Hand Soft Tissue
Congenital finger deformity and syndactyly
Curly fingers, symphalangism, Apert syndrome, cleft hand and hand size discrepancy
45 questions
7 source pages
1 images
1 fact-check flags
Images appear with the first question taken from each source page — tap a question to open it.
Q1What is the pathophysiology and clinical presentation of congenital trigger thumb?▸
- Nodular thickening of FPL causing size mismatch between flexor sheath and FPL, disrupting gliding
- IPJ flexion deformity with MCPJ compensatory hyperextension
- Notta's nodule at FPL; bilateral in 30%
- Associations: mucopolysaccharidosis, Gaucher's disease, arthrogryposis
Q2What is the differential diagnosis of congenital trigger thumb?▸
- Clasp thumb: extensor agenesis/hypoplasia
- Hypoplastic thumb
Q3What is the management of congenital trigger thumb and when is surgery indicated?▸
- 1st line stretching if flexible; 50% resolve by 2 years
- If unresolved >2 years, only <10% resolve --> OT
- Release before 3 years, otherwise increased IPJ FFC if done after 4 years
- Release A1 pulley and preserve oblique pulley; 90% successful, low risk of recurrence
Q4What is congenital clasp thumb and how is it classified (Tsuyuguchi)?▸
- Extensor agenesis/hypoplasia
- Associations: arthrogryposis (congenital joint contractures affecting two or more areas of the body), digitotalar dysmorphism, Freeman-Sheldon syndrome, X-linked MASA syndrome
- Type I: supple with no other digital anomaly; Type II: contracture +/- other digital anomalies
- Type III: rigid associated with arthrogryposis and marked soft-tissue deficits
- Mx: serial splint/stretching; tendon transfer PI to EPL; reconstruction at 3-5 years old
Q5What is camptodactyly and how is it classified (Benson)?▸
- Congenital FFC of PIPJ with webbed volar skin and no crease; DIPJ normal
- Cause: abnormal lumbrical/FDS/extensor; LF > RF
- Benson: 1 infant (most common, stretching); 2 adolescent from abnormal FDS; 3 multiple digits with syndrome (non-op)
- Benson 4: Kirner deformity = 2-plane deformity of LF, apex dorsal-ulnar
- Mx: 1st line stretching; OT if FFC >60 degrees; FDS transfer/tenotomy/fusion
Q6How is Benson type 2 camptodactyly managed?▸
- Adolescent presentation due to abnormal FDS
- If flexible, perform FDS to radial LB transfer
- For comparison: type 1 (infant) is most common and treated with stretching; type 3 is non-operative and treated later with osteotomy/fusion
Q7What is clinodactyly and what are its types?▸
- LF curved towards RF; autosomal dominant
- Type I: normal length (most common); Type II: short length; Type III: significant angulation with delta phalanx
- Delta phalanx = C-shaped epiphysis and longitudinal bracketed diaphysis
- Partial closure of PP head or MP base physis; USG screening for Down syndrome (look for simian crease as well=single palmar crease)
Q8Describe the classification of the Av pulley of the thumb.▸
- Type I: transverse, parallel to A1, with a gap between Av and A1
- Type II: no gap between Av and A1
- Type III: triangular/oblique Av pulley with fibres converging to the radial side
Q9What is the genetic basis of Apert syndrome and how does it relate to the phenotype?📷▸
- Acrocephalosyndactyly type 1; FGF family receptor mutation (FGFR2)
- Severe craniofacial + mild hand: gain of function in FGFR2c affinity for FGF2 (expressed in craniofacial area)
- Mild craniofacial + severe hand: loss of function in FGFR2c specificity, now binds FGF10 (more expressed in hands)
Q10What are the hand features of Apert syndrome?▸
- Spoon shaped with tapered ends
- Border: simple +/- clinodactyly; middle 3 complex
- Triphalangeal thumb
Q11Describe the Upton classification of the Apert hand.▸
- I: spade (IF to RF fused), thumb free
- II: mitten (thumb to RF fused)
- III: rosebud (all fused)
Q12List the craniofacial features of Apert syndrome.▸
- Frontal bossing, flat occiput
- Wideset eyes, lower outer canthus
- Short maxilla, prominent jaw
- MR (mental retardation)
