Knee Replacement Surgery

FAQS on Total Knee replacement

What are the materials used to make knee replacement components?

Components used in Knee Replacement

Knee after and before surgery- side view

After surgery- front view

The materials used in most modern knee prostheses are generally comparable. The vast majority of thigh bone components (femoral components) are made of cobalt-chromium alloy and shin bone components (tibial components) are made of titanium/ cobalt-chromium alloy. The joint space (interface between the thigh bone and shin bone components) is maintained using an ultra-high molecular weight polyethylene polymer component.

How soon can I drive after my knee replacement surgery?

You may drive an automatic car as early as 2 weeks after a knee replacement surgery, if you had it on your left knee and you can comfortably sit in your car and apply an emergency brake. You may need to inform your insurer. If the surgery was on your right knee or you have a manual car (even if the surgery was on the left knee), you will need to wait until you have regained satisfactory pain relief, knee range of motion and muscle co-ordination. It will take approximately 6 weeks to achieve this.

How will I know it is safe to drive a car?

My advice is to get into the driving seat of your car, without inserting the keys into the ignition, and practice the application of an emergency brake and clutch. If you can comfortably use those, you could drive the car in an open (safe) place before resuming driving. It is important to appreciate that the knee could be stiff and painful after keeping it still for prolonged periods. You should therefore avoid going for long drives during the initial stages.

What activities can be pursued after total knee replacement?

The activities that can be undertaken include low impact activities such as bowling, ball room dancing, square dancing, golf, swimming, tennis (preferably doubles tennis), croquet, cycling, table-tennis, walking etc. Less favourable activities but possible activities include down-hill skiing, scuba -diving, inline skating, ice-skating, speed-walking, horse riding etc. The activities to be preferably avoided include high impact sport like squash, football, basketball, baseball, hockey, gymnastics, jogging, rock-climbing, parachuting, hand-gliding etc.

One needs to wait until muscle strength and co-ordination are regained following surgery before returning to recreational and athletic activities. This will take approximately 6 weeks to 3 months after knee replacement. The general advice is to avoid high impact and pivoting sports which could potentially reduce the longevity of the prosthesis by causing accelerated wear of the bearing surfaces (polyethylene insert). Such activities also subject the replaced knee to additional injuries that can predispose to early loosening of the components.

How long will a replaced knee last?

Approximately 15-20 years. The longevity is more in people who are less physically active. E.g. older patient’s knees tend to outlive them.

Does this mean that I must have a new knee prosthesis every 15 years of my life?

No. In practice patients tend to have one revision surgery in their life time, if they had their knee replacement at less than 50 years’ age.

Is the revision (re-do) surgery less successful than the first time one?

In general, there is higher risk for complications with revision (re-do) surgery than primary (first time) surgery. The outcomes may be comparable.

Is there a maximum number of times one could have knee surgery?

No. However, it is preferable to minimise the number of surgeries to reduce the risks for complications.