This particular type of knee arthroplasty surgery started in the 1970's. Over the past 3 decades it has become a very common procedure. The goal of the Total Knee Arthroplasty operation is femoral replacement by replacing the severely arthritic ends of the femur and the tibia with a man made device (prosthesis). The underneath surface of the patella is also commonly replaced. These devices are combinations of metal and plastic and occasionally ceramic materials. They are fixed to the bone either using bone cement or by using a metal stem with a rough surface which relies on your bone growing into the artificial implant for long term stability. It may be reinforced with screws on the tibial side. In between the two components is a special plastic liner made out of polyethylene. The total system is engineered to closely mimic the function of a normal knee.
Living the remainder of your life with a painful knee does not have to be your only alternative. During knee arthroplasty, your arthritic knee joint is replaced with an artificial joint called a prosthesis. Post-operatively you can expect to eventually move more easily and without pain. The majority of patients may expect the following benefits from this procedure.
Knee arthroplasty eliminates or nearly completely reduces all knee pain related to the arthritis.
Knee replacement enhances quality of life by allowing you to do your activities of daily living and low impact activities in greater comfort.
Knee replacement enables you to rest or sleep in comfort.
Knee arthroplasty provides years of reliable function with activities of daily living and enhanced exercise activities such as walking. Most total knee replacements last for many years.
The knee joint consists of the femur, tibia and patella. The femur or thigh bone is the long bone connecting the hip to the knee and forms the upper end of the knee joint. The tibia or shin bone connects the knee to the ankle and makes up the lower side of the knee joint. The patella or kneecap is the small bone in front of the knee. The fibula is a shorter and thinner bone running parallel to the tibia on its outside.
The knee bones are connected at the joint by strong ligaments and surrounded by muscles. The ligaments of the knee joint stabilize the knee allowing it to function normally. The cruciate ligaments (anterior and posterior) are important internal non-elastic structures, which guide the knee in its normal motion.
Articular cartilage is the smooth lining which makes up the surfaces at the end of the femur and tibia. It is the damage to this surface, by either injury, disease or age which causes arthritis.
The menisci are specialized structures within the knee joint between the femur and tibia. There is a medial and lateral meniscus. These tissues help distribute load, absorb shock, and stabilize the knee while aiding in lubrication.
Damage to one or more parts of the knee can become painful and movement may become restricted. Over time cartilage (the smooth covering at the ends of the bone in the joint) starts to crack, thin and wear away. When this happens the actual bone surfaces at the joint rub together.
No matter your age, a knee problem may keep you from activities you enjoy. Pain and stiffness may even limit your day-to-day activities. Problems with the knee joint tend to cumulative and progressive over time.
The following is a description of problems that may lead to joint damage and eventual knee pain;
Injuries to ligaments causing instability and abnormal motion of the knee can and usually do lead to premature arthritis. If possible, it is encouraged that the patient seriously consider reconstructive stabilization of this type of injury to minimize the effects of accelerated arthritis
The aging process can lead to normal wear and tear and become cumulative in nature. Cartilage may begin to wear away (osteoarthritis). As the ends of the bones rub together they become rough and pitted. This leads to stiffness, swelling and pain. Previous meniscectomies and damage to the anterior cruciate ligament inevitably can lead to osteoarthritis.
There are particular conditions where the lining of the joint becomes inflamed and secretes material that destroys the joint cartilage. In these conditions more than one joint is usually affected. The joints are hot, swollen and painful and deformity is common.The presence of this type of condition is usually confirmed by blood tests and rheumatologist physicians.
This condition occurs as a result of loss of blood supply to the end of the bone at the joint surface. It can occur for no reason (idiopathic) or can be secondary to a number of conditions such as long-term use of alcohol or steroids. If the bone dies (necrosis), the joint will become arthritic. This pain often comes on quite suddenly and may increase rapidly. This can happen at any age and may also be caused from a traumatic injury such as dislocation.This problem can typically be diagnosed with X-Rays.
A bad fall or blow to the knee can break (fracture) the bone. If the broken bone does not heal in proper alignment or the joint surface is damaged during the injury the joint may slowly wear out like an improperly balanced car tire.
Adolescent Knee Problems
Occasionally knee pain results from a problem which may have started in childhood such as osteochondritis dissecans, trauma, and juvenile rheumatoid arthritis.
