Radial Longitudinal Deficiency Janelle Dubbins MD May 3, 2012

Radial Longitudinal Deficiency  Spectrum of upper limb dysplasia and hypoplasia involving the thumb, wrist, forearm  Ranges from mild thumb hypoplasia to complete absence of the radius  Bony abnormalities most pronounced  Deficiencies of the accompanying muscles, nerves, vessels, joints greatly influence function & surgical management

Etiology & Embryology  Etiology remains unknown  Proposed insults to developing limb:  Intrauterine compression  Vascular insufficiency  Environmental insults  Maternal drug exposure  Genetic mutations  Upper limb develops in weeks 4-7  Starts at day 26 with appearance of limb bud  Completed by day 47  Coincides with the appearance of the cardiac, renal, and hematopoietic systems 1.Apical ectodermal ridge 2.Ectoderm 3.Mesenchymal core 4.Mesenchymal primordia of bones 5.Digital ray 6.Loose mesenchchyme 7.Cartilaginous bone models 8.Radius 9.Humerus 10.Ulna 11.Carpus

Syndromes Commonly Associated with Radial Longitudinal Deficiency SyndromeAssociated ConditionsInheritance Holt-OramASD Arrhythmias Upper limb abnormalities Autosomal dominant VACTERLV- vertebral anomalies A- anal atresia C- cardiac abnormalities TE- tracheoesophageal fistula R- renal agenesis L- limb defects Sporadic Fanconi anemiaPancytopenia- develops between 5- 10yo Autosomal recessive Thrombocytopenia & absent radius (TAR) Thrombocytopenia/anemia- at birth, improves during 1 st year Absent radius with normal thumb Autosomal recessive

 Retrospective review  164 pts, 245 extremities  67% associated anomaly (n=110)  35% established syndrome (n=55)  TAR (n=25)  VACTERL (n=22)  Hold-Oram (n=7)  Fanconi anemia (n=1)  Most common associated anomalies were cardiac The Journal of Hand Surgery. Vol 31A No 7. Sept 2006

Associated Conditions  May occur in isolation, but frequently associated with other congenital malformations  No correlation between severity of deformity and presence of associated syndrome or anomaly  All children presenting with radial longitudinal deficiency require additional workup:  Careful physical exam (cardiac auscultation, spinal exam)  CBC  Renal ultrasound  ECHO  Spine imaging

Thumb Hypoplasia Grade I: -Slight decrease in thumb size, slender phalanges and metacarpal -Normal intrinsic muscles & distal radius Grade II: -Smaller thumb, 1 st web space contracture, lender phalanges and metacarpal -Unstable MCPJ UCL, CMCJ instability - Underdevelopment or absence of thenar muscles Grade III: -Short thumb, severe 1 st web space contracture -Absence of proximal portion of 1 st MC - MCPJ often unstable -Absence of thenar muscles -Variable absence of trapezium, scaphoid, & radial styloid Grade IV: -Distal midaxial origin of floating thumb “pouce flottant” - Absent thenar & extrinsic thumb muscles -Fully developed neurovascular pedicle -Abnormal position of radial artery -Variable absence of trapezium, scaphoid, & radial styloid Grade V: - Complete absence of thumb -Absent 1 st dorsal interosseus in 50% -Absent radial carpal bones & radial styloid -Hypoplasia of distal radius Buck-Gramcko Classification Grade I: -Slight decrease in thumb size, slender phalanges and metacarpal -Normal intrinsic muscles & distal radius Grade II: -Smaller thumb, 1 st web space contracture, lender phalanges and metacarpal -Unstable MCPJ UCL, CMCJ instability - Underdevelopment or absence of thenar muscles Grade III: -Short thumb, severe 1 st web space contracture -Absence of proximal portion of 1 st MC - MCPJ often unstable -Absence of thenar muscles -Variable absence of trapezium, scaphoid, & radial styloid Grade IV: -Distal midaxial origin of floating thumb “pouce flottant” - Absent thenar & extrinsic thumb muscles -Fully developed neurovascular pedicle -Abnormal position of radial artery -Variable absence of trapezium, scaphoid, & radial styloid Grade V: - Complete absence of thumb -Absent 1 st dorsal interosseus in 50% -Absent radial carpal bones & radial styloid -Hypoplasia of distal radius

Radial Longitudinal Deficiency Type I: - Short radius (distal radial physis >2mm proximal to distal ulnar physis on PA wrist x-ray) -Due to delayed appearance of the distal radial epiphysis -Forearm straight, modestly shortened -Sufficient bony support to the hand & carpus Type II: - Grossly diminished radius -Deficient growth of both the proximal and distal radial epiphyses -Forearm is short - Ulna is thick and bowed -Hand is poorly supported, with radial displacement & angulation Type III: - Partial absence of radius -Deficiency may arise proximally, distally, or centrally -Usually, proximal radius is present, providing support to elbow -Ulna significantly bowed - Type IV: -Most common - Complete absence of radius -Ulna is bowed - Marked radial and palmar displacement of the hand -Pseudoarticulation between carpus & radial border of ulna Bayne & Klug Classification

Initial Non-Surgical Management  Serial splinting & stretching  Initiated as early as is feasible  Lengthen the shortened radial soft tissues  Obtain passive correction of wrist deformity  Reduce the hand/carpus on the distal ulna & prevent radial contraction deformity  Serial exams  Careful attention to elbow stiffness and/or contracture

Nonsurgical Management  May be definitive in children with minimal deformity & stable joints  Contraindications to surgical reconstruction:  Older children with established patterns of functional compensation  Mild deformities with good function & cosmesis  Associated medical anomalies that preclude safe surgical reconstruction  Severe bilateral elbow extension contractures in patients who rely on wrist flexion & radial deviation of the hand to reach the face

Surgical Management  Goals:  Optimize upper limb length  Straighten forearm axis  Reconstruct or ablate thumb  Pollicize index finger  Initial operation age 6-12 months  Realign and stabilize the hand/carpus on the distal ulna  6 months later:  Thumb reconstruction/ablation  Complete all reconstruction by 18 months  Allow child to achieve normal developmental milestones

Surgical Management Wrist Realignment - Achieve deformity correction & stability - Optimize growth, improve ROM, enhance function - Preserve bony carpus & distal ulnar physis - Often use soft-tissue distraction devices to diminish soft-tissue tension preop and avoid carpal bone deletion - May perform osteotomy of the bowed ulna at the apex of the deformity to achieve angular correction Thumb Reconstruction - Opponensplasty to recreate pinch (tendon transfer) - Stabilization by reconstructing the UCL of the MCPJ - Reconstruct 1 st web space (Z- plasty) - Ablation and pollicization - Preferred in Grade IIIB-IV due to poor cerebrocortical representation of the thumb - Aesthetic reconstruction will not restore functional use to an ignored digit

Summary  Spectrum of disease from mild thumb hypoplasia to severe deformity of the upper extremity  Commonly associated with other anomalies/syndromes  All patients diagnosed with radial deficiencies require additional workup  Surgical & non-surgical management strategies exist  Goals of reconstruction: limb length, joint stability, preserve growth potential, creation of a functional thumb  Good cosmesis does not guarantee good function