Knee replacement is now a very common and successful operation. National statistics show that more than 90% of people who have a knee replacement are pleased with the outcome. However it is well understood that the speed of recovery after knee replacement is improved with knee replacement exercises and the long term success of a knee replacement does depend on the effort and time that a person invests into their rehabilitation afterwards.
The speed of recovery and improvement after knee replacement does vary from person to person and is influenced by a number of factors including:
- Age and general fitness. People who are older and have other health problems may take longer to recover from the effects of the surgery than others.
- Range of movement before the operation. Generally the more the knee could move before the operation the quicker the movement is likely to be regained after the operation. In knees which have been very stiff for many years prior to surgery it is unlikely that a significant improvement in movement will be gained afterwards. This is because the soft tissues around the joint will have adapted over the years to the limited range of movement and will have become tight. Stretches and exercises can improve the movement in this case, but it must be remembered that the prime reason for doing a knee replacement is for pain relief and regaining more movement is a secondary benefit.
- Strength of muscles before the operation. If the quadriceps muscles (thigh muscle) is strong before the operation then control and movement of the knee will be regained more quickly afterwards. This is one of the reasons why physiotherapy and exercises before a knee replacement is a good idea.
- Type of surgery - Surgeons use different techniques of knee replacement and this will have an effect on the recovery afterwards. Some surgeons now use minimally invasive techniques, which means that the cut through which the surgery is done is smaller, thus there is less damage to the muscle and recovery is quicker. If the arthritis only affects part of the knee then sometimes it is possible to have a half knee, known as a unicompartmental replacement. The recovery from this tends to be quicker than if a full knee is done.
- Commitment to rehab. Like any form of training, muscles strengthen and movement improves in line with the amount of time and effort that is put into using them. There is however a middle line, excessive force and exercise in the early stages can make the joint sore and swollen.
Knee Replacement exercises: Immediately after Surgery
The rehab after knee replacement commences immediately after surgery.
- Many centres use something known as a continuous passive movement machine or CPM. The is a machine that the leg rests on and continually, slowly and gently, bends the knee up and down through a movement that is comfortable.
- Ice may be used to help with swelling and pain.
- Exercises that are important in this phase include moving the ankle up and down to keep the blood pumping through the calf and decrease the risk of a blood clot.
- Tensing the thigh muscles, this is known as a static quads contraction.
- It is also important to start gently bending the knee.
Knee Replacement Exercises: Returning Home after the First Few Days
A progressive exercise programme to increase amount of knee bend, improve muscle strength, improve balance and walking is important over the few weeks to months after returning home form hospital. After an injury or surgery the body heals by creating new tissue, the strength and extensibility (which determines the amount of movement at a joint) of the new tissue is determined by the movement that this tissue is subjected to whilst it is being made. In other words if a knee after replacement is allowed to stay straight and is not moved in the initial stages then the bend will be very difficult to regain.
- Gradually the intensity of the exercises can be increased. It may still be necessary to use regular and effective pain relief. It is better to take pain relief and exercise, within reason, than not to take any pain relief and rest.
- Ice can still be helpful in reducing pain and swelling. It is important not to put the ice directly onto the wound/ skin as this can cause an ice burn, instead wrap the ice bag in something like a damp tea cloth.
- Quads exercises can be progressed and can start to include exercises like standing at the kitchen worksurface, holding on for balance and doing small knee bends.
- Knee bending work can also gradually be increased. An example of an exercise that may be helpful with this is to place the foot of the knee that has been replaced on the bottom step of the stairs, then to gently push forwards bending the knee.
- It is important at this stage to work on balance as good balance is necessary to be able to walk easily and normally.
- It may also be necessary, especially if a person has been having pain and difficulty for a prolonged period before the surgery, to work on other muscle groups, in particular those around the hip, in order to be able to walk more easily and without a limp.
Knee replacement exercises: Sport after a knee replacement
This is something that must be discussed with the individual surgeon who has done the operation, however most surgeons recommend that low impact activities such as walking, swimming and cycling can be resumed eventually after knee replacement. Higher impact activities and contact sports are generally not recommended. Many people continue to have difficulty kneeling after knee replacement.
Want to find out more about Knee Replacement exercises?
This article can only give a brief overview of the importance of knee replacement exercises along with a few examples. Our physio team is able to provide a personal exercise programme.
Disclaimer: The information on this page is written as an introduction to knee replacement exercises. If you have any concerns around your recovery after knee replacement you should always seek advice from a qualified medical person such as your GP, orthopaedic surgeon, or a Chartered Physiotherapist.