Note - Osgood Schlatters disease does not cause arthritis.
Infection- Infection can destroy the cartilage lining leading to osteoarthritis.
Advanced arthritic changes as demonstrated on X-Ray, combined with pain and stiffness in the joint can result in all or some of the following.
Severe disability and immobility.
Creates difficulty in job performance.
Interferes with your leisure or sporting activities.
Interferes with your walking or in home mobility.
Wakes you at night despite non-surgical treatment such as pain medicine and anti-inflammatories.
Failure of conservative treatment such as analgesia, anti-inflammatories, weight loss, physical therapy and aids like crutches or a cane.
Total Knee Joint Replacement is an elective procedure and should only be performed when you are no longer prepared to put up with your pain and disability. Your physician will help you understand the benefits versus the risks involved.
You will be requested to attend a pre admission "Total Joint Class" at the main office. At this Class, the following will be reviewed:
• Nature of Knee Arthritis
• Nature of the Surgical Procedure
• Normal Post-Operative Course
• Do's and Don't before and after surgery
• This will be an excellent opportunity to learn more about the condition and to ask questions
Within a day before your surgery you will be asked to visit the hospital clinic where the procedure is to be performed. The following procedures will be conducted;
Blood Tests - You will have simple blood tests to make sure your blood count is normal.
ECG - A Cardiograph of your heart will be taken to make sure you have no underlying cardiac problems.
X-Rays - Always bring X-Rays of your knee to hospital.
Urine Sample - a urine sample is required to make sure you do not have a urinary tract infection. An infection anywhere before surgery e.g. infected toenail, skin lesion, throat infection, gum or dental infection can greatly increase your chances of infection of the joint replacement following surgery. If an infection is found it can be treated with simple antibiotics prior to surgery. INFORMATION - The clinics are a good opportunity for you to ask any questions you may have of your upcoming surgery. Cease aspirin and anti-inflammatory medications (e.g. voltaren, feldene) 10 days prior to surgery as they can cause bleeding. Cease any naturopathic or herbal medications 10 days before surgery as these can also cause bleeding. Continue with all other medications unless otherwise specified. Notify your surgeon if you have any abrasions or pimples around the knee. You are advised to stop smoking for as long as possible prior to surgery.
The anaesthetist will see you before the surgery. They will discuss with you the type of anaesthetic you will have.
After you are taken to the operating room, while you are still awake, you are placed on the operating table and set up for surgery with a tourniquet placed around your thigh.
A urinary catheter will be placed in your bladder to measure your fluid balance during and after surgery.
A cut is made in the skin and underlying tissues to expose the knee.
Special instrumentation is used to make very accurate cuts in the bone to fit the prosthesis.
Trial components are put in first to make sure everything fits properly.
The real components are then fixated.
Drains are usually inserted to reduce swelling.
The wound is then closed, dressings applied, and you will be admitted to the recovery room.
To control swelling and minimize occurrence of blood clots, your leg will be placed in a special surgical hose from the groin to the toes.
Your fluid input and output is measured carefully. A drip in the arm will be used to give you fluid, replace blood during the operation and for antibiotics.
Pain is normal after the operation but if your pain is not reduced be sure to tell the nurse. Pain medication may be injected into a muscle or delivered by IV into the blood stream.
Patient Controlled Analgesia (PCA) allows you to control your own pain medication. When you push a button pain medication is pumped through an IV line. PCA pumps can provide a steady level of pain relief and with they're built in safety features you will be assured that you will not get too much medication.
The IV drip, drains and catheter are removed on your surgeon's advice at approximately 24 hours after surgery.
Blood will be taken 24 to 48 hours after the operation to check your hemoglobin and blood chemicals levels.
Your exercise regime will begin as soon as you are capable and this will continue during your stay in hospital and once you are at home. This will be supervised by a physical therapist.
You will be discharged approximately 5 days after surgery depending on your progress. In most cases you will be sent to a rehabilitation center before you go home to have functional training and physical therapy. Sutures are usually dissolvable but if not are removed at about 10 days.
You will be in the hospital approximately 5 days. On the second day you will get up on a walker and then progress to crutches and then to a cane usually by 4- 6 weeks.
You usually go from hospital to rehabilitation and you are in rehabilitation for one to two weeks. This will include aggressive physical therapy and functional training to progress you back to Activities of Daily Living.
