Cleft Hand

Cleft hand (ectrodactyly) is a central longitudinal deficiency characterized by absence of one or more central rays, creating a V-shaped cleft. Classified as typical (sporadic, U-shaped cleft, good first web, better function) or atypical (syndromic/familial, V-shaped cleft, poor first web, worse function). Manske-Halikis classification (I-V) grades severity based on thumb web status and central defect. Associated with EEC syndrome (ectrodactyly-ectodermal dysplasia-clefting). Treatment focuses on functional reconstruction: cleft closure (Snow-Littler procedure), first web deepening, and syndactyly release at 12-18 months. First web space depth is the key determinant of function.

Cleft hand (also called ectrodactyly, split hand, or lobster claw deformity) is a congenital longitudinal deficiency characterized by the absence of one or more central rays (metacarpals and phalanges), creating a V-shaped or U-shaped cleft in the central portion of the hand.

Epidemiology

• Incidence: Split-hand/split-foot malformation (SHFM, the umbrella term encompassing cleft hand) occurs in approximately 1 in 8,500 to 1 in 25,000 newborns (Holder-Espinasse et al, Eur J Hum Genet 2019)
• Proportion of limb defects: SHFM accounts for approximately 15% of all limb reduction defects
• Bilateral: Both hands are frequently involved, and many patients have concurrent foot involvement (true split hand-split foot malformation)
• Gender: Broadly equal distribution male:female
• Typical vs Atypical: The historical typical/atypical split is descriptive; "atypical cleft hand" is now largely reclassified as symbrachydactyly (a transverse/dysplastic process) rather than a true central longitudinal deficiency

Genetics and Inheritance

• Inheritance: Most commonly autosomal dominant with incomplete penetrance; X-linked and autosomal recessive forms also occur (Holder-Espinasse et al, 2019)
• Recognised loci (SHFM1-6): SHFM1 at 7q21.2 (DLX5), SHFM2 at Xq26, SHFM3 at 10q24 duplication (the most frequently identified cause), SHFM4 at 3q27 (TP63), SHFM5 at 2q31 and SHFM6 (WNT10B, 12q13)
• EEC Syndrome: Autosomal dominant, caused by TP63 mutation (3q27 / SHFM4 locus)

Associated Syndromes

• EEC Syndrome (Ectrodactyly-Ectodermal dysplasia-Clefting): Most common
• SHFM (Split Hand-Split Foot Malformation): Isolated limb defects
• Other: Cornelia de Lange syndrome, Adams-Oliver syndrome

Embryology

• Develops during limb bud formation (4-8 weeks gestation)
• Failure of formation of central rays (index, middle, ring fingers)
• Zone of Polarizing Activity (ZPA) and Apical Ectodermal Ridge (AER) disruption
• Suppression or absence of central digital rays during differentiation
• First web space development affected in atypical forms

Normal Hand Development

• Digital Rays: 5 rays form from radial (thumb) to ulnar (small finger)
• Central Rays: Rays 2, 3, 4 (index, middle, ring) are central rays
• AER and ZPA: Control proximal-distal and radial-ulnar patterning
• Programmed Cell Death: Normal interdigital tissue apoptosis

Pathologic Anatomy in Cleft Hand

• Central Ray Absence: One or more of rays 2, 3, 4 are completely or partially absent
• Metacarpal Absence: May involve metacarpals, phalanges, or both
• Soft Tissue Cleft: V-shaped or U-shaped defect extends proximally
• Syndactyly: Border digits often joined (index-middle or ring-small)
• First Web Contracture: Variable suppression of thumb-index web space

Typical Cleft Anatomy

• U-Shaped Cleft: Wider, more shallow cleft
• Normal First Web: Good thumb-index web space preserved
• Central Deficiency Only: Isolated to central rays
• Better Function: Opposition and grasp relatively preserved
• Single Ray Absence: Often middle finger (ray 3) only

Atypical Cleft Anatomy

• V-Shaped Cleft: Narrow, deep cleft extending to carpus
• Suppressed First Web: Thumb-index web is tight, narrow, adducted
• Multiple Ray Absence: Often 2 or 3 central rays absent
• Transverse Bones: Abnormal transverse metacarpal elements
• Worse Function: Poor opposition and grasp

Key Anatomical Considerations

• First Web Space Depth: THE critical determinant of hand function
• Neurovascular Bundles: May have abnormal course around cleft borders
• Tendons: Extrinsic tendons may be absent or misdirected
• Thumb Position: May be radially deviated or adducted
• Border Digits: Often stiff, may have joint contractures

History

• Birth Presentation: Cleft visible at birth - obvious deformity
• Family History: Important to ask - atypical forms are familial
• Syndromic Features: Ask about skin/hair (ectodermal dysplasia), cleft palate
• Bilateral: Examine both hands AND both feet
• Developmental Milestones: Usually normal motor development

