Total Knee Replacement
The knee is the largest joint in the body and carries almost half of your weight. In a healthy knee, the joint is lined with cartilage, acting as a cushion and a smooth surface for easy movement. Arthritis destroys the cartilage, and also alters the bone surfaces and ligaments in the knee, making movement difficult and painful.
The decision to proceed with knee replacement surgery is yours and does not need to be rushed. During the surgery, surgical instruments are used to resurface the ends of the femur and tibia. The knee cap (patella) may or may not be relined. This is done after making a vertical incision over the front of the knee to gain access to the joint surfaces. There are numerous tools including computer navigation, robotics and patient specific instrumentation to assist in the accuracy of your knee replacement.
Total Knee Replacement: Before Surgery
In most cases you should continue with any regular prescribed medications. I need to know your medical history to plan the best treatment for you in hospital.
Particularly, please let me know if you:
- have bleeding disorders or previous problems with blood clots in the legs or lungs
- are taking any blood thinners
- have heart or lung troubles or diabetes
- have had previous joint infections
- are smoking: although smoking is not advisable for your overall health, it is particularly important to cease smoking prior to any joint replacement as it increases your risk of complications, particularly wound healing and infection.
It is a good idea to remain as active as possible leading up to your surgery, and if possible low impact activity should be continued.
It is important to have a support person or network around you when recovering from your knee replacement. You will need help getting to and from hospital, travelling to and from appointments and with general household tasks.
Total Knee Replacement: Anaesthesia
Knee joint replacement can be performed under general or spinal anaesthesia. My assistant will give you the details of my anaesthetist at the time of your surgical booking. They will contact you prior to surgery to discuss the plan for your anaesthesia, and risks that may be specific to you.
Total Knee Replacement: Day of Surgery
You will be admitted to hospital on the day of surgery. My assistant will provide you with the admission time and fasting details.
Total Knee Replacement: Post-Operative Care
Currently, hospital stays can range from 3-7 days. Some patients will be transferred to a rehabilitation centre after surgery for more care – this is organised during your inpatient stay, however most patients can go directly from hospital to home provided they have the right support.
First 2 Weeks
Your goals in the first 2 weeks after surgery are:
- increase your comfort level with your new knee
- allow for swelling to settle – ice and elevate your knee every two hours
- work on the range of movement in the knee
- regain function of your leg muscles, particularly your quadriceps muscle at the front of your thigh
- begin walking on your new knee with the aid of crutches or a frame
Total Knee Replacement: Wound Care
Overlying the surgical incision is an adhesive dressing, which if clean and dry can be left in place. The nursing staff in hospital will help you with any questions you have regarding your dressings, and I will check the healing of your wound at our follow-up appointment approximately 2 weeks after surgery.
Total Knee Replacement: Pain Relief
Knee replacement surgery has traditionally been painful, although with current techniques patient comfort is greatly improved. In general you will require some regular pain relief each day, including regular paracetamol and anti-inflammatories (if indicated). For periods of increased pain during the day (breakthrough pain), you will have a faster acting pain reliever to take. Some of these pain relievers can have side effects such as nausea, stomach upset or sedation. It might be necessary to avoid certain activities (e.g. driving) if you are taking these types of pain relievers.
Total Knee Replacement: Follow Up
I will review you in the rooms approximately 2 weeks after surgery. If you are unsure of your follow-up appointment, please call my assistant on 08 9212 4292.
First 3 Months
The focus is on improving your function and comfort levels, with:
- reduced use of crutches and frames
- further improvements in range of motion and swelling
- increased strength
- hydrotherapy and stationary cycling
There is gradual improvement in knee function, where the benefits gained on a day to day basis will be less noticeable. Generally complete recovery takes at least 12 months.
Total Knee Replacement: Driving
The exact time to return to driving is variable depending on your recovery and the leg you had operated on. The Australian Orthopaedic Association recommends a period of at least 6 weeks before you consider recommencing driving.
Total Knee Replacement: Return to Work
This will vary depending on the nature of work you do. You should have a least 2 weeks off to allow the incision to heal and your pain levels to reduce. Most patients will require more time off work.
Total Knee Replacement: Physiotherapy and Exercise
I recommend you see a physiotherapist on a regular basis until you have recovered to a satisfactory level.
Total Knee Replacement: Dental Work
Any planned dental work or current dental problems should be dealt with prior to your knee replacement. If you have dental work at any time after your knee replacement, let your dentist or surgeon know that you’ve had joint surgery. The dentist may opt to prescribe you antibiotics to prevent infections that can spread from the mouth to the knee joint replacement via the bloodstream.
Total Knee Replacement: Problems
The risk of infection around the prosthesis is about 1 in 100. This can happen any time after surgery, as infection can spread to your knee from any part of your body via the bloodstream. In the event you do have a deep infection, it is important to seek treatment as soon as possible. Simple tablet antibiotics will not treat this problem and you will require surgery to wash the knee joint. If you have a resistant infection, you may require a surgery where the existing knee replacement is removed and a new replacement inserted after a period of antibiotics (Revision Knee Replacement).
If you are concerned about an infection, please contact me as soon as possible. During business hours the best point of contact is via my assistant on 08 9212 4292. After hours, please contact the hospital where you had your surgery, and ask them to get in touch with me. Failing this, present to your local Emergency Department for review.
Superficial Infection is not common, although can occur. Superficial infection occurs around the wound sites in the superficial tissue of the lower leg. It is important to contact me if this is the case, as it will need treatment to prevent infection spreading to the knee joint.
Stiffness Rarely, the knee replacement can become extremely stiff, requiring a manipulation of the knee replacement or even revision surgery.
Numbness over the front of the knee after surgery is common, although it is rarely a big problem and generally improves with time.
Foot and Ankle Swelling
Foot and Ankle Swelling is normal to an extent, and generally reflects the effects of gravity on the swelling around your knee.
Blood clots can form in the deep veins of the calf or leg, and occasionally these clots can travel to your lungs (pulmonary embolus), affecting your breathing. During your inpatient stay I use blood thinners to help prevent clot formation. In the event you do have a large clot in your legs (DVT) or in your lungs, you will need to take longer term blood thinning medication until the clots have resolved.
Prosthesis wear and revision surgery
For most people, a knee replacement will last for life. We know from experience that, at 10-15 years after surgery, 95 out of 100 knee replacements are still functioning well. However, if the prosthesis wears out or breaks, revision surgery will be required to remove the existing prosthesis – and insert a new one. Revision surgery is generally more complex than the initial surgery.
Damage to structures inside the knee
Damage to structures inside the knee is very rare, but there have been instances of damage to the bones, arteries, nerves and veins in the leg. Some of these require repair during surgery, and others will improve or resolve with time.
PLEASE CONTACT ME IMMEDIATELY IF YOU EXPERIENCE ANY OF THE FOLLOWING:
- temperature higher than 38.5C or chills
- severe pain or tenderness
- heavy bleeding from incisions
- redness around an incision that is spreading
- nausea or vomiting
- worsening flexibility or inability to bend the knee
- loss of mobility after a fall
- any concerns you may have after surgery
If you are considering having a total knee replacement, please make an appointment to discuss your treatment options.