Arthritis of knee can cause severe pain, stiffness, swelling and deformity of knee. This can result in significant disability by affecting individuals day to day and work related activities. Total knee replacement is an effective and safe surgical procedure in relieving these symptoms when the non-operative treatment methods are no longer helpful. The knee replacement was performed for the first time in England in 1968 and is still remains to be one of the most successful knee operations of all the time. Approximately 650,000 total knee replacements are carried out each year worldwide and about 72 000 total knee replacement operations are carried out in England and Wales each year.
The knee is the largest joint in the body and is made up of lower end of thigh bone (femur), upper end of shin bone (tibia), and the kneecap (patella). The joint is held in place by strong ligaments around the knee joint. The ends of these bones are covered by a special tissue layer called articular cartilage which allows smooth and painless movement of knee joint. The knee joint is lined by a thin layer of tissue called synovial membrane that makes the lubricating fluid for the knee joint to move without friction. When the articular cartilage of your knee is damaged by arthritis, the ends of bone rub against each other causing pain, stiffness, swelling and disability.
In total knee replacement the damaged surfaces of your knee joint are removed and replaced with an artificial joint made up of metal and plastic components. The artificial joint is usually attached to the prepared bone ends with bone cement. The kneecap usually does not need to be replaced but it may be necessary to replace the kneecap with a plastic component in certain clinical conditions.
Normal knee function is necessary to perform the majority of day to day and work related activities. Arthritis of your knee joint can affect these activities and result in severe disability. Osteoarthritis, rheumatoid arthritis and post traumatic arthritis are common types of arthritis that can affect knee joint. Various non-operative measures such as pain killers, physiotherapy, weight reduction, injections and sometimes braces (knee supports) are usually tried first to relieve knee arthritis symptoms. If these non-operative treatment measures fail to relieve your knee arthritis symptoms, many patients consider total knee replacement as a last-resort but very effective treatment option.
You may consider total knee replacement when you have following symptoms:
- Severe pain limiting your activities-walking, going up and down stairs etc.
- Severe knee pain when you are resting-day or night
- Severe knee pain at night-affecting your sleep
- Knee inflammation not relieved by rest or medications
- Knee deformity such as bowing in or out of knee
- Stiffness of knee that makes it difficult to bend or straighten the knee
- Failure of non-operative treatment to relieve your knee arthritis symptoms
- Intolerance to pain killers or anti-inflammatory medication
It is very important for a patient considering total knee replacement surgery to understand what to expect from the procedure. The majority of patients with total knee replacement have a successful outcome following the operation and enjoy improved quality of life.
The majority of patients report dramatic pain relief with improved ability to perform day to day activities they haven’t been able to do easily for long time. Knee movement will be improved but full restoration of knee movement is uncommon. The movement after total knee replacement is mainly dictated by the range of movement you have in your knee before operation. Kneeling can be uncomfortable after the operation. It can take up to 3 to 6 months, sometimes even a year, for an optimum functional recovery following total knee replacement.
It is essential to understand that:
The total knee replacement is usually made up of several parts.
The lower end of thigh bone (femur) and upper end of shin bone
(tibia) are reshaped and fitted with metal surfaces. These are
usually fixed to the bone with the help of bone cement. A plastic
(polyethylene) insert or spacer is then inserted between these metal
surfaces for a smooth and painless knee movement. The back of knee
cap (patella) is sometimes (but not always) replaced with a plastic
button especially when its articular cartilage is badly damaged.
What happens before the knee replacement operation?
Orthopaedic examination: You will be evaluated by the Orthopaedic Surgeon to confirm the diagnosis and assess the severity of disability. Orthopaedic Surgeon will ask you questions about your knee problem, disability and your medical health. He will obtain x-rays of your knees to assess the severity of arthritis.
Sometimes special scans such as MRI (magnetic resonance imaging) are performed to assess soft tissues around the knee joint.
