What is Above-Knee Amputation?
Above-knee amputation (AKA), or transfemoral amputation is a surgical procedure performed to remove the lower limb above the knee joint when that limb has been severely damaged or diseased. Most AKAs are performed due to peripheral vascular disease, or severe disease of the circulation in the lower limb. Poor circulation limits healing and immune responses to injury. Foot or leg ulcers may develop and not heal. They may become infected, and the infection may spread to the bone and become severe enough to be life threatening. Amputation is performed to remove the diseased tissue and prevent further spread of infection. Above-knee amputations are performed when the blood flow is inadequate in the lower leg or infection is so severe it prohibits a lower-level surgery.
If an AKA surgery is necessary, it is usually performed by a vascular or orthopedic surgeon. The diseased or severely injured part of the limb will be removed, keeping as much of the healthy tissue and bone as possible. The surgeon shapes the remaining limb to allow the best use of a prosthetic leg after recovery.
The need for AKA is caused by conditions including:
Peripheral vascular disease
Trauma, causing the lower leg to be crushed or severed
How Can a Physical Therapist Help?
Prior to AKA surgery, your physical therapist may:
Prescribe exercises for preoperative conditioning to improve your upper and lower extremity strength and flexibility
Teach you how to walk with a walker or crutches
Educate you about what to expect after the procedure
Immediately after surgery: You should expect to stay in the hospital for approximately 5 to 14 days. Your wound will be bandaged, and you may also have a drain at the surgery site. Pain will be managed with medication.
Physical therapy will begin soon after surgery when your condition is stable, and the doctor clears you. A physical therapist will review your medical and surgical history, and visit you at your bedside. Your first 2 to 3 days of treatment may include:
Gentle stretching and range-of-motion exercises
Learning to roll in bed, sit on the side of the bed, and move safely to a chair
Learning how to position your surgical limb to prevent contractures (the inability to straighten the knee joint fully caused by keeping the limb bent too much)
When you are medically stable, the physical therapist will help you learn to move about in a wheelchair, and stand and walk with an assistive device like a walker.
Prevention of contractures: A contracture is the development of soft tissue tightness that limits joint motion. The condition occurs when muscles and soft tissues become stiff and fibrous from lack of movement. With an AKA, the hip muscles can easily become shortened due to sitting in the same position for a long time. The muscles adapt to the position.
Contractures can become permanent if not addressed following surgery, throughout recovery, and after rehabilitation is completed. Contractures can make it difficult to wear your prosthesis and make walking more difficult, increasing the need for an assistive device, such as a walker.
Your physical therapist will help you maintain normal posture and range of motion at your hip. Your therapist will show you how to position your limb to avoid development of a contracture, and teach you stretching and positioning exercises to maintain normal range of motion.
Swelling and Compression: It is normal to experience postoperative swelling. Your therapist will help you maintain compression on your residual limb to protect it, reduce and control swelling, and help it heal. Compression can be accomplished by:
Wrapping the limb with elastic bandages
Wearing an elastic shrinker sock
These methods also help shape the limb to prepare it for fitting the prosthetic leg.
In some cases a rigid dressing, or plaster cast may be used instead of elastic bandages. An immediate postoperative prosthesis made with plaster or plastic may be applied. The method chosen depends on each person’s situation. Your therapist will help monitor the fit of these devices and instruct you in their use.
Pain Management: Your physical therapist will help with pain management in a variety of ways, including:
The use of electrical stimulation and TENS (transcutaneous electrical nerve stimulation) for pain modification. Gentle electrical stimulation of the skin helps relieve pain by blocking nerve signals from underlying pain receptors.
Performing manual therapy, including massage and joint manipulation to improve circulation and joint motion.
Providing residual limb management, including skin care and stump sock use.
Desensitization to help modify how sensitive an area is to clothing pressure or touch. Desensitization involves stroking the skin with different types of touch to help reduce or eliminate the sensitivity reaction to the stimulus.
See the Physical Therapist’s Guide to Phantom Limb Pain for more information about amputation pain.
Your physical therapist will work with the prosthetist to prescribe the best prosthesis for your life situation and activity goals. An above knee prosthesis includes a socket, knee joint, ankle joint, and foot components. You will receive a temporary prosthesis at first while your residual limb continues to heal and shrink/shape over several months of healing. The prosthesis will be modified to fit as needed over this time.
