Frequently Asked Questions on Total Knee Replacement
Q: How long do I need to stay in hospital?
A: Usually between 3 to 5 days.
Q: How long is the surgery?
A:Usually between 1.5 to 2 hours for 1 knee.
Q: Is it done under anaesthesia?
A: Yes, it is done either under general anaesthesia or regional anaesthesia (spinal).
Q: Is it a painful procedure?
A: My patients routinely get a continuous nerve block at the front of the thigh of the operated knee. This provides excellent post-surgery pain relief for the next 3 days.
Q: When can I start walking?
A: You get to walk usually on the day of the surgery or the following day. You will require the aid of a walking frame for the first 7 to 10 days. Thereafter most patients can walk without aids.
Q: When do I remove the stitches?
A: There are no stitches for removal. The surgical wound can be exposed at about 10 days after the surgery.
Q: Do I need physiotherapy after surgery?
A: It is good to have a physiotherapist for the initial few weeks post-surgery to help you improve quickly. However, some of my motivated patients can do the knee exercises on their own and with great results.
Q: Can I squat after a total knee replacement?
A: The answer is it depends on the following patient factors:
- If the painful osteoarthritic knee has very poor range of motion prior to surgery (say less than 90 degrees of bending), it is unlikely that the patient will be able to squat after surgery.
- If the painful osteoarthritic knee has reasonable degree of knee bending prior to surgery (say up to 130 degrees of bending), than it may be possible for the patient to squat after surgery.
- It will help if the patient is motivated to improve the knee range of motions after surgery either by doing exercises by themselves or with the help of a physiotherapist and to strengthen the muscles around the knee.
A lot of my patients who have undergone knee replacement surgeries have been able to return to squatting post-surgery.
I have a video showing a collection of these patients but I cannot show it to you on this website due to regulations set out by the Ministry of Health, Singapore. Do request me to show it to you during your consultation with me.
Q: When can I travel?
A: Long distance travel requiring prolonged sitting can result in deep vein thrombosis of the leg veins in those who had a recent knee replacement surgery. It is advisable to wait about 6 weeks before considering long haul flights. However, if it is necessary to fly, it is best to use compressive stockings in both legs and to ask your doctor to obtain DVT prophylaxis. Oral tablets for this purpose are available.
Q: What are the risks of this surgery?
A: Risks of knee replacement surgery can be related to anaesthetic risks which the anaesthesiologist will explain to you. The main risks that we tell our patients include:
Infection – it ranges from 1% to 4% depending on whether you have pre-existing conditions such as diabetes, renal failure etc.
Deep vein thrombosis – this risk is reduced by walking the patient early and using anti-thrombotic leg stockings. Prophylaxis with medications in high risk individuals may sometimes be needed.
Pulmonary embolism – this is a potentially fatal complication where the blood clot from the deep vein thrombosis of the leg veins break off and end up in the heart and blood vessels of the lungs.
Neurovascular Injuries – this is an uncommon complication if the surgeon uses meticulous surgical techniques.
Periprosthetic Fractures – this is another rare complication where the bone at the surgical site fractures.
Q: When will I fully recover from my knee replacement surgery?
A: The post-surgery pain is worse during the initial few days. Subsequently it is usually painful at night where the patient feels a deep seated soreness around the surgery area. The pain generally fades away by 6 weeks post-surgery. Most patients would become more active and walk more by 6 weeks post-surgery. This can result in activity-related inflammation of the operated knee which patients feel as stiffness during the initial few steps of walking followed by pain after prolonged walking. Most patients feel much better by 3 months post-surgery. In a small proportion of patients, the full recovery may take up to 6 months.
Q: Why does my operated knee feel warm?
A: The operated knee will feel warm for about 6 months. It settles down thereafter. Do not be concerned.
Q: Why is the skin on the outer aspect of my knee incision scar numb?
A: All patients will have this issue. It is due to the midline surgical incision over the front of the knee which cuts the tiny sensory nerves on the skin of the knee. As the knee travels from medial to lateral in front of the knee, the numbness will be felt on the outer aspect of the knee. It is advisable to apply skin moisturiser to the numb area of the skin to prevent dryness and itch.
Q: Can I use Medisave for my knee replacement surgery?
A: Yes, but it is limited to about $6000 only and can only pay for a portion of your entire hospitalisation fee. For the estimated fee of a total knee replacement surgery, you can visit the MOH website. A screen capture from MOH website on 14th Nov 2018 shows: