Pediatric Limb Deficiencies 23rd Annual Prosthetics Course Deborah Mowery, MD

Following this lecture you will be able to: Objectives Following this lecture you will be able to: Identify major etiologies of congenital and acquired pediatric limb deficiencies. Classify limb deficiencies. Determine when it is appropriate to fit a pediatric patient with a prosthesis and which prosthetic device is developmentally appropriate for a pediatric amputee. List common causes of acquired pediatric amputation and possible surgical management techniques. Discuss the family approach and functional outcome in pediatric amputee.

Congenital Limb Deficiencies

* 40% congenital deficiencies = left transverse radial Incidence Congenital 60% Acquired 40% 5 - 9.7 per 10,000 live births 6% of all birth defects Upper > Lower Limb (2:1) Unilateral upper limb – 50% Unilateral lower limb – 27% Multiple limbs – 24% * 40% congenital deficiencies = left transverse radial Left: Right 2:1 in unilateral UE Transverse Deficiency Acquired: 12% <21 years 5% <11 years

Etiology - Congenital Failure of formation of part or all of limb bud Proximal to distal limb development

Etiology - Congenital Mesodermal formation of the limb bud: 26 days - 8 weeks gestation Upper limb develops slightly ahead of lower limb

Prenatal vitamins = ↓ risk Etiology - Congenital Unknown? Vascular Genetic syndromes Teratogens Thalidomide – only known Smoking – digit abnormalities? Valproic acid, Ca++ channel blockers Maternal Diabetes, including gestational diabetes Intrauterine infection Mechanical factors Uterine abnormalities Amniotic band syndrome Prenatal vitamins = ↓ risk Pediatric Rehabilitation Principles and Practice, Forth Edition, alexander, Michael A., Matthews, Dennis J. Demos Medical, New York, 2010: 335 - 337

Terminology Amelia - Complete absence of a free limb (exclusive of girdle). Meromelia - Partial absence of a free limb (exclusive of girdle). Terminal Deficiency - Absence of all skeletal elements distal to the proximal limit of the deficiency, along the designated axis (longitudinal or transverse). Intercalary Deficiency - Absence of middle part(s) lying between a proximal-distal series of limb components; elements proximal to and distal to the absent part(s) are present. Transverse - Absence extending across the width of the limb. Longitudinal - Absence extending parallel with the long axis of the limb (forearm and/or hand, or leg and/or foot), either pre-axial, postaxial, or (as in the hand or foot) central in nature.

Terminology Pre-axial - Absence of the portion of the fore- arm and/or hand, or leg and/or foot on the thumb or the great-toe side of the limb (radial or tibial portion). Postaxial - Absence of the portion of the fore- arm and/or hand, or leg and/or foot on the side of the limb opposite the thumb or the great toe (ulnar or fibular portion). Ray - A digit. Central - Absence of one or more of the intermediate digital rays (for example, Ray III). Rudimentary - A remnant of an osseous element. If the remnant is identifiable (for example, the humerus), the term "rudimentary humerus" would be applicable. If the remnant cannot be identified, the symbol "X" (unknown) would be cited (i.e., "rudimentary X").

Terminology – Frantz and O’Rahilly O'Rahilly, Ronan, Morphological patterns in limb deficiencies and duplications, Am. J. Anat., Philadelphia, 89:155-187, September 1951.

Terminology – ISPO/ISO Transverse Deficiencies Prosthetics and Orthotics International, 1991, 15, 67-69 The ISO/ISPO classification of congenital limb deficiency H. J. B. DAY Formerly of Disablement Services Centre, Withington Hospital, Manchester, UK International Organization for Standardization - Restricted to skeletal radiological deficiency

Terminology – ISPO/ISO Longitudinal Deficiencies UPPER LOWER

Syndromes Holt Oram Syndrome (AD) Fanconi Pancytopenia Syndrome (AR) TAR Syndrome (AR) EEC Syndrome (AD) VACTERL Association (sporadic) Trisomies (13, 18)

(Cardiac-Limb Syndrome) Syndromes Holt Oram Syndrome (Cardiac-Limb Syndrome) Limb: wrist (carpal bones) abnormalities missing thumb or long thumb that looks like a finger partial or complete absence of bones in the forearm underdeveloped bone of the upper arm abnormalities of the collar bone or shoulder affect one or both of the upper limbs left side is usually more severely affected than the right sidez Cardiac: ASD VSD Conduction abnormalities

Fanconi Pancytopenia Syndrome Syndromes Fanconi Pancytopenia Syndrome Radial Abnormalities Pancytopenia Skin hypopigmentation or café-au-lait spots Short stature Malformed or absent kidneys Defects of the urinary tract Gastrointestinal abnormalities Eye abnormalities small or abnormally shaped eyes Malformed ears and hearing loss Malformations of the reproductive system Abnormalities of the brain and spinal cord hydrocephalus or microcephaly Heart defects

(Thrombocytopenia – Absent Radius Syndrome) Syndromes TAR Syndrome (Thrombocytopenia – Absent Radius Syndrome) Autosomal recessive Radial Aplasia Thumbs present! Thrombocytopenia with risk for ICH within first year Short stature and additional skeletal abnormalities Underdevelopment of other bones in the arms and Heart and kidney defects micrognathia, prominent forehead, and low-set ears Cow's milk allergy

(Ectrodactyly–ectodermal dysplasia–cleft syndrome) Syndromes EEC Syndrome (Ectrodactyly–ectodermal dysplasia–cleft syndrome) Radial Aplasia Thumbs present! Thrombocytopenia with risk for ICH within first year Short stature and additional skeletal abnormalities Underdevelopment of other bones in the arms and Heart and kidney defects micrognathia, prominent forehead, and low-set ears Cow's milk allergy

