The knee joint is a hinge joint comprising three bones, femur(thigh bone), tibia(shin bone) and the patella (knee cap). The lower surface of femur and upper end of tibia is covered with cartilage. The cartilage in turn is covered by a synovial membrane that produces synovial fluid which helps in reduction of friction. Menisci are crescent shaped wedges present between the tibia and femur. Multiple ligaments present inside and around this joint provide it with stability while the surrounding muscles provide strength to the knee joint. Conditions like osteoarthritis and rheumatoid arthritis may lead to chronic knee pain which interferes in the normal daily functioning. When medical and physical rehabilitation aren’t able to provide relief from symptoms your doctor might refer you to an orthopaedic surgeon for a total knee arthroplasty. Annually 600,00 Americans undergo this procedure.
On the day of the surgery you will be admitted to the hospital. The anaesthesia team will evaluate you and with their input help you decide the type of anaesthesia to be used for the surgery. The surgery can be done under general, epidural, or regional block anaesthesia. After the effect of anaesthesia sets in your surgeon will proceed to remove the damaged cartilage and a small amount of bone from the affected knee joint. The damaged cartilage and bone is replaced with a metal prosthesis that mimics the joint surface. Depending upon the type of prosthesis it is cemented or ‘press fit’ into the bone. A plastic spacer is introduced between the metallic surfaces to ensure smooth movement. The patella may or may not be resurfaced.
Many conditions lead to chronic knee pain leading to difficulty in performing normal day to day activities. These include:
Amongst patients suffering from these conditions total knee arthroplasty is recommended for individuals with:
Preparing for a total knee arthroplasty will require multiple tests and possible lifestyle changes to ensure a swift recovery and reduction in long term complications following the surgery.
Total knee arthroplasty is a relatively safe procedure, with serious complications seen only in 2% of patients. The complications encountered are:
Following the surgery you will be constantly monitored during your stay in the hospital. Multiple measures will be taken to reduce the risk of formation of blood clots in your leg. These measures are
You will be staying in the hospital for a few days after the surgery. Before you are discharged from the hospital you will be taught several exercises to restore movement and strengthen your knee joint. It is essential that you perform these exercise two to three times a day, for a few weeks at your home. To restore motion you will be advised to use a machine called Continuous Passive Motion (CPM) exercise machine; it passively moves your knee while you are at rest. You will be advised to slowly increase your mobility. Most patients are able to resume light daily activity in 3-6 weeks after the surgery. Driving can be resumed after you are able to bend your knee enough to sit in a car, and have regained enough muscle control to use the brake and accelerator with an adequate reaction time; this generally happens 4-6 weeks after the surgery. It is essential to keep the wound clean and dry until it heals.
Contact your doctor immediately in you experience any of the following symptoms: