Manipulation

• Physiotherapy to elbow and wrist prevents progressive stiffness and maintains range of motion.
  
  
  
  • Parents should do this at least twice a day.
  
  
• Mildest deformities can be treated with physiotherapy alone.
  
• Splintage is difficult to apply and adds little benefit.
  
• External fixators are widely used to distract radial soft tissues prior to surgery.

Surgery

• Performed around 12 months, but this varies.
  
• The following abnormalities may be found:
  
  
  
  • Variable deficiencies of the radial forearm structures.
    
  • Aberrant radial wrist extensors and extrinsic thumb muscles.
    
  • Absence of the radial artery.
    
  • Absence of the radial nerve below the elbow.
    
  • Median nerve is always present—often the most radial structure of the wrist.
  
  
• Centralisation
  
  
  
  • Carpus is repositioned over the ulna and stabilised with a pin through the third metacarpal and carpus into the ulna.
    
    
    
    • Usually requires extensive soft tissue release.
    
    
  • Radial wrist extensors are transposed onto extensor carpi ulnaris (ECU) to counter the radial deforming force.
    
  • Some recommend transposing redundant skin from the ulnar wrist to release the radial contracture.
  
  
• Radialisation
  
  
  
  • Scaphoid is placed over the ulna and secured with a pin through the second metacarpal.
    
  • Transfer of flexor carpi radialis (FCR) and flexor carpi ulnaris (FCU) to the ulnar carpus or fifth metacarpal decreases the radial deforming force.
  
  
• Microvascular joint transfer
  
  
  
  • Centralisation and radialisation are associated with high recurrence rates.
    
  • They also have the potential to injure the distal ulnar physis, causing growth arrest.
    
  • Vilkki described vascularised transfer of the second MTPJ to avoid these problems.
    
  • It is technically demanding and not widely practised.
  
  
• Pollicisation of the index finger
  
  
  
  • Indicated for cases with a severe hypoplastic thumb.
    
  • Aims to reproduce thumb function by shortening and rotating the index finger.
    
    
    
    1. A radial palmar incision is made, creating skin flaps at the base of the index finger.
       
       
       
       • Allows subsequent creation of a first webspace.
       
       
    2. Ulnar digital nerve is mobilised by interfascicular dissection of the common digital nerve to the index-middle finger web.
       
    3. Radial digital artery to the middle finger is ligated and divided.
       
    4. Interossei are elevated from the index finger metacarpal.
       
    5. Index metacarpal is removed, except for its head, which forms the new trapezium.
       
       
       
       • The epiphysis is resected to prevent subsequent growth.
       
       
    6. Metacarpal head is rotated 160°—this will subsequently relax to 120°, ideal for opposition.
       
       
       
       • Secured with K wires in 40° of palmar abduction with metacarpophalangeal joint (MCPJ) hyperextended.
       
       
    7. The length of metacarpal removed is measured and a similar length of flexor and extensor tendon is excised.
       
       
       
       • Some do not remove tendon because they are said to shorten over time.
       
       
    8. Rebalancing the intrinsics is essential:
       
       
       
       • First dorsal interosseous is sutured to the radial lateral band to become abductor pollicis brevis (APB).
         
       • First palmar interosseous is sutured to the ulnar lateral band to become adductor pollicis.
         
       • Extensor indicis proprius (EIP) acts as extensor pollicis longus (EPL).
         
       • Extensor digitorum communis (EDC) to the index finger acts as the abductor pollicis longus (APL).
         
       • Many children require opponensplasty between 5 and 8 years.

Ulnar deficiency

• One-tenth as common as radial deficiency.
  
• Spectrum of abnormalities, from hypoplasia of ulnar digits to absence of ulna.
  
• Hand and carpus are always affected: missing digits, syndactyly, thumb abnormalities.
  
• It differs from radial deficiency:
  
  
  
  • The wrist is stable but elbow unstable.
    
  • Associated more with musculoskeletal abnormalities than cardiovascular.
    
  • Total absence is most common for the radius; partial absence is most common for the ulna.
    
  • Less likely to occur as part of a syndrome.

Classification

• Classified by Bayne into four types:
  
  
  
  • Type I: hypoplasia of the ulna (both proximal and distal epiphyses present)
    
  • Type II: partial aplasia of the ulna (absence of the distal or middle third)
    
  • Type III: total aplasia of the ulna
    
  • Type IV: radiohumeral synostosis.

