Apert Syndrome, Constriction Band Syndrome, Postaxial Polydactyly & Camptodactyly

Apert Syndrome

Essential Information
The complex osseous-syndactyly of Apert syndrome represents a severe type of fused digits.  Eugene Apert, a French physician, described the first cases of acrocephalosyndactyly syndrome in 1906.i

Etiology
  • Apert syndrome is classified as a branchial arch syndrome and
  • Aberrancy of the fibroblast growth factor receptor-2 (FGF-2)
    • Causes premature fusion of growth plates
    • Has the potential to suppress the selective apoptosis needed for separation of the digits
Genetics
  • The syndrome is caused by a mutation in the gene encoding fibroblast growth factor receptor-2.
  • Most cases are sporadic, but autosomal dominant inheritance has also been reported.ii
Incidence
  • The prevalence of Apert syndrome ranges from 7.6 to 22.3 per million live births
  • Male to female ratio of 1.5 : 1
 
Clinical Evaluation:
History / Exam Findings
  • The syndrome is characterized as a combination of:
    • Acrosyndactyly = Fusion of the digits occurs distally, w/ proximal fenestrations
    • Symphalangism = Ankylosis/Fusion of IP joints
    • Often radial clinodactyly of the thumb = Curvature of a digit
  • Other broader clinical features of Apert syndrome include craniosynostosis, hyperhidrosis, decreased eyesight and hearing, strabismus and impairment in language development and motor skills.  
Imaging / Lab Studies
  • X-rays should always be obtained
Classification Schemes
  • Upton has classified the Apert syndrome hand into type I, II, and III to guide decision-making.iii
    • Type I hand, “spade” hand:  There is a radially deviated small thumb with a shallow first web. The index, long, and ring fingers display complete or complex syndactyly. The little finger is attached by a simple complete or incomplete syndactyly
    • Type II hand, “mitten” or “spoon” hand: The thumb is radially deviated and has an incomplete or complete simple syndactyly with the index. The index, long, and ring fingers are distally fused, creating a curve in the palm with divergent metacarpals. The little finger is attached to the ring with a mostly complete but simple syndactyly. 
    • Type III hand, “rosebud” hand:  The thumb, index, long, and ring are distally fused either cartilaginous or bony attachments. The thumb can be very difficult to identify separately from the index. The little finger is united to the ring by simple complete syndactyly. The nails can be confluent.  Proximal synostosis at the base of the fourth to fifth metacarpal can be present, as well as carpal fusions.
 
Treatment:
  • The goals of surgical treatment are centered around three things:
    • Separation of digits, including the thumb
    • Correction of thumb function
    • Mobilization of the little finger
  • The ultimate objective is to create a more useful extremity with the ability to grip or perform pincer grasp in as few operations as possible.
  • Staged reconstruction:iv
    • A well separated thumb is crucial and therefore deepening or creation of the 1st web space is often the first step in surgical treatment. 
      • The exact method behind this is variable and can involve a 4-5 limb Z-plasty or dorsal skin graft. 
    • The second stage often involves creation of the 4th web space followed by separation of the remaining digits.
    • If present, proximal metacarpal synostosis should also be separated early to improve mobility of the fifth ray
Outcomes:
  • Prognosis
    • Hand function and prognosis is best with the combination of thumb and little finger separation. 
      • Thus, allowing a tripod pinch and thumb based grip.
    • Movement of the fingers is typically isolated to the metacarpal phalangeal joints.
  • Potential Complications
  • Complications with the surgical treatment of Apert’s syndrome are common.v
    • The need for revision surgery of web space contracture varies among authors from 3–18%. 
    • Barot and Caplan report a 22% incidence of partial skin graft loss.
  • Aberrant growth plates can cause clinodactyly after separation and osteotomies may be needed later on.

References
[i] Apert ME. De l’acrocephalosyndactylie. Bull Soc Med Hop. 1906;23:1310–1313. 
 

[ii] Lajeunie E, Cameron R, El Ghouzzi V, et al. Clinical variability in patients with Apert’s syndrome. J Neurosurg. 1999;90(3):443–447. 
 

[iii] Upton J. Apert syndrome. Classification and pathologic anatomy of limb anomalies. Clin Plast Surg. 1991; 18(2):321–355. 
 

[iv] Guero SJ. Algorithm for treatment of Apert hand. Tech Hand Up Extrem Surg. 2005;9(3):126–133. 
 

[v] Barot LR, Caplan HS. Early surgical intervention in Apert’s syndactyly. Plast Reconstr Surg. 1986;77(2): 282–287. 

