In the US, 3-4 percent of amputations are related to trauma and the rest are due to a combination of peripheral vascular disease and diabetes mellitus. The prevalence of lower extremity amputations from trauma is higher because these people tend to live longer after their injury than do those who have amputations from medical reasons.
Traumatic lower extremity amputation is largely a problem of young men. More than 85 percent of the population is male and were younger than 40 years of age. The use of motor vehicles accounts for about 75 percent of these amputations. These included occupants of motor vehicles, pedestrians, and especially motorcycle riders. Some will have isolated leg injuries while a small percentage have head and neck injuries, thoracic injuries, and abdominal injuries.
The most common type of amputation is transtibial amputations, which account for half of all amputations. The rest are from transfemoral injuries, partial foot amputations, and hip disarticulations. Other amputations occur at the level of the knee with disarticulation of the knee.
The Mangled Limb
One of the challenges the surgeon faces with regard to the mangled limb is whether to save it or amputate the limb. Attempts have been made to quantify exactly at which point the limb has no chance of salvage and when amputation is the only available option. There are specific measures that have been used to make this assessment.
Local extremity factors include the extent of soft tissue injury or defect, the presence or absence of blood vessel injury, the presence and extent of nerve injury and the location of the bony fracture. The various measures used on amputations are, unfortunately, not very good in identifying those who will eventually need an amputation but may be better in identifying those limbs that can be salvaged.
Can it be determined at the time of injury in the emergency room who will have an extremity that is salvageable and which will require amputation? In an ideal world, it would be advantageous to predict at the time of injury whether an amputation is necessary or whether the leg can be salvaged but there are no outcome measurement tools that address this question. It is up to the surgeon and the physical medicine and rehabilitation specialist to try to anticipate the outcome of either a limb amputation or salvage of the limb.
Rehabilitation in the Perioperative Period
It is the role of the rehab specialist during the perioperative period to assist the surgeon in the decision-making regarding whether or not to amputate. Informed consent must be given before an amputation can be undertaken. It is used to facilitate quality physician-patient interaction and to enable shared decision-making in terms of healthcare interventions. This allows the patient to know his or her treatment options, the general risks, benefits and probable outcomes of each option. It is critical that the patient be informed of the treatment options and potential outcomes. The physiatrist will play a role in the decision-making.
It is important to know if the limb can be salvaged but especially if the limb can be returned to its preinjury level of functioning. The first step is to understand the patient’s level of functioning before the injury happened. This includes knowing their vocation and recreational interests. They need to know whether the individual needs to stand, clime, walk, or go over complex terrain. The second step is to try to determine the relative importance of preserving the various functional tasks and the psychological aspects of preserving the cosmetic and body image aspects of losing the leg.
Can the leg be salvaged from a technical aspect? The answer to this may need input from the orthopedic surgeon, the vascular surgeon and possible a plastic surgeon. The surgeon must determine the percentage probability that the limb can be successfully salvaged.
It is also important to determine what would be involved in the salvage process. They need to determine the number of surgical procedures required to repair the limb, the time course of future reconstructions, and the extent of function during the course of the salvage. The salvage may take up to 18 months during which time the patient may be unable to return to work and may have to take a great deal of analgesic medications.
The final determination is to know whether or not the salvaged limb will return to its normal state of functioning. With the salvage mean there may be extensive skin grafting that may be prone to skin breakdown over the long term. There may be contractures, sensory, or motor impairment that will limit the functionality of the limb.
The physiatrist is in an excellent position to play a big role in amputation rehabilitation, should one be necessary. Things to consider regarding the amputation are the patient’s vocation, recreational interests, psychological status, support system, and the existence of other medical and surgical disorders. A complete physical examination should be undertaken to make sure the individual will be able to function at the relative amputation levels. The time course of recovery will be determined.
If the decision is made that an amputation is necessary, the patient and family may have a wide variety of psychological reactions. Most patients are unfamiliar with the outcomes after amputations and have many questions. There are often concerns about mobility, sexuality, and the ability to function as a spouse or parent. They may worry about being a burden on their family. Some psychological reactions may include anxiety, despair, and depression.
One of the goals of education is to bring about a state of hope. A sense of hopelessness in many cases is associated with a poorer outcome. In the case of the amputee, it is important to instill a sense of “realistic optimism”. This goal can be accomplished through a direct physician/patient relationship as well as the use of an appropriately selected peer support person.
Important things to include in the education include where the amputation will take place, the typical postoperative management strategies, and information about how long the pain usually lasts and whether or not there will be phantom pain. The patient will want to know the typical time to get a prosthetic fitted and what the rehabilitation process will be like.
Early Post-Amputation Management
The key issues in early rehabilitation of the amputee are to enhance the wound healing, shape the limb to fit the prosthesis, reduce or prevent joint contractures, reduce pain, and prevent secondary complications associated with bed rest and immobility.
The most important goals of limb management in this period are to prevent proximal joint contracture, protect thee healing incision line, enhance healing, reduce edema, and shape the residual limb in preparation for the prosthetic fitting.