Treatment

• Depends on the nature and severity of the deformity; there is no consensus view.
  
• Release of the fibrous anlage with realignment of the carpus and forearm.
  
  
  
  • The anlage, present in types II and IV, is claimed to increase ulnar deviation of the hand and ulnar bowing of the radius as the child grows.
  
  
• Hand function is improved as required by:
  
  
  
  • Separating any syndactyly
    
  • Deepening the first webspace
    
  • Thumb reconstruction: opponensplasty, rotation osteotomy or pollicisation.
  
  
• Rotation osteotomy of the humerus improves hand position for some cases of radiohumeral synostosis.

Central deficiency

• Also known as cleft hand.
  
• Historically, cleft hand was divided into typical and atypical types.

Typical cleft hand

• V-shaped cleft in the centre of the hand; one or more digits may be absent.
  
• Often bilateral; frequently involves both the hands and feet.
  
• Family history is common—inheritance is autosomal dominant.
  
• May form part of a syndrome, e.g. split-hand/split-foot, EEC (ectrodactyly, ectodermal dysplasia, facial clefts).
  
• First webspace often narrowed.
  
• ‘Transverse metacarpals’ can further widen the cleft over time.
  
• Phalanges may have longitudinally bracketed epiphyses or duplications.

Classification of typical cleft hand

• The Manske and Halikis classification focuses on the first webspace:
  
  
  
  • Type I: normal web
    
  • Type IIA: mildly narrowed web
    
  • Type IIB: severely narrowed web
    
  • Type III: syndactylised web (first webspace is obliterated)
    
  • Type IV: merged web (index ray suppressed; first webspace merged with the cleft)
    
  • Type V: absent web (thumb elements suppressed; first webspace not present).

Treatment of typical cleft hand

• Patients usually have good hand function.
  
• Labelled ‘a functional triumph, but a social disaster’.
  
• Early surgery may be required to prevent progressive deformity:
  
  
  
  1. To separate syndactyly between unequal digits, especially thumb-index.
     
  2. To remove transverse bones that would worsen the cleft with growth.
  
  
• Other surgery can be postponed until between 1 and 2 years:
  
  
  
  1. Release or reconstruction of the first webspace.
     
  2. Closure of the cleft.
     
     
     
     • Snow-Littler technique: palmar-based flap from the cleft is transposed to the first web.
       
     • Miura and Komada method: simpler—palmar and dorsal flaps are redraped.
       
     • 2nd metacarpal is transferred to the 3rd metacarpal base and secured with K wires.
       
       
       
       • Transposing the 2nd metacarpal at the level of its neck may preserve the adductor pollicis origin from the 3rd metacarpal.
       
       
     • Deep transverse metacarpal ligament is reconstructed using adjacent A1 pulleys, unfolded towards one another.
     
     
  3. Creation of a thumb for cases where it is absent.
     
     
     
     • Pollicisation or, if no radial ray available, free toe transfer.
     
     
  4. Addressing the foot deformity
     
     
     
     • Only indicated when there are difficulties fitting footwear.
       
     • The fibular ray is the most important for weight bearing and gait.
       
     • The tibial toe can usually be transferred to the hand if required.

Atypical cleft hand

• Now known as symbrachydactyly.
  
• Characterised by short vestigial digits, like small nubbins.
  
  
  
  • Often have vestigial nails.
  
  
• May occur with Poland’s syndrome.
  
• Symbrachydactyly, in contrast to central ray deficiency:
  
  
  
  • Is usually unilateral
    
  • Seldom involves the feet
    
  • Is not usually associated with a family history.
  
  
• Its place within Swanson’s classification is controversial.
  
  
  
  • Probably not a longitudinal central ray deficiency.

Classification of symbrachydactyly

• Blauth and Gekeler classify symbrachydactyly into four types:
  
  
  
  • Short finger type—a thumb and four short stiff digits
    
  • Oligodactylic type—central aplasia—the classic ‘atypical cleft hand’
    
  • Monodactylic type—a thumb and four nubbins
    
  • Peromelic type—complete absence of fingers and thumb.

Treatment of symbrachydactyly

• Short finger type usually have excellent function.
  
  
  
  • Some may require syndactyly release or free phalangeal bone transfer.
  
  
• Oligodactylic type achieve pincer grip with thumb and little finger.
  
