of Cobalt Chromium tibial trays and some systems have ceramic and oxidized zirconium metal surfaces.
Now the shape of the implants is such that it fits perfectly the bones of the patients and provides high range of knee movements. Some of the types are fixed bearing and some are rotating platform knee implants.
The rationale behind all these developments and advancements is that the knee replacement surgery should be a one-time surgery and should last the lifetime of the patient. For this all the above factors matter, as the use of good knee implant, good surgical skill, and a skillful adaption to the standard protocols. Currently, more than 90% of modern total knee replacements are still functioning well 15 years after the surgery. The patient has to be aware and talk to his Joint replacement surgeon regarding the best-suited knee replacement.