Knee Replacement Surgery: All You Need To Know About

13 March,2024

Are you suffering from knee pain that has limited your range of motion? Are you unable to enjoy your life to the fullest because of severe knee pain? Have medications stopped working for you? If the answer to any of these questions is yes, you might require knee replacement surgery. 

After a certain age, the bones and cartilage become damaged and stop working as they should. Replacing the worn-out joint with a prosthetic one is the most suitable option. But just age is not the criteria for knee replacement anymore. The procedure has seen significant improvement after the first knee replacement surgery in 1968. Over 1 million knee replacement surgeries are now done annually worldwide.

This article is a complete guide that will help you learn about various types of knee replacement surgeries, their indications, procedures, and how to recover. 

What is Knee Replacement Surgery?

Knee arthroscopy is better known as knee replacement surgery. The word arthroscopy means repairing the joint surgically. Knee replacement surgery involves reconstruction and replacement of the degenerated/deteriorated knee joint using prosthetics or artificial joints. 

The knee joint consists of three bones: the femur (thighbone), tibia (shinbone), and patella (kneecap). Soft tissues like muscles, tendons, and ligaments keep the knee joint intact and help with movement. The meniscus is the cartilage cushion between the bones that helps absorb shock. 

Depending upon the severity of your condition, the surgeon might recommend either of the following knee replacement surgeries.

• Total Knee Replacement: TKR or total knee replacement is the complete replacement of the knee joint from both sides (inner and outer). It is the most widely performed knee replacement surgery. The procedure usually takes 1 hour to complete, and patients can start walking within 24 hours of the surgery.
• Partial Knee Replacement: In young patients who have had trauma or early arthritis, a partial knee replacement is recommended. The orthopedic surgeon will replace only one side of the knee (mostly the inner side).

Why Do You Need Knee Replacement Surgery?

A knee replacement surgery is the last sought option for people experiencing severe knee pain. There can be numerous reasons for knee pain, but the most common ones are – 

• Osteoarthritis: It is an age-related wear and tear type of arthritis that primarily affects people aged over 50. There is a gradual loss of cartilage, which makes the knee bones rub against each other, causing severe pain.
• Rheumatoid arthritis (RA): RA is an autoimmune condition in which the synovial membrane surrounding the knee joint thickens. The body identifies the cushioning in the knee joint as a foreign body part and starts attacking it. With the reduced amount of soft tissue, there is pain and restriction in the range of motion.
• Posttraumatic arthritis: It is followed after a severe injury to the knee. Ligament tears and bone fractures can cause articular cartilage damage over time, ultimately causing pain. 

Apart from the conditions mentioned above, the orthopedic surgeon recommends knee replacement surgeries for patients with –

• Severe knee stiffness and pain while performing everyday activities like walking, climbing stairs, getting in and out of bed/chair
• Constant pain while resting, irrespective of day and night
• Deformities in the knee joint
• Chronic inflammation and swelling in the knee that does not improve with rest and medicines

A knee replacement surgery is usually done when medical treatments like pain medicine, anti-inflammatory medicines, cortisone injections, glucosamine supplements, physical therapy, use of walking aids (cranes), weight loss, etc., are no longer beneficial to the patient. 

What to Expect Before Knee Replacement Surgery?

• Before performing the knee replacement surgery, the orthopedic surgeon will inform you about the complete procedure, its benefits, and the risks involved. The surgery will be conducted only after getting proper consent from the patient. 
• You will have a consultation with the assigned surgeon, who will discuss your past medical history and family history. The surgeon will also carry out a physical examination to make sure you are ready for the surgery.
• You might also undergo a series of tests like liver function, kidney function, blood, viral marker, and imaging tests before the surgery.
• You must tell the surgeon and the operating team if you are allergic to any medications or anesthetic agents. Inform them in advance about the medications, including prescribed, over-the-counter, and herbal drugs you take.
• Notify the doctors about any blood disorder you have or blood thinning and anticoagulant medications like warfarin or aspirin you take. The doctor might ask you to stop these before the procedure.
• An eight-hour fasting is necessary before the replacement surgery. You may also receive a sedative to help you relax.

How is Knee Replacement Surgery Performed?