Syndromes VACTERL Association V = Vertebral/vascular A = Anal malformations C = Cardiac TE = Tracheoesophageal fistula/ esophageal atresia R = Renal anomalies L = Limb anomalies (radial)

Proximal Femoral Focal Deficiency PFFD Proximal Femoral Focal Deficiency Clinical Presentation: –Shorter lower limb (above knee) –Knee non-existent or in proximal position –Usually normal foot Spectrum may include: –Lack of integrity, stability and mobility of hip and knee joints –Bone malorientation, bone malrotation –Soft tissue contractures of the hip and knee

Proximal Femoral Focal Deficiency PFFD Proximal Femoral Focal Deficiency Goal: Limb Equalization Options: Lifts Prosthesis

Proximal Femoral Focal Deficiency PFFD Proximal Femoral Focal Deficiency Creative solutions!! Goal: Limb Equalization Options: Lifts Prosthesis

PFFD Proximal Femoral Focal Deficiency Van Ness Rotationplasty Femur rotated Ankle = knee joint Weight-bearing on foot Toes can provide sensory feedback Can be used with osteosarcoma with partial amputation of lower leg above the knee. Rotation of lower limb with fusion of tibia with proximal femur More common in Canada where Dr. Van Ness was from.

Longitudinal Fibular Deficiency Fibular Hemimelia Longitudinal Fibular Deficiency Clinical presentation: Shorter limb (below knee) Frequently with foot deformity Possible ankle and knee instability

Longitudinal Fibular Deficiency Fibular Hemimelia Longitudinal Fibular Deficiency Associated deformities: foot ray deficiency sub-talar coalition ball and socket ankle joint ankle joint malorientation diaphyseal angular deformity apex anteromedial congenital shortening of the tibia femoral malformation (coxa vara, PFFD,…)

Treatment Physicians – Ortho, PM&R Prosthetist PT/OT Social Worker Team Approach Physicians – Ortho, PM&R Prosthetist PT/OT Social Worker Nurse Coordinator

Treatment Healthy body image Maintain choice for prosthetic options Goals Healthy body image Maintain choice for prosthetic options Patient and family acceptance OPTIMAL FUNCTION

Treatment Biomechanical Losses Upper Limb Lower Limb Loss of prehension (varied) Inequality of arm lengths Malrotation Inadequacy of proximal and distal musculature Instability of proximal joints Also loss of sensory function Prosthesis = mechanical tool Exposed skin of deficient limb may be preferable to encased limb Lower Limb Inequality of leg lengths Malrotation Inadequacy of proximal musculature Instability of proximal joints

Treatment Healthy body image Maintain choice for prosthetic options Goals Healthy body image Maintain choice for prosthetic options Patient and family acceptance OPTIMAL FUNCTION

Treatment Goals Factors for Prosthetic Acceptance by Children Parent Acceptance Age of fit (UE <2 years old) Level of amputation Increase in function Upper vs. Lower extremity

Surgical Management Principles Treatment Surgical Management Principles Preserve length Preserve epiphyses/growth plates Disarticulation rather than Transosseous amputation Preserve epiphyseal growth plates and ensure longitudinal growth Avoids terminal overgrowth of bone Longer lever arm maintained Enhance suspension and rotational control in prosthesis Improve tolerance of distal weight-bearing Preserve knee joint whenever possible Stabilize and normalize proximal portions of limb For example the distal epiphysis is the major source of growth for femur (70%), so disarticulation is preferred over transfemoral amputation.

Developmental Milestones Prosthesis Developmental Milestones

Developmental Milestones – Upper Extremity Readiness Prosthesis Developmental Milestones – Upper Extremity Readiness

Fitting Timetable: Upper Extremity Prosthesis Fitting Timetable: Upper Extremity Passive prosthesis 3-6 months Active control of terminal device >12-15 mos Active control of elbow 3-3.5 yrs Myoelectrics 3-5 yrs single site control if <3 yrs 2-site control if ≥ 3 yrs Early prosthetic fitting designed to encourage bimanual tasks, establish a wearing pattern, increase overall independence, provide for symmetrical crawling and reduce “stump dependence” – sensory dependence on the end of the residual limb. There is a narrow window of opportunity for prosthetic acceptance with UE limb deficiency within the first 2 years to encourage bilateral hand use.

Fitting Timetable: Lower Extremity Prosthesis Fitting Timetable: Lower Extremity Fit when pulling to stand 9-12 mos Knee joint when climbing stairs 2.5-3 yrs Toddler gait: Wide based, hip flexion and abduction, knee flexion, total foot initial contact = no knee component Limits for prosthetic acceptance with high levels of amputation such as hip disarticulation and hemipelvectomy.

Considerations in Pediatric Prosthetic Rx Prosthesis Considerations in Pediatric Prosthetic Rx Developmental Stage/Readiness Growth Durability Comfort Weight Cosmesis Simplicity in construction and in requirements for operation COST – 3D printing of prosthetic limbs

Prosthesis Replacement for Growth Evaluate every 3-6 months through adolescence: Possible adjustments to socket/harness for fit/alignment.

Prosthetic modifications for Growth Prosthesis Prosthetic modifications for Growth Socket: Double walled with removable growth liner Thick elastomeric liner with decreased thickness of liner with growth Socks Pylon: Replace for length in prosthesis with otherwise good fit/function Knee, foot-ankle units: Re-use components