Total – Knee Replacement
Total knee replacement surgery is generally a highly successful operation, most commonly performed for severe arthritis of the knee arthritis and associated pain that significantly affects their daily activity and sleep. Dr Viral Shah uses latest technology and minimally invasive surgery for our joint replacement surgeries.
Knee replacement is usually used for advanced arthritis, but other common causes include:
- Increased stress (from overuse or increased body weight)
- Connective tissue disorders
Knee arthritis pain frequently treated with knee replacement is often pain which significantly reduces the ability to
- Undertake normal daily activities.
- Walking to and around the shops.
- Play golf, tennis or lawn bowls.
- Experience a good night’s sleep.
Knee replacement surgery is not the first thing that we generally recommend. Before undergoing surgery, it is important to exhaust all non-surgical pain management options, including:
- Pain medications
- Weight loss
- Activity modification
The aim of a total knee replacement is to relieve pain and improve function.
A total knee replacement surgery is rarely urgent surgery and proper patient preparation, usually with the assistance of your physiotherapist or exercise physiologist, as well as one of our rehabilitation physicians, is vital.
Prehabilitation aims to maximise your range of motion and hip strength to prepare you for post-operative rehabilitation and recovery. Our Rehabilitation physicians work together with your orthopaedic surgeon to design a customised program that suits your needs.
Prehabilitation usually runs over 4-6 weeks before surgery. Your pre-operative workup may also include:
- Planning imaging including a CT
- Blood tests
- Swabs for MRSA (“golden staph”)
- Cariology review to ensure there are no issues with your heart during the surgery
- Bariatric surgery assessment
We need to know about your medications, especially those for diabetes or blood pressure, as well as any blood thinning or anticoagulant medications, as some or all may need to be ceased temporarily before surgery.
If you are a smoker, you should refrain from smoking for as long as possible prior to and after surgery to ensure the best outcome.
Take caution to ensure that your knee remains free from scratches or grazes in the weeks before surgery, so avoid gardening during that period. If you do sustain trauma to the skin around the knee, or an obvious infection, please notify your surgeon immediately, as surgery may need to be delayed to reduce the risk of a post-operative infection.
You will arrive at the hospital 1-2 hours before your surgery, and will have fasted prior to that according to our instructions.
The most common anaesthetic for knee replacement surgery is a spinal block with a general anaesthetic. A urinary catheter is placed before the operation but this will be removed in recovery in most cases.
The incision will be down the front of the knee. Damaged bone and cartilage at the end of the femur (thighbone) and tibia (shin bone) are removed at the appropriate angles using specialized jigs. Your surgeon will then insert temporary prosthetics to ensure the accuracy of these cuts and determine what thickness of plastic should be placed in between these two components. After confirming the size and shape of the cuts, the surgeon will insert the actual prosthetics, which may require use of a cement to bind them to the bone. The metallic knee components are secured the femur and tibia, and a special plastic insert is placed between the metal components to act as a cushion and allow smooth knee bending. Your wound is usually closed with a dissolvable suture to minimise scarring.
The knee replacement is strong enough for you to walk on immediately, and the team will have you walking within several hours of waking up.
Your waterproof dressing should be left intact until you have your wound check at around 2 weeks. A small amount of ooze is common over the first 24-48 hours. You can shower with the dressing, however avoid soaking in the bath or pool. If the dressing becomes loose or gets soaked, please replace it. We do not advise hydrotherapy within the first 3 weeks of joint replacement surgery, preferring to wait until the wound is healed.
It is sometimes safe for patients to go home on the same day of surgery but most stay overnight or couple of days in hospital.
A walking aide such as a frame or crutches, will be arranged for you to use in the early post-operative period. During the first 2 weeks following surgery, you will need to take the painkillers so that you can do the exercises needed to regain flexibility back into the knee and strengthen your thigh muscles.
A few patients require inpatient rehabilitation services, but most can be rehabilitated post-operatively with a customised post-operative rehabilitation program designed by our rehabilitation physician, in conjunction with your physiotherapist and exercise physiologist.
Returning to work and sport depends on your type of work and sporting activities. Office-based roles can be restarted as soon as you are comfortable and not needing strong pain killers. More arduous physical activities such as climbing ladders and staircases, or carrying heavy loads, should be avoided for a minimum of 12 weeks.
Return to sport is a much more gradual process, guided by your pain levels and recovery progress with physiotherapy. Some sporting activities, such as swimming for example can be restarted after 3 weeks when the wound has healed and you are comfortable. More intensive sports such as golf etc will take at least 6 weeks. We do not recommend running on your knee replacement unless previously authorised by your surgeon.
We do not recommended driving until you can safely perform an “emergency stop” and are no longer taking strong pain medication. A minimum of 6 weeks after a knee replacement should pass before driving an automatic vehicle. Please check with your surgeon and/or rehabilitation specialist before you start driving after surgery.
All surgery involves a risk of complications. Fortunately, serious complications are uncommon.
Risks of surgery involve those related to:
- Anaesthetic, including allergic reactions, blood loss needing transfusion, heart attack, stroke and death.
- General surgical complications including blood clots (DVT/PE) in the veins, wound infection and breakdown, injury to blood vessels and nerves.
- Specific surgical complications including:
- Damage to the small branches of the saphenous nerve which supply sensation over the front of the knee, causing numbness. In many cases this area remains permanently numb and can cause discomfort when kneeling. It does not cause any weakness.
- Knee stiffness – Some knees remain stiff even after 2 months and can require further procedures to help them bend again.
- Wearing out of the plastic components, which may require replacing.
- Metal components can become loose and may need replacing.
- Kneecap instability or dislocation.
- Damage to the common peroneal nerve by retractors or from straightening up a knee which was very stiff. This can lead to ‘foot drop’ and numbness which can be permanent in some cases.
- Leg length discrepancy, which is uncommon.
Partial – Knee Replacement
Most patients with severe knee osteoarthritis requiring surgery will require a total knee replacement. But in patients with osteoarthritis limited to only one compartment, a unicompartmental knee replacement (partial knee replacement) may be suitable. This knee replacement option has faster recovery and can be done through a smaller incision than a total knee replacement.
There is less soft tissue and bony interference compared to with a total knee replacement, usually resulting in less pain and swelling, and faster rehabilitation. The structure of the rehabilitation process is similar to that following total knee replacement. By around 6 weeks post-op you will be able to return to most activities of daily living. Return to driving is similar to after a total knee replacement.
The risks of surgery are similar to following a total knee replacement.
Recovery and Rehabilitation
after Knee Replacement
Summary of Recovery Phases after Knee Replacement
Each physiotherapist have their own protocol and tailors it to individual patient. However, in general following is the protocol.
Phase 1 (weeks 1-3)
During the first 6 weeks, there is normally swelling and stiffness of the knee joint involved, and the healing wound requires meticulous care.
Phase 2 (weeks 3-8)
This phase includes the commencement of a tailored physical therapy and rehabilitation program, with a progressive increase in in joint movement and loading aimed to return you to your usual physical activities. This is where the rehabilitation physicians at Precision Integrated Orthopaedics play a crucial role, working closely with your physiotherapist or exercise physiologist. Planning for this phase commences during your prehabilitation program before surgery.
Phase 3 (8 weeks and beyond)
During this phase, your physical capacity is progressively increased to improve you to beyond the level at which you started. Strength, fitness and function are emphasised, to allow you to keep up with the grandchildren or to return to playing your chosen sport safely and sustainably.
Early Stages After Knee Replacement Surgery
Minimisation of discomfort in the early weeks after knee replacement surgery is critical. This is typically achieved with a combination of:
- Judicious use of regular painkillers.
- Sleep optimisation, with use of sleeping tablets where needed, and adoption of the most comfortable sleeping position.
- A walking aid may be used for a short period of time if needed.
- Elevation, icing and compression of the leg, if it swells.
- Involvement of one of the Precision Pain Specialists if pain management is challenging, or where the patient was on large doses of pain medications pre-operatively.
During this time, it is best to avoid:
- placing a pillow under the knee (to prevent a permanently bent knee)
- kneeling on the operated knee during the first 6 months.
Knee Swelling After Surgery
It is completely normal for the knee to feel warm and look swollen for months after surgery. Swelling may extend into the calf or thigh, and can vary from hour to hour or day to day depending on activity level.
The sutures are usually dissolvable, and the wound should be kept dry for 2-3 weeks after surgery (if it get wet, particularly with unclean water before it has healed, the risk of infection is much higher).
The wound may occasionally become red or inflamed or may even ooze. This may require a short course of oral antibiotics. If occurs, please contact your Precision Integrated Orthopaedic Surgeon or one of our Practice Nurses immediately.
Hydrotherapy is often of great benefit to patients. The Precision Integrated Orthopaedic Specialists are generally happy for hydrotherapy to start at around 3 weeks following surgery as long as –
- The wound is clean and dry
- The wound has been reviewed by one of our rehabilitation physicians beforehand.
Your orthopaedic surgeon will ensure you are discharged from hospital on the most appropriate pain medication, however most patients only need Panadeine or Panadol. Where required, our pain specialists may also become involved before or after surgery to ensure that stronger pain medications are used effectively and safely, with the risk of long-term dependence.
Physical Activity After Surgery
We recommend that you limit your activities in the first 3 months after surgery to:
- Walking with support of a stick or crutches
- Gentle swimming or hydrotherapy (once the wound has been cleared by a doctor).
We advise against the following activities for at least 3 months after surgery:
High impact sports, including running should be discussed before the procedure, as they may impact on the lifespan of the prosthesis.
Activities that put the knee in extreme positions such as yoga are not advised after knee replacement.
You can have sex whenever you feel up to it after the surgery.
We generally recommend that you do not drive for the first 6 weeks following knee replacement surgery, however before you resume driving you should discuss this with your orthopaedic surgeon as the laws around driving after surgery vary from one State to the next. From a safety viewpoint, you must be sure that you are safe to control the pedals, particularly the brake.
Air Travel After Knee Replacement Surgery
It is usually safe to take a short flight a week after surgery as long as you don’t have blood clots in the legs. In fact, many of our patients are from country areas or interstate, so they often fly to us for surgery and then fly home. We do not advise taking a long-haul flight in the first 3 months after surgery as there is an increased risk of deep venous thrombosis (DVT). If you do need to fly, then we advise that you wear TED stockings and mobilise (walking around) during the flight as much as possible. We also advise that you stay well hydrated, limit alcohol intake, perform frequent ankle exercises and calf raises, and elevate your legs as much as possible when seated. Please discuss any travel plans this with your Precision Integrated Orthopaedic surgeon prior to surgery.
Once you have had a joint replacement, it is critical to be vigilant for any infections elsewhere in the body, even many years after surgery. Any infection can travel via the bloodstream to the knee joint and infect the metalwork, resulting in a need for further operations and antibiotics. Please beware of tooth decay, dental abscesses and mouth infections. Always tell your dentist that you have had a knee replacement before any type of dental work.