Disease/ Disorder
Definition
Acquired upper and lower limb amputations in children are described using similar nomenclature as adult amputations, based on the level of limb loss. In the upper extremity, levels from proximal to distal include shoulder disarticulation, transhumeral (above elbow), elbow disarticulation, transradial (below elbow), wrist disarticulation, and partial hand. Lower extremity amputations (proximal-distal) include hemipelvectomy, hip disarticulation, transfemoral (above knee), knee disarticulation, transtibial (below knee), ankle disarticulation, and partial foot.
Etiology
Acquired amputations in children have a wide variety of causes. Traumatic causes of limb loss in children include severing injuries, crush injuries, or burns. Motor vehicle accidents, power tool injuries, and gunshots are some of the most common causes of traumatic injuries, although they vary by region and age1. Children are also susceptible to illness-related causes, such as tumors and vascular etiologies (i.e. thrombosis due to infectious disease or frostbite). Some acquired amputations are a result of surgical conversions of congenital limb deficiencies, such as ablation of a foot in a child with proximal femoral focal deficiency. Distal sites are at the highest risk for acquired amputations. The average age of acquired amputation was 6.18 years. Males are three times more likely than females to have an acquired amputation. The most common traumatic amputation mechanisms include limbs caught between two objects, machinery, powered lawn mowers, motor vehicle collisions, gunshot wounds and off-road transport. A limb being caught between objects is the leading cause of all amputations with finger amputations being the most common presentation.2 Osteosarcoma is the most common etiology in children over 10 years old and Ewing sarcoma occurs in children under 10 years old.
Epidemiology including risk factors and primary prevention
Since trauma is the most common cause of acquired amputations, prevention is key. In rural areas, children sustain amputations from lawnmowers, farm equipment, and high-tension wire injuries. In 1-4-year-old group, household injuries and lawnmowers pose the greatest risks. Older children are more commonly injured by car or motorcycle crashes, burns, gunshot wounds, or power tools. Propeller injuries from boats also occur. Public awareness and political activism for removal of existing land mines and banning the manufacture from use of mines would reduce injuries from these to children, who are now the primary victims3. Catastrophic injuries to children resulting in major morbidity or mortality may be more than 70% preventable3.
Patho-anatomy/physiology
Limb salvage versus definitive amputation depends on the nature of the injury and the integrity of the remaining structures. Careful consideration of potential prosthetic fit, vascular supply, innervation, skin integrity, and musculature of the residual limb must be considered. Ideally, the patient would be managed by an orthopedic and / or a plastic surgeon. When amputation is warranted the surgical team should aim to conserve as much of the viable physis as possible to allow for bone development in a growing child4
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)
- New Onset/Acute: Acute acquired amputations in children may present challenges to wound healing from irregular residual limbs or presence of skin grafts. Immediate postoperative prosthetic fitting may be appropriate in children old enough to understand and cooperate with weight-bearing restrictions. Many children have post-operative surgical and neuropathic pain. Prosthetic fitting and functional prognosis may correlate with the mechanism of injury; a transverse amputation may be easier to close and shape compared to a limb that was crushed.
- Sub-acute: Psychological adjustment to disability can be a challenge, and patients should be monitored for signs and symptoms of depression or post-traumatic stress disorder.
- Chronic/Stable: Once wound healing is complete, options for a prosthetic device should be discussed with the patient and family. A prosthetist experienced with pediatric patients can aid in the fabrication of an appropriate device.
Specific secondary or associated conditions and complications
The most common complication in a skeletally immature child is bony overgrowth, or spiking. Bony overgrowth can occur in 40% of children and is usually in children with amputations acquired before the age of twelve5. This occurs at the terminal end of the residual limb and risk is increased if the amputation is through the metaphysis. Initially, it presents as swelling, warmth, tenderness, or poor socket fit. If untreated, it can cause skin penetration. Overgrowth most commonly occurs in the humerus, followed by fibula, tibia, and femur. Numerous surgical revisions may be required secondary to the consequences of osseous overgrowth. Osseous overgrowth can be reduced by capping the stump with autologous material from the injured limb as compared to resection and revision or the use of a plastic caps4Terminal overgrowth warrants surgical intervention if there is skin ulceration, persistent pain, and/or an ill-fitting prosthesis as a result. There is a high recurrence rate even after surgical resection in younger children. Leg length inequality or tibia-fibula synostosis can lead to varus deformity.
