Unicondylar Knee replacemnt - 2

As we have seen in the previous article, unicondylar knee replacement is a natural evolution of total knee replacement. It has advantages. It is done using a minimally invasive technique. There is less cutting of skin and tissue. Muscles are not cut. This results in a faster recovery and little postoperative pain and swelling. The amount of bone removal and blood loss is less. The surgery is safer than traditional knee replacement.
The incision for unicondylar knee is half the length of a total knee replacement. The surgery is done using special instruments designed for minimally invasive surgery (MIS). The quadriceps (thigh muscle) is spared. The muscle strength remains intact after surgery. Patients can walk comfortably without a walker. As against this, the quadriceps is cut in total knee replacement, which results in weakness post-surgery. After traditional knee replacement, all patients need a walker to help them walk surgery for as long as 3-4 weeks. 
Safety has been a long standing concern of total knee replacement, especially because the surgery is performed in elderly patients. The cutting of muscle, removal of bone and blood loss puts a stress on the body. This stress becomes significant in those who have preexisting compromises like a weak heart, lung or kidney. Surgeons are worried for infection with diabetic patients. With Unicondylar surgery the stress is reduced. More patients are now eligible for knee replacement with much less risk! 
To be able to sit on the floor is important for our religious customs and traditions. This vital function was snatched away from patients after traditional knee replacement! It is the primary reason for dissatisfaction. Do we finally have an answer?
Ligaments play an important role in knee function. They give the knee stability and allow people to do high demand activities like running, squatting and sitting on the floor. In a traditional knee replacement, the ligaments (anterior cruciate ligament & posterior cruciate ligament) are cut. This I strongly believe is a loss. It is the absence of ligaments after traditional knee replacement, which does not allow patients to squat in an Indian toilet comfortably or sit on the floor. In unicondylar knee replacement, both ligaments are preserved (ACL and PCL). Preserving the ligaments has advantages. After surgery the knee feels like the natural knee. It remains stable and strong. Unicondylar surgery gives the patient the confidence to perform all daily activities in a normal fashion just like they used to when they were younger! It is a cure in the true sense. After this surgery, patients are allowed to sit on the floor, sit cross legged and even squat in an Indian toilet!
So can all arthritis patients benefit from this surgery? Ligaments are not only preserved in this surgery, they are also crucial for the success of this surgery. Unfortunately, in the arthritis process, sometimes ligaments are also damaged along with the cartilage. In patients with damaged ligaments, Unicondylar surgery does not work. For them traditional knee replacement remains the only way out. Your doctor will be the best judge to decide if you can benefit from Unicondylar surgery.       

Unicondylar Knee Replacement

Total knee replacement is an excellent surgery. It has evolved over the decades to become one of the most successful procedures in all of medicine. Patients are cured of pain and disability. They regain their ability to walk normally, without a limp or support. They can resume living normal lives again. Without surgery, they are stuck in a rut of suffering and handicap with a lifelong dependency on kidney destroying medicines.

However, total knee replacement comes with a bag of its own problems. It is not without reason that patients fear the surgery. The foremost fear is that the surgery is a major surgical adventure.

Major surgery means more risk! The risk of an adverse event in the peri-operative period is always lurking round the corner.

Major surgery means more pain! Post operative pain is dreaded! Only recently have we truly succeeded in pain control with the use of ultrasound and nerve locator guided nerve blocks and LIA (local infiltration analgesia). 

Major surgery means more weakness! Patients routinely require a walker to walk for a week or two after surgery. 

Major surgery means a longer recovery! Patients take up to 3 months to return to normalcy and actually start experiencing the benefits of the surgery. 

What is a half knee (or partial knee) replacement? The knee is made of 3 different compartments. Two compartments are between the thigh and leg bone and the third compartment is between the knee cap and the thigh bone. In total knee replacement, we replace all three compartments and sacrifice two ligaments (out of 4) and both menisci (natural shock absorbers found in the knee). However, arthritis does not damage all compartments equally. Most of the times, it is only the medial or inner compartment that suffers the brunt of the destruction. In partial knee replacement, only this compartment is replaced with sacrifice of a single meniscus. Two compartments, all 4 ligaments and one meniscus is preserved. Many studies have shown this procedure to be as effective in relieving pain as total knee replacement. The survival of partial knee prosthesis is also as good as total knee prosthesis. 