Knee replacement surgery is a one to two-hour process done under general anesthesia. On the day of the procedure, a healthcare professional will take you to the operating room and clean the surgical site. Knee replacement surgery generally involves the following four steps – 

• Preparing the Bone: The surgeon will make an incision of 8-10 inches over the knees to access the joint. After that, the surgeon will move the patella aside and remove the damaged cartilage from the ends of the femur and tibia bone, along with some underlying bone.  
• Place the Implants: After removing the damaged cartilage, the surgeon will place the prosthetic implants and recreate the joint surface. Different combinations of implants, like metal on metal or metal on ceramic, can be used depending on your choice and condition. Earlier cements were used to fix the joints, but today’s implants have porous surfaces where the bone grows naturally. 
• Resurfacing Patella: The next step involves cutting the undersurface of the kneecap (patella) and resurfacing it with a plastic button. 
• Spacer Insertion: The final part is placing a medical-grade spacer to make a smooth, gliding surface for the metal implants. After placing the spacer, the surgeon closes the incision using sutures. 

With advancements in surgical techniques, there has been a reduction in the size of incisions. The minimally invasive surgery (MIS) requires a smaller incision of about 4 to 5 inches. Robotic knee replacement has significantly improved the precision of placing implants in the correct position. The surgeon can substantially reduce post-operative complications and recovery time using these innovative techniques.

How Long Will You Take to Recover After a Knee Replacement Surgery?

• Once the surgery is complete, the paramedical staff will take you to the recovery room to monitor your heartbeat and respiratory rate. You will wake once the anesthesia withers off. 
• You might stay at the hospital for a few days after the knee replacement surgery. During your stay, a rehabilitation team will help you understand the recovery process. It will include physiotherapy sessions to help you strengthen the knee joint and start moving again. 
• The surgeon will discharge you if there are no post-operative complications and prescribe pain medicines.
• The physical therapist will provide you with a complete exercise plan to speed up your recovery. Your movements will gradually increase over time. 
• Not two patients are the same. However, the general timeline of recovery after a knee replacement is as follows –
  • In the first 24 hours, you can move in and out of the bed and walk short distances using aids like walkers.
  • In the first week following knee replacement surgery, you will receive physiotherapy to increase the range of motion and strength of muscles. The therapist will work with you to restore your walking pattern.
  • In the next three weeks, you can expect a similar pattern of rehabilitation. By the end of three weeks, you can expect a switch from a walker to a cane. You will be able to walk longer distances. The pain medication is usually stopped by this time.
  • After 4 to 6 weeks, you can drive vehicles and go to the office if you have a desk job. You will observe a reduction in the swelling and inflammation by the end of 6 weeks. 
  • If you diligently follow the physical therapist's advice, you can start swimming and cycling after 12 weeks. 
  • Most people resume their pre-surgery activities after three months. They observe a significant reduction in pain and can efficiently perform everyday activities. 

How Long Will Your Knee Implant Last?

Gone are those days when you would be requiring repeated knee replacement surgeries due to the poor quality of implants. With improvements in surgical techniques and the quality of implants, most knee replacement surgeries last for 20+ years. Avoiding high-impact sports like football, rugby, and basketball will help increase the artificial joint's longevity. 

Are There Any Risks Associated with Knee Replacement Surgery?

Every surgery has some risks associated with it. The same is the case for knee replacements. There is a chance that the implants will get infected or loosened over time. The nerves and the blood vessels can get damaged during the procedure, leading to weakness or numbness. Other risks of knee replacement surgery are –

• Bleeding
• Deep vein thrombosis
• Blood clots
• Anesthesia complications
• Allergic reactions

The frequency of these complications is less than 5%, making knee replacement a highly successful procedure. 

The Bottom Line

If you are suffering from painful knees that cannot be managed with medications anymore, you can be a potential candidate for knee replacement surgery. It is a reliable procedure that provides significant relief from arthritis pain. However, learning about the surgical procedure is crucial before deciding whether to get a knee replacement. The surgery is a well-established and safe procedure, with more than 90% of implants functioning well after 10-15 years. Having constant follow-ups with the surgeon helps ensure that the artificial joint stays in good condition for a longer time.