When you are discharged from the hospital you will most likely still require pain medications but no injections. You will be encouraged to wean your medications down to minimal levels as soon as possible.
It is best to avoid anti-inflammatory medications should you need it for arthritis elsewhere for one week to avoid any possible bleeding.
Your pain should diminish by 75 % by week six and 95 % diminished by week twelve. By twelve weeks you can usually walk as far as you desire.
Regaining range of motion early on is extremely important, getting the knee straight is equally important as bending. Refrain from putting anything under the knee even though it feels comfortable as it prevents it from straightening.
People usually can return to work somewhere from eight to twelve weeks after surgery. Heavy manual work may take longer. Normally by three months you can play sports like golf, bowls, stationary bike ride, hike, doubles tennis and swim.
Any operation big or small can be risky. We have attempted to list some potential complications that can occur with this type procedure,and some rarer complications may also be possible. It is impossible to discuss every complication, and there will be some, which no surgeon may anticipate or may never have heard of. Care is taken at all times during surgery to prevent these complications. At Cary Orthopaedic Sportsmedicine Specialists, we are subspecialized and operate within our defined area of experience and expertise. We firmly believe this helps to minimize the risk of complications.
The following list is not complete and some are explained in more detail in the various sections to which they may be more appropriate.
Complications of Surgery
One of the risks after total knee replacement is infection. Infection may be superficial (i.e., in the skin) or deep (around the prosthesis). The risk is approximately 1%. If you do get an infection it will be treated aggressively with antibiotics but occasionally a second surgery is necessary to clean out the infected material. In very rare circumstances, sometimes the knee replacement is removed and another one put in at a later time, six to eight weeks later when the infection has been eliminated.
Fracture (break) of the Femur, Tibia or Patella
This may occur during surgery and may at times not be recognized. It may require additional surgery during the operation and occasionally additional surgery a few days later.
Arthro-fibrosis (Stiffness) (lack of movement)
Some people form excessive scar tissue after total knee replacement The average and desirable long-term flex of total knee replacement is 110 degrees. If you are not achieving an ability to bend beyond 90 degrees by six weeks you may need to be readmitted to hospital and under epidural or spinal anaesthetic the knee is manipulated to break the scar tissue, which is the physical block limiting your bend.
Damage to Nerves or Blood Vessels
Surgery requires a great deal of dissection and exposure of nerves and blood vessels. During the operation, nerves or blood vessels may become impaired or damaged. These injured tissues may be repaired at the time if recognized but may require a second operation to explore or repair any damage. It is very rare that a damaged nerve does not recover on its own. A damaged nerve that does not recover can lead to improper function of the leg below the joint replacement such as a foot that does not work properly due to weakness or sensory loss.
Blood clots can form in the calf muscles and they can travel to the lung. These can be serious and even life endangering. These blood clots will be treated immediately and every measure is taken to avoid these occurring. You will be given a blood thinning agent by injection during your stay in hospital. Stockings will be provided for you which aid in trying to prevent blood pooling in the veins in the calf and you should wear these for six weeks post operatively. A calf pump is also used during the operation on the non operated leg. You will also be given an anti-coagulant medication (unless it is contraindicated in you) to thin the blood after you leave hospital.
Wound Irritation or Breakdown
The operative scar will always cut some skin nerves so you will have numbness around the wound particularly on the outer side of the knee. This does not affect the function of your joint but may be irritating to you over the short term. Eventually this numb feeling improves slightly and does not worry most people. Occasionally, you may experience a burning or a hypersensitive sensation in the wound. This usually settles down over many months but occasionally can be long term and troublesome. Occasionally there may be aching around the scar for the first year after surgery which may worsen in colder weather but this usually is not comparable to the pain you experienced before the operation.
Wound breakdown is rare but if it does occur it may require surgery to correct it. You may experience a reaction to the sutures used, creating an abscess at the stitch site, this usually appears as a small pimple on your scar. They can normally be treated with an antiseptic dressing but occasionally require a short course of antibiotics.
Excessive Joint Wear
The long-term complication of total knee replacement is wearing of the plastic liner. If you place undue stress on the joint,such as someone who does heavy manual labor, participates in a repetitive impact sport like jogging or is excessively overweight should expect accelerated wear on the replaced joint than a more sedentary person.