Physical Examination

Inspection

• Cleft Configuration: V-shaped vs U-shaped
• Number of Digits: Count present digits and identify missing rays
• First Web Space: Assess depth and width (CRITICAL for function)
• Syndactyly: Check for fusion of border digits
• Thumb Position: Assess for radial deviation or adduction contracture

Palpation

• Metacarpals: Palpate to determine which are present/absent
• Transverse Bones: Feel for abnormal transverse metacarpal elements (atypical)
• Soft Tissue: Assess tightness of first web space skin
• Neurovascular: Identify digital arteries/nerves (may be anomalous)

Functional Assessment (MOST IMPORTANT)

• Opposition: Can thumb oppose to remaining fingers?
• Pinch Strength: Assess tip pinch, key pinch, three-point pinch
• Grasp: Power grip capability with remaining digits
• First Web Span: Measure distance between thumb-finger when maximally abducted
• Activities: Can child manipulate objects, feed self, grasp toys?

Red Flags Requiring Syndrome Workup

• Sparse Hair/Teeth: Suggests ectodermal dysplasia (EEC syndrome)
• Cleft Lip/Palate: EEC syndrome
• Cleft Feet: Split hand-split foot malformation (SHFM)
• Multiple Limb Defects: Consider broader genetic syndrome
• Developmental Delay: Suggests syndromic etiology

Associated Findings

• Cleft Feet: 60% have split foot deformity
• Syndactyly: Common in border digits
• Polydactyly: May coexist with central ray absence
• Thumb Hypoplasia: May have underdeveloped thumb
• Stiffness: Border digits often have joint contractures

Radiographic Assessment

Plain Radiographs (Essential)

• AP and Lateral Views: Document bony anatomy
• Identify Present Rays: Determine which metacarpals/phalanges present
• Carpal Bones: May have carpal anomalies in atypical forms
• Transverse Bones: Look for abnormal transverse metacarpal elements
• Syndactyly: Assess bony vs soft tissue fusion

Findings on X-ray

• Typical: Usually absence of middle finger ray (ray 3) only
• Atypical: Multiple ray absence, transverse bones, carpal anomalies
• First Metacarpal: May be short or deviated radially
• Phalanges: May have hypoplastic or absent phalanges

Genetic Testing

• Indicated if: Familial pattern, syndromic features, bilateral involvement
• TP63 Gene: EEC syndrome mutation
• Chromosomal Microarray: Identify deletions/duplications
• Genetic Counseling: Essential for familial cases

Syndromic Workup (If Indicated)

• Skin/Hair/Teeth Assessment: Ectodermal dysplasia features
• Craniofacial Evaluation: Cleft lip/palate assessment
• Foot Examination: Look for cleft feet
• Ophthalmology: Eye anomalies in some syndromes
• Audiology: Hearing assessment if syndromic

Functional Assessment Tools

• Hand Function Tests: Age-appropriate functional testing
• Grip/Pinch Strength: Objective measurements (if child cooperative)
• Video Recording: Document baseline function before surgery

Algorithm

View larger

Treatment Goals (In Order of Priority)

1. Function First

• Maximize opposition capability (thumb-finger pinch)
• Improve grasp and release
• Deepen first web space if suppressed

2. Appearance Second

• Close cleft for cosmetic improvement
• Create more normal hand contour
• Improve social acceptance

3. Growth Preservation

• Maintain growth plates during surgery
• Avoid damage to viable digits

Conservative Management

Observation (Acceptable For)

• Manske Type I: Good function, normal first web - surgery optional
• Manske Type II: Mild impairment - may not require surgery
• Unilateral with Good Bilateral Hand Function: Non-dominant hand may not need surgery

Occupational Therapy

• Adaptive Strategies: Teach compensatory techniques
• Strengthening: Maximize function of existing digits
• First Web Stretching: If mild contracture present
• ADL Training: Feeding, dressing, writing adaptations

Surgical Management Principles

Timing: 12-18 months optimal

• Early enough to integrate before fine motor development
• Late enough for safe anesthesia and tissue handling
• Before social awareness (2-3 years)

Goals of Surgery:

• Close the cleft (improve appearance, prevent trauma to cleft margins)
• Deepen first web space (improve opposition and grasp - MOST IMPORTANT)
• Release syndactyly (if present in border digits)
• Maintain viability (preserve neurovascular supply to digits)

Intraoperative Complications

• Neurovascular Injury: Anomalous NV bundle course increases risk (1-2%)
• Excessive Bleeding: Difficult hemostasis in vascular anomalies
• Inadequate Release: Incomplete first web deepening
• Skin Flap Necrosis: Tension or poor design

Early Postoperative Complications (Less than 6 weeks)

• Flap Necrosis: 2-5% incidence - poor flap design or tension
• Infection: 1-3% - treat with antibiotics, may need debridement
• Hematoma: Rare - evacuate if compressing neurovascular structures
• Wound Dehiscence: More common if excessive tension during closure
• Skin Graft Loss: 5-10% of grafts may fail (syndactyly release)

Late Complications (More than 6 weeks)