Q13Describe the surgical plan in Apert syndrome.▸
- Staged surgery
- Border digit separation at 6 months - PP osteotomy, fix mid axis with K wire
- Central digits at 1 year
- Correct delta phalanx
Q14Describe the clinical photo and diagnosis.▸
- Deformity of the left hand; grossly short I/F, M/F and R/F with nail plate still visible
- L/F angular deformity; thumb appears normal
- Symbrachydactyly: short central digits with thumb and little finger preserved; starts at MP
Q15How does symbrachydactyly differ from constriction band and cleft hand?▸
- Different from constriction band: nail/DP present, no acrosyndactyly/fenestrations, no constriction bands
- Different from cleft hand: metacarpals present
Q16How is symbrachydactyly assessed?▸
- Hx: birth history; look for other anomalies such as Poland syndrome
- PE local: assess if pinch is achieved; assess flexor and extensor tendon function
- Systemic assessment for associated anomalies
Q17What are the associations and pathogenesis of symbrachydactyly?▸
- Association: Poland syndrome - hypoplasia of chest wall (absence of sternocostal head of pec major), hypoplasia of breast, syndactyly, brachysyndactyly
- Middle phalanx chondrification and differentiation of the 2 heads of pec major occur at a similar time (44-47 days)
- Proposed vascular mechanism: subclavian artery hypoplasia
Q18What is the management of symbrachydactyly?▸
- Lengthen MC so thumb can touch the tip of other digits
- Transfer with a mobile joint (at least 1 digit for pinch)
- Vascularized/non-vascularized toe transfer; bilateral second toe for thumb + little finger pincer grip
- In-phasic tendon transfer; deep webspace; prosthesis
Q19Describe the Blauth and Gekeler classification of symbrachydactyly.▸
- Type 1 = short fingers
- Type 2 = oligodactylic = atypical cleft hand (central portion aplastic, border digits less affected)
- Type 3 = monodactylic (all fingers gone except thumb aplasia)
- Type 4 = peromelic (resembles transverse amputation at the MCPJ level)
Q20What is symphalangism and how is it managed?▸
- Fusion of PIPJ
- Hereditary or non-hereditary
- Non-hereditary: related to Poland's syndrome and Apert's syndrome; hereditary is related to hearing loss
- Mx: observation / bone / soft tissue procedure
Q21What are the features of a cleft hand?▸
- Absent MF to radial digit (thumb); LF always present
- Absent MC as evident by cleft proximal to MCPJ
Q22Which associations should be looked for in cleft hand?▸
- Cleft foot
- Bilaterality
Q23Describe the Manske classification of cleft hand.▸
- 1-3: thumb and IF present
- 1: thumb web normal; 2A: mild narrowing; 2B: severe narrowing
- 3: syndactylised thumb + IF syndactyly
- 4: merged web (thumb and/or IF absent)
- 5: absent web (thumb absent)
Q24What are the genetic associations of cleft hand?▸
- FHx AD
- Ectrodactyly-ectodermal dysplasia-cleft (EEC) syndrome
- Sensorineural hearing loss
- Syndactyly and polydactyly
Q25What are the steps of cleft hand reconstruction?▸
- Recreate web commissure
- Excise intervening MC + reconstruct interMC ligament
- Transposition if >3 MC present
- Type 5 - pollicization
Q26Which cleft hand types are observed and what is the surgical timing?▸
- Function okay in type 1 and 4 --> observe
- Type 2, 3, 5 --> surgery
- Type 3: separation at 6 months; others at 1 year
Q27What is the pathology of cleft hand?▸
- Central deficiency with varied absence of the long ray
- Due to wedge-shaped degeneration at the centre (AER)
Q28Describe the findings in these clinical photos.▸
- Left: band over distal leg, distal edema, no ischaemic change
- Right: 4 fingers with gross shortening, incomplete syndactyly with proximal region not fused and fenestrations visible --> acrosyndactyly
Q29Describe the Patterson classification of constriction band syndrome.▸
- 1: simple
- 2: distal edema
- 3: acrosyndactyly (fusion between the more distal portions of the digits)
- 4: amputation
Q30What are the risk factors for constriction band syndrome?▸
- Prematurity