By doing this selective procedure we gain many advantages. This surgery is done by a minimally invasive technique. It involves less cutting of skin, muscle, tissue and bone. Most of the knee is left untouched as it is healthy. Hence this is not a major surgery.

Risk of an adverse event is less!

Pain is very less! Lesser volume of trauma coupled with modern pain management makes post op pain negligible.  

Less muscle cutting means minimal weakness! Patients can stand and walk without a walker on the same day, a few hours after surgery. All this translates into a faster recovery. No longer do patients have to wait for 3 months to get back to normal.  

Partial knee replacement or unicondylar knee replacement is a natural evolution of a total knee replacement. It retains all the effectiveness of a total knee and brings with it significant advantages! I have pointed out the advantage of less risk and quicker pain-free recovery in this article.....but it doesn't stop here! Stay tuned for the next article. 

PAINLESS - Total Knee Replacement

Total knee replacement is a highly successful surgery. Patients disabled with knee pain who can barely walk on their deformed legs undergone a dramatic transformation after the surgery. They experience complete relief from pain and complete correction of deformity. After surgery they don't need pain killers. They can walk normally without a stick or walker and at a normal pace. 

However the surgery is a major procedure involving cutting of muscle and bone. This leads to a slow and painful recovery. Post surgery pain after knee replacement can be unbearable and remains as a major deterrent to someone who wants to undergo the operation. Traditional methods of pain control include intravenous or intramuscular analgesic injections and epidural pumps. Intravenous medicines have safety issues and are not effective. Epidural pumps involve placing an epidural catheter (a very thin tube) in the epidural space near the spinal cord. Through this tube medicine is administered which numbs the spinal nerves and relieves pain. A well functioning epidural pump is very effective but has certain problems. Firstly, placing an epidural catheter is a blind procedure and many times the catheter is not in an ideal position. As a result it fails to reduce pain. Secondly, epidural pumps may cause a drop in blood pressure in some patients which requires constant monitoring. Lastly, epidural medicines may cause temporary sensory loss and motor weakness in the legs which makes walking after surgery difficult. 

In recent years, technological advancements in the science of anaesthesia and pain management have made painless knee replacement possible. Patients are standing and walking by evening on the day of surgery! Nerve blocks are a known technique of analgesia (pain relief). Two technologies have become available to the anaesthetist in the operation theatre which have revolutionized the efficacy of nerve blocks. First is a nerve locator. As its name suggests it helps in precisely locating a peripheral nerve which then can be blocked by administrating medicine. Second is portable ultrasound. Combining these technologies increases the accuracy of locating a nerve to 95%. This allows the anaesthetist to confidently block peripheral nerves (nerves outside the spinal cord) with predictable success. In the case of knee replacement, a femoral block and an adductor canal block is used to numb the pain. These blocks are effective and safe. There is no drop in blood pressure and no motor weakness. As a result we have successfully eliminated the need for epidural pumps. 

Another advance that we routinely use is called LIA - Local Infiltration Analgesia. This involves injecting a combination of medicines in the local tissues around the knee joint at the end of the surgery. With modern drugs and optimal doses, this technique alone numbs the knee for 12 to 24 hours. Again the technique is safe and effective. it does not require monitoring of blood pressure and does not cause any weakness. 

The last addition is that of pain patches. Newer opioid analgesics (artificial morphine substitutes) are available as pain patches. A single patch can work for a week. The action is not only long lasting but fast as the medicine is directly absorbed in the blood from the skin (bypassing the stomach). 

Not only is total knee replacement a highly successful surgery, it is now a comfortable and pleasant experience as well. Today’s analgesia is safe and effective. All patients are able to walk on the day after surgery and many manage to walk on the same day. Nerve blocks, LIA and Pain Patches are so effective that they have made painless knee replacement a reality today.