Total Knee Replacement

Introduction

Total Knee Replacement (TKR) is a procedure that replaces an arthritic knee joint with artificial metal or plastic replacement parts called the ‘prostheses’.

The procedure is usually recommended for older patients who suffer from pain and loss of function from arthritis and have failed results from other conservative methods of therapy.

The typical knee replacement replaces the ends of the femur (thigh bone) and tibia (shin bone) with plastic inserted between the bones. The underside of the kneecap (patella) is also resurfaced

Arthritis

Other causes include

  • Trauma (fracture)
  • Increased stress e.g., overuse, overweight, etc.
  • Infection
  • Connective tissue disorders
  • Inactive lifestyle e.g., Obesity, as additional weight puts extra force through your joints which can lead to arthritis over a period of time
  • Inflammation e.g., Rheumatoid arthritis

In an 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 capsule of the arthritic knee is swollen
  • 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.

Diagnosis

The diagnosis of osteoarthritis is made on history, physical examination & X-rays.

There is no blood test to diagnose Osteoarthritis (wear & tear arthritis).

Benefits

The decision to proceed with TKR surgery is a cooperative one between you, your surgeon, your family and your family physician.

The benefits following surgery are relief pain and stiffness and a return to normal activities

  • Symptoms of arthritis that may lead to knee replacement include: Severe pain that limits your everyday activities including walking, shopping, visiting friends, getting in and out of chair, gardening, etc.
  • Pain waking you at night
  • Deformity- either bowleg or knock knees
  • Stiffness

Prior to surgery most patients will have tried conservative treatments such as analgesics, weight loss, anti-inflammatory medications, modification of activities, canes, or physical therapy.

Once these non-operative measures have failed it is time to consider surgery. Most patients who have TKR are between 50 to 80 years, but each patient is assessed individually and patients as young as 20 or old as 90 are can expect with good results. A successful knee replacement can last 20 or more years.

Pre-Operation

  • You will be asked to undertake a general medical check-up with a physician and undergo lab tests and an EKG.
  • You should have any other medical, surgical or dental problems attended to prior to your surgery
  • Make arrangements for help around the house when you return home after surgery
  • Cease aspirin or anti-inflammatory medications 7 days prior to surgery as they can cause bleeding
  • Cease any naturopathic or herbal medications 10 days before surgery
  • Stop smoking as long as possible prior to surgery
  • The hospital will make arrangements for you to meet with the anesthesia team one week prior to surgery
  • Please make plans to attend the hospital pre-operative education class.

Day of your surgery

  • You will go directly to the holding area, immediately outside the operating room
  • You will meet the nurses and answer a few questions to complete your medical record
  • You will meet your anesthesiologist who will review anesthetic options
  • You will be provided with a hospital gown. Make sure to bring exercise clothes to wear during your recovery.

Surgical Procedure

Each knee is individual and knee replacements take this into account by having different sizes for your knee. If there is more than the usual amount of bone loss, sometimes extra pieces of metal or bone are added.

Surgery is performed under sterile conditions in the operating room under spinal or general anesthesia. You will be on your back and a tourniquet applied to your upper thigh to reduce blood loss. Surgery takes approximately one hour.

The surgery involves an incision down to the bone to expose the bones of the knee joint.

The damaged portions of the femur and tibia are then cut at the appropriate angles using specialized jigs. Trial components are then inserted to check the accuracy of these cuts and determine the thickness of plastic required to place in between these two components. The undersurface of the patella (knee cap) is also replaced. The actual components are then inserted with cement and the knee is again checked to make sure things are working properly. The knee is then carefully closed, and the knee dressed and bandaged.

Post-Operation Course

You will wake up in the recovery room with a number of monitors to record your vitals. (Blood pressure, Pulse, Oxygen saturation, temperature, etc.)

Post-operative X-rays will be performed in recovery.

Once you are stable and awake you will be taken to the total joint unit.

Upon arriving at the door to your room, you will be assisted in walking from your stretcher to the bed. Early ambulation leads to faster recovery. Most patients sit up for dinner and take short walks on the evening of surgery

The day following surgery, you will change into exercise clothes and take several walks with the physical therapy team and attend a post-operative class to teach you about life with your new joint replacement.