  
  
  • Metacarpal rotation osteotomy can improve the position of these digits.
  
  
• Some oligodactylic and monodactylic types may be suitable for toe-to-hand transfers if metacarpals and extrinsic tendons are present.
  
• Peromelic type is difficult to reconstruct due to lack of proximal structures.

Intersegmental deficiency

• ‘Phocomelia’ is the historical term for intercalated deficiency of the upper limb.
  
  
  
  • Phocomelia derives from the Greek, meaning ‘seal limb’, i.e. a flipper.
  
  
• The hand is always present.
  
• Prevalent in the 1960s due to the use of thalidomide for hyperemesis gravidarum.
  
  
  
  • Worldwide, thalidomide is still used as an anti-angiogenic drug to treat leprosy and myeloma.
  
  
• Frantz and O’Rahilly classify phocomelia into three types:
  
  
  
  • Type I: complete—the hand is directly attached to the trunk
    
  • Type II: proximal—the forearm and hand are attached to the trunk
    
  • Type III: distal—the hand is attached to the humerus at the elbow.
  
  
• A prosthesis may be required if the hand cannot reach the mouth.
  
• Surgery, usually to stabilise the limb, is rarely indicated.

Syndactyly

• Derived from the Greek, ‘syn’—‘together’ and ‘dactylos’—‘digit’.
  
• May result from failure of apoptosis in interdigital tissue.
  
• Occurs once every 2000 live births.
  
• One of the two most common upper limb malformations, the other being polydactyly.
  
• 20% have a family history (autosomal dominant); 50% are bilateral.
  
• Twice as common in males.
  
• Most common in Caucasian races.
  
• May be associated with other deformities such as Apert’s and Poland’s.

Classification

• Complete—digits fused to the level of the tips.
  
• Incomplete—fusion does not extend to the tips.
  
• Simple—only soft tissue connections between the digits.
  
• Complex—soft tissue and bony connections between the digits.
  
• Complex complicated—associated accessory digits or phalanges within the syndactyly.
  
• Acrosyndactyly—characterised by fused distal parts of the fingers.
  
  
  
  • Small spaces (fenestrations) are always present between the digits proximally.
    
  • Pathogenesis of acrosyndactyly is different from other forms of syndactyly:
    
    
    
    • Distal parts of the digits are thought to re-fuse due to constriction ring syndrome.

Clinical features

• Middle-ring finger web is most commonly affected—58% of cases.
  
  
  
  • 27% ring-little finger web.
    
  • 14% middle-index web.
    
  • 1% thumb-index web.
  
  
• Nail fusion (synonychia) with loss of the paronychial fold suggests synostosis of the distal phalanges.
  
• Associated limb, chest wall and foot abnormalities.
  
• Radiographs may show synostosis, synpolydactyly or other anomalies.
  
• More complex syndactyly is associated with tendon, nerve and vessel anomalies.
  
• Variable vascular anatomy and distal bifurcation of common digital vessels can lead to vascular compromise following separation.

Indications for surgical correction

• Not usually performed before 1 year of age.
  
• Aim to have separation completed by school age.
  
• Indications for earlier surgery, as soon as the child is deemed fit, include:
  
  
  
  • Syndactyly of thumb-index or little-ring fingers.
    
    
    
    • Released early because length discrepancy can cause deformity with growth.

Principles of surgical correction

• Aim to separate the digits, provide a lined commissure, create minimal scarring.
  
• The normal webspace slopes 45° dorsal to palmar and runs from the metacarpal heads to the midpoint of the proximal phalanx.
  
• Most techniques share the following principles:
  
  
  
  • Release only one side of a digit at a time to avoid jeopardising finger vascularity.
    
  • If multiple digits are involved, surgery is staged:
    
    
    
    • First stage: release thumb-index and middle-ring fingers.
      
    • Three months later: release index-middle and ring-little fingers.
    
    
  • The bifurcation of the digital NVB may be distal to the position of the new webspace.
    
    
    
    • Web release is therefore limited to the level of the bifurcation, unless:
      
      
      
      • The other side of the finger is not operated on, allowing the bifurcation to be divided.
        
      • There is definitely a second digital artery to supply the finger.
      
      
    • Alternatively, vein grafts can be used to lengthen the artery.
    
    
  • The nerve can be separated by interfascicular dissection.
    
  • Linear incisions are avoided due to the risk of scar contracture.
    