- Low birth weight
- Maternal smoking
- Drug exposure (decongestants, NSAIDs, antihypertensives)
Q31What are the associations and investigations in constriction band syndrome?▸
- Rare for only one ring to be present as an isolated malformation
- Associations: club foot, Cleft lip/ palate
- Local: NV status; associated hand anomalies - syndactyly, hypoplastic digits, brachydactyly
- Ix: X-ray for presence of complex syndactyly
Q32What is the surgical technique for constriction band release?▸
- Excision of the ring and subcutaneous tissue combined with Z-plasty
- If circulation compromised (EOT): release the band by longitudinal incision first to improve circulation
- Deep band: single side first, wait 3 months, then complete, to prevent NV compromise
Q33What is the timing of surgery in constriction band syndrome?▸
- Timing of OT depends on the Patterson type
- Simple --> can be elective OT
- Acrosyndactyly: border at 6 months, central at 1 to 1.5 yrs old
Q34What is constriction band syndrome (Streeter dysplasia)?▸
- A malformation due to intrauterine rings or bands which constrict fetal tissue
- Sporadic with no hereditary predisposition
Q35Describe the diagnosis and classification of this hand.▸
- Discrepancy in size of the entire left hand, most marked in the index finger; angular deformity of the middle finger
- Macrodactyly
- Swanson classification: overgrowth; OMT classification: dysplasia (hypertrophy)
Q36What associations should be screened for in macrodactyly?▸
- NF, Proteus syndrome, Ollier's disease, Maffucci syndrome
- Congenital lymphoedema (Milroy's disease)
- Klippel-Trenaunay-Weber syndrome, Beckwith-Wiedemann syndrome
Q37Describe the natural history and classification of macrodactyly.▸
- No known cause; 90% unilateral; 70% more than one finger; I/F is the most common
- Associated with lipofibromatous hamartoma of nerve, especially the median nerve
- Natural history - it will grow!
- Static = large at birth, proportional growth to other digits; dynamic = progressive disproportionate (more associated with NF)
Q38What history, examination and investigation are needed in macrodactyly?▸
- Hx: functional problems, birth history, family history
- Local PE: joint, tendon, collaterals, NV; digital Allen test
- Systemic: screen for associated syndromes (NF, Proteus, Ollier's, Maffucci, Milroy's, KTWS, Beckwith-Wiedemann)
- Ix: X-ray
Q39What are the principles and bone procedures in macrodactyly management?▸
- Principle: preserve a functional digit if possible; prime parents for multiple operations and even amputation; refer paediatrician
- Longitudinal growth: epiphysiodesis when digit reaches adult size
- Circumferential overgrowth: serial reduction osteotomy or longitudinal narrowing osteotomy
Q40What soft tissue and nerve procedures are used in macrodactyly?▸
- Debulking done half at a time, 3 months apart
- Nerve stripping
- Nerve: median nerve excision (lipohamartoma) / neurectomy
- Amputation
Q41What are the complications of macrodactyly treatment?▸
- Digital stiffness
- Chronic digital pain or edema
Q42What is symphalangism?▸
- Failure of PIPJ formation
- Failure of segmentation
Q43What are the clinical features and associations of symphalangism?▸
- Clinically absent skin crease and stiff joint
- Associated with syndactyly, Poland syndrome and Apert syndrome
Q44What are the aetiological types of symphalangism?▸
- Hereditary or non-hereditary
- Non-hereditary: related to Poland's syndrome and Apert's syndrome
- Hereditary: related to hearing loss
Q45What is the management of symphalangism?▸
- Observation
- Bone or soft tissue procedure if indicated
Fact check
50% of congenital trigger thumbs resolve by 2 years and only <10% resolve if unresolved beyond 2 years — imprecise/optimistic — Published resolution rates vary widely: about 30-50% over several years, with some studies reporting 32-76% by 5 years; resolution is uncommon after age 2 and surgery is generally not advised before age 3. — (medium confidence) — source