• Web Space Contracture Recurrence: 10-20% - most common complication
• Scar Contracture: Linear scars contract - use Z-plasties to prevent
• Stiffness: Border digits may become stiff (5-10%)
• Growth Disturbance: If physis injured during surgery (rare with careful technique)
• Cold Intolerance: Vascular insufficiency in border digits
• Neuroma: If nerve transected or entrapped in scar

Functional Outcomes

Good Outcomes (Typical Cleft)

• Near-normal hand function achieved in 70-80%
• Good cosmetic result
• Improved opposition and grasp

Fair Outcomes (Atypical Cleft)

• Function improved but not normal in 50-60%
• First web space may re-contract requiring revision
• Multiple surgeries often needed

Poor Outcomes

• Severe first web contracture recurrence: 10-20% (especially atypical)
• Stiffness limiting function: 5-10%
• Neurovascular compromise: 1-2%

Revision Surgery

• Indications: Web space re-contracture, inadequate initial correction, scar contracture
• Timing: Wait at least 6-12 months for scar maturation
• Techniques: Repeat Z-plasty, skin grafting, free flap coverage
• Success: Lower success rate than primary surgery

Immediate Postoperative Period (0-2 weeks)

• Immobilization: Well-padded splint in position of function
• Thumb Position: Abducted if first web deepened
• Elevation: Keep hand elevated to reduce swelling
• Pain Management: Acetaminophen, avoid NSAIDs (may increase bleeding)
• Wound Care: Keep dressing clean and dry
• First Dressing Change: 7-10 days (or earlier if concerns)

Early Rehabilitation (2-6 weeks)

• Splint Removal: 3-4 weeks post-op
• Gentle ROM: Start passive range of motion exercises
• No Forceful Stretching: Allow tissues to heal before aggressive therapy
• Scar Massage: Begin gentle massage once incisions healed
• Occupational Therapy: Initiate therapy for hand function training

Late Rehabilitation (6 weeks - 6 months)

• Active ROM: Progress to active exercises and strengthening
• First Web Maintenance: Aggressive stretching to prevent re-contracture
• Functional Activities: Encourage use in age-appropriate play and ADLs
• Night Splinting: May use abduction splint at night for 3-6 months
• Scar Management: Silicone gel sheets, massage, moisturization

Long-Term Follow-Up

• Growth Monitoring: Annual follow-up through skeletal maturity
• Functional Assessment: Assess hand function at each visit
• Revision Planning: Identify need for further surgery as child grows
• Psychosocial Support: Address appearance concerns, school integration

Occupational Therapy Protocol

Phase 1 (Weeks 3-6)

• Gentle passive ROM
• Edema control
• Scar management initiation

Phase 2 (Weeks 6-12)

• Active ROM exercises
• Strengthening with therapy putty
• Fine motor skill development

Phase 3 (Months 3-12)

• Advanced strengthening
• Bilateral hand coordination activities
• Writing/drawing skills (age-appropriate)
• Adaptive equipment trial if needed

Cleft hand must be distinguished from other central and transverse failures of formation, because management and prognosis differ markedly. The single most important modern distinction is between true central longitudinal deficiency (cleft hand) and symbrachydactyly of the cleft/atypical type, which is a transverse/dysplastic process and follows symbrachydactyly principles.

Global epidemiology

• Split-hand/split-foot malformation (SHFM), the umbrella entity for cleft hand, affects approximately 1 in 8,500 to 1 in 25,000 newborns and represents about 15% of all limb reduction defects (Holder-Espinasse et al, Eur J Hum Genet 2019).
• Inheritance is most often autosomal dominant with incomplete penetrance; this drives the need for genetic counselling and examination of relatives in apparently isolated cases.
• Cleft hand is a central longitudinal deficiency in the IFSSH-endorsed OMT classification (Tonkin et al, J Hand Surg Am 2013).

Guidance and standards, side by side

There are no disease-specific randomised guidelines for cleft hand; practice is built on classification systems and specialist consensus. Standards that genuinely shape practice are summarised below.

Registry evidence

There is no dedicated international cleft-hand registry, and joint-replacement registries (NJR, AJRR, AOANJRR, SHAR) do not apply. Population-level data derive instead from congenital anomaly surveillance networks (for example EUROCAT in Europe and the ICBDSR international clearinghouse), which capture SHFM among limb reduction defects and underpin the 1 in 8,500-25,000 incidence figure.

Global practice variation

• High-resource settings: early multidisciplinary assessment (hand surgery, plastics, genetics, occupational therapy), functional surgery individualised to thumb-web status, and access to four-flap Z-plasty, microsurgical toe-to-hand transfer and pollicization for severe cases.
• Limited-resource settings: emphasis on the highest-yield functional interventions (first-web deepening, syndactyly release) with less reliance on microsurgical reconstruction; genetic testing and prosthetics may be unavailable.
• Across all settings the shared principle is constant: function is governed by the thumb web, so web reconstruction takes priority over cosmetic cleft closure.

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