Amputation

Terminology and Surgical Anatomy

Definitions

• Amputation: separation of a portion of or an entire limb of the body
• Complete amputation: complete separation (tissues and bones)
• Partial amputation: Some soft tissue Soft Tissue Soft Tissue Abscess remains, connecting the body part to the body.
• Traumatic amputation: secondary to accident or injury on the field, usually manifests as a partial amputation
• Surgical amputation: amputation performed in the OR
  • Elective
  • Urgent (life saving)
• Disarticulation: amputation performed at a joint

Anatomy

The surgeon should be familiar with the anatomical landmarks and important corresponding structures (nerves, vessels) of the amputation site to avoid injury. As an amputation can be performed at any point along the length of the limbs, a review of the anatomy depends on the site that is selected:

Upper limb amputation:

• Forearm Forearm The forearm is the region of the upper limb between the elbow and the wrist. The term “forearm” is used in anatomy to distinguish this area from the arm, a term that is commonly used to describe the entire upper limb. The forearm consists of 2 long bones (the radius and the ulna), the interosseous membrane, and multiple arteries, nerves, and muscles. Forearm: Anatomy (transradial): forearm Forearm The forearm is the region of the upper limb between the elbow and the wrist. The term “forearm” is used in anatomy to distinguish this area from the arm, a term that is commonly used to describe the entire upper limb. The forearm consists of 2 long bones (the radius and the ulna), the interosseous membrane, and multiple arteries, nerves, and muscles. Forearm: Anatomy
• Elbow disarticulation: elbow joint Elbow joint The elbow is the synovial hinge joint between the humerus in the upper arm and the radius and ulna in the forearm. The elbow consists of 3 joints, which form a functional unit enclosed within a single articular capsule. The elbow is the link between the powerful motions of the shoulder and the intricate fine-motor function of the hand. Elbow Joint: Anatomy
• Above elbow (transhumeral):
  • Axilla Axilla The axilla is a pyramid-shaped space located between the upper thorax and the arm. The axilla has a base, an apex, and 4 walls (anterior, medial, lateral, posterior). The base of the pyramid is made up of the axillary skin. The apex is the axillary inlet, located between the 1st rib, superior border of the scapula, and clavicle. Axilla and Brachial Plexus: Anatomy and brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region
  • Cubital fossa Cubital Fossa The cubital fossa is the region anterior to the elbow joint. The cubital fossa is seen as the triangular depression between the brachioradialis and pronator teres muscles. The 4 important structures of the cubital fossa (from lateral to medial) are the radial nerve, tendon of the biceps brachii muscle, brachial artery, and median nerve. Cubital Fossa: Anatomy
  • Arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy
• Shoulder disarticulation: shoulder complex Shoulder complex The shoulder complex comprises the glenohumeral joint, sternoclavicular joint, acromioclavicular joint, and the scapulothoracic articulation, and connects the upper limb to the trunk. This group of joints consists of the clavicle, scapula, and humerus bones, multiple muscles and supporting ligaments, cartilage, and bursae. Shoulder Joint: Anatomy
• Digit (transphalangeal, finger disarticulation): hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy
• Hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy (transmetacarpal, transcarpal, and wrist disarticulation): wrist joint Wrist joint The wrist connects the forearm to the hand. It consists of 8 carpal bones, multiple joints, and various supporting ligaments, as well as the distal bones of the forearm and the proximal portion of the 5 metacarpal bones of the hand. Wrist Joint: Anatomy

Lower limb amputation:

• Hip disarticulation:
  • Pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy
  • Gluteal region Gluteal region The gluteal region is located posterior to the pelvic girdle and extends distally into the upper leg as the posterior thigh. The gluteal region consists of the gluteal muscles and several clinically important arteries, veins, and nerves. The muscles of the gluteal region help to move the hip joint during walking, running, standing, and sitting. Gluteal Region: Anatomy
  • Hip joint Hip joint The hip joint is a ball-and-socket joint formed by the head of the femur and the acetabulum of the pelvis. The hip joint is the most stable joint in the body and is supported by a very strong capsule and several ligaments, allowing the joint to sustain forces that can be multiple times the total body weight. Hip Joint: Anatomy
  • Femoral region and hernias
• Above-knee amputation: thigh Thigh The thigh is the region of the lower limb found between the hip and the knee joint. There is a single bone in the thigh called the femur, which is surrounded by large muscles grouped into 3 fascial compartments. Thigh: Anatomy
• Knee disarticulation:
  • Knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy
  • Popliteal fossa Popliteal fossa The popliteal fossa or the “knee pit” is a diamond-shaped, fat-filled, shallow depression on the posterior aspect of the knee joint. The popliteal fossa is located at the dorsal aspect of the knee and contains an increased number of lymph nodes as well as structures of the neurovascular system that travel from the thigh to the lower leg. Popliteal Fossa: Anatomy
• Below-knee amputation: leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy
• Ankle disarticulation (Syme procedure): ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot.
• Foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy amputations: foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy
  • Midfoot (transmetatarsal)
  • Hindfoot
  • Toes

