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CONGENITAL

 * Absent and Hypoplastic Disorders
 * Brachial Plexus Birth Injury
 * Cerebral Palsy
 * Embryology and Classification
 * Finger and Thumb Anomalies
 * Hand and Wrist Fractures and Dislocations
 * Physeal Injury (Traumatic and Acquired)
 * Polydactyly
 * Syndactyly and Symbrachydactyly
 * Wrist and Upper Limb Anomalies


GENERAL PRINCIPLES

 * Anesthesia (including WALANT)
 * Compartment Syndrome
 * Imaging
 * Infections
 * Medical Conditions
 * Principles of Hand and Wrist Arthroscopy


HAND AND WRIST: BONE AND JOINT

 * Carpal Fractures (including Malunion and Nonunion)
 * Distal Radius and Ulna Fractures (including Malunion and Nonunion)
 * DRUJ Arthritis
 * DRUJ Injury and Reconstruction
 * Intercarpal and Radiocarpal Arthritis
 * Metacarpal Injuries (including Malunion and Nonunion)
 * Osteoarthritis of Fingers (including Arthroplasty)
 * Osteoarthritis of the Thumb (including Arthroplasty)
 * Phalangeal Injuries (including Malunion and Nonunion)
 * PIP Dislocations and Fracture Dislocations
 * Scaphoid Fractures
 * Scaphoid Fractures (Nonunion)
 * Scapholunate Ligament Injuries and Reconstruction
 * Thumb Fractures and Ligament Injuries
 * Wrist Dislocations and Instability (not including SL)


HAND AND WRIST: SOFT TISSUE

 * Acute Flexor Tendon Injuries
 * Burns
 * Extensor Tendon Injury
 * Fingertip and Nail Bed Injuries
 * Flexor Tendon Reconstruction
 * Free Tissue Transfer
 * Local and Regional Flaps for Hand Reconstruction
 * Replantation
 * Tendinopathies
 * The Mangled Hand and Amputation


NERVE

 * Adult Brachial Plexus Injuries (Reconstruction, Nerve Transfers, Late
   Reconstruction)
 * Median Nerve Compression
 * Median Nerve Injury, Repair and Tendon Transfers
 * Nerve Injury and Repair
 * Radial Nerve Compression
 * Radial Nerve Injury, Repair and Tendon Transfers
 * Ulnar Nerve Compression
 * Ulnar Nerve Injury, Repair and Tendon Transfers


DISORDERS AND DISEASES

 * AVN of Hand and Wrist
 * Complex Regional Pain Syndrome (CRPS)
 * Dupuytren Disease
 * Primary Bone Tumors
 * Psychological Aspects of Arm Illness
 * Rheumatoid and Inflammatory Arthropathies
 * Soft Tissue Tumors
 * Tetraplegia and Stroke
 * Upper Limb Amputation, TMR, Prosthetics
 * Vascular Disorders

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Congenital


EMBRYOLOGY AND CLASSIFICATION

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INTRODUCTION

 * Upper limb malformations relatively common
   * 1/500 live births
 * Limb formation requires precise process and timing
 * Understanding normal process improves understanding of congenital hand
   anomalies
 * Important genes (Table 1)

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LIMB FORMATION

 * Begins 24th day after fertilization
   * Process complete by 52nd day
 * Presumptive upper limb-forming field
   * Between somites 8–12
   * Formed from lateral plate mesoderm
   * Eventually becomes limb bud
   * Transplantation of cells from the presumptive limb-forming field results in
     an ectopic limb
   * Wnt and retinoic acid upregulate Tbx5
     * Tbx5 stimulates Fgf10 -> proliferation of lateral plate mesoderm
 * Controlled by homeobox gene family (HOX A–D) (
   Fig. 1
   )
   * Continuous group of genes activated sequentially
   * Hox genes control multiple processes
     * Limb bud formation and positioning, limb segmentation, cell
       differentiation
 * Tissue origins
   * Lateral plate mesoderm cells differentiate into several cell types
     * Cartilage, perichondrium, dermis, connective tissue, ligaments, tendons
   * Ectoderm -> epidermis, nail structures
   * Nerves originate from spinal cord and neural crest cells
   * Muscles originate from somites

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UPPER LIMB AXES (
FIG. 1
)