The main aim of the preoperative assessment procedure is to make sure that you are fit for knee replacement surgery and recover well after operation. As a part of this assessment you may have a general medical examination and undergo few tests.
Medical examination: You may be reviewed by a medical specialist to make sure your general health is in satisfactory condition to undergo knee replacement and complete recovery after the operation. You may also be seen by a specialist medical doctor such as a Cardiologist or Nephrologist if you have chronic medical problems such as angina, kidney problems.
Tests: Routine blood and urine tests and an ECG may be carried out. A chest x-ray may be needed.
Medication: Inform Mr Samsani or his team about all the medicines you are taking. Please carry a list of your medicines with you including the name, dosage, and how often you take it. Mr Samsani or his team will advise you which medicine you should stop or can continue taking before surgery.
Preparing your skin: Presence of an infection in the body at the time of operation markedly increases the risk of wound infection. Make sure that you do not have any infection either on the leg or anywhere else on your body before surgery. Contact Mr Samsani or his team if you notice any infection and get it treated before the operation.
Dental evaluation: If you suffer from any dental problems or diseases, you should get it treated before knee replacement operation. Dental procedures (dental extractions, periodontal work) release bacteria into the blood steam which increases the risk of wound infection.
Urinary problems: People with history of urinary infections may require urological assessment to rule out any ongoing urinary infection before surgery. Severe prostate conditions may have to be treated before knee replacement surgery.
Weight loss: Being overweight may increase the risk of complications during surgery. It may also reduce the lifespan of the total knee replacement prosthesis. Therefore Mr Samsani or his team may advise you to lose some weight before the operation to reduce the risk of complications.
Blood donations: Some blood loss can occur during or after knee replacement surgery and you may need blood transfusion to after the operation. Therefore Mr Samsani or his team may ask you to donate your own blood before operation. This will be stored in the blood bank in case you need it after surgery.
Help from family and friends: After knee replacement surgery you will be walking with the help of crutches or a frame. However you will benefit from some help for several weeks with day to day activities such as cooking, bathing, shopping and laundry.
Home planning: Some home modifications are required to make your home return easier during your recovery from knee replacement surgery. Following are the list of home modifications that can make your home easier to navigate after surgery.
- Secure handrails along stairways.
- Safety bars or handrails in your shower or bath
- A stable high chair with two arms and a firm seat cushion
- Stable bench or chair for bathing
- A long handled sponge for bath
- Sock aid, long-handled shoe horn
- A reacher to pick up objects from the floor
Your knee replacement operation is performed under either general anaesthesia or regional anaesthesia (spinal or epidural anaesthesia). Operation usually takes between 1 to 2 hours.
A longitudinal skin cut measuring 15 to 20 cm is made over the front of your knee joint. The damaged cartilage over the lower end of the thigh bone and upper end of shin bone (tibia) is removed and the bone ends are shaped to fit the metallic components of the knee replacement with the help of special instrumentation. The metal components are then attached to the bone ends with special surgical cement. Sometimes the back side of these metal components are coated with a special material to allow bone growth and attached to bone without the cement. A plastic insert or spacer is then inserted between the metal components to allow smooth and painless knee movement.
The knee cap is usually not replaced however it may be replaced when the back of the kneecap is badly damaged. The soft tissue releases are performed to balance the knee joint. A drain may be inserted to remove excessive blood collected in the knee and the soft tissues and skin will then be closed with clips or sutures. A soft wool and bandage is wrapped around the knee for support.
Immediately after the operation you will be transferred to recovery which is very close to the operation theatre. You will be closely monitored here to prevent or detect any early problems that may occur after operation. When Mr Samsani and the anaesthetist are happy with your recovery, you will then be moved to a ward where the rest of your post-operative recovery will take place until discharge from hospital. Sometimes patients with major surgery or complex medical problems may be transferred to a high dependence ward (HDU) or intensive care unit (ICU) for intense monitoring before moving back to the ward. You will have the following in the recovery or early postoperative period;
Intra-venous drip attached to a vein of the arm to give fluids, medications and sometimes blood transfusion.
