The knee can be divided into three compartments: Patellofemoral: the compartment on the front of the knee which contains the knee cap, medial compartment: the compartment on the inside of the knee, and lateral compartment : which is the area on the outside of the knee joint.

Arthritis is a general term covering numerous conditions where the joint surface or cartilage wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for several reasons; often the definite cause is not known.

When the articular cartilage wears out the bone ends rub on one another and cause pain. This condition is referred to as Osteoarthritis or “wear and tear” arthritis as it occurs with aging and use. It is the most common type of arthritis.

SYMPTOMS

Knee Arthritis causes pain and decreased mobility of the knee joint. In the arthritic knee, there is an absent joint space that shows on X-ray.

ARTHRITIC KNEE

The cartilage lining is thinner than normal or completely absent. The degree of cartilage damage and inflammation varies with the type and stage of arthritis. The joint space is narrowed and irregular in outline; this can be seen in an X-ray image. Bone spurs or excessive bone can also build up around the edges of the joint. The combinations of these factors make the arthritic knee stiff and limit activities due to pain or fatigue.

CONSERVATIVE TREATMENT OPTIONS

Conservative treatment options refer to management of the problem without surgery. Some conservative treatment measures for knee osteoarthritis includes:

• Activity Modification and Limitations
• Weight Reduction
• Anti-inflammatory Medications
• Physical Therapy
• Orthotics such as canes, braces, or insoles
• Injection of steroid and analgesic into the knee joint.

Surgery

A total knee replacement, also known as total knee arthroplasty, involves removing the arthritic parts of the bones at the knee joint (the tibia: the shin bone; the femur, or thigh bone; and the patella, or kneecap) and replacing them with artificial parts. These parts consist of a metal cap at the end of the femur and a cemented piece of metal in the tibia with a plastic cap on it to allow the surfaces to move smoothly. When appropriate, the back part of the kneecap also may be replaced with a smooth plastic surface. This generally takes 60-75 min per knee joint. Typically, the knee replacemet surger is done under spinal anaesthesia. Most patients are mobilised on the same or the next day from surgery.

POST-OPERATIVE RECOVERY

Common Post-Operative guidelines includes:

• You will be taken to the recovery room and monitored.
• You will be given pain medication to keep you comfortable.
• Swelling is normal after knee surgery. Ice, compression, and elevation of the knee will be used to minimize swelling and pain.
• You will be given specific instructions regarding activity. Usually there are few activity restrictions.
• You will be referred to a rehabilitation program for exercise and strengthening.
• Eating a healthy diet and not smoking will promote healing.

RISKS AND COMPLICATIONS

As with any major surgery there are potential risks involved. Specific Complications related to Bicompartmental Knee Resurfacing surgery includes:

• Infection:
  Infection can occur with any operation. In the knee this can be superficial or deep. Infection rates are approximately 1%. If it occurs it can be treated with antibiotics but may require further surgery.
• Deep Vein Thrombosis: -
  DVT are blood clots that can form in the calf muscles and travel to the lung (Pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify the hospital whre you got operated or any local hospital ASAP.
• Injury to blood vessels or nerves: -
  rare but can lead to weakness and loss of sensation in part of the leg. Damage to blood vessels may require further surgery if bleeding is ongoing.
• Arthrofibrosis:-
  This is the development of thick, fibrous material around the joint that often occurs after joint injury or surgery and can lead to joint stiffness and decreased movement.
• Wear: -
  The components eventually wear out over time, usually 10 to 15 years, and may need to be changed.
• Fractures or breaks: -
  Can occur during surgery or afterwards if you fall. To fix these, you may require surgery.

INDICATIONS FOR TOTAL KNEE REPLACEMENT

Total knee replacement surgery is commonly indicated for severe osteoarthritis of the knee. I may advise total knee replacement if you have:

• Severe knee pain that limits your daily activities (such as walking, getting up from a chair or climbing stairs)
• Moderate-to-severe pain that occurs during rest or awakens you at night
• Failure to obtain pain relief from medications, injections, physical therapy or other conservative treatments

WHAT TO EXPECT DURING AND AFTER TKR?

It is a major decision on the part of the patient to choose total knee replacement surgery and there are many fears and misconceptions around it. Here we will try to address some of those.

• Fear of pain-
  This is a valid fear. The procedure is extensive and involves removal of diseased bone, cartilage and soft tissue. So some amount of pain is to be expected. However , with modern techniques of surgery and anaesthesia in the intra and post op period, including various blocks, infiltration drug cocktails and post op catheters, the pain can be controlled to a great extent.
• Duration of hospital stay-
  Usually the patient is admitted a day before the procedure and discharged between 2-3 days post operatively. The exact duration of stay depends upon the general fitness of the patient, pain level and physiotherapy milestones achieved after surgery.
• Use of blood products-
  Significant blood loss is uncommon, but may need transfusion if preoperative hemoglobin was low. Hemoglobin is checked on the day after surgery and this is used to determine if a transfusion is necessary.
• Duration of dependency on walking aids-
  Every patient wishes that he or she be back to walking unaided as soon as possible after surgery. In reality this again depends upon the pre op fitness levels of the patient, the post op physical therapy and the quality of the surgery. Generally patients take between 2 weeks to 6 weeks to be able to walk independently. Patient can expect to experience improvement up to one year after surgery.
• Ability to squat or use Indian toilets--
  Generally, it is advised post surgery to avoid squatting or using Indian toilets as this tends to put excessive repeated stresses on the bones and implants. A patient may not have the muscle strength and coordination to be stable and may fall causing a fracture. Most patients however are able to sit cross legged on sofa/ bed.