© Mr Amer Karim (2016)

Mr Amer Karim

 MBBS(London), DIC(Orth Eng), MD(Res)                

FRCS(Trauma & Orth), FRSA(UK)


Consultant Trauma & Orthopaedic Surgeon

Full British Training & Specialist Certification

Knee Replacement Surgery

About the knee

The knee is composed of 3 separate joints:

 The medial joint line (the inner half of the knee joint)

 The lateral joint line (the outer half of the knee joint)

 The patello-femoral joint (the joint between the knee cap and the thigh bone)

These joints are normally covered in a layer of articular cartilage. This shiny, super smooth layer allows the knee to move smoothly with no friction and also acts as a shock absorber within the knee. In addition, the knee is held together with strong ligaments inside the knee as well as around the outside of the joint.

What is arthritis?

Arthritis is a process where the protective articular cartilage is worn away. This causes pain and stiffness when walking and even at rest in severe cases. The ligaments inside and around the knee can also be affected. They stretch, resulting in deformity of the knee joint (makes your legs wonky, causing your knees to no longer be straight or to bend properly).

Arthritis can be hereditary (inherited from your parents and grandparents), or post traumatic (following an injury to the knee or an infection in the knee).

When pain and disability are having an effect on your life, that is when you should consider a replacement.

What is a knee replacement?

A knee replacement is a surgical procedure, where the inflamed, painful, worn out articular cartilage is removed and the knee is then resurfaced with metal and plastic components. It is very successful and will provide you with:

 Pain relief

 It can correct deformity (give you back a straight leg)

 Cure symptoms of giving way and catching when you walk

 Improve your quality of life

How long will my replacement last ?

All knee replacements have a limited life, depending on the age and activity of the patient. But about 90% of knee replacements last between 15 to 20 years. If and when they do wear out, they can usually be redone, but this is a bigger operation.

Will I have restrictions after surgery ?

You will be advised against participating in high impact activities such as running, singles tennis, squash, jumping or contact sports. However you are encouraged to participate in low impact activities such as: dancing, doubles tennis, golf, cycling, swimming, gardening and some types of gym work.

When can I drive or return to work ?

Most patients can drive within 2 weeks and return to work within 6 weeks of the surgery if you have a sedentary job. The exact timing of your return to function will depend on your progress after the surgery.

What happens before the operation ?

Before the surgery, you will be reviewed by the anaesthetist to ensure that you are medically fit enough to undergo the operation. I will also discuss the risks and benefits of the operation with you in detail and get you to sign a consent form. You will be given ample opportunity to ask questions at every stage of the process.

There are 2 types of anaesthesia available, a spinal or a general anaesthetic. Your anaesthetist will discuss the benefits and risks of each so together you can make a decision on which will be the best for you.

Are there any risks?

With any operation there are risks, but the chances of a complication are low, usually less than 2%, however if they do occur, they are serious and so you should be aware of them:

 Bleeding during or after the surgery (you may also require a blood transfusion)

 Infection

 Neuro / Vascular injury

 Blood clots in the legs (DVT) or lung (PE)

 Chest infection

 Urine infection

 Haematoma (blood collection in the muscles)

 Heart failure, heart attack or stroke

 Loosening or wearing out of the replacement

 Stiffness after surgery

 Persisting pain

 Tender scar

 leg swelling

The procedure is made as safe as possible through experience and I have performed hundreds of these operations without incident.

What can I do to prepare for a replacement?

 General exercise: Keep as fit as possible, commence exercises on your hip (if not too painful)

 General health: Stop smoking, stop alcohol intake, eat healthily and try and lose some weight

 Foot and skin care: You must take good care of your skin, feet and nails before a hip replacement (to reduce the chance of infection). See a podiatrist and get your feet and nails looked after. All skin conditions must be healed. Any signs of a skin, foot or nail infection on the day of surgery will result in your operation being cancelled.

 Dental care: It is advisable to visit a dentist prior to your surgery to ensure that your teeth are in good condition and there is no evidence of infection that could spread to your hip joint.

Hospital admission

You will be admitted to hospital the day before your surgery. This will give you time to settle in and for your observations and laboratory tests to be performed. You may also have a new x-ray taken of the knee if your previous x-rays are over 6 months old.  You will also be asked to wear medical leg stockings, these help reduce the incidence of clots in the legs after the surgery.

On the day of surgery, you will be asked to have a shower with medicated soap in the morning (to help reduce the rate of infection), before getting into a surgical gown. You will then be brought to the theatre for your operation.

After the operation, you will commence physiotherapy as soon as possible. It is important to start to move the knee straight away to promote blood flow, prevent stiffness and to help the healing process. You may have a drain placed in the knee to drain out any excess blood that has collected in the knee joint after the surgery. This drain will be removed the next day on the ward (don't worry it is not painful to remove).

Physiotherapy and discharge from hospital?

The physiotherapists will work with you everyday to get your knee bending and to make sure you can mobilise safely with the help of a frame initially, and then crutches. You will not be discharged home until you can bend your knee to 90 degrees, your wound is dry and you are safe on crutches.

Rehabilitation after Surgery?

Upon discharge, it is advisable to stay with an able family member who can assist you while you continue your recovery. You should walk often and commence physiotherapy at home. Your wound stitches will be removed in about 2 weeks and you should keep the wound dry and covered up until then.

It usually takes 6 to 8 weeks for you to return to your normal function after a replacement, however it may sometimes take up to 12 months to fully recover from the surgery.

You should then continue your physiotherapy at home, everyday for life !!

Follow up?

I will see you in my outpatient clinic 2 weeks after the surgery to check the wound and remove the stitches. I will then arrange regular long term follow up in my clinic on a 3 monthly and then 6 monthly basis to monitor your progress, depending on your performance.

Should you wish to see me sooner or if you have any other questions, please phone my secretary and she will book you in at a time of your convenience.

Want more information ?

More information can be found on my website:  www.amerkarim.com