The most common reason patients require knee replacement surgery is for Osteoarthritis. This is a condition where the tough, smooth cartilage which cushions the bones of the joint when they move, is worn away. Occasionally this process can be due to trauma. The destruction of the protective layer over time leads to bone rubbing on bone, which is very painful and results in swelling, joint stiffness and limits mobility.
The aim of knee joint replacement is to both relieve pain and restore function.
A Knee Joint Replacement uses an implant (prosthesis) to re-cap the worn, exposed bone ends. After surgical removal of the worn surface of the femur, a metal alloy similar in size and shape to the original contour of the bone is pressed or cemented onto the end of the femur. The tibia is cut across the bone, and a metal plate is inserted and a plastic spacer is then added to act as a cushion. The under surface of the knee cap (patella) may also be resurfaced with a plastic liner cemented into place. The ligaments are preserved so that the joint remains stable.
The majority of surgeries go very smoothly without any major complications.
Serious complications include infection and blood clots. To reduce the risk of infection, Dr Schluter will prescribe antibiotics during your stay, and additionally he and the surgical team take extra precautions in the operating room to reduce your risk of infection. To reduce your risk of clots you will be given blood thinners and compression stockings and a calf compression device may also be used. As you recover, keeping mobile, performing ankle pumps and taking any prescribed blood thinners will also help reduce your risk of clots.
There are also general risks of having a knee replacement that are not orthopaedic related. These risks often relate to your underlying health and your Anaesthetist will be the best person to answer these questions but include:
Not being able to empty the bladder
As a guide, most patients will be in hospital for 3-5 days following a knee joint replacement. Dr Schluter will ensure you have achieved several specific goals before you can be discharged home. These include being safe with mobilising with crutches or a frame, being able to dress, shower and access the bathroom and being able to safely move in and out of bed and a chair.
There are a number of things you can do to make sure you are ready for your surgery.
Stay fit and active leading up to your surgery date – it is important to make sure you are in the best condition possible before undergoing surgery. Eat well and get plenty of sleep. Light walking for 10-15 mins every day and light strength exercises will help your recovery. Remember, don’t do any exercises that are painful for you.
Stop taking herbal medicines ( for example St john’s wort, ginger, ginko biloba, ginseng, garlic, echinacea, kava-kava ) 4 weeks before your surgical date as these can interfere with hospital medicines.
Stop Smoking - smoking slows the healing process and can increase blood clotting. Stopping smoking at least 6 weeks before your surgery will increase your ability to heal. You can contact your GP or Quitline 0800 778 778 ( www.quit.org.nz ) for further assistance.
Practice deep breathing exercises – these exercises will keep your lungs healthy and prevent pneumonia after the operation. The nursing staff on the ward will also assist you with these in the days after your surgery.
Make sure you are ready for your trip to the hospital by checking you have your hospital bag packed and have included all your important documentation.
DO NOT EAT OR DRINK after midnight, unless otherwise instructed.
Some patients will be given specific instructions regarding essential morning medications – please follow these carefully. You may brush your teeth and rinse with water in the morning.
We schedule between two and three hours for your operation. The surgery itself generally takes around 2 hours.
The process starts with the staff preparing you for surgery and completing a series of essential check lists. Dr Schluter will meet with you, cover any further questions you may have, check the consent and also mark the operation site.
You will also meet your Anaesthetist (Specialist Doctor) who will review your medical history and discuss with you the type of anaesthesia best suited to you. An IV line (drip) will be inserted, and you may be given some preoperative medications. Once in the operating room, and a final patient check is completed, you will be ready for anaesthesia and then surgery
What should I Expect Immediately After the Surgery ?
After the operation, you will spend around half to one hour in the recovery room where nursing staff monitor your progress and commence your post-operative pain regime before returning to your room in the surgical ward.
Your knee should not be painful due to the anaesthetic and also the injection of local anaesthetic around your knee.
The wound will have been closed with staples
Your knee will be wrapped up in a big bandage.
There may be a drain coming out of your knee.
You will have an IV line (drip) going into one of your veins.
You will have compression stockings on both legs with mechanical pumps helping blood flow in your calf muscles.
Dr Schluter will call your contact person to let them know you are in the recovery room
During your entire stay, the nursing team will regularly monitor your observations (Blood pressure, heart rate, temperature) and keep track of your fluid input and output. They will also monitor your pain score and administer pain medications that have been charted for you.