A blood pressure cuff around the arm to measure blood pressure regularly.
A pulse-oximetre attached to your toe or finger to measure pulse rate and oxygen levels in the blood.
A bulky wool and bandage dressing wrapped around the operated knee to cover the wound.
Sometimes a drain tube is attached to drain excessive blood from the knee wound. This will be removed in 24 to 48 hours later on the ward.
IV antibiotics are administered to minimise the risk of wound infection
Injections or oral medicine are given to reduce the risk of blood clot formation.
Patient is allowed to drink and eat as soon as they feel better. Patient is generally encouraged to drink plenty of fluids to prevent dehydration and also to flush out the anaesthetic medicines from the body. Nausea and vomiting can occur after the operation which usually settles down with time but sometimes medicines are given to control these symptoms. You may sometimes require blood transfusion due to blood loss as result of operation.
Total knee replacement is a major operation and some amount of discomfort is common in the knee after the operation. The pain is usually controlled with pain killers given either through a vein or by mouth or a combination of both. Pain killers are taken at regular intervals to prevent any breakthrough pain in the initial days and after that they are usually taken on demand (when the pain is felt). Adequate postoperative pain relief is also essential to start early mobilisation and physiotherapy. If you experience any discomfort please speak to a nurse for immediate pain relief.
After the operation you will have few blood tests to make sure that your haemoglobin and electrolytes in blood are within satisfactory limits. You will also undergo an x-ray of the operated knee to make sure position of the prosthesis is satisfactory. If your haemoglobin is found to be low and having symptoms related to low haemoglobin, you may then require a blood transfusion
After operation, a physiotherapist will visit you in 24 to 48 hours. The physiotherapist will teach you how to use the artificial knee and advise about exercises. It is very important to start the exercises early and regularly after the operation to allow quick recovery. Range of movement exercises to improve flexion and extension of the knee joint, and quadriceps strengthening exercises are very important. Normally a range of movement from 0 to 100 degrees of flexion can be expected after total knee replacement but the ultimate range of movement is mainly dictated by the pre-operative range of movement in the knee.
You will be able to go home after total knee replacement when:
- You are walking safely with the help of crutches
- The condition of knee wound is satisfactory.
- Pain is adequately controlled with oral pain killers
- You are able to eat and drink well
- Home situation is satisfactory
Successful outcome following total knee replacement depends on how well you follow the instructions given by Mr Samsani and his physiotherapy team. Some amount of pain or discomfort is expected especially in the first few weeks after operation and should be able to be adequately controlled with pain killers.
Wound care: Ensure that wound is dry until it is completely healed. You will have stitches or staples running along the wound and these stitches or staples will be removed a few weeks after surgery. You can have a shower once the wound is completely healed and dry. Some swelling and bruising of the knee is common and can take up to a few months for complete improvement.
Diet: You should try and eat well after the operation. Also you should also drink at least 3 or more litres of water or other soft drinks to prevent dehydration and to flush out various drugs from your system. A balanced diet with iron supplementation, high fibre foods, salads and fruits is important to help the wound heal quickly and to restore muscle strength.
Activity: Normal activities are gradually restored and continuing with exercises at home is very important. Most activities of daily living are resumed in 6 to 8 weeks after total knee replacement. Some pain or discomfort after activity and at night is common for 3 to 4 weeks after total knee replacement. Your home activity programme includes;
- A progressive walking programme to increase your walking ability with or without the help of walking aids.
- Gradual return to normal day to day activities such as sitting, standing and climbing stairs.
- Specific exercises to strengthen leg muscles and improve range of movement at knee. These exercises should be performed several times a day and should be continued for several months until optimum strength and movement are restored.