  • The web is reconstructed with proximally based dorsal or volar flaps.
    
    
    
    • Skin grafts in the web spaces can result in web creep.
    
    
  • Dorsal and volar interdigitating flaps close defects along the borders of the digits.
    
    
    
    • Full thickness skin grafts may be required to resurface residual raw areas.
    
    
  • Mild first web syndactyly can be released with local flaps, e.g. four-flap Z-plasty.
    
  • Severe syndromal syndactyly may require transposition flaps, tissue expansion or distant/free flaps.
    
  • Hyponychial interdigitating flaps, described by Buck-Gramcko, can reconstruct the lateral nail fold.
  
  
• Complications include: vascular compromise, infection, dehiscence, graft loss.
  
  
  
  • The commissure may be pulled distally by scar contraction (web creep).
    
  • Scars may cause joint contracture.
    
  • Joint instability, due to insufficient collateral ligaments.

Camptodactyly

• From the Greek, meaning ‘bent finger’.
  
• Characterised by progressive flexion deformity of the proximal interphalangeal joint (PIPJ).
  
• Often bilateral; most commonly involves the little finger.
  
• Affects <1%.
  
• Virtually anything crossing the volar aspect of the finger may cause camptodactyly.
  
  
  
  • Most commonly an abnormal lumbrical insertion or short flexor digitorum superficialis (FDS).
  
  
• Examining PIPJ extension with the MCPJ alternately flexed and extended can differentiate between intrinsic and extrinsic causes.
  
• Function is rarely affected; treatment is usually sought for the appearance.
  
• Bone and joint abnormalities on x-ray are usually secondary changes rather than the primary cause.

Classification

• Type I: presents during infancy; most common type. Most do not require treatment.
  
• Type II: presents during preadolescence (age 7–11); affects girls more than boys.
  
  
  
  • Often progresses to a severe deformity.
  
  
• Type III: severe type associated with various syndromes.

Treatment

• The majority of cases with contractures <40° are treated conservatively.
  
  
  
  • Involves stretching exercises, splinting and serial casting.
  
  
• Difficult to correct surgically.
  
• Radiological signs that indicate the deformity may be difficult to correct:
  
  
  
  • Narrowing of the joint space
    
  • Indentation of the neck of the proximal phalanx
    
  • Flattening of the head of the proximal phalanx.
  
  
• Surgical options:
  
  
  
  • Exploration and release of any tethering structures.
    
  • FDS tendon transfer to the extensor surface.
    
  • Angulation osteotomy.
    
  • Arthrodesis.

Trigger thumb

• ‘Congenital’ trigger thumb is a misnomer because it is not found in newborns.
  
  
  
  • Also, the thumb does not usually ‘trigger’—it is typically fixed in flexion.
  
  
• Prevalence at 1 year is 3 per 1000; bilateral in up to 30%.
  
• Trigger thumb likely develops with postnatal growth.
  
• Notta’s nodule is always present.
  
  
  
  • May be palpable within flexor pollicis longus (FPL) just proximal to the A1 pulley.
  
  
• Trigger finger is less common than trigger thumb.
  
  
  
  • The pathology may lie at the A1 pulley and/or at the decussation of FDS.

Treatment

• Observation is reasonable under 1 year of age.
  
  
  
  • 30% resolve spontaneously within the first year.
  
  
• Joint contractures do not occur if release is delayed until age 3.
  
• When to operate is agreed between surgeon and parents, considering the risks and benefits.
  
• Surgical treatment involves release of the A1 pulley.

Clasped thumb

• A spectrum of congenital thumb abnormalities ranging from deficiency of thumb extensor mechanism to more severe problems with thenar muscles and first web contracture.
  
  
  
  • Also associated with arthrogryposis.
  
  
• Diagnosis often delayed because infants hold thumbs in their palms for the first 3 months.
  
• Extension lag of the MCPJ differentiates it from trigger thumb.

Treatment

• Goal of treatment is to restore the thumb’s ability to grasp.
  
• Initial treatment is splintage in extension for up to 6 months.
  
  
  
  • Effective when commenced <1 year.
  
  
• Surgery indicated if splintage fails, or the child is older than 2 years.
  
• Adduction contracture requires release of the first web.
  
• Tendon transfers or grafts to the extensor mechanism for severe deformities that remain passively correctable.
  
• Joint fusions for malpositioned fixed deformities.

Arthrogryposis

• From the Greek, meaning ‘curved joint’.
  