There are soft dressings, rigid dressings, immediate postoperative prostheses, removable rigid dressings, pneumatic dressings, and Unna dressings. Some work on different amputation levels while others can be used for just about any level of amputation. Just exactly the correct choice of dressing to use has not yet been made clear.
Soft dressings using gauze and Ace wraps for compression are commonly used, especially by non-orthopedic surgeons. These are easy to apply and allow the doctor to observe the healing incision line in cases where there is a wound complication that may require frequent dressing changes. The disadvantages of this type of dressing include a lack of protection of the residual limb from external trauma if the patient would happen to injure it during a transfer. There is also no way to immobilize the proximal joint, which can suffer from contractures. Physical therapy and the use of a posterior splint can decrease the likelihood of a contracture.
Rigid dressings have been used in all major lower extremity amputation levels past and including the level of hip disarticulation. Their use has largely been abandoned except for trans-tibial, Symes, and transmetatarsal amputation levels. The dressing involves gauze, foam padding, and layers of elastic and conventional plaster. The dressing is suspended from the through a waist belt or by compression of the cast as it hardens over bony prominences. This immobilizes the knee in extension so the risk of contractures is less.
The immediate postoperative prosthesis technique has been largely abandoned except for those amputations across the middle of the tibia. This technique uses a rigid dressing with the distal attachment of a pylon and an artificial foot. It allows for rapid weight-bearing after surgery. Early weight-bearing may help shape the residual limb and can have psychological and physiological benefits.
The removable rigid dressing has been used exclusively at amputations across the tibia. It includes a soft dressing over the wound with a rigid cast that extends only to the level of the kneecap. There is no pylon or foot attached. Weight bearing is begun using the end of the plaster cast propped up with a pommel that is padded. Potential disadvantages include the lack of effective suspension systems except for a waist belt and there may be a greater risk of knee contracture. It may reduce edema, however, and might help shape the residual limb better than a soft dressing.
There have been a variety of pneumatic compressive devices to help shape and immobilize the residual limb. These function similarly to a rigid dressing but are lighter in weight and allow for a reduction in swelling and an increase in shaping of the extremity. They are also removable so that the wound can be inspected and the dressings to be changed. Some are non-weight bearing and others allow for partial weight bearing.
The Unna dressing is a bandage that is usually used for venous stasis ulcers. It is imbedded with a number of medications that forms a semi-rigid dressing. It is used in a trans-femoral and trans-tibial level amputations. It has been known to enhance healing and help with prosthetic fitting so that successful ambulation can occur quickly.
Outcome after Amputation
Pain is primarily related to the amputation but pain is also important in the healthy limb. Phantom limb pain is a common complication of lower extremity amputations and has been known to occur in just about everyone. Severe phantom limb pain is seen in about 25 percent of lower limb amputees.
Residual limb pain is also an important cause of disability. About 36 percent of people complain of either severe continuous or intermittent limb pain. In one study, it was found that sixty percent of amputees reported moderate to severe residual limb pain. Other things that add to disability are things like skin irritation and perspiration, occurring in about 24 percent of the population. Even so, prosthetic use is extremely high, averaging about 80 hours a week. Still, there is only a moderate probability that a lower extremity amputee will return to work. The return to work rate in one study was only about 58 percent and, for those who returned, they returned to less physically demanding jobs.
There is a high prevalence of low back pain as well (at 52-76 percent of patients). Individuals with amputations across the femur have a higher degree of back pain when compared to those with lower amputations. There is also a risk of pain and degenerative arthritis, especially of the knee on the good side.
In summary, traumatic amputation of the lower extremity has a significant toll on the survivors with 48 percent reporting that their health is somewhat or much worse than prior to their amputation. Only 58 percent returned to employment and pain/physical limitations are much higher than age-matched control individuals. Prosthetic use is very high but there is a lot of dissatisfaction with the function of the prosthesis.
Outcome after Salvage
It is important to know if those who have had their limb salvaged do any better than those who have had an amputation. About 90 percent are satisfied overall with their results. However, depression was common at 28 percent and only 64 percent return to work. Fifteen percent of patients need to walk on crutches and about 28 percent could walk less than a kilometer. There is pain at rest and with ambulation. Some studies showed improved physical functioning scores in the limb salvage group while others showed no differences in the ability to walk, run, jump, and climb stairs in the limb salvage patients when compared to normal people. There was, however, a decrease in ability to engage in recreational activities.
These individuals tend to by young and male so that the economic impact and financial status as well as disability costs are high over a lifetime. The return to work rate is surprisingly low. In one study, the return to work rate was the same in the amputation group as it was in the limb salvage group. Those with amputation tend to work faster than those in the limb salvage group.
In summary, there are few differences between those who have salvage of their limb and those who have an amputation. Pain, ultimate sense of well-being, psychological status, and probability of employment are similar between the two groups.
The Edward A Smith Law Offices is currently a member of the Million Dollar Advocates Forum.