Phantom limb sensation (PLS) and phantom limb pain (PLP) also occur in children at variable rates depending on the mechanism and location. The prevalence of PLP due to congenitally-related amputation is lower than the prevalence due to a traumatic amputation6 and cancer-related amputations.7 Those with traumatic amputation, PLP is higher after a lower limb loss than after an upper limb loss.8
Acquired amputations at any age are associated with risk of skin breakdown from a poorly fitting prosthesis.
Essentials Of Assessment
History
A comprehensive history should include the cause of limb loss, surgical history, and level of injury. Documentation of a developmental assessment, understanding previous and current functional status, and identifying comorbidities such as vision or hearing impairments is important. The child’s hobbies and recreational interests should be elicited, including parent and child goals for resuming these activities. Assistive devices should be provided to allow participation in desired activities. In the case of acquired amputation due to tumor, it is important to understand whether limb salvage procedures were attempted prior to the amputation6.
Physical examination
Range of motion of the joints of the residual limb must be assessed, as well as strength of muscles crossing those joints. Residual limb length and discrepancy of limb lengths relative to an intact contralateral limb should be monitored, as well as joint alignment with the contralateral lower extremity. The residual limb should be evaluated for tenderness or swelling. Skin integrity should be assessed. It is important to provide a comprehensive evaluation to avoid missing concurrent injuries, even if the limb loss is the most obvious.
Functional assessment
During assessment of mobility status in a child with a lower extremity limb loss, it is important to evaluate appropriateness of current prosthetic and assistive devices. Self-care skills should be assessed at a developmentally appropriate level. There may be special equipment for the child with upper extremity limb loss to assist with ADLs. Cognitive assessment for both a typical and developmentally delayed child is critical to prescribing an appropriate prosthetic device and guiding therapy goals. Wee FIM is used to measure functional outcomes. K-levels are used in adult lower extremity amputees to guide prosthetic prescriptions, and this scale can be helpful for a clinician to think about appropriate prosthesis prescribing in older children or adolescents.
Imaging
After acquired limb loss, x-rays, CT scans, and MRI scans are useful to determine the integrity of the remaining structures in the residual limb. X-ray can characterize bony overgrowth in a child with remote acquired limb loss.
Early predictions of outcomes
Cognitive status, age at the time of limb loss, and level of amputation contribute to the determination of ultimate functional status.
Environmental
Home set-up is important for prosthetic and assistive device planning. Knowing about the child’s environment, leisure activities, and community set-up is important to choose an appropriate prosthesis. Prostheses should be selected that will help the child achieve their functional, leisure, and vocational goals.
Social role and social support system
It is important to gauge the family’s acceptance of a prosthetic device prior to prescribing one, as well as their willingness to have their child participate in therapy and return for follow up visits with the physician and prosthetist will impact outcomes. Without parental support, it is unlikely that a child will become a functional prosthetic user5. Quality of life studies show children do well with daily activities but there is a decline in scores for high-level functional activities and sports depending on functional level.9
Professional Issues
In children with tumors and severe trauma, the decision between limb salvage procedures versus early amputation can be controversial.
Rehabilitation Management and Treatments
Available or current treatment guidelines
Surgical guidelines differ for pediatric acquired limb loss in comparison to those for adults, including: preserve as much length as possible, maintain integrity of growth plates, choose disarticulation rather than transosseous amputation, keep the knee joint, and stabilize proximal portions of the limb.
Prosthetic replacement for growth is indicated for children with extremity amputations annually for the first 5 years of life, every 2 years from ages 5-12 years, and then every 5 years. Components must be evaluated for age- appropriateness, considering comfort, weight, durability, cosmesis, and function, as well as maintenance availability.
