Limb loss is the loss of all or part of an arm or leg due to trauma, infection, diabetes, heart disease, cancer or congenital anomalies[1]. It has been estimated that around 2 million people in the United States are living with limb loss[2]. Congenital amputation is the absence of a limb or part of a limb at birth[3]. Statistics show that one in 2,000 babies is born with all or part of a limb missing[3]. For most cases, the causes for such limb absence are unknown[3]. Studies suggest that most birth defects have one or more genetic factors and environmental factors, but what the actual factors are in any given case is often difficult, if not impossible[3]. Limb deficiencies fall into two types, longitudinal, which is more common, and transverse[4]. Longitudinal deficiency is the absence of a part of a limb. For example, the fibula bone in the lower leg is missing, but the rest of the leg is intact[3,4]. On the other hand, transverse deficiency, or Amelia[3], is when the complete limb is missing[4].
References
[1] C. D. C., “Limb Loss Awareness,” Centers for Disease Control and Prevention, 2015. [Online]. Available: http://www.cdc.gov/ncbddd/disabilityandhealth/features/limb-loss-awareness.html. [Accessed: 28-Oct-2016].
[2] “Amputee Coalition,” Amputee Coalition, limb loss resource cente. [Online]. Available: http://www.amputee-coalition.org/limb-loss-resource-center/resources-by-topic/limb-loss-statistics/limb-loss-statistics/. [Accessed: 28-Oct-2016].
[3] “Congenital amputation,” Congenital Amputation, Health of Children. [Online]. Available: http://www.healthofchildren.com/c/congenital-amputation.html. [Accessed: 28-Oct-2016].
[4] “Common Congenital Limb Defects,” Merck Manuals Professional Edition. [Online]. Available: http://www.merckmanuals.com/professional/pediatrics/congenital-craniofacial-and-musculoskeletal-abnormalities/common-congenital-limb-defects. [Accessed: 28-Oct-2016].