After you move from acute care to rehabilitation, you will learn to function more independently. Your physical therapist will help you master wheelchair mobility and walking with an assistive device, such as crutches or a walker. Your physical therapist will also teach you the skills you need for successful use of your new prosthetic limb. You will learn how to care for your residual limb with skin checks and hygiene, and continue contracture prevention with exercise and positioning.
Your physical therapist will teach you how to put your new prosthesis on and take it off, and how to manage a good fit with the socket type you receive. Your physical therapist will help you to gradually build up tolerance for wearing your prosthesis for increasingly longer times, while protecting the skin integrity of your residual limb. You will continue to use a wheelchair for getting around, even after you get your permanent prosthesis, for the times when you are not wearing the limb.
Prosthetic training is a process that can last up to a full year. You will begin when the physician clears you for weight bearing on the prosthesis. Your physical therapist will help you learn to stand, balance, and walk with the prosthetic limb. Most likely you will begin walking using parallel bars, then progress to a walker, and later, as you get stronger, you may progress to using a cane before walking independently without any assistance. You will also need to continue strengthening and stretching exercises to achieve your fullest potential for a return to many of the activities you performed before your amputation.
Can this Injury or Condition be Prevented?
It is believed that 60% of amputations are preventable. The leading cause of AKA is complications from diabetes, such as peripheral vascular disease, open wounds, and infection. Prevention and management of diabetes and lower-extremity circulation problems can greatly reduce the risk of developing conditions that lead to the need for lower-extremity amputation.
To help prevent problems when you have diabetes, make sure you protect your lower limb/feet by wearing adequate footwear that fits well. It is also important to examine your lower extremities and feet daily for signs of skin problems, including redness, discoloration, swelling, blisters, scratches, or open wounds. It is important to promptly consult your primary health care provider or physical therapist, should you notice a problem. Prevention of infection is a primary way to prevent amputation.
It is also important to stop smoking. Smoking cigarettes can interfere with healing, and is associated with a reamputation risk for smokers 25 times greater than that of nonsmokers.
Real Life Experiences
Jim is a 68-year-old man who has diabetes and peripheral artery disease affecting both of his lower limbs. He has an open wound on his left leg. Despite good wound care and diabetic control, the wound has become severely infected and has spread to his bone. Because the infection is threatening Jim’s health and well-being, the decision is made to amputate his leg above the knee. Jim is referred to physical therapy for preoperative exercise instruction, and to learn how to walk with a walker before his scheduled surgery.
The day after Jim’s surgery, a hospital physical therapist comes to his room to begin treatment. She teaches Jim some isometric tightening exercises for his hip muscles, and range-of-motion exercises for his uninvolved leg and arms. She helps him roll in bed. She shows him how to keep his thigh straight on the amputated side, and how to support his residual limb to reduce swelling.
As Jim heals, his doctor clears him for activity out of bed. His physicial therapist helps him get out of bed to sit in a chair. She teaches him to stand on 1 leg with a walker next to his bed. As he gets stronger, Jim works every day to advance to 1-leg walking with a walker, with close assistance from the physical therapist.
When Jim is medically stable, he transfers to a rehabilitation facility. There, he works closely with the rehabilitation physical therapist to learn how to care for the skin on his residual limb, how to position and stretch his leg to prevent contractures, and how to wrap the stump and use shrinker socks to reduce swelling and shape his residual limb. Soon, he is able to get around by propelling his wheelchair. He also works hard doing strengthening and stretching exercises as directed by his physical therapist. He gains strength and balance, allowing him to walk farther without becoming tired.
Jim receives a temporary prosthesis. The prosthetist fabricates a socket from a cast of his residual limb, and connects it to a knee component and prosthetic foot. Jim is now ready to begin his gait training in physical therapy with weight bearing on his amputated leg. Jim and his physical therapist will monitor the fit of the socket several times a day and after weight bearing to avoid pressure points on his residual limb.
Jim progresses over several weeks and is now able to function with minimal assistance. He is discharged home. His family has been trained to help him function safely at home. Jim continues physical therapy as an outpatient to continue to improve his strength and walking ability; he advances to walking with 2 canes.
When he receives his permanent prosthesis, he works with his physical therapist to ensure a good fit. He continues to work with her to achieve his goal of walking independently without an assistive device. After much hard work, Jim is discharged from physical therapy having achieved his goals.