  
  
  • Also known as arthrogryposis multiplex congenita.
  
  
• A syndrome of non-progressive joint contractures present at birth.
  
• Spectrum of severity and many different types, including clasped thumb and windblown hand.
  
• Most common types occur sporadically; can be part of Freeman–Sheldon syndrome.
  
• Proposed aetiology is lack of motion during fetal development, leading to joint contractures.
  
  
  
  • Can be caused by neuromuscular abnormalities, restricted intrauterine space, vascular insufficiency or maternal illness.
    
  • There may be reduced numbers of spinal anterior horn cells.

Clinical findings

• Congenital contractures, usually symmetrical and bilateral.
  
• Adduction and internal rotation of the shoulders.
  
• Elbows fixed in extension with pronated forearms.
  
• Wrists flexed with the hand in ulnar deviation.
  
• Flexed and stiff digits.
  
• Lack of subcutaneous tissue and muscle wasting.
  
• Thin, waxy skin with no joint creases.
  
• Lower limb involvement is an important consideration.

Treatment

• Goals of treatment:
  
  
  
  1. Independent function for feeding and perineal care.
     
  2. Maintaining or increasing passive and active motion.
     
  3. Preserving bimanual function.
  
  
• A team approach is required, with the help of adaptive equipment.
  
• Treatment begins early:
  
  
  
  • Dynamic and static splintage.
    
  • Passive stretching and range of motion exercises.
  
  
• Surgical intervention is controversial; indicated for specific functional problems:
  
  
  
  1. Recalcitrant elbow contracture release.
     
  2. Restoration of elbow flexion with muscle transfers.
     
     
     
     • Examples include partial triceps, pectoralis major or free gracilis.
     
     
  3. Distraction lengthening of wrist soft tissues.
     
     
     
     • Dorsal wedge osteotomy of the radius and tendon transfer may allow use of a keyboard.
     
     
  4. Reconstruction of a clasped thumb.

Clinodactyly

• From the Greek, meaning ‘inclined finger’.
  
• Characterised by curvature of a digit in the radio-ulnar plane.
  
• Associated with many syndromes, including 25% of Down’s syndrome.
  
• Most commonly affects the little finger.
  
• Usually turns the fingertip towards the middle finger.
  
• The cause is usually deformity of the middle phalanx—often a triangular shaped delta phalanx.
  
  
  
  • Formed by a J- or C-shaped epiphysis, which extends onto the lateral side of the phalanx.
    
  • Also known as a longitudinal bracketed epiphysis.
  
  
• Growth from the longitudinal arm of the epiphysis results in abnormal lateral growth of the bone.
  
• Kirner’s deformity should not be confused with clinodactyly:
  
  
  
  • Progressive palmar-radial curvature of the distal phalanx, usually the little finger.
    
  • Develops in adolescence; can be inherited or occur sporadically.
    
  • Almost never affects function.

Treatment

• The majority of cases are mild and should be discouraged from surgery.
  
• Surgery considered if function is limited.
  
  
  
  • This should be delayed until skeletal maturity.
  
  
• Wedge osteotomy corrects the angulation.
  
  
  
  • Usually an opening wedge because the finger is often short.
    
  • Exchange wedge osteotomy inserts the wedge excised from the longer side of the phalanx into an opening wedge osteotomy on the shorter side.
  
  
• Soft tissue shortage may require Z-plasty or local flaps.
  
• Resection of the epiphyseal bracket with interposition fat graft was described by Vickers.

Symphalangism

• Congenital fusion of one phalanx to another within the same digit.
  
• Associated with a number of other conditions, including:
  
  
  
  • Syndactyly
    
  • Apert’s syndrome
    
  • Poland’s syndrome
    
  • Radial longitudinal deficiency.
  
  
• Flexion and extension creases over the affected joints are absent.
  
• Radiological changes:
  
  
  
  • Short middle phalanges
    
  • Poorly developed joints and epiphyses.

Treatment

• Managed conservatively with physiotherapy and splintage.
  
• Osteotomy or arthrodesis is considered once skeletally mature.

Synostosis

• Abnormal fusion of two bones.
  
• Can occur at any site where two bones are adjacent to one another.
  
• Synostosis between phalanges occurs in complex syndactyly.
  
• Carpometacarpal, intercarpal and radiocarpal synostosis seldom require surgery.
  
