Your leg has been amputated between your ankle and knee joint. More energy will now be required to mobilise; however, you still have a functioning knee joint which is a great benefit. This level of amputation allows you the opportunity to continue your life at a level that, in time should be close to the level of function prior to your amputation. It is much easier for you to walk on all terrains, go up and down stairs and slopes with your own knee than with a prosthetic knee. The muscles in your thigh are normally intact and can power and control your knee movement through these activities.
Below-knee amputation
What it means to be a below knee amputee
Your leg has been amputated between your ankle and knee joint. More energy will now be required to mobilise; however, you still have a functioning knee joint which is a great benefit. This level of amputation allows you the opportunity to continue your life at a level that, in time should be close to the level of function prior to your amputation. It is much easier for you to walk on all terrains, go up and down stairs and slopes with your own knee than with a prosthetic knee. The muscles in your thigh are normally intact and can power and control your knee movement through these activities.
What is a Below-Knee Amputation?
A Below Knee amputation, also known as a Trans Tibial amputation, is a surgical procedure performed to remove the lower limb below the knee joint when a limb has been severely damaged or is diseased. Most below knee amputations (60%–70%) are due to peripheral vascular disease, or circulatory issues. Poor circulation limits the healing and immune responses to injury. Ulcers on the foot or leg may form as a result, which may not heal and develop an infection that can spread to the bone and become life-threatening. The amputation is then performed to remove the diseased tissue and prevent further spread of infection. Amputations may also occur as a result of congenital reasons, crush or other injuries where the limb is partially or completely severed.
The surgery is usually performed by a vascular or an orthopaedic surgeon. The diseased or severely injured part of the limb is removed, keeping as much of the healthy limb as possible. The surgeon will shape the remaining limb to allow the best use of a prosthetic leg after recovery. Care is taken by the surgeon to ensure that the residual limb is not too long so that the prosthetist has enough space for options of component selection for the fitting of a prosthetic foot under the socket. If it’s too short, the prosthetist may have an issue suspending the prosthesis on the residual limb. In planned surgeries, the Surgeon may consult a prosthetist for optimum residual limb length.
The need for a below knee amputation may be as a result of one of the following conditions:
- Peripheral vascular disease (poor circulation)
- Diabetes
- Infection
- Foot ulcers
- Trauma causing the lower leg to be crushed or severed
- Tumors
Below Knee Amputation – the positives
While an amputation is never ideal, there are some positives when it comes to a below knee amputee.
- A below knee prosthesis is usually easier to use than a prosthesis for amputations at a higher level. The higher the level of the amputation the more energy is required to ambulate.
- Depending on your physical condition and with proper training on the prosthesis, independence from assistive devices such as crutches can be achieved after 4 to 12 weeks from the date of receiving the prosthesis.
- Swimming, running, returning to sports are all possible depending on your physical condition and your prosthetic components.
Discussing what you would like to achieve in the future is an extremely important conversation to have with your prosthetist. Knowing the limitations and understanding what is possible and what isn’t possible with a prosthesis will help set your expectations as the prosthetic user and guide your prosthetist with the component selection.
The Socket
As with all prosthetic sockets, the fit is extremely important. A Below Knee socket is custom made according to the shape and size of the residual limb. The prosthetists expertise come into the design and understanding of your unique needs. The design determines where you can take pressure on your residual limb and how much and what areas need to be avoided. It is important that you discuss with your prosthetist any concerns or explain as best as you can where you are feeling pain or discomfort in the socket. You are the one wearing it and you need to be comfortable in it.
The prosthesis is suspended by various methods, these methods will be discussed during your assessment. The main suspension methods are vacuum (active or passive) or via pin lock. Both methods have pros and cons, your prosthetist will advise you on the method they recommend based on your specific needs. For suspension, a liner is used. This can be a silicone, gel or polyurethane liner. The liner is soft “sock” that is rolled on to your residual limb to forma soft and protective layer between your residual limb and the socket.
The Prosthetic Foot
The prosthetic foot chosen will be based on your weight, activity level and specific needs. There are a wide variety of feet available and options will be discussed with you in detail ensuring we match your foot to your needs. Prosthetic feet vary in their capabilities depending on the level of activity they are selected for. Some are activity specific such as running blades, they are designed specifically for running and not for day to day walking due to their energy return capabilities. They are designed for you to put a lot of weight/energy into the foot for it to release energy to propel you forward, as you can imagine, not ideal for day to day walking. The same could be said for an entry level foot, its purpose is to facilitate a smooth roll over while walking and provide a broad base of stability. Trying to run with this type of foot will lead to it failing and can cause pain or discomfort to your residual limb.
Your prosthetist will be able to advise you based on your needs as to what they think will be best suited for you. Please bear in mind that the first prosthetic foot will not necessarily be your last, as you progress through your prosthetic journey your needs may change and you may require a different type of foot. Speak to your prosthetist and ask them what they would recommend.
The Look of the Prosthesis
This is determined by the shape and size of your residual limb as well as the intended use of the prosthesis. Some prosthetic users like to have the components of their prosthesis exposed, others a High Definition silicone cover to match their sound limb. The decision is yours and again this is something that needs to be discussed with your prosthesis so they can advise on what is possible and what isn’t. Setting expectations in this regard is extremely important.