overview Overview amputations are done urgently and electively to reduce pain, provide independence, and restore function the goals of amputation are preserve functional length preservation of useful sensibility prevention of symptomatic neuromas prevention of adjacent joint contractures early prosthetic fitting early return of patient to work and recreation Epidemiology Incidence 1.7 million individuals in the United States with an amputation Risk factors 80% of amputations are performed for vascular insufficiency Etiology Pathophysiology Amputations may be indicated in the following trauma login to view 1 more bullet infection tumor vascular disease login to view 1 more bullet congenital anomalies Metabolic Demand Metabolic cost of walking increases with more proximal amputations perform amputations at lowest possible level to preserve function exception login to view 1 more bullet inversely proportional to length of remaining limb Ranking of metabolic demand (% represents amount of increase compared to baseline) Syme - 15% transtibial traumatic - 25% average login to view 2 more bullets vascular - 40% transfemoral traumatic - 68% vascular - 100% thru-knee amputation varies based on patient habitus but is somewhere between transtibial and transfemoral most proximal amputation level available in children to maintain walking speeds without increased energy expenditure compared to normal children bilateral amputations BKA + BKA - 40% AKA + BKA - 118% AKA + AKA - >200% Wound Healing Dependent on vascular supply nutritional status immune status Improved with albumin > 3.0 g/dL ischemic index > .5 measurement of doppler pressure at level being tested compared to brachial systolic pressure transcutaneous oxygen tension > 30 mm Hg (ideally 45 mm Hg) toe pressure > 40 mm Hg (will not heal if < 20 mm Hg) ankle-brachial index (ABI) > 0.45 total lymphocyte count (TLC) > 1500/mm3 Hyperbaric oxygen therapy contraindications include chemo or radiation therapy pressure-sensitive implanted medical device (automatic implantable cardiac defibrillator, pacemaker, dorsal column stimulator, insulin pump) undrained pneumothorax Upper Extremity Amputation Indications irreparable loss of blood supply severe soft tissue compromise malignant tumors smoldering infection congenital anomalies Amputation versus limb salvage and replantation mangled upper extremity has a far greater impact on overall function than does a lower extremity amputation upper extremity prostheses have much more difficulty replicating native dexterity and sensory feedback provided by the native limb results of nerve repair and reconstruction are more successful in upper extremity than lower extremity superior functional outcomes can be expected in replanted limbs compared with upper extremity amputations diminishing outcomes from replantation are expected the more proximal the level, especially about the elbow Levels of amputation wrist disarticulation or transcarpal versus transradial amputation wrist disarticulation advantages login to view 3 more bullets disadvantage login to view 2 more bullets transradial advantages login to view 2 more bullets transhumeral versus elbow disarticulation elbow disarticulation advantages login to view 1 more bullet Techniques general All named motor and sensory branches within operative field should be identified and preserved login to view 2 more bullets transcarpal transect finger flexor/extensor tendons anchor wrist flexor/extensor tendons to carpus wrist disarticulation preserve radial styloid flare to improve prosthetic suspension requires healthy and intact DRUJ transradial amputation middle third of forearm amputation maintains length and is ideal residual 5cm of ulna is required for elbow motion, but at this level will have limited pronation/supination transhumeral amputation maintain as much length as possible ideal level is 4-5cm proximal to elbow joint if more proximal amputation is required: login to view 1 more bullet shoulder disarticulation retain humeral head to maintain shoulder contour Targeted Muscle Reinnervation designed to improve control of myeolectric prostheses used for amputation general transfer amputated large peripheral nerves to reinnervated functionally expendable remaining muscles to create a new discrete muscle signal for the myoelectric prosthesis control secondary benefit of alleviating symptomatic neuroma pain Transfemoral Amputation Maintain as much length as possible however, ideal cut is 12 cm (10-15cm) above knee joint to allow for prosthetic fitting Technique 5-10 degrees of adduction is ideal for improved prosthesis function adductor myodesis improves clinical outcomes creates dynamic muscle balance (otherwise have unopposed abductors) provides soft tissue envelope that enhances prosthetic fitting Osseointegration metal implant is directly anchored to the residual bone, which is then attached to a prosthetic limb using a transcutaneous connector through a stoma reported increased prosthesis wear, improved mobility, quality of life, and extremity proprioception compared to those with socket prostheses most common complication is low-grade infection that can be managed