- Driving can be resumed when your knee has achieved sufficient bend to enter and get out of the car comfortably and when you have adequate muscle control in the leg for breaking and acceleration. The majority of patients resume driving at 6 to 8 weeks after surgery.
Total knee replacement is a common and very successful operation. A general or regional (spinal or epidural) anaesthesia or combination of both techniques is required to perform the procedure. A small risk of complications is associated with administration of any of these anaesthetic techniques. Sometimes nerve blocks are administered to achieve prolonged pain relief after operation. Before the operation an anaesthetist will come and see you and explain the pros and cons of the anaesthetic technique you will have for your operation.
Before undertaking the surgery, Mr Samsani will explain to you (both at the time of consultation as well as before operation), in detail about the possible risks of the surgery and on approximate rehabilitation time.
There is always a small risk associated with administration of general or regional (spinal or epidural) anaesthesia. Major medical complications such as heart attacks, strokes or chest infection are less common. The risk is increased if the patient is older and has multiple medical conditions which may have affected the functions of vital organs such as heart, lung, liver and kidneys. A complete pre anaesthetic assessment will be carried out before surgery to optimise medical condition and minimise the risks associated with anaesthesia and surgery.
Total Knee Replacement Surgery Risks:
Major bleeding: Very rare and blood transfusion(s) may be required when this happens.
Infection: Incidence of infection after total knee replacement is very rare. The risk of infection is reduced by administration of prophylactic antibiotics in the perioperative period. Infection may occur in the hospital or after you go home. Superficial infections are usually treated with antibiotics and deep infections may require washout of the wound in addition to administration of antibiotics. Rarely the deep infection may not respond to the antibiotics alone and may require implant removal and reinsertion of implant after some time as a two stage procedure. If you experience any signs of infection in the operated knee such as swelling, redness, excessive pain or discharge from wound, you must contact Mr Samsani’s team for immediate assessment and treatment.
Deep Venous Thrombosis and Pulmonary Embolism: Blood clots can occur after any type of knee surgery including knee replacement. This risk is reduced by administration blood thinning Injections or tablets after surgery. Other measures such as elevation of legs, TED stockings and calf compression devises are also used to reduce the risk of blood clots. Exercises and early mobilisation after surgery also reduces this risk. Rarely, if not detected and treated properly, a portion of the blood clot can break off and migrate to lungs causing pulmonary embolism ( about 0.4%), a serious and life threatening condition.
Stiffness: Occasionally stiffness of the knee joint can occur after following knee replacement particularly in patients who are overweight or have diabetes. In majority of cases the stiffness improves with physiotherapy and exercises and rarely may require manipulation under anaesthesia to reduce the stiffness.
Reflex sympathetic dystrophy: It is also called as “complex regional pain syndrome”, a rare condition that can result in knee becoming painful, stiff and hypersensitive after surgery. Majority of cases respond to non-operative measures and may require specific treatment from a pain specialist.
Fracture of thigh and leg bone: fracture of thigh bone or leg bone can occur during the surgery but is very rare. The fractures that occur during surgery are usually treated immediately with wiring or plating. It is very rare to see these fractures after the surgery unless you have been involved in a bad accident.
Loosening of prosthesis: Majority of the artificial knees may not last forever. They can wear out or become loose during an individual’s life time. If the prosthesis becomes loose it may require revision.
Damage to nerves and vessels: Damage to major nerves (tibial and peroneal nerves) around the knee joint is very rare. However it is very common to have an area of numbness over the outside of your knee where a superficial skin nerve is always cut to perform surgery. This numbness will not affect functional outcome after operation. Sometimes these nerves get stretched during the operation and may result in temporary paralysis of the affected nerves. Permanent damage to these nerves is very rare. Damage to major vessels is also very rare.
Haematoma: occasionally persistent bleeding following surgery in the tissues around knee joint can result in formation of a haematoma. This may sometimes require surgical drainage.
Scarring: Scar tends to be thicker in some patients than others and usually does not cause any major problem.
