A common orthopedic surgery that can replace a diseased or worn-out knee, a knee replacement typically is one of the most common elective surgeries. The procedure can include all or some of the following steps, depending on specific conditions:
* Surgery: incision, debridement (removal of damaged tissue)
* Reduction and fixation
* Prosthesis placement: implants or prostheses with components such as bearings, plastic bushings, circular rings and other parts that provide stability and protection during weight bearing.
* Customization: adjusting prosthesis for optimal fit and comfort
* Post-surgical care
It is necessary for the doctor to determine if a knee replacement is necessary. Typically, after an evaluation and x-rays, it is determined if the patient’s knee is so damaged that a knee replacement surgery would be required. There are many factors including age, medical history, weight and past surgeries or trauma that help determine if a knee replacement should be performed. Typically there will be substantial pain and stiffness in the knees which can make it difficult to perform activities of daily living such as walking up stairs or even standing up.
There are many reasons someone may require a knee replacement.
The most common reasons include:
* Rheumatoid arthritis
* Total/Partial knee replacement or resurfacing
Osteoarthritis is the most common condition that leads to a knee replacement. Arthritis is caused by a progressive wearing away of the cartilage and bones in the joints. This wearing down typically prevents the smooth movement of one bone over another which results in pain and stiffness in the joints. There are two common types of osteoarthritis: post-traumatic osteoarthritis and degenerative joint disease (DJD). Post-traumatic arthritis is caused by trauma to the joint such as a fall, being hit by a car or some other means. Degenerative joint disease occurs naturally as a person ages. It is usually more common in women than men over 60 years old.
Osteoarthritis can also be caused by lifestyle choices that deteriorate the knee joints such as obesity, excess pressure on the knees from strenuous activities and prolonged weight bearing on one leg during sleep.
Any person at any age can get osteoarthritis but it is often seen in people over the age of 50. Rheumatoid arthritis is a progressive disease that occurs when the body’s immune system attacks healthy cells and tissue in the joints. This type of arthritis is usually not present at birth or in childhood but develops with age. It can get worse over time resulting in pain and stiffness as well as swelling, redness and warmth of the joints.
Rheumatoid arthritis can also cause some wear in the cartilage of the knee joint which may make it necessary to perform a knee replacement surgery at some point.
A knee replacement can also be used for other reasons and include:
* Total knee replacement
* Partial knee replacement
Total knee replacement involves the complete removal of the entire joint surface, cartilage and all bones. In a total knee replacement only the damaged tissue is replaced. A metal or plastic implant is typically used to replace the damaged bone. While it may sound harsh, this is considered one of the most successful types of surgeries that orthopedic surgeons perform.
Partial knee replacements are similar in nature to a total knee replacement except that a portion of the damaged area is left intact while only one or two components are replaced. The most common part is the femur (thigh bone).
A partial knee replacement is typically performed for younger people who have less need for joint protection than older people. The material used in a partial knee replacement can be plastic, metal or ceramic.
Aftercare after a knee replacement surgery can be somewhat complicated. The first 24 hours following the surgery one may experience some pain as the muscles and joints heal. After that, it is typical to experience some swelling and stiffness in the knee area but these should diminish within two weeks of recovery. When wearing compression stockings during recovery there may be a slight loss of feeling or numbness or pain in the knees which can last for up to six months until those areas heal completely.
Recovery can be difficult for some patients because of the sudden loss of motion, it may be necessary for the patient to use crutches or a walker. A cane can also help give support and comfort until a full range of motion is restored which typically happens in four to six weeks after surgery.
Patients who have undergone a knee replacement are typically prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen to help relieve pain and inflammation as well as reduce swelling. The patient will also receive individualized advice on activities they can resume such as walking or golfing within 36 months after surgery.
Home safety measures are important after any surgery but especially with a knee replacement. The patient should have a friend or family member assist him or her in getting out of bed and into chairs. It might be impossible to get on or off the toilet without assistance. The use of ramps are recommended when possible to avoid the need to carry heavy objects up or down stairs. Also, it is crucial that the patient do not put any weight on the operated side for four to six weeks after surgery it can result in serious complications such as an infection, blood clot, nerve damage or a repeat surgery.
After recovery, some patients will feel it necessary to strengthen their muscles and joints with physical therapy and exercise. A knee brace may also help give support when needed by the patient. It’s important that they continue to schedule follow up appointments with their surgeon.
There are many risks associated with having a knee replacement from general anesthesia to infections. According to the American Academy of Orthopedic Surgeons, the death rate for major orthopedic surgery such as knee replacements is about 1 in 10,000 people or 0.01%. Another risk is that some patients may not get relief from their pain once the surgery is completed and some serious complications may arise including nerve damage, blood clots and infections.
If a knee replacement fails there are two common reasons behind this failure: infection and loosening of the implant (loosening can occur over time). If a knee replacement was faulty it can cause pain and discomfort. Knee replacements that fail may need to be removed and replaced with a new one.
A study conducted by the Finnish National Social Insurance Institution Health Examination Survey concluded that the number of knee replacement surgeries performed in Finland has doubled over the past ten years (from 6,230 to 13,831). It is estimated that this trend will continue over time meaning there will be more patients having knee replacements in the future.
This increase can be attributed to several factors including people living longer and more active lifestyles as well as an increase in obesity in Finland.
Other factors that may contribute to the increase in knee replacement surgeries include:
1. Women are living longer than ever before which means they have a greater chance of developing joint problems and arthritis.
2. Finland is ranked as one of the most active countries in the world by The International Index for Physical Activity, making it easier for people to take part in regular exercise and sports.
3. Obesity has become a major problem according to Statistics Finland, over 25% of adults aged 18-59 years old are obese and an increase in obesity can cause wear and tear on joints leading to more knee replacement surgeries being performed in the future.
Knee replacement surgeries have doubled in Finland over the past decade and it is expected that the number of surgeries will continue to rise. Finland has a high life expectancy of 82.6 years and 20% of the population being obese. Obesity is linked to an increase in sports activities, which can also be a factor of this increase.