RADIAL LONGITUDINAL DEFICIENCY: Treatment and Emerging Techniques Neil Tarabadkar Department of Pediatric Surgery April 18, 2013

Radial Longitudinal Deficiencies Encompass a spectrum of hypoplasias and dysplasias involving the thumb, wrist, and forearm. Radial Club Hand Cleft Hand Deformity Ulnar Club Hand Radial Hypoplasia Absence of the Radius

Radial deviation, ulnar bowing, instability

Anatomic Manifestations NOT an isolated deformity but a spectrum of dysplasia Bony abnormality of thumb/radius most pronounced Associated with muscle, nerve, joint and vessel deficiency Hand is usually radially deviated with a short ulna

Etiology UNKNOWN Upper Limb Development occurs during the first 4-7 weeks of life, along with cardiac, renal, and hematopoeitic systems Several factors have been proposed Intra-uterine compression Vascular Insufficiency Environmental Insults Maternal Drug Exposure Genetic Mutations

Incidence Between 1 in 30,000 and 1 in 100,000 live births Male to Female ratio of 3:2 Bilateral involvement from 38%-58% When unilateral, right upper extremity is involved twice as much as the left

Syndromes with Radial Defects Holt-Oram VACTERL Fanconi’s anemia Thrombocytopenia and Absent Radius -Severe deformity can often direct attention way from underlying defects -All pediatrics with RLD require a renal ultrasound, echo, and CBC to evaluate for genetic syndromes -Holt-Oram: Mutation in the TBX5 gene, AD, Absent radium, ASD, 1st degree heart block -Fanconi’s anemia: Increased risk of cancer, mylodysplastic syndrome, AML,

Classification of Radial Longitudinal Deficiency Class I: Short and mildly dysplastic radius, arising from delayed growth from epiphysis Class II: Growth noticeably diminished secondary to decreased elongation and proximal and distal epiphysis Class III: Partial absence of the radius Class IV: Complete absence of the radius Types II and IV are operative

Pre-Operative Management Plays an essential role in functional outcome Serial splinting and stretching to lengthen taut radial soft tissue Passive correction (stretching) of wrist deformity Definitive treatment in pediatrics with mild deformity and Patients too sick to undergo surgery -Stretching of wrist deformity: longitudinal traction, ulnar deviation, and extension with stabilization of ulno-carpal joint

Hand-Forearm angle -defined by the intersection of a line drawn down the longitudinal axis of the third metacarpal (b) with a line drawn perpendicular to the distal ulnar physis -Normal is around 30, the larger the angle, the worse the deformity.

Classical Treatment: Wrist Centralization First performed by Sayer in 1893 Initial surgery performed between 6-12 months Realign/stabilize hand/carpus on distal ulna Distal ulna aligned with long finger metacarpal and stabilized with K-wire, ECU transferred distally, FCU dorsally Goal: maintain deformity correction while optimizing growth, improving digit/wrist motion, enhancing function Hand-Forearm angle is most critical factor -Thumb reconstruction occurs six months after wrist realignment -All operations should be completed by age 18 months in order to allow achievement of developmental milestones -Must watch out for median nerve and preserve distal ulnar physis -Must detach radial extensors as well as BR and FCR -Goal: improves hand function by eliminating radial deviation and putting the hand in more outstretched position

Disadvantages High recurrence rate Increased risk of injury to ulnar physis Often need fusion later in life

Changing Paradigm: Soft Tissue Distraction and Joint transfer First decribed by Kessler Stretching of the soft tissue via application of a distraction device Goal: controlled and gradual stretching of radial soft tissues Distraction at 1mm/day until passive correction achieved 2nd MTP and Proximal Phalanx can be transferred with a viable physis -Performed at 2.5-4 years of life in order to allow MCP time to grow -1st and 2nd dorsal metatarsa; artery provides the blood supply to the graft

Outcomes Vilkki et al and de Jong et all Average final hand-forearm angle post op 28 degrees Average wrist motion 83 degrees Average length of the ulna was 66% of the contralateral side

Complications Pin tract infection Vascular complications Inadequate growth of the MTP physis

References Jong, J. “Changing Paradigms in the Treatment of Radial Club Hand”. Clinical Orthopaedic Surgery. 4:1:36-45. 2011 Mashcke, S. “Radial Longitudinal Deficiency”. JAAOS. 15:1:41-52. 2007 Buffart, L. “Hand function and Activity Performance of Children with Radial Longitudinal Deficiency”. JBJS. 14:90:2408-15. 2008 Bora, William. The Pediatric Upper Extremity. W.B Saunders Publishing. 1986