Knee replacements historically have about an 85 to 95% percent fifteen year survival. Multiple factors, affect the long term survival rate. Constant improvements in technology make these components more likely to have increased longevity. We believe that the today's total knee replacements will function better and last longer than those in the past.Time will be the ultimate testament to these beliefs.
Significant wear in the joint may result in the liner needing replacement. Wear can sometimes result in loosening of the joint resulting in the entire joint needing replacing. It will be important that you stay in contact with the practice in an effort to assess how your knee is performing for you.
This condition is defined as reabsorption or disappearance of part of the bone. This can occur as a result of small wear particles creating a reaction in the body causing this bone reabsorbtion. Occasionally we may recommend you have a procedure to change the liner (bearing surface) or perform a bone graft to correct these defects before they become major problems.
Ligaments (collaterals, quadriceps, patella) are non-elastic tissues surrounding and stabilizing the knee which can be damaged before or after surgery. Damage to these ligaments can cause instability of the knee or the inability to straighten the knee. Circumstances may dictate the use of a brace or further surgery.
This means bone forms in the soft tissues surrounding the knee. Excess bone formation may cause discomfort and stiffness and occasionally needs to be excised. This is quite rare in the knee.
The knee may be more swollen than the other one or it may be a different shape then prior to surgery. This is normal as we place the knee in its proper alignment during surgery. It will appear different due to its pre-operative abnormal shape due to the arthritis. Also the scar might be unsightly or thickened.
Breakage of the Implant
This is very rare. If this were to occur, reoperation to remove the broken implant and replace it with a new one would be required.
This is an irritation of a superficial nerve resulting in pain, tingling and hypersensitivity around the scar area.
Reflex Sympathetic Dystrophy (RSD)
This is an unexplained condition where nerves become hyperactive and the limb painful. This may occur following minor trauma or surgery. This usually but not always resolves over time but may require referral to a specialized pain clinic.
Pressure on areas of the body in the operating room causing nerve damage.This condition is also rare and usually resolves over time once the pressure is relieved.
Failure to Relieve Pain
Uncommon and unfortunately, some operations may not be entirely successful in relieving pain.
Limp can occur from muscle weakness or lack of range of motion.
Bed sores occur from pressure areas on the skin during bed rest.
Other - Any medical complication you have heard about can occur especially if you already have a pre-existing medical problem. Such complications include heart attack, stroke, kidney failure, pneumonia, bowel obstruction, bladder infection or obstruction etc. Serious medical problems can lead to ongoing health concerns, prolonged hospitalization or rarely death.
This operation is considered to be generally very successful. It has proven to be an excellent procedure to improve a person's quality of life. Post operatively, 95 percent of people report good or excellent results. Good is defined as meaning occasional aches and pains that do not require pain medicine, and excellent means no significant pain or discomfort with a high level of return to desired functional activities. There are some people who will have unexplained pain.
It is important to remember that your new knee is an artificial knee and must be treated with care.
In general, the more active you are the quicker your knee will wear out.
You can drive when you have regained muscle control, usually by 6 weeks.
Avoid unsteady or uneven situations where you might fall.
Your knee may sound the alarm in a metal detector at the airport. You can receive documentation from our office to show you have had a joint replacement.
Prevention of infection is very important. If you have any infections anywhere make sure you see your family doctor immediately for treatment. If you get increasing pain in your joint and are sick and have temperatures you should go to hospital to get for assessment.
This operation is one of the most cost effective and beneficial operations performed in orthopaedic medicine. By far the majority of people are happy with their joint replacement. Although there is a lot of information above, it is important to read it all so you can make an informed decision to undergo surgery. You must not proceed until you are confident that you understand this procedure and particularly the complications.You should feel confident that you have had your questions answered and that you have secured a dedicated support team to assist you in your recovery once you have returned to your home.
Although every effort has been made to explain the complications there will be complications that may not have been specifically mentioned. This is because they are extremely rare. Additionally, you may access other sources of information from the Internet, other patients and your orthopaedic doctor. A good level of knowledge about this operation and recovery will alleviate much of the stress you may have.
For more information on how the knee replacement specialists at Cary Orthopaedics can help you, contact us today at 919-467-4992 for an appointment!
Cary Orthopaedics serves patients from Raleigh, Garner, Cary, Apex, Holly Springs, Fuquay-Varina, Clayton, Chapel Hill, and Pittsboro, NC.