Patients with multiple and/or bilateral lower extremity limb loss may require a wheelchair for long distances. Adaptive or gait aids may be required for maximal function after upper or lower extremity amputation, respectively. Children with multiple high level amputations may elect these alternatives to function without prostheses. Most children with unilateral limb loss function age-appropriately, including sports activities, with their prostheses and demonstrate good psychosocial adjustment relative to their peers. Intensive therapy is not typically required.
Regular monitoring of prosthetic fit, skin integrity, and bony overgrowth is important to prevent complications.
At different disease stages
Recommendations for prosthetic fitting for children with acquired amputations are similar to those for congenital limb deficiency.
| UPPER LIMB PROSTHETICS | AGE |
| PASSIVE UPPER EXTREMITY DEVICE | 6 MONTHS WHEN SITTING INDEPENDENTLY |
| ACTIVE TERMINAL DEVICE | 12-15 MONTHS WHEN AMBULATORY |
| BODY POWERED PROSTHESIS | AS YOUNG AS 1 YEAR OLD, WHEN ABLE TO OPERATE |
| MYOELECTRIC DEVICE | AS YOUNG AS 2 YEARS OLD |
| LOWER LIMB PROSTHETICS | AGE |
| SOLID-ANKLE CUSHION-HEEL (SACH) | INFANCY |
| ENERGY STORING-RELEASING FEET | TODDLER |
| KNEE JOINT | 2-3 YEARS OF AGE |
Younger children have an easier time adapting to new hand dominance. Children as young as 5 years of age may be independent with donning lower limb prostheses. Wear time of the prosthetic device is related to comfort, appearance, and ease of repair; it also correlates with parents’ ratings of satisfaction3. Unsatisfied patients often have less independence and more disability.
Coordination of care
Care of children with acquired amputations is ideally interdisciplinary, with coordination between surgical and rehabilitation providers. A multidisciplinary team can include physiatry, orthopedics, a prosthetist, physical therapist, and an occupational therapist. Additional services from psychology, child life, and recreational therapists are extremely helpful members of the care team when available.
Patient & family education
Families should understand weight control in order to optimize prosthesis use and mobility. Body temperature regulation can be disrupted due to loss of body surface area. Children with multiple and/or high levels of amputation may become febrile more easily or have higher fevers. There may be an increase in flushing or sweating due to decreased skin surface area to dispel heat.
Parents should be taught how and when to assist their child. Therapists can work with families to establish a home program for range of motion, strengthening, and function. Parents should encourage prosthetic use and problem solving through trial and error. The prosthesis should be incorporated into regular play.
Emotional support is essential for children with acquired limb amputations in an age appropriate manner. Children younger than six may benefit from using dolls or puppets to help them understand the changes taking place in their bodies. Older children may benefit from contact with peers who have limb loss or participation in sports programs.
Emerging/unique interventions
There are advances in surgical techniques for amputee patients. In adults, surgical innovations such as targeted muscle reinnervation (TMR), targeted nerve implantation (TNI), regenerated peripheral nerve index (RPNI) and surgical sensory implants are being investigated. Other techniques include research in intracortical microstimulation (ICMS) and osseointegration of prostheses into bone. Virtual reality has also been used to optimize function and use of prosthesis. TMR and TNI have also been explored to help with terminal neuroma pain.
Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills
Early prosthetic prescriptions can help increase patient acceptance and functional use of the device. Sockets can accommodate circumferential growth more easily by adding one or several inner socket layers that can be removed, also known as onion skinning. SACH feet are lightweight and durable. Anterior foot alignment promotes stability. Exoskeletal shanks are used for increased durability. Children can tolerate more distal loading of residual limbs than adults. Alignment of the lower limb prosthesis is usually abducted and flexed for infants and wide based with external hip rotation for toddlers to most closely mimic typical gait in these very young children.