Indications and Contraindications

Indications

• Unsalvageable limbs due to:
  • Extreme injury (e.g., mangled limb, crush injury Crush injury Excessive compression of parts of the body that causes muscle swelling, fracture, and/or neurological disturbances in the affected areas. Crush injury with systemic manifestations is referred to as crush syndrome. Crush Syndrome)
  • Failed primary reconstruction
• Ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage:
  • Frostbite-related gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction
  • Critical limb ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage:
    • Peripheral vascular disease
    • Large venous thromboembolic burden
    • Compartment syndrome Compartment Syndrome Compartment syndrome is a surgical emergency usually occurring secondary to trauma. The condition is marked by increased pressure within a compartment that compromises the circulation and function of the tissues within that space. Compartment Syndrome
• Infection (in high-risk individuals):
  • Treatment-resistant necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis
  • Severe osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis
  • Pressure wounds (heels of individuals who are bedridden)
  • Diabetic wounds/ulcerations
• Malignancy Malignancy Hemothorax:
  • Large, recurrent tumors in the proximal upper limb region
  • Unresectable malignant tumors derived from bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types, muscle, nerves, blood vessels, or soft tissue Soft Tissue Soft Tissue Abscess
• Deformity Deformity Examination of the Upper Limbs:
  • Congenital Congenital Chorioretinitis
  • Charcot deformity Deformity Examination of the Upper Limbs

Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation

• Vascular insufficiency Vascular insufficiency Anal Fissure or active cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis at the site of a planned, elective amputation
• The individual is unstable for anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts.

Procedure

General surgical principles

Therapeutic goals:

• Preserve life despite the relative loss of functionality (e.g., hemorrhage or infection).
• Salvage maximum amount of tissue for the creation of a functional residual limb.

Selection Selection Lymphocyte activation by a specific antigen thus triggering clonal expansion of lymphocytes already capable of mounting an immune response to the antigen. B cells: Types and Functions of amputation type and level:

• Age: In children, the metaphyseal cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology is preserved to allow for proportional growth of the remnant limb.
• Level of activity
• Indication for amputation
• Available prosthesis for rehabilitation
• Presence of local infection

Preoperative care Preoperative Care Thorough preoperative care is important for patients scheduled to undergo surgery so that they can have the best possible outcomes after their surgical procedure. The preoperative process begins once the decision has been made to proceed with a surgical procedure. Preoperative Care

Emergency:

• Stabilize shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock (i.e., hemodynamic stability) before the procedure.
• Apply tourniquet to control hemorrhage (traumatic amputation).
• Assess vascular supply to the limb.
• Tetanus prophylaxis Tetanus Prophylaxis Overview of Bone Fractures
• Antibiotic prophylaxis Prophylaxis Cephalosporins
• Blood transfusion if needed

Elective:

• Complete preoperative evaluation (especially cardiac status).
• Psychological analysis: screen for depression
• Thromboprophylaxis (for lower limb amputations)
• Perioperative antibiotics (to be administered within 1 hour of incision)
  • Vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides
  • 1st-generation cephalosporins Cephalosporins Cephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins

Operative care

General techniques to minimize tissue ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage and complications:

• Handle soft tissue Soft Tissue Soft Tissue Abscess gently.
• To prevent ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage to the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions flaps, do NOT separate fascia Fascia Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs. Cellulitis from the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions.
• Identify and name arteries and veins Arteries And Veins ACES and RUSH: Resuscitation Ultrasound Protocols, and ligate and suture accordingly.
• Ligate nerves proximally before transection.
• Stabilize muscle groups using myoplasty (suturing to bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types).
• Avoid the use of cauterization and ligate instead.
• Bevel and file the sharp bony prominence.
• Closure:
  • Done in layers
  • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions closed off using nonabsorbable sutures Nonabsorbable Sutures Surgical Instruments and Sutures
  • Compressive stump dressing to avoid edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema

Postoperative care Postoperative care After any procedure performed in the operating room, all patients must undergo close observation at least in the recovery room. After larger procedures and for patients who require hospitalization, observation must continue on the surgical ward. The primary intent of this practice is the early detection of postoperative complications. Postoperative Care