Your team of nurses and I will work hard to control pain. We use a multi-modal strategy that has been shown to be effective at alleviating pain.

You can put full weight on your new joint. Sutures are generally dissolvable.

You can shower on the second post-operative day.

Most patients go home in one or two days following surgery. Initially you will use a walker but will progress rapidly to a cane. Physical therapy can begin as soon as you return home

Risks and Complications

  • As with any major surgery, there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages
  • It is important that you are informed of these risks before the surgery takes place

Complications can be medical (general) or local complications specific to the Knee

Medical complications include those of the anesthetic and your general well being. Almost any medical condition can occur so this list is not complete. Complications include:

  • Allergic reactions to medications
  • Blood loss requiring transfusion with its low risk of disease transmission
  • Heart attacks, strokes, kidney failure, pneumonia, bladder infections Complications from nerve blocks such as infection or nerve damage Serious medical problems can lead to ongoing health concerns, prolonged hospitalization or rarely death

Local Complications

Infection

Infection can occur with any operation. In the knee this can be superficial or deep. Infection rates vary. If it occurs, it can be treated with antibiotics but may require further surgery. Very rarely your new knee may need to be removed to eradicate infection.

Blood Clots (Deep Venous Thrombosis)

These can form in the calf muscles and can 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 your doctor.

Stiffness in the Knee

Ideally your knee should bend beyond 100 degrees but on occasion, the knee may not bend as well as expected. Sometimes manipulations are required. This means going to the operating room where the knee is bent for you and under anesthetic.

Wear

The plastic liner may wear out over time but generally lasts 20+ years.

Wound Irritation or Breakdown

The operation will always cut some skin nerves, so you may have some minor numbness around the wound. This does not affect the function of your joint. You can also get some aching around the scar. Vitamin E cream and massaging can help reduce this.

Occasionally, you can get reactions to the sutures or a wound breakdown that may require antibiotics or rarely, further surgery.

Cosmetic Appearance

The knee may look different than it was because it is put into the correct alignment to allow proper function.

Leg length inequality

This is also due to the fact that a corrected knee is more straight and is unavoidable.

Dislocation

An extremely rare condition where the ends of the knee joint lose contact with each other or the plastic insert can lose contact with the tibia (shinbone) or the femur (thigh bone).

Patella problems

Patella (knee cap) can click and pop. This generally resolves with therapy and time. . Damage to Nerves and Blood Vessels

Rarely these can be damaged at the time of surgery. If recognized they are repaired, but a second operation may be required. Nerve damage can cause a loss of feeling or movement below the knee and can be permanent.

Fractures or breaks in the bone can occur during surgery or afterwards if you fall. To repair these, you may require surgery.

Discuss your concerns thoroughly with your Dr. Fleeter prior to surgery.

Ligament injuries

There are a number of ligaments surrounding the knee. These ligaments can be torn during surgery or break or stretch out any time afterwards. Surgery may be required to correct this problem.

Damage to Nerves and Blood Vessels

Rarely these can be damaged at the time of surgery. If recognized they are repaired, but a second operation may be required. Nerve damage can cause a loss of feeling or movement below the knee and can be permanent.

Fractures or breaks in the bone can occur during surgery or afterwards if you fall. To repair these, you may require surgery.

Discuss your concerns thoroughly with your Orthopaedic Surgeon prior to surgery.

Summary

Surgery is not a pleasant prospect for anyone, but for some people with arthritis, it could mean the difference between leading a normal life or putting up with a debilitating condition. Surgery can be regarded as part of your treatment plan—it may help to restore function to your damaged joints as well as relieve pain.

TKR is one of the most successful operations available today. It is an excellent procedure to improve the quality of life, take away pain and improve function. In general 90-95% of knee replacements survive 15 years, depending on age and activity level.

Surgery is only offered once non-operative treatment has failed. It is an important decision to make and ultimately it is an informed decision between you, your surgeon, family and medical practitioner.

Although most people are extremely happy with their new knee, complications can occur and you must be aware of these prior to making a decision.