Cutting Edge/ Emerging and Unique Concepts and Practice
Myoelectric devices for the upper extremity are being used in younger amputees. As new components are developed and prosthetics become more lightweight, they may be more adaptable to pediatric patients with limb loss. 3- Dimensional (3D) printing is becoming more widely used as a cost effective option for upper extremity amputations. However quality evidence to support functional outcomes is lacking. Computer aided designs are starting to be incorporated for prosthesis fabrication.
Gaps in the Evidence- Based Knowledge
Early amputation versus limb sparing procedures remains controversial in relation to outcomes. There is not current evidence to guide when body weighted support for ambulation may be helpful in improving functional outcomes for a given patient. Targeted muscle innervation has not been explored for the pediatric population. Community based gait performance measures for K level assessment and validated outcome tools for pediatric patients are needed.
References
- Jain S. Rehabilitation in Limb Deficiency. 2. The Pediatric Amputee. Arch Phys Med Rehabil. 1996;77(3 Suppl):S9-S13.
- Borne A, Porter A, Becicar J, Maxson T, Montgomery C. Pediatric Traumatic Amputations in the United States: A 5-Year Review. J Pediatr Orthop. 2017; 37(2):e104-e107.
- Herring JA, Birch JG, eds. The Child With a Limb Deficiency. 1st ed. Rosemont, IL: American Academy of Orthopedic Surgeons; 1998:235-288.
- Kahn MA. Pediatric traumatic limb amputation: the principles of management and optimal residual limb lengths. World journal of plastic surgery. 2016; 5(1): 7-14.
- Soldado F, Kozin SH. Bony Overgrowth in Children after Amputation. Journal of Ped Rehabil Med: An Interdisciplinary Approach 2. 2009; 235-239.
- Melzack R, Israel R, Lacroix R, Schultz G. Phantom limbs in people with congenital limb deficiency or amputation in early childhood., Brain, Volume 120, Issue 9, Sep 1997; 1603–16207.
- DeMoss P, Ramsey LH, Karlson CW. Phantom Limb Pain in Pediatric Oncology. Front Neurol. 2018;9:219.
- Poor Zamany Nejat Kermany M, Modirian E, Soroush M, Masoumi M, Hosseini M. Phantom Limb Sensation (PLS) and Phantom Limb Pain (PLP) among Young Landmine Amputees. Iran J Child Neurol. Summer 2016; 10(3):42-47
- McQuerry J, Gammon L, Carpiaus A, Talwalkar V, Iwinski H, Walker J, Jacobs C, Muchow R. Effect of amputation level on quality of life and subjective function in children. J of Pedatr Orthop. 2019; e524-530.
Bibliography
Alexander MA, Matthews DJ, eds. Pediatric Rehabilitation: Principles and Practice. 4th ed. New York, NY. Demos Medical; 2010: 335-360.
Pruitt SD, Varni JW, Seid M, Setoguchi Y. Prosthesis Satisfaction Outcome Measurement in Pediatric Limb Deficiency. Arch Phys Med Rehabil. 1997;78:750-754.
Mitra R. Principles of Rehabilitation Medicine . McGraw-Hill Medical; 2019.
Le J, Scott-Wyard S. Pediatric limb differences and amputations. Phys Med Rehabil Clin N Am. 2015; 26:95-108.
Bryant Ph, Pandian G. Acquire limb deficiencies. 1. Acquired limb deficiencies in children and young adults. Arch Phys Med Rehabil. 2001; 82 (Suppl 1): S3-8.
Original Version of the Topic
Ashlee M. Goldsmith, MD; Linda Michaud, MD. Pediatric acquired upper and lower limb deficiency. 9/20/2014.
Previous Revision(s) of the Topic
Talia Collier, MD, Gabrielle Nguyen, MD, Mariella Hillebrand, MD. Pediatric acquired upper and lower limb deficiency. 6/28/2018.
Author Disclosure
Mariella Hillebrand, MD
Nothing to Disclose
Talia Collier, MD
Nothing to Disclose