 

Constriction Band Syndrome

Essential Information
Constriction band syndrome refers to a highly variable spectrum of anomalies that occur in association with amniotic bands and result in the deformity or disruption of the developing limp in utero.
 
Etiology
  • Intrinsic Theory: 
    • Abnormality in the differentiation and development of the germplasm
    • Teratogenic exposure, vascular insult, viral infection
  • Extrinsic Theory:
    • Amniotic rupture in which floating strands entangle, constrict, deform and possibly amputate affected parts of limbs 
  • Level of involvement may depend upon the timing of the disruption
 
Genetics
  • No genetic/hereditary predisposition
 
Incidence
  • 1:1,200 to 1:15,000 live births
  • Males and females are equally affected
 
Risk Factors
  • Associated conditions have been noted between 60-80% of patients
  • Syndactly, hypoplastic digits, camptodactyly and brachydactyly
  • Other less common conditions include cleft lip, cleft palate, clubfoot and craniofacial defects
 
Clinical Evaluation:
History / Exam Findings
  • Clinical manifestations range widely from subtle dimpling to complete amputations
  • Bands are almost always transverse to the axis of the digit or limb
  • Central digits are more often affected than border digits
  • The majority of bands affect the digits followed by the forearm and then brachium. 
 
Imaging / Lab Studies
  • Plain radiographs to delineate bone morphology
 
Classification Schemes
  • Patterson
    • Type I: Superficial skin involvement
    • Type II: Distal deformity or lymphedema
    • Type III: Associated acrosyndactyly
    • Type IV: Congenital amputations
 
Treatment:
  • Release of the constrictions
    • Simple bands may be excised with Z-plasty flaps in series or rotational flaps
  • Separation of the fenestrated syndactyly
    • Partial fusions should be separated early to prevent worsening deformity
    • Reconstruction of the interdigital spaces can be staged
  • Treatment of the amputated digits
    • Surgical procedures are typically not required unless it involves the thumb
    • First web space deepening
    • Thumb reconstruction by elongation, digital transfer or toe transfer
 
Outcomes:
  • Prognosis
    • Usually patients adapt well
    • May function as “assist hand” depending on the severity and level of the deformity
  • Potential Complications
    • Vascular compromise can be severe if not caught early and constriction band released
    • Lymphedema distal to the constriction band
    • Other complications are related to specific surgical procedures
 
 
References
1. Light TR and Ogden JA. Congenital constriction band syndrome. Pathophysiology and treatment. Yale J Biol Med. 1993 May-Jun; 66(3): 143–155.
2.  Patterson, TJ. Congenital ring-constrictions. BR J Plast Surg. 1961;14:1-31
3. Miura T. Congenital constriction band syndrome. J Hand Surg Am. 1984;9:82–88. 
4. Tada K, Yonenobu K, Swanson AB. Congenital constriction band syndrome. J Pediatric Orthop. 1984;4:726-730

 

Postaxial Polydactyly

Essential Information
Polydactyly is a disorder in which patients have more than five digits on one or more extremities. Postaxial polydactyly is characterized by an extranumerary digit specifically on the ulnar border of the hand. The term polydactyly is first described by Kerckring in 1670.
Etiology

  • Exact etiology unknown,
Genetics
  • Autosomal dominant with incomplete penetrance and variable expressivity
  • Mutations on Chromosome 19, 13 and 7 including abnormalities in the Gli3 gene
Incidence
  • The incidence can range from 2% to 30% when considering all types of polydactylies 
  • 1:1400 births (Caucasians)
  • 1:150 births (African heritage)
  • Twice as common in males
Risk Factors
  • Common associated syndromes: Bardet-Biedl, Smith-Lemi-Opitz, Trisomy 13, Greig syndrome
  • Can be Associated with syndactyly and polydactyly of the feet
  • Ulnar polydactyly is often bilateral
 
