Peds

Question 1

Leg Length Discrepancy

Answer 1

Congenital

• Part of limb - DDH, Coxa vara , PFFD, Hemimelia, Club foot
• whole limb
  
  • Hemihypertrophy (asymmetry is more than 5% )
  • NF, Klippel Trenauney , Beckwith Wiedmann, Proteus

atrophy

• Acquired
  
  • Inflammatory - JRA
  • Spasctic - CP, AMC
  • Physis - Infection, tumor, trauma , NF

Apparent

• Flexion adduction contracture
• Fixed pelvic obliquity - Scoliosis,

Question 2

Three types of tibial bowing exist in children

• anterolateral bowing (neurofibromatosis)
• posteromedial bowing (physiologic)
• anteromedial bowing ( Fibular hemimelia)

Answer 2

Associated conditions

• anteromedial tibial bowing - most common cause is fibular hemimelia
• ankle instability - secondary to a ball and socket ankle
• talipes equinovalgus
• tarsal coalition (50%)
• absent lateral rays
• femoral abnormalities (PFFD, coxa vara)
• developmental dysplasia of the hip
• cruciate ligament deficiency
• genu valgum- secondary to lateral femoral condyle hypoplasia
• significant leg length discrepancy
• shortening of femur and/or tibia

Goals -

• treatment determined by the stability and level of foot and ankle function, as well as the degree of limb shortening
• not based on amount of fibula present

Question 3

Bowing -

AL - NF 1 ( 10%)

Crawford classification - CT based classification ]

1. Thickening of the cortex
2. Thinning of canal - susceptible for fracture - Prophylactic - bracing, total contact and pinning
3. Cyst
4. Frank pseudoarthrosis - free fibular bone graft Chanley-Williams Rod

Two classification criteria have been proposed to guide treatment:

• The presence or absence of fracture
• The age at which fracture occurs
  
  • Early onset” < 4 years old
  • Late onset” > 4 years old

Answer 3

Surgical fixation

• goals
  
  • resection of pseudarthrosis to grossly normal bone
  • correction of alignment
  • bone grafting and stabilization of the remaining segments
  • intramedullary splinting of the bone is desired

techniques

• intramedullary nailing with bone grafting
• Resect the pseudarthrosis
• Tibial shortening
• Fixation with intramedullary rodBone graft
• free vascularized fibular graft (Farmer’s Procedure)
• the contralateral fibula is used, ipsilateral is involved in pseudarthrosis
• Ilizarov or circular frame fixation with lengthening or bone transport

Question 4

bilateral Perthes: (requires skeletal survey as part of work up);

• hypothyroidism
• multiple epiphyseal dyspasia
• spondyloepiphyseal dysplasia tarda
• sickle cell

-

Answer 4

unilateral Perthes:

• septic arthritis
• • sickle cell
• • spondyloepiphyseal dysplasia tarda
• • gaucher’s disease
• • eosinophilic granuloma
• • transient synovitis

Question 5

Radial Clubhand (radial deficiency). - Sonic Hedge hog gene

Bayne and Klug Classification

Type I Deficient distal radial epiphysis

Type II Deficient distal and proximal radial epiphyses

Type III. Present proximally (partial aplasia)

Type IV Completely absent (total aplasia - most common)

Answer 5

Associated with

• TAR. -
  
  • autosomal recessive condition with thrombocytopenia and absent radius
  • different in that thumb is typically present
• Fanconi’s anemia
  
  • autosomal recessive condition with aplastic anemia
  • Fanconi screen and chromosomal breakage test to screen
  • treatment is bone marrow transplant
• Holt-Oram syndrome
  
  • autosomal dominant condition characterized by cardiac defects
• VACTERL Syndrome
  
  • vertebral anomalies, anal atresia, cardiac abnormalities, tracheoesophageal fistula, renal agenesis, and limb defects)
• VATER Syndrome
  
  • vertebral anomalies, anal atresia, tracheoesophageal fistula, esophageal atresia, renal agenesis)

Question 6

Blauth classification

Answer 6

1. Type I Minor hypoplasia
   
   • All musculoskeletal and neurovascular components of the digit are present, just small in size
2. Type II All of the osseous structures are present (may be small)
   
   1. MCP joint ulnar collateral ligament instability Thenar hypoplasia
3. Type IIIA

Musculotendinous and osseous deficiencies

CMC joint intact

Absence of active motion at the MCP or IP joint

4. Type IIIB

Musculotendinous and osseous deficiencies.

Basal metacarpal aplasia with deficient CMC joint

Absence of active motion at the MCP or IP joint.

5. Type IV

Floating thumb

Attachment to the hand by the skin and digital neurovascular structures

6. Type V

Complete absence of the thumb

Question 7

Common causes of LLD

• congenital disorders
  
  • hemihypertrophy
  • dysplasias
  • PFFD
  • DDH
  • unilateral clubfoot
• paralytic disorders
  
  • spasticity (cerebral palsy)
  • polio
• physis disruption
  
  • infection
  • trauma
  • tumor

Answer 7

• General assumptions
  
  • growth continues until 16 yrs in boys and until 14 yrs in girls
• Methods to project LLD at maturity
  
  • Mosley graph
    
    • estimation technique leg grows 23 mm/year, with most of that coming from the knee (15 mm/yr)
    • proximal femur - 3 mm / yr (1/8 in)
    • distal femur - 9 mm / yr (3/8 in)
    • proximal tibia - 6 mm / yr (1/4 in)
    • distal tibia - 5 mm / yr (3/16 in)
• Can be tracked
  
  • Green-Anderson tables uses extremity length for a given age
  • Moseley straight line graph
    
    • improves on Green-Anderson method by reformatting data in a graph form
    • accounts for differences between skeletal and chronologic age
    • minimizes error
    • averages serial measurements
• Multiplier method
  
  • prediction based on multiplying the current discrepancy by a sex and age specific factor
  • most accurate for congenital LLD
  • 1/2 of final leg length
  • girls at age 3
  • boys at age 4

Question 8

LLD Assessment

Answer 8

Predicted LLD at skeletal maturity - 4 types ( MEGA)

• Multiplier ( Paley) - App
• Eastwood Cole - Graphs look at different time point
• Growth remaining ( Moseley / Green Anderson )
• Arithmetic ( Menelaus) - Two assumption
  
  • Girls 14, Boys 16
  • Most growing occurs from knee
  • 15 mm – 9 mm distal femur and 6 mm from proximal tibia