Total Knee Replacement

INTRODUCTION:

Total knee replacement (T.K.R)  also known as knee arthroplasty.It is a procedure of replacing the articulating surfaces of the joints by prosthesis,so that the artificial joint functions as earlier  normal joint.

INDICATIONS:

Knee replacement is appropriate for you if you have severe pain or significant disability resulting from one or more of the following conditions:

Deterioration of the knee joint cartilage (osteoarthritis).

Inflammation in the lining of the knee joint (rheumatoid arthritis).

Physical injury to the knee joint resulting in arthritis (traumatic arthritis).

Moderate valgus (bowlegged), varus (knock-kneed), or flexion (bending) deformities.

A loss of blood supply to the lower portion of the upper leg bone (femoral condyle) which leads to tiny breaks within the bone and possible collapse (avascular necrosis).

To correct problems caused by previously failed surgeries.

Certain breaks in the knee joint bones (fractures).

CONTRAINDICATIONS:

Doctor may decide that knee replacement surgery is not appropriate if:

There is an infection.

Do not have enough bone or the bone is not strong enough to support the prosthesis.

Injured  nerves and/or nerve networks in the knee area.

Injured or non-functional knee muscles.

Knee is severely unstable, possibly due to unstable knee ligaments.

One of several conditions known as neuromuscular disease.

A stable fusion of knee joint (arthrodesis) which is functional and painless.

In addition, implanting a unicompartmental knee is not appropriate if:

You have rheumatoid arthritis.

You have a varus or valgus deformity greater than 15 degrees.

There is evidence of calcium being deposited in the joint cartilage (chondrocalcinosis or pseudogout).

DIAGNOSIS:

A complete history andphysical examination: this allows the physician to determine any correlation between symptoms of pain with past history and demands that have been placed upon the knee. The physician will also inquire about experiencing episodes of instability. The examination should focus on the assessment of swelling, range of motion, ligament stability, and knee alignment.

X-rays are used to show the extent of damage to the joint and they may suggest a cause for the degeneration.

  • Blood tests may be required to rule out inflammatory arthritis (such as Rheumatoid Arthritis) or infection in the knee if there is reason to believe that these conditions are contributing to the degenerative

DIFFERENT TYPES OF KNEE REPLACEMENT:

TKR is divided according to region as:

1)      UNICOMPARTMENTAL : is either medial or lateral condyle replaced.

2)      BICOMPARTMENTAL:both medial and lateral condyles are replaced.

3)      TRICOMPARTMENTAL:patella along with medial and lateral condyle are replaced.

Broadly speaking, there are four basic categories of knee replacements depending on the degree of mechanical stability provided by the design of the artificial knee:

  • Non-constrained
  • Semi-constrained
  • Constrained or hinged
  • Unicondylar

The highly successful non-constrained implant is the most common type of artificial knee. It is termed non-constrained because the artificial components inserted into the knee are not linked to each other and have no stability built into the system. It relies on the person’s own ligaments and muscles for stability. This is the key feature of this group of artificial implants helping to maintain the stability of the knee.

The semi-constrained implant is a device that provides increasing stability for the knee. This type of artificial knee has some stability built into it. It is used if the surgeon needs to remove all of the inner knee ligaments(some surgeons prefer to do this), or if the surgeon feels the new knee will be more stable with this type of implant.

Constraint or hinged variety implants are rarely used as a first choice of surgical options. In this case, the two components of the knee joint are linked together with a hinged mechanism. This type of knee replacement is used when the knee is highly unstable and the person’s ligaments will not be able to support the other type of knee replacements. It is useful in the treatment of severely damaged knees particularly in very elderly people undergoing a revision replacement procedure. The disadvantage of this type of knee joint is that it is not expected to last as long as the other types.

A unicondylar knee replacement replaces only half of the knee joint. It is performed if the damage is limited to one side of the joint only with the remaining part of the knee joint being relatively spared. It is now possible for the surgeon to replace only that area of the knee joint which is severely damaged. However, even with only half of the joint destroyed, many surgeons prefer doing a total knee replacement believing this is a better procedure than the half-knee (unicondylar) replacement. But equally, there are surgeons who believe it is more appropriate to perform a unicondylar knee in the right circumstance

PROCEDURE:

The artificial knee joint consists of the following parts

1)A “U” shaped femoral component to cap a prepared lower end of femur.

2)A tibial base plate to cover the cut flat surface of the upper end of the tibia

3)A plastic tray(spacer)inserted between the above two metallic components.

4) A patellar button made of polyethylene to replace the damaged surface of the patella.

RISKS AND COMPLICATIONS:

As with all major surgical procedures, complications can occur. Some of the most common complications following knee replacement are:

  • Deep Venous Thrombosis (DVT)
  • Infection
  • Stiffness
  • Loosening
  • Osteolysis

PHYSIOLINE’S WARNINGS AND PRECAUTIONS:

Excessive physical activity, injury, and obesity can result in loosening, wear, and/or fracture of your knee implant.

Failure to follow through with the required rehabilitation program or failure to govern your physical activities as directed by your physician may cause your knee implant to fail.

Activities that place a lot of stress on the joint implants, as may be the case with more active patients, may reduce the service life of the prosthesis. Implant loosening and wear on the plastic portions of the implant can lead to additional surgery to replace the worn components, or all of the components. Talk with your doctor about the following points, and how they might affect the longevity and success of your knee replacement:

Staying healthy.

Avoiding “impact loading” sports such as running, jogging, downhill skiing, singles tennis, etc.

Consulting your surgeon before beginning any new sport or activity, to discuss what type and intensity of sport or activity is appropriate for you.

Any restrictions on movement.

Maintaining appropriate weight.

PHYSIOLINE’S SPECIALISED PHYSIOTHERAPY HAS VITAL ROLE TO PLAY

At Physioline, all the members of the rehabilitation team work together so as to provide proper care and the therapy in order to:

  • Improve circulation
  • Pain relief
  • Reduce swelling
  • Reduce joint stiffness
  • Increase range of motion
  • Muscle strengthening exercises
  • Prevention of complications.
  • Gait training

Visit Physioline for further consultation and treatment.