 * Proximal-distal axis
   * Controlled by apical ectodermal ridge (AER)
   * Fgf10 induces Wnt 3 secretion
     * Wnt3 induces AER to secrete Fgf8 which has a positive feedback loop with
       Fgf10
       * + feedback critical to proximal-distal growth
 * Anterior-posterior axis (radial ulnar axis)
   * Controlled by zone of polarizing activity (ZPA)
     * Induced by Hand2 to produced Sonic hedgehog (Shh)
       * Hand2 also inhibits anterior factors
   * Anterior limb bud
     * Irx3/5, Alx4, Gli3 play critical role
       * Radius/thumb development
 * Dorsal-ventral axis
   * Controlled by dorsal ectoderm
     * Wnt7a expressed in the dorsal ectoderm (
       Fig. 4
       )
       * Induces Lmxb1 expression
         * Lmxb1 mutations result in Nail-Patella Syndrome
     * En1 expression in ventral ectoderm inhibits Wnt7a

--------------------------------------------------------------------------------


LIMB SEGMENTATION (
FIG. 2
)

 * Three limb regions
   * Upper arm (stylopod)
     * Retinoic acid from the flank results in upregulation of Meis1 in proximal
       limb bud
       * Shox2 also expressed in proximal limb bud
   * Forearm (zeugopod)
     * Predominate signals from HoxA11 and Shox
   * Hand (Autopod) (
     Fig. 3
     )
     * HoxA13 expression is important in segmentation
     * Shh interacts with Gli3 to maintaining its active form in the ulnar
       aspect of the hand
       * In the absence of Shh, Gli3 Gli3R, which promotes radial digit
         patterning, reduces digit number
     * Hand plate width correlates w/ number of digits that can form
     * Phalanx forming region
       * Promotes phalanx growth and segmentation
       * Mesodermal condensation on tip of each digit
       * AER between these regions regresses and apoptosis creates web spaces

--------------------------------------------------------------------------------


VESSEL FORMATION

 * Limb bud initially supported by central artery
   * From primitive subclavian artery
 * Marginal sinuses return blood to primitive central venous system
   * Early limb bud
   * Proximal veins merge centrally to form primitive subclavian vein
 * Vascular system changes by three methods
   * Primitive vascular channels coalesce, angiogenesis (new vessels sprout),
     entirely new vessels form (vasculogenesis)
     * Angioblast migrate into limb
       * Remodel capillary system into larger vessels
       * Somite derived
       * VegF important signaling molecule
 * Vessels remodel from proximal to distal and ulnar to radial
   * Major vessels of arm and forearm—day 48
   * Palmar arches and digital vessels—day 52

--------------------------------------------------------------------------------


SKELETON FORMATION

 * Sox 5+6 promote transformation of chondrogenic precursors -> chondrocytes
 * Day 35—Y-shaped cartilage anlagen
   * Eventual humerus, radius, and ulna
 * Days 37–44 distal end of limb bud expands and autopod formation occurs
   * Carpals, metacarpals, proximal/middle phalanges, distal phalanges form by
     different mechanisms
   * Digits form in a reliable pattern (
     Fig. 5B
     )
     * Digit 4 forms first, Digit 1 forms last
 * Runx2 key transcription factor resulting in osteoblast differentiation
   * Subsequently cartilage anlagen ossifies
 * Joint formation
   * Occurs at interzones that expand, become hypocellular, and cavitate
   * Gdf5 is required for joint formation
   * Joint movement results in mechanical reshaping of the articular surface

--------------------------------------------------------------------------------


MUSCLE FORMATION (
FIG. 6B
)

 * Muscle and tendon formation occur concurrently and are interdependent
 * Occurs from proximal to distal
 * Muscles are evident in arm and forearm at day 41
 * Myocytes migrate from the somite

--------------------------------------------------------------------------------


INNERVATION (
FIG. 6C
)

 * Sensory and motor nerve fibers have different origins
   * Motor neurons form in developing spinal cord
     * Prior to limb bud outgrowth
     * Shh from notochord specifies motor neuron differentiation
   * Sensory neurons reside within the dorsal root ganglia
     * Arise from neural crest cells
     * Ngn1/2 expression induces formation

--------------------------------------------------------------------------------


CLASSIFICATION

 * Improves communication between providers and specialties
 * Swanson Classification
   * Original scheme
   * Based on morphology
 * Oberg-Manske-Tonkin Classification (Table 2)
   * Adopted by IFSSH in 2014, updated in 2020
     * Periodic modification allows improvement over time
   * Based on etiology of congenital conditions
   * High intra- and inter-rater reliability
   * Three main categories
     * Malformations, deformations, dysplasia
     * Also allows for classification of syndromes associated with congenital
       hand differences
   * Multiple codes can be applied to patients with more than one diagnosis




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