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Amputation Mamoun Nabri Trauma Fellow 03/23/2010 History • 1700 BC, Babylonian code of Hammurabi, the earliest literature discussing amputation • Hippocrates, therapeutic amputation for vascular gangrene History • The patient would be held down by a number of assistants and be given alcohol (usually rum). • The patient would essentially be awake and aware during the procedure. History • 1st century, cautery, ligatures, removal of gangrenous extremity through the viable tissue edge with a bone cut shorter than the soft tissues • 1529 - Ambroise Pare, thick ligature used as a tourniquet • 1588 – William Cloves – 1St AKA History • 1781 – John Warren successful shoulder amputation • 1943 – Major General Norman T. Kirk, guillotine amputations Introduction • USA, 30,000-40,000 amputations are performed annually. • 1.6 million individuals living with the loss of a limb in 2005; expected to be 3.6 million year 2050 • Dysvascular amputation , 15-28% contralateral limb amputations within 3 years. • Elderly, amputations, 50% survive the first 3 years. • 1965, above-knee amputations to below-knee amputations was 70:30, the value of retaining the knee joint, so the ratio became 30:70. Pathophysiology • The higher the level of a lower-limb amputation, the greater the energy expenditure. • As the level of the amputation moves proximally, the walking speed of the individual decreases, and the oxygen consumption increases. • The soft-tissue envelope of the residual limb now becomes the proprioceptive end organ for the interface between the residual extremity and the prosthesis Pathophysiology • For effective ambulation, this envelope should consist of a sufficient mass of mobile nonadherent muscle and full-thickness skin and subcutaneous tissue that can accommodate axial and shear stress within the prosthetic socket. • Load Transfer/Weight-Bearing • Pain is still a problem for many patients who have undergone lower-extremity amputations. Metabolic cost of walking with an amputation Indications • Circulatory disorders – Diabetic foot infection or gangrene (the most common reason for nontraumatic amputation) – Sepsis with peripheral necrosis • Neoplasm • Trauma – Severe limb injuries – Traumatic amputation • Deformities – Deformities of digits and/or limbs – Extra digits and/or limbs (e.g. polydactyly) • Infection – Soft tissue – Bone infection (osteomyelitis) • Burn, Frostbite When to Amputate • Trauma is the leading indication for amputations in younger patients • Scores: – The Predictive Salvage Index (PSI) – The Limb Injury Score (LIS) – The Limb Salvage Index (LSI) – The Mangled Extremity Syndrome Index (MESI) – The Mangled Extremity Severity Score(MESS) Predictive Salvage Index (PSI) • Combined orthopaedic and vascular injuries. • Intent to help prevent the attempted salvage of a doomed or useless limb. • A limb-salvage score was developed that weighted: – Level of the vascular injury – Degree of osseous injury – Degree of muscle injury – Warm ischemia time Limb Salvage Index (LSI) • Limb trauma associated with vascular injury. • Absolute indications for amputation included a score of 6 or more. • Seven components related to injury: – – – – – – – Arterial Nerve Bone Skin Muscle Deep venous injury Warm ischemia time Mangled Extremity Severity Score (MESS) • Skeletal / soft-tissue injury Low energy (stab; simple fracture; pistol gunshot wound): Medium energy (open or multiple fractures, dislocation): High energy (high speed MVA or rifle GSW): Very high energy (high speed trauma + gross contamination): Limb ischemia Pulse reduced or absent but perfusion normal: Pulseless; paresthesias, diminished capillary refill: Cool, paralyzed, insensate, numb: Shock Systolic BP always > 90 mm Hg: Hypotensive transiently: Persistent hypotension: Age (years) < 30: 30-50: > 50: * Score doubled for ischemia > 6 hours , Johansen et.al. 1990 1 2 3 4 1* 2 3* 0 1 2 0 1 2 Surgical Principles • Determination of Amputation Level • Technical Aspects – Meticulous attention to detail and gentle handling of soft tissues • Skin and Muscle Flaps – stabilized by myodesis (suturing muscle or tendon to bone) – at their normal resting functional length. – Jaegers et al. showed that transected muscles atrophy 40% to 60% in 2 years if they are not securely fixed • Hemostasis – a tourniquet is highly desirable, pressures of 135 to 255 mm Hg for the upper extremity and 175 to 305 mm Hg for the lower extremity were satisfactory for maintaining hemostasis. Younger et al – Major blood vessels should be isolated and individually doubly ligated – A drain should be used in most cases for 48 to 72 hours. Surgical Principles • Nerve; – Gentle traction, – Nerves should not be clamped, as this iatrogenic crush injury might lead to late neurogenic pain, even if the crushed nerve is removed. • Bone ; avoid excessive periosteal stripping • Wounds should not be repaired under tension, since doing so risks infection, tissue failure, or a nonresilient soft-tissue envelope. • Open amputation Surgical Principles • Bony prominences around disarticulations are removed with a saw and filed smooth. • Maintaining the maximal extremity length possible is desirable. • One application guide is to make a limb 2.5 cm long for every 30 cm of body height. • However, below-knee amputations are best performed 12.5-17.5 cm below the joint line for nonischemic limbs. • For ischemic limbs, a higher level of 10-12.5 cm below the joint line is used because making limbs longer than this can interfere with prosthetic use and design. Complications • • • • • • Hematoma Infection Wound necrosis Contractures Pain Dermatological problems Pain • Chronic pain appears to be more related to the crushing nature of the injury than to the amputation itself. • The pain literature suggests that early neural blockage is the best method to minimize late, residual or phantom limb, or neurogenic pain. • This is probably best accomplished with an indwelling epidural catheter placed at the time of the initial treatment or with postoperative infusional continuous regional anesthesia (PICRA) “High-technology” transfemoral prosthesis • Lightweight prosthesis has a flexible ischial containment socket, • High-performance hydraulic knee • Dynamic elastic response prosthetic foot with a shock absorber to dissipate the stresses of weight bearing References • Murdoch G, Wilson AB Jr, eds. Amputation: Surgical Practice and Patient Management. St Louis, Mo: ButterworthHeinemann Medical; 1996. • Tooms RE. Amputations. In: Crenshaw AH, ed. Campbell's Operative Orthopedics. Vol 1. 7th ed. St. Louis, Mo: MosbyYear Book; 1987:597-637. • http://www.wheelessonline.com/ortho/mangled_extremity_sev erity_score_mess • Pinzur, M.S., Gold, J., Schwartz, D., et al. Energy demands for walking in dysvascular amputees as related to the level of amputation. Orthopaedics 15:1033–1037, 1992 • Browner: Skeletal Trauma, 4th ed • Canale & Beaty: Campbell's Operative Orthopaedics, 11th ed