Risks of Surgery

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As with all procedures, a total knee replacement carries some risks and complications.  

 

The common risks (2-5%) of the procedure include Pain, Bleeding, Blood clots, Stiffness, Prosthesis wear/loosening.

 

The less common risk (1-2%) of the procedure is Infection.  If infected, the joint will likely require one or more additional operations and prolonged antibiotics, with a risk of increased disability and dissatisfaction.

 

The rare risks (<1%) of the procedure include Pulmonary embolism, Altered wound healing, Altered leg length, Joint dislocation, Nerve damage, Fracture, Blood vessel damage, Death.

 

All complications can lead to a temporary or permanent deficit which can affect your ability to carry out activities of daily living or specific tasks related to your occupation, hobbies, or interests.

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 The Operation

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Upon arrival on the day of your surgery, you will be evaluated by a member of the Anaesthesia team. The most common types of anaesthesia are spinal anaesthesia (you are awake but your body is numb from the waist down) or general anaesthesia (you are asleep). Either option may be combined with a nerve block for added pain control during and after the operation. The anaesthesia team will make a joint decision with you to determine which type of anaesthesia is best.

 

The procedure usually takes 60 – 90 minutes.

 

The basic steps of a knee replacement procedure are as follows:

 

1. Bone preparation. The damaged cartilage surfaces at the ends of the femur and tibia are removed along with a small amount of bone.

2. Implantation of the metal prostheses. The removed portions are replaced with metal components that recreate the surface of the joint.

3. +/- resurfacing of the patella. Depending on the wear behind the patella (kneecap), the under surface may be cut and resurfaced with a plastic button.

4. Insertion of a spacer. A polyethylene spacer is inserted between the metal components to create a smooth gliding surface.

​After the Operation

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• ​Pain relief – Making sure that you are comfortable, and your pain is acceptable after surgery is one of the main tasks of the team of people who will be looking after you.

 

Pain management begins whilst you are in the theatre suite and continues according to your individual requirements throughout your admission.

 

The anaesthetic used is focused on minimising pain after your operation, but pain is a normal part of the recovery process.  The aim of pain relief after your operation is to make the pain bearable and to allow you to get up and start using your new joint.  It is not possible to eliminate pain altogether and a certain level of pain should be expected. 

 

Early mobility is very important in helping to prevent post-operative complications and can speed up your general recovery.  You should be able to take a deep breath and move with the minimum of discomfort.

 

• Hospital stay is usually 1 - 3 days.

 

• Physical therapy – Your rehabilitation and its effect on your outcome is down to you. You will start to put weight on the knee with support from a frame or crutches from the day of your surgery. You should expect to be able to walk independently by 6 weeks following your surgery.

 

It is important to do your exercises regularly and increase your activity day-by-day. This not only improves your rehabilitation and functional outcome, but it also helps prevent complications like a blood clot. Movement also helps to unlock the pain cycle.

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• Wound care - Your wound will be covered with a special dressing in theatre.  We do not disturb the dressing unless it is heavily soiled, this allows healing to take place and reduces the risk of infection.  The dressing will be reviewed daily by the nursing team whilst you are in hospital.

 

Your skin closure will be performed with dissolvable sutures or staples. It will take approximately 10-14 days to heal. If staples are used then they will be removed after this time. A waterproof dressing will be used to cover the wound and showers are permitted, but it is recommended that you do not immerse the dressing in a bath or expose the wound to water until it has healed.

 

Mr. White and/or your physiotherapist are more than happy to discuss in more detail issues surrounding:

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• Returning to work

• Using your knee following your operation

• Driving

• Anticipated length of rehabilitation.

 

Please notify us if undergoing any other operations, hospital tests, dental work, or if you develop any infections or soft tissue wounds before your scheduled operation. Your operation may have to be deferred to reduce the risk of developing a deep infection of your total knee replacement. If you are unsure, then please discuss this with Mr. White and the team.

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Avoiding Problems after Surgery

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Preventing Infection

 

A common cause of infection after a knee replacement is from bacteria that enters your bloodstream during dental procedures, urinary tract infections, and/or skin infections. Theses bacteria can lodge in your knee replacement and cause a deep infection.

 

After a knee replacement, patients with certain risk factors may need to take antibiotics prior to dental work and before any surgical procedure that could allow bacteria to enter the bloodstream.

 

Warning signs of infection. Notify Mr. White, your GP, and/or seek immediate medical attention if you develop any of the following signs of a possible knee replacement infection:

• Persistent fever

• Chills

• Increasing redness, tenderness, or swelling around the knee wound

• Drainage from the knee wound

• Increasing knee pain with both activity and rest

 

Avoiding Falls

 

A fall after your surgery can damage your new knee and may result in a need for further surgery, due to loosening of the components, wound issues, or a fracture around the replacement joint. Stairs are a particular hazard until your new knee is strong and mobile. You should continue to use crutches, a walker, handrails, and/or have someone to assist you until you have improved your balance, confidence, and strength.

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Outcomes

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Currently, more than 90% of modern total knee replacements are still functioning well 15 years after surgery.

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Living with a Knee Replacement

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Improved range of motion is one of the goals of knee replacement, but restoration of a full range of motion is uncommon. The motion regained by surgery is often predicted by the range of motion that you have in your knee before surgery. Most patients can expect to be able to almost fully straighten the replaced knee and to bend the knee sufficiently to climb stairs and get into and out of a car. Roughly 50% of patients struggle to kneel on their replaced knee due to discomfort, but this is not harmful to the knee.

 

Most people experience some numbness around the incision. You may also get some stiffness, especially with excessive bending exercises.

 

Most patients feel or hear some clicking of the metal and plastic with knee movement or walking, and are aware that they have a mechanical joint. This is normal. This tends to diminish with time and most patients find these symptoms tolerable when compared to the pain, limited function, and reduced quality of life experienced prior to surgery.

 

Your new joint may activate metal detectors at security checks in airports and some buildings. Please inform the security agent about your knee replacement if the alarm is activated.