Excerpt from Elbow and Above-Elbow Amputations

Please click here to view the full topic text: Elbow and Above-Elbow Amputations

Upper extremity amputations largely follow the same basic principles as those of any amputation. This article highlights the special considerations involved in acquired amputations at or above the elbow. Below-elbow amputations are discussed in separate articles (see Wrist and Forearm Amputations and Digital Amputations). Although acquired amputations in children are discussed (because pediatric patients deserve special consideration), patients with congenital limb amputations and deficiencies are beyond the scope of this article.

History of the Procedure

Amputation is one of the oldest surgical procedures. Archeologists have uncovered evidence of amputation—congenital and acquired through surgery or trauma—in prehistoric humans. While surgical amputation has evolved significantly since the days of quickly severing a limb from an unanesthetized patient and dipping the stump in boiling oil to achieve hemostasis, modern ideas of amputation and prosthetics were not developed until World War I and II. Particularly since the late 20th century, prosthetic research and rehabilitation engineering centers supported by federal funding have disseminated new information regarding biomechanics and prosthetic design.

With the advent of physical and rehabilitative medicine, surgeons now realize that care for a person who has undergone an amputation does not end with the removal of sutures. (See also the eMedicine articles Cancer and Rehabilitation and Upper Limb Prosthetics.)

Problem

The surgeon faces many challenges over the course of treating an individual via amputation. The surgeon must determine the salvageability of a limb, an assessment that is often made quickly in cases of trauma or sepsis. Once the decision to amputate has been made, the level of amputation must be determined. The functional limitations of amputation levels and prosthetic designs, as well as the patient's emotional, physical, and vocational background, must be considered carefully, especially with upper-extremity amputations. As a result, the surgeon walks a precarious tightrope. Preservation of length in the upper extremity is paramount, but it is often at the sacrifice of stump viability, appropriate bone coverage and padding, and, occasionally, optimal prosthetic fitting.

The surgery itself has its own risks from anesthesia and cardiovascular collapse, as well as early postoperative infections and pulmonary embolism. Later, and perhaps more specific to individuals with amputations, are occurrences of joint contractures, phantom limb pain, neuroma formation, stump breakdown, and, in children, bony overgrowth.

Unlike some orthopedic patients, individuals with amputations should undergo comprehensive physical and emotional rehabilitation. A person with an amputation is a patient for life. Close coordination with a team of specialists in physiatry or rehabilitative medicine, as well as with a prosthetist, a physical therapist, and a psychologist, is ideal.

The following are major goals of upper extremity amputation surgery:

• Preservation of functional length
• Durable coverage
• Preservation of useful sensation
• Prevention of symptomatic neuromas
• Prevention of adjacent joint contractures
• Minimization of short- and long-term morbidity
• Early prosthetic fitting, when applicable
• Early return of the patient to work and play

Frequency

The true frequency of acquired amputation at or above the elbow is unknown. Published estimates of the number and rate of limb amputations, including of the upper extremities, vary significantly; totals ranging from 350,000-1,000,000 persons with amputations have been cited, as have rates of 20,000-30,000 persons per year for patients undergoing amputation.

Etiology

See Clinical.

Clinical

Patients with vascular compromise or occlusion present very differently, depending on the etiology. For example, patients with vascular occlusion secondary to acute embolic phenomena from a more proximal arterial graft typically present with a cold, pale, initially painful portion of the upper extremity with absent capillary refill.

Because of collateral circulation, the location of embolic occlusion is often difficult to determine based on clinical appearance. In such individuals, arteriography or magnetic resonance angiography (MRA) confirm the location of the occlusion and assist in determining the level of intervention. In persons with acute occlusion, medical or surgical thrombolytic recanalization or vascular bypass efforts should be pursued. However, if these efforts fail or if the devascularized tissue has undergone irreversible injury, then amputation is indicated. (See also the article Upper-Extremity Revascularization Procedures: Introduction, on Medscape.) 

Incidents of chronic ischemia, such as in persons with diabetes or peripheral vascular disease, occur less often in the upper extremity than in the lower extremity. Furthermore, the incidence of chronic ischemia resulting in amputations above the elbow is uncommon given the relative size of the vessel and the proximity to the heart. Revascularization efforts in this situation are less successful and frequently proceed to amputation. Chronic ischemic injury begins distally and usually progresses proximally to more viable tissue. For this reason, the extent of ischemic injury may not be appreciated fully soon after the initiation of clinical changes.

In individuals with chronic vascular insufficiency, patients remain quite functional for many years despite intermittent reports of mild pain with activity or cold intolerance. The only skin changes, if any, may be those of atrophy (shiny hairless skin). For example, patients may present with acute onset of pain in the ipsilateral index and long digits with no or minimal skin discoloration acutely. Over the course of 24-72 hours, skin usually turns cyanotic, and pain is replaced with decreased sensation. Provided the patient is not acutely ill from sepsis, amputation at this time is discouraged. In persons with chronic ischemia, allowing the extent of the ischemia to declare itself clinically is far preferable.

Cyanotic fingers may turn black with time, and assumed viable tissue more proximally may follow, with cyanosis observed in the fingers. Once the progression of ischemia has stabilized, plans for definitive amputation may commence. If the level of amputation is in question, specific tests may be performed to assess the viability and healing potential of the tissue in question.

Thermal burns and frostbite rarely result in amputation more proximal to the hand. However, with extensive injury, amputation may be required. In general, thermal burns and frostbite injuries should be managed nonoperatively until the extent of the damage can be assessed accurately and the amputation can be performed at the most distal level consistent with good healing. Pyrophosphate nuclear scanning has been demonstrated to be useful in predicting the need for amputation in these situations.¹

Even in the trauma setting, the level of amputation may be difficult to determine. Most cases of trauma involve significant avulsion and crush components that leave obvious devitalized tissue exposed. The complete extent of the injury zone may not be apparent on initial presentation. When in doubt, especially in grossly contaminated wounds, it is wise to proceed with open amputation to allow the wound to declare itself prior to closure over a definitive stump length.

Neglected compartment syndromes in the upper extremities commonly necessitate amputation. Initially, fasciotomies are performed, and provided that the patient remains systemically stable, initial debridement should remove tissue that is obviously dead. Tissue that is neither contractile nor bleeding should be removed at this time. Tissue that is noncontractile but bleeding and that otherwise appears to be healthy should be left intact; fasciotomies should be left open and have a sterile dressing that prevents desiccation. The patient should then return to the operating room within 24-48 hours for a second observation of the tissues, and the tissues should be debrided as described above. This conservative process continues until the tissues have stabilized and the surgeon is convinced that all remaining tissue is viable.

Although this step-wise, conservative debridement is labor-intensive, it ensures that the absolute minimal tissue has been removed and that the patient is left with maximal function. Even in severe instances in which amputation is indicated, this step-wise process dictates the level of amputation and ensures maximum length for the remaining portion of the extremity; otherwise, an arbitrary guess at the amputation level may be necessary, possibly leaving the remainder of the extremity inappropriately long (resulting in failure of healing) or inappropriately short (resulting in decreased functional potential). However, the step-wise process is contraindicated in patients with systemic sepsis, renal compromise secondary to disseminated myoglobin, or some other critical illness that leaves the patient unable to sustain multiple surgeries.

Please click here to view the full topic text: Elbow and Above-Elbow Amputations