Total Knee Replacement- Minimally Invasive

When is total knee replacement required?

Total knee replacement is often advised for patients with severely damaged or degenerated knee joints. Knee joint degeneration can occur due to the following issues:

• Knee Osteoarthritis (Knee OA) is the inflammation and breakdown of the protective cartilage at the ends of the bones. It is very common in weight-bearing joints like knees, hips, spine, shoulder, etc. and leads to pain, stiffness, tenderness, loss of flexibility, and swelling of the affected joint. Over time, patients may even lose complete mobility and need joint replacement.
• Knee Rheumatoid arthritis (Knee RA), also known as inflammatory arthritis, is an autoimmune and inflammatory disease in which the immune system starts attacking the joint tissues and causes inflammation in joints all over the body. It commonly affects multiple joints simultaneously and leads to chronic pain, instability of the joints, and joint deformities, most commonly in knee, hand, wrist, and hip joints.
• Post-traumatic arthritis is inflammation of the joints due to improperly treated injuries. Over time, the joints will start degenerating. It most commonly affects the ankle, knee, hip, and elbow joints; and is characterized by pain, swelling, stiffness, and instability of the affected joint.

You should start considering total knee replacement surgery if you have:

• Severe chronic knee pain that is limiting your mobility
• Moderate to severe knee pain that happens throughout the day
• Chronic inflammation of the knee joint that can’t be treated even with rest and medications
• Knee joint deformities, i.e., bowing in or out of the knee joint
• Inability to get pain relief even after medications and exercises

Types of total knee replacement

• Unilateral total knee replacement
• Bilateral total knee replacement

What happens during total knee replacement?

If you’ve made up your mind regarding the surgery, you will need to undergo thorough diagnosis to help assess the severity of the condition, determine the type of implant to be used, etc. Diagnosis involves physical examination of the affected joints, imaging tests like CT scan, MRI scan, X-rays, etc., followed by a general health check up.

Total knee replacement procedure takes about 1 to 3 hours and can be performed under either general or spinal anesthesia. During the surgery, the surgeon creates an incision over the affected knee, removes the generated joints, and places the chosen prosthetic in its place. Then the wound is closed, using sutures or clips, and dressed. 

The surgery can be performed traditionally or arthroscopically. In minimally invasive surgery, there is very little bleeding, and the procedure usually does not need any blood transfusions. However, open/traditional surgery requires more care.

What are the different types of knee implants?

There are three main components in a knee implant:

• Femoral component is directly attached to the femur and has a groove that allows the patellar component to slide while you are bending the knee joint.
• Tibial component is a flat two-piece part of the implant that is attached to the tibia. It may have a plastic part that acts as a cushion between the tibial and femoral components.
• Patellar component is a plastic dome-shaped component that is resurfaced to match the shape of the patella. 

The plastic components of the implant are made of polyethylene, while the metal component is usually made of cobalt-chromium, titanium, zirconium, and nickel. Knee implants can be categorized into four categories based on what they are made of:

• Metal on plastic
• Ceramic on plastic
• Ceramic on ceramic
• Metal on metal

Your orthopedic surgeon will discuss your treatment and prosthetic options with you and help you decide the best prosthesis for you.

What to expect after total knee replacement surgery?

Proper recovery and rehabilitation are crucial for the success of total knee replacement. If the patient doesn’t take proper care during this period, the surgery can fail. Rehabilitation generally lasts for 12 weeks, but can take longer, if needed.

You will start walking with support from an assistive device like a walker, crutches, cane, etc., immediately after the surgery. Most patients are discharged within 1-3 days of the surgery, based on the type of surgery, type of implant, etc. 

You may have to wait 5-7 days before showering and 3-4 weeks before swimming, bathing, etc., to avoid soaking the wound. You may be able to start walking without support after 2-3 weeks. You will notice significant improvement in joint strength and range of motion within 4-6 weeks. Mild exercises can be started around the 7-12 week interval.

What are the benefits of total knee replacement surgery?

Some common benefits of total knee replacement surgery are:

• It will return mobility to the affected joint. In patients who have become completely bedridden due to degeneration of both knee joints, it can provide a new lease on life.
• It will enable the patient to perform realistic activities like walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other low-impact sports.
• It will provide long-term relief from knee joint pain and inflammation to the patient for a better quality of life.

How to improve recovery after total knee replacement?

5 tips to help you promote your healing and reduce recovery period:

• Keep the operated knee joint straight. Wear a knee brace to prevent any unnecessary strain. Use a crutch or wheelchair whenever possible.
• Follow your physiotherapy routine, as approved by your physiotherapist and surgeon.
• Avoid strenuous activities like running, gym exercises, lifting heavy objects, etc. to avoid straining the prosthetic before it has healed completely.
• Avoid twisting your knee. Be careful while bending, kneeling, and sitting.
• Don’t schedule any other procedures before you have recovered completely.
• Avoid smoking and drinking during the recovery period. Alcohol can react with pain medications and cause postoperative complications, and smoking can delay the healing process.
• Use ice packs to massage the operated area to reduce postoperative swelling. On that has reduced, use heat packs for massaging to relax the joint muscle and ligament tissues and promote healing.
• Eat a healthy diet to avoid constipation and boost the immune system.

Generally, outpatient physical therapy after knee replacement treatment lasts about 4 to 8 weeks. Your physiotherapy duration and requirement after total knee replacement surgery depends on:

• The required range of motion of the joint
• Patient’s gait and mobility especially while using assistive devices.
• Strength of the joint muscles
• The amount of scar tissue
• Post-operative inflammation

What are the risks and complications associated with total knee replacement surgery?

Although minimally invasive knee replacement surgeries are very safe, in rare cases, some complications that may occur are:

• Anesthetic complications such as headache, nausea, drowsiness, sore throat
• Heart attack or stroke
• Infection or bleeding
• Blood clots formation, i.e., deep vein thrombosis, pulmonary embolism, etc.
• Failure to resolve pain and other symptoms
• Nerve or artery damage
• Allergic reaction to the implant or failure of implant to integrate