Clinical Evaluation:
History / Exam Findings
  • Examination should begin from proximal to distal and careful attention should be paid to hypothenar musculature, creases, joint mobility,
    • The most common presentation is a small pedicle digit attached along the ulnar border of proximal phalanx
    • Usually a neurovascular bundle is present
    • Flexor tendons and extensor tendons are usually bifurcated and asymmetric
  • Functional impairment from minimal to severe
Imaging / Lab Studies
  • X-rays are typically obtained to assess bony involvement
Classification Schemes
  • The International Federation of Societies for Surgery of the Hand: Group III
  • Temtamy and McKusick:
    • Type A: Extra little finger at the MCPJ or CMCJ.  Can be hypoplastic or fully developed
    • Type B: Pedicled nubbin or nonfunctional little finger
Treatment:
  • Typically treated surgically for both aesthetic and functional reasons
  • Timing
    • Pedicle/floating digits can be removed shortly after birth in the nursery
    • Type A and more developed digits are removed after the first year of life
  • Although not as commonly needed for ulnar polydactyly the thought process should include adjusting skin coverage, aligning articular surfaces, performing ligament reconstructions, and balancing tendon insertions
Outcomes:
  • Prognosis
    • Definitive outcome can only be assessed after growth has been completed
  • Potential Complications
    • Follow patients for nail deformities, movement and stability of joints, and appearance of the skin.
 
 
References
1. Biesecker LG. Polydactyly: how many disorders and how many genes? Am J Med Genet. 2002;112(3): 279–283.
2. Upton J. Disorders of duplication. In: Mathes SJ, ed. Plastic surgery. 2nd ed. Philadelphia: Saunders Elsevier; 2006:215–228.
3. Swanson AB, Swanson GD, Tada K. A classification for congenital limb malformation. J Hand Surg Am. 1983;8(5 Pt 2):693–702.


 

Camptodactyly

Essential Information
Camptodactyly describes a contracture of the PIPJ in the anteroposterior direction.
The term camptodactyly was first used by Landouzy in 1906. Campylo = arched and Dactylos = finger
 
Etiology

  • A consequence of anatomical imbalance between the extrinsics and anomalous insertion of intrinsics to the affected finger
    • Primary etiology: Anomalous lumbrical insertion to the superficial flexor 
    • Secondary etiology: “Parrot beak” deformation of the articulating bones with a stiff joint and deficient skin on the palmar side leading to contracture. 
Genetics
  • About 30% of cases have a familial background and can be inherited in an autosomal dominant pattern
  • The remaining cases are sporadic
Prevalence
  • < 1% of the population
Risk Factors
  • Common associated syndromes: Arthrogryposis, CACP arthropathy, Holt–Oram syndrome and Poland syndrome 
Clinical Evaluation:
History / Exam Findings
  • The fifth finger is the most affected (>70%), followed by the fourth finger (<20%). 
  •  The physical exam:
    • Can the PIPJ be actively extended?
    • Does skin blanching occur in max extension?
    • Does the PIPJ flex and extend passively by tenodesis effect?
    • Is the FDS of the small finger independent of the fourth finger?
Imaging / Lab Studies
  • X-rays are typically obtained to assess bony involvement and deformity
Classification Schemes
  • Foucher et al. recognized four conditions:
    • Type IA: The early and stiff
    • Type IB: the early and correctable camptodactylies
    • Type IIA: the late and stiff
    • Type IIB: the late and correctable deformities. 
Treatment:
  • Functional defect is mostly limited and therefore appearance is often the main the concern 
Non-Operative
  • A splint is applied for all cases in which the PIPJ is not supple
  • Reduction to <30° extension lag is the goal
  •  3 to 24 month period of splinting
Surgical
  • > 60° that is unresponsive to stretching/splinting
  • Interferes with grasp or pinch, progressive in children younger than 5 years old
  • Correctable PIPJ:
    • Skin and fibrous bands release +/- FDS transfer to lateral band
  • Non correctable PIPJ:
    • Extensive skin release (Malek flap), checkreins, accessory ligament +/- palmar plate
    • FDS tendon transfer to lateral or central band
    • +/- corrective osteotomy
  • +/- K-wire fixation in extension 2-4 weeks
Outcomes:
  • Prognosis
    • Splinting of the stiff PIPJ results in 80–92% improvement rate
    • Results vary but can correct up to 40 degrees
    • If no satisfactory improvement with splinting, surgical improvement rates vary widely and range from 14% to 88%
  • Potential Complications
    • Extension lag of the PIPJ
    • Digital ischemia
    • Osteoarthritis, recurrence of contracture, stiffness and pain. 
 
References:
1. Smith PJ, Grobbelaar AO. Camptodactyly: a unifying theory and approach to surgical treatment. J Hand Surg Am. 1998;23(1):14–19. 
2. Foucher G, Lorea P, Khouri RK, et al. Camptodactyly as a spectrum of congenital deficiencies: a treatment algorithm based on clinical examination. Plast Reconstr Surg. 2006;117(6):1897–1905. 
3. Hori M, Nakamura R, Inoue G, et al. Nonoperative treatment of camptodactyly. J Hand Surg Am. 1987;12(6):1061–1065. 

 
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