• Radio-ulnar synostosis poses functional problems if both forearms are affected.
  
• Rotational osteotomy through the synostosis is performed around 5 years of age.
  
  
  
  • Aims to fix the dominant limb in 10°–20° pronation and the other midprone.
    
  • Allows eating, writing, bimanual manipulation and perineal care.

Treatment

• Type I: excised under local anaesthetic in the first few weeks of life.
  
  
  
  • Avoids a residual nubbin resulting from simple ligation.
  
  
• Types II and III: surgical excision and reconstruction of soft tissue elements:
  
  
  
  • Attachments of the ulnar collateral ligament (UCL) and abductor digiti minimi (ADM) are transferred to the adjacent finger.

Treatment

• Types I and III: excision with soft tissue reconstruction.
  
• Type II synpolydactyly may share tendons, nerves and vessels with adjacent fingers.
  
  
  
  • The most suitable skeletal and tendinous elements are selected to create the best digit.

Classification

• Wassell’s classification, with prevalence of each type:
  
  
  
  • Type I: bifid distal phalanx (2%)
    
  • Type II: duplicated distal phalanx (15%)
    
  • Type III: bifid proximal phalanx with duplicated distal phalanx (6%)
    
  • Type IV: duplicated proximal and distal phalanx (43%)
    
  • Type V: bifid metacarpal with duplicated proximal and distal phalanx (10%)
    
  • Type VI: duplicated metacarpal, proximal and distal phalanx (4%)
    
  • Type VII: triphalangeal thumb accompanied by a normal thumb (20%).

Surgical correction

• The goal is to create the best thumb possible using parts of each duplicate:
  
  
  
  • A well-aligned thumb with stable joints, balanced motor functions and a cosmetic nailplate.
  
  
• Surgery is usually done at 1 year, prior to development of thumb-index pinch.
  
• In deciding which duplicate to retain, consider:
  
  
  
  • Size—occasionally one is rudimentary.
    
  • Deviation—at the point of duplication or at distal joints.
    
  • Function—can differ between duplicates; functions may be shared.
    
    
    
    • Flexion in one but extension in the other.
    
    
  • Passive mobility—both normal and abnormal.
    
  • Radiological appearances—may reveal a triphalangeal thumb.
  
  
• Surgical options:
  
  
  
  1. Removing one duplicate and reconstructing the other.
     
     
     
     • For types III and IV, or types I and II with significant asymmetry.
       
     • The radial duplicate is usually proximal and smaller than the ulnar.
       
     • Radial collateral ligaments should be reconstructed.
       
       
       
       • Usually by taking a periosteal sleeve from the digit to be amputated.
       
       
     • Intrinsic muscles are reattached in a similar fashion.
       
     • Additional articular facets of the proximal joint surface are excised.
       
       
       
       • Improves angular deformity.
       
       
     • The reconstruction is protected with a transarticular K wire for 4 weeks.
       
     • Principles of treatment are similar for types V and VI.
       
       
       
       • More complex reconstruction of the intrinsics is required.
         
       • In addition, first webspace narrowing may need to be addressed.
     
     
  2. Removing parts of both duplicates and combining the remaining tissue.
     
     
     
     • Symmetric types I and II are treated this way.
       
     • The Bilhaut-Cloquet procedure shares equal parts of each:
       
       
       
       • Remove adjacent inner halves of each duplicate.
         
       • The remaining outer segments are brought together and secured with sutures or K wire.
       
       
     • Problems include nail deformity, epiphysiodesis and joint stiffness.
       
     • Proposed modifications involve unequal sharing of parts:
       
       
       
       • The entire nail bed is taken from one of the duplicates.
         
       • Bone resection preserves the entire physis and joint surface from one of the duplicates.

Triphalangeal thumb polydactyly

• The duplicate has three rather than two phalanges.
  
• Relatively common; usually an autosomal dominant trait.
  
• The extra ‘middle’ phalanx may be:
  
  
  
  1. Triangular (a delta phalanx)
     
  2. Rectangular but short
     
  3. Rectangular and normal length.
  
  
• Treatment follows the principles above.
  
• If the triphalangeal duplicate is retained, the extra interphalangeal joint (IPJ) must be addressed:
  
  
  
  • Any delta phalanx is excised and soft tissues reconstructed.
    
  • If the extra phalanx is rectangular—chondrodesis of the least mobile joint.