The Physiotherapist will see you in the morning each day you are in hospital. They will provide you with information on gentle exercises and supervise your rehabilitation and assess your ability to meet discharge goals.
DAY ONE : You will be assisted out of bed and helped with showering and dressing and then seated in reclining chair. If you had a wound drain, this may be removed today. If you have a urinary catheter it will also be removed. The antibiotics will be stopped but you will continue on blood thinning injection until you go home. You will have a blood test and you may have an Xray. Dr Schluter will visit you on the ward.
DAY TWO: The nursing staff will be there to assist you, but it is expected that you do more for yourself each day. You may notice pain in your knee and though it may be sore, it hopefully will be controlled with regular oral pain medications. Gentle exercises are encouraged, and you may be able to move around the ward for a short time. Some patients progress from a frame onto crutches
DAY THREE: Each day until discharge you will aim to be doing more for yourself and become increasingly mobile.
On discharge, you will be given crutches, a pain relief and blood thinner (generally aspirin) prescription and a staple remover which you need to take to your GP at 12 days for removal of your wound staples.
You will also be given an ice pack and instructions to take with you.
Most patients go directly home after discharge as it is usually preferable to recover in the comfort of your own surroundings. Depending on your progress, for the first week or so you will need some assistance with food preparation and other household tasks. If you live alone, a family member or friend needs to be available to help if possible.
Preparing ahead of time can let you concentrate on your recovery. Before you leave for the hospital, putting clean linens on the bed, doing the laundry and housework, and making some meals for the freezer will reduce your need for extra help.
You can also make sure your house is safe and avoid tripping hazards by
making sure rugs are smooth and secure,
having non-skid matts in the bathroom and kitchen,
removing cables and extension cords from areas you walk
consider putting in night lights in hallways and the bathroom to improve visibility.
and remember to avoid wearing open toe or slip-on footwear
You can place frequently used items in the kitchen, bathroom and bedroom where they can be easily reached without bending, stretching or having to use a step stool.
Make sure you have arranged for someone to collect you from the hospital (generally late morning) and be aware you may need to stop at a pharmacy on the way home to collect your post-operative medications.
Recovery takes time. You may still need assistance from a partner, friend or relative for several weeks after you return home.
All patients will experience swelling which can take 3 – 4 months to settle. You may also notice numbness of the skin around the wound. Your knee will feel stiff, especially if you have been immobile, but this will settle with time.
It is normal to have a small amount of bleeding into the dressing for up to a week. If there is bleeding that completely soaks the dressing, this will need review – please contact Dr Schluters rooms for advice.
Crutches are provided to help you balance when walking. The crutches may be needed for a month or so while you build up muscle strength, and the pain and swelling resolves. As your balance improves and you regain strength, you should use one crutch for support before walking for periods without assistance.
Pain will gradually improve and movement will increase.
You will gain more independence and will start to feel better about having had the replacement performed.
You will need to see your GP at 12 days for staple removal. Please take the supplied staple remover with you.
An exercise regime will help strengthen muscles and prevent the joint getting stiff
For the first 4 weeks, gentle daily walking on even surfaces is a good form of exercise
From 4 – 6 weeks onwards, daily use of an exercycle if possible is excellent for your recovery
The dressing on your wound is waterproof, and it is fine to shower with it.
YOU CANNOT DRIVE FOR THE FIRST 6 WEEKS if the RIGHT knee has been replaced. There may be some negotiation at the 4-week mark if the LEFT knee is replaced.
As a routine, Dr Schluter will see you in 6 weeks after the operation.
It is important to follow your progress so we can check the integrity of the prosthesis (implant). A routine xray and consultation with Dr. Schluter is recommended at I year and again at 10 years, or sooner if required.
Please do not hesitate to contact me or your GP if you develop any of the following:
Temperature higher than 38.5 °C (fever) or chills.
Sudden severe pain or tenderness at the wound site or in the joint.
Significant new swelling in the calf or thigh, especially if associated with pain or heat
Redness around the incision that continues to spreads.
Heavy bleeding from the incision.
Worsening flexibility or an inability to bend the knee.
Loss of mobility after a fall.
Any concerns you may have regarding your knee replacement.