without antibiotics Gritti-Stokes amputation amputation through the femur near level of adductor tubercle synovium is excised to prevent postoperative effusion patella is arthrodesed to the end of femur for improved end bearing prepatellar soft tissue is maintained without iatrogenic injury improved outcomes as compared to transfemoral amputation Through-Knee-Amputation Indications ambulatory patients who cannot have a transtibial amputation non-ambulatory patients Technique suture patellar tendon to cruciate ligaments in notch use gastrocnemius muscles for padding at end of amputation Outcomes (based on LEAP data) slower self-selected walking speeds than BKA similar amounts of pain compared to AKA and BKA worse performance on the Sickness Impact Profile (SIP) than BKA and AKA physicians were less satisfied with the clinical, cosmetic, and functional recovery Consequence of poor soft tissue envelope from loss of gastrocnemius padding require more dependence with patient transfers than BKA Below-Knee-Amputation (BKA) Long posterior flap 12-15 cm below knee joint is ideal (10-16cm of residual tibia bone) ensures adequate lever arm longer than this gets into the achilles tendon which has a suboptimal blood supply and ability for soft tissue cushioning need approximately 8-12 cm from ground to fit most modern high-impact prostheses "dog ears" preventable with well-designed incision lines if present, left in place to preserve blood supply to the posterior flap Modified Ertl designed to enhance prosthetic end-bearing argument is that the bone bridge will enhance weight bearing through the fibula and increase total surface area for load transfer increased reoperation rates have been reported technique the original Ertl amputation required a corticoperiosteal flap bridge the modified Ertl uses a fibular strut graft login to view 2 more bullets Ankle/Foot Amputation Syme amputation (ankle disarticulation) patent tibialis posterior artery is required more energy efficient than midfoot even though it is more proximal stable heel pad is most important factor used successfully to treat forefoot gangrene in diabetics technique medial and lateral malleoli are removed flush with distal tibia articular surface the medial and lateral flares of the tibia and fibula are beveled to enhance heel pad adherence heel pad is secured to anterior tibia Pirogoff amputation (hindfoot amputation) removal of the forefoot and talus followed by calcaneotibial arthrodesis calcaneus is osteotomized and rotated 50-90 degrees to keep posterior aspect of calcaneus distal allows patient to mobilize independently without use of prosthetic Chopart or Boyd amputation (hindfoot amputation) a partial foot amputation through the talonavicular and calcaneocuboid joints primary complication is equinus deformity avoid by lengthening of the Achilles tendon and transfer of the tibialis anterior to the talar neck leads to apropulsive gait pattern because the amputation is unable to support modern dynamic elastic response prosthetic feet Lisfranc amputation (midfoot amputation) equinovarus deformity is common caused by unopposed pull of tibialis posterior and gastroc/soleus prevent by maintaining insertion of peroneus brevis and performing achilles lengthening a walking cast is generally used for 4 week to prevent late equinus contracture Energy cost of walking similar to that of BKA Transmetatarsal amputation more appealing to patients who refuse transtibial amputations almost all require achilles lengthening to prevent equinus Great toe amputations preserve 1cm at base of proximal phalanx preserves insertion of plantar fascia, sesamoids, and flexor hallucis brevis reduces amount of weight transfer to remaining toes lessens risk of ulceration Complications Wound healing Contractures adjacent joint contractures are common prevent with early aggressive mobilization and position changes Heterotopic ossification more common in trauma-related setting Infection trauma-related amputation have an infection rate of around 34% Postamputation Neuroma occurs in 20-30% of amputees prevent with proper nerve handling at the time of procedure treatment targeted muscle reinnervation login to view 1 more bullet Phantom limb pain occurs in 53-100% of traumatic amputations mirror therapy is a noninvasive treatment modality Bone overgrowth most common complication with pediatric amputations treatment login to view 1 more bullet Prognosis Outcomes are improved with the involvement of psychological counseling for coping mechanisms Involves a close working relationship between rehab physicians, prosthetists, physical therapists, as well as psychiatrists and social workers High rate of late amputation in patients with high-energy foot trauma 1st metatarsal fracture fracture involving all five metatarsals Amputation vs. reconstruction LEAP study impact on decision to amputate limb login to view 6 more bullets outcome measure login to view 5 more bullets METALS study study focused on military population in response to LEAP study slightly better results in regard to patient-reported outcomes for the amputation group with a lower risk of PTSD login to view 3 more bullets