Treatment

• Passive stretching and mobilisation of the elbow.
  
• Fabrication of a first webspace.
  
• Pollicisation and reducing the number of fingers.
  
• It is a rarely performed operation, even for congenital hand specialists.

Classification

1. Static macrodactyly: the enlarged finger grows in proportion to the rest of the hand.
   
2. Progressive macrodactyly: the enlarged finger grows out of proportion to the rest of the hand.

• Flatt classifies macrodactyly according to the pathology:
  
  
  
  • Type I: Lipofibromatosis
    
    
    
    • Epineural and perineural fibrosis with fatty infiltration of the nerve.
    
    
  • Type II: Neurofibromatosis
    
    
    
    • Occurs in conjunction with plexiform neurofibromatosis.
    
    
  • Type III: Digital hyperostosis
    
    
    
    1. Osteochondral periarticular nodules but no nerve enlargement.
    
    
  • Type IV: Hemihypertrophy
    
    
    
    • Commonly known as Proteus syndrome.

Surgical correction

• Complicated by delayed healing due to relative vascular insufficiency (vessels are rarely enlarged).
  
• Surgical options are usually inadequate:
  
  
  
  • Soft tissue reduction, including digital nerve stripping
    
  • Osteotomy
    
  • Epiphysiodesis
    
  • Amputation.

Classification

• Blauth’s classification has been modified into five groups:
  
  
  
  • Type I
    
    
    
    • Minor generalised hypoplasia.
    
    
  • Type II
    
    
    
    • Hypoplastic thenar muscles.
      
    • Adduction contracture of the first web.
      
    • Insufficiency of the UCL at the MCPJ.
    
    
  • Type III
    
    
    
    • Features of type II plus abnormal extrinsic tendons.
      
    • Skeletal abnormalities further subclassify type III (Manske et al.):
      
      
      
      • A: stable carpometacarpal joint (CMCJ)
        
      • B: unstable CMCJ.
    
    
  • Type IV
    
    
    
    • Small thumb attached to the hand by a soft tissue bridge.
      
    • Known as a floating thumb or ‘pouce flottant’.
    
    
  • Type V
    
    
    
    • Total absence of the thumb.

Surgical correction

• Usually done at 1–2 years when thumb function is developing.
  
• Type I: good function; do not require surgery.
  
• Type IIIB, IV and V: ablation of any thumb elements and pollicisation.
  
  
  
  • Pollicisation is described under ‘Radial deficiency’.
  
  
• Type II and IIIA are reconstructed as follows:
  
  
  
  1. First webspace release with, e.g. four-flap Z-plasty.
     
     
     
     • May require release of the first dorsal interosseous from the second metacarpal.
     
     
  2. UCL reconstruction.
     
     
     
     • UCL deficiency may be primary or secondary to a pollex abductus.
       
       
       
       • This is an abnormal connection between FPL and EPL.
       
       
     • Any pollex abductus is released and the MCPJ stabilised:
       
       
       
       • Chondrodesis (joint fusion), or
         
       • Tendon graft to augment the vestigial UCL, or
         
       • UCL reconstruction incorporated into an FDS opponensplasty.
     
     
  3. Opponensplasty to augment hypoplastic thenar muscle function.
     
     
     
     • Using the ring finger FDS is favoured by many due to its length, power and ability to reconstruct the UCL.
       
     • Others prefer the Huber transfer (ADM to APB).
     
     
  4. Extrinsic tendon reconstruction.
     
     
     
     • EIP can be transferred to EPL.
       
     • Reconstructing FPL may need pulley reconstruction in addition to tendon transfer.

Treatment

• Surgery is seldom required—function is relatively well preserved.
  
  
  
  • Surgery frequently produces stiff fingers.
  
  
• Brachymetacarpia may be corrected by distraction osteogenesis to restore normal cascade.

Treatment

• No treatment is required for painless deformities.
  
• Surgery may involve:
  
  
  
  1. Resection of Vickers’ ligament and dome osteotomy to correct the radius.
     
  2. Closing wedge osteotomy of the radius with ulnar shortening.
     
  3. Opening wedge osteotomy of the radius.
     
  4. Osteotomy of the radius and distal ulnar resection.
     
  5. Osteotomy of the radius and a Sauvé–Kapandji procedure.
     
     
     
     • This fuses the distal radio-ulnar joint (DRUJ) and resects a segment of ulna to allow forearm rotation.