Leg swelling: Slight swelling of operated leg and foot is common after the knee operation. It resolves usually with elevation, exercises and time.
The ability to perform activities after total knee replacement procedure may vary from patient to patient. The following are general recommendations for activity levels after total knee replacement:
- Expected or recommended levels of activity: walking, swimming, golf, driving, recreational biking, ball room dancing, normal stair climbing.
- Activities that exceed usual recommendations: vigorous walking or hiking, skiing, tennis, lifting of heavy weights.
- Dangerous activities: running, contact sports, jumping sport, high impact aerobic activities.
It is very important to understand that the primary aim of the total knee replacement operation is to improve the quality of life by relieving pain and improving function in the knee. Movement in the knee will improve but may not be fully restored after total knee replacement operation. Movement in the knee after knee replacement is mainly determined by the range of movement you have in the knee before the operation.
Kneeling can cause discomfort due to pressure on the scar and is not generally harmful.
Numbness around the scar especially on the outside of the knee is very common after operation. This numbness does not affect the functional outcome after operation.
Majority of patients also experience clicks or clunks in the artificial knee due to the metal and plastic components in the knee during bending of knee or walking. This is normal and again does not affect the functional outcome of your new knee. These clicks or clunks usually disappear with time.
Your new knee may activate metal detectors at airports or other security places. Inform the security officer that you have an artificial knee.
Prevention of infection: Infection after total knee replacement is rare. However presence of an active focus of infection in the body can spread the bacteria through the blood steam. These bacteria can then lodge at the knee replacement site and result in infection. Common causes of such infection are urinary tract infections and skin and nail bed infections and must be treated with antibiotics immediately. You must also take prophylactic antibiotics too before any dental procedure to prevent spread of bacteria through blood stream.
You must contact Mr Samsani or his team immediately if you develop any of the following signs of possible infection in the knee replacement:
- High fever
- Redness, swelling and tenderness of knee wound.
- Discharge from knee wound
- Severe pain in the knee at rest and night.
Prevention of Blood clot: Blood clots can occur in the legs after knee replacement. Early mobilisation and continuation of exercises after operation combined with administration of blood thinning medication reduces the risk of blood clots in legs.
You must contact Mr Samsani or his team immediately if you develop any of the following signs of possible blood clots in your legs:
- Increasing pain in your calf
- Increasing swelling in your calf, foot and ankle.
- Tenderness in the calf
Very rarely the blood clot can dislodge from legs and migrate to lungs resulting pulmonary embolism. The following are warning signs of pulmonary embolism:
- Sudden onset of chest pain
- Sudden onset of breathlessness
- Cough with chest pain
You must go to the nearest Emergency Department or see a qualified doctor immediately to treat this life threatening condition.
Preventing falls: For a few weeks after the operation, due to pain stiffness and lack of strength in leg muscles, your gait may be little unsteady and falls may occur. Stairs and uneven surfaces are particularly hazardous. Falls immediately after operation can cause serious damage to your new knee and may result in need for further surgery. Therefore you should use a walking stick, crutches, frame or have someone to help you until your balance, flexibility and strength is improved.
Continue with regular light exercise programme to maintain the strength in the muscles of leg and mobility in the artificial knee
- Avoid falls
- Take prophylactic antibiotics before any dental procedures
- Regular follow up examination as advised by Mr Samsani or his team
- Try and avoid putting excessive weight to reduce stress on the artificial joint
Most of the knee replacements will continue to perform well for the reminder of the patient’s life. Current knee replacements are expected to function for at least 10 to 20 years in 90 percent of the patients.
After total knee replacement it is important to review patients at regular intervals to make sure the artificial joints are functioning well and also to detect any problems early. You will normally be reviewed at the following dates after total knee replacement:
6 to 8 weeks after surgery: clinical review
6 months after surgery: clinical review and questionnaire
12 months after surgery: clinical review, x-ray and questionnaire
Then every 2 years...