• Wound care:
  • Daily examination of the wound for signs of infection
  • Inspect for ulcers in weight-bearing areas ( sacrum Sacrum Five fused vertebrae forming a triangle-shaped structure at the back of the pelvis. It articulates superiorly with the lumbar vertebrae, inferiorly with the coccyx, and anteriorly with the ilium of the pelvis. The sacrum strengthens and stabilizes the pelvis. Vertebral Column: Anatomy) and the bony protuberance.
  • Foley catheters may be left in place in above-knee amputations to avoid contamination of the surgical wound.
  • Individuals with diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus should be advised strict glycemic control.
• Postoperative pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Acute:
    • Related to the initial trauma or trauma of surgery
    • Subsides in a few weeks
  • Optimize analgesia Analgesia Methods of pain relief that may be used with or in place of analgesics. Anesthesiology: History and Basic Concepts (combination of epidural, IV, and oral analgesics).
  • Screen for mental state and signs of depression.
• Ambulation after lower limb amputations must be avoided for 6 weeks until complete wound healing Wound healing Wound healing is a physiological process involving tissue repair in response to injury. It involves a complex interaction of various cell types, cytokines, and inflammatory mediators. Wound healing stages include hemostasis, inflammation, granulation, and remodeling. Wound Healing has occurred.

Rehabilitation

• Multidisciplinary
• Psychological support is a priority.
• Prosthesis:
  • Must be started early, during wound healing Wound healing Wound healing is a physiological process involving tissue repair in response to injury. It involves a complex interaction of various cell types, cytokines, and inflammatory mediators. Wound healing stages include hemostasis, inflammation, granulation, and remodeling. Wound Healing
  • Early fittings promote stump maturation.
  • Temporary prostheses for weight-bearing (lower) limbs may facilitate early ambulation.
  • Definite (long term) prostheses require readjustments (every 2–3 years) as the stump remodels.
  • Individuals are equipped with a prosthesis fitted for their needs.

Complications

Local complications

• Wound infection
• Stump pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways due to:
  • Hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception
  • Ulcer
  • Symptomatic neuroma
• Flexion Flexion Examination of the Upper Limbs contracture
• Need for reamputation/stump revision: very common in lower limb amputations

Medical complications

• MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction:
  • Many individuals requiring amputation often have debilitating systemic illnesses (e.g., uncontrolled diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, peripheral vascular disease) and multiple cardiac risk factors (i.e., diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases, hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension).
  • The risk of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction is very high in the postoperative phase.
  • Optimizing preoperative health is key to preventing morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status.
  • Individuals who have undergone lower limb amputation are at increased risk.
• Deep venous thrombosis Venous thrombosis The formation or presence of a blood clot (thrombus) within a vein. Budd-Chiari Syndrome ( DVT DVT Deep vein thrombosis (DVT) usually occurs in the deep veins of the lower extremities. The affected veins include the femoral, popliteal, iliofemoral, and pelvic veins. Proximal DVT is more likely to cause a pulmonary embolism (PE) and is generally considered more serious. Deep Vein Thrombosis) and pulmonary embolism Pulmonary Embolism Pulmonary embolism (PE) is a potentially fatal condition that occurs as a result of intraluminal obstruction of the main pulmonary artery or its branches. The causative factors include thrombi, air, amniotic fluid, and fat. In PE, gas exchange is impaired due to the decreased return of deoxygenated blood to the lungs. Pulmonary Embolism (PE):
  • 50% of lower limb amputations lead to DVT DVT Deep vein thrombosis (DVT) usually occurs in the deep veins of the lower extremities. The affected veins include the femoral, popliteal, iliofemoral, and pelvic veins. Proximal DVT is more likely to cause a pulmonary embolism (PE) and is generally considered more serious. Deep Vein Thrombosis.
  • Above-knee amputations pose the greatest risk.
  • Proper thromboprophylaxis and monitoring are important in these cases.

Adverse outcomes

• Loss of functionality, especially with thumb/ hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy amputations
• Phantom limb pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the area of the lost limb
  • Centrally mediated pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and paresthesia, generally neuropathic in nature
  • “Telescopes” with time (i.e., painful phantom area shrinks proximally toward the stump)
• Chronic pain Chronic pain Aching sensation that persists for more than a few months. It may or may not be associated with trauma or disease, and may persist after the initial injury has healed. Its localization, character, and timing are more vague than with acute pain. Pain Management of the remnant limb:
  • Stump-related pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways ( compression Compression Blunt Chest Trauma of soft tissue Soft Tissue Soft Tissue Abscess elements by bony elements)
  • Neuroma-related pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Prosthesis-related pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Permanent disfigurement
• Depression