SLIP CAPITAL FEMORAL EPIPHYSIS (SCFE)

02 Dec SLIP CAPITAL FEMORAL EPIPHYSIS (SCFE)

EPIDEMIOLOGY

• SCFE is a slippage oft he femoral neck epiphysis anteriorly and externally rotated through hypertrophic zone of physics.
• commonly seen in adolescent obese male
• Diagnosis can be confirmed with radiograph
• Treatment is usually in situ fixation
• RISK FACTORES
  • Male to female 3:2
  • Obese
  • Rapid growth period
  • African American
  • Acetabular retroversion and femoral retroversion
  • age 10-14 yrs
  • incidence – 1:1000
• Contralateral pinning (JBJS 1996 Stasikelis et al retrospective review)
  • Southwick angle > 50%
  • obese male
  • endocrine problem
  • age < 10 yrs
  • Chronic renal insufficiency
  • Poor patient compliance
• Aetiology
  • idiopathic
  • endocrine – Hypothyroidism, hypogonadism
  • Mechanical/Anatomical thinning of perichondria ring

Clinical presentation

• Knee pain in a child is from hip until proved otherwise
• Out toe gait
• loss of hip internal rotation, abduction and flexion.
• Most commonly atraumatic
• Pain in hip, groin and thigh. Knee pain in 50% of patients due to medial obturator nerve
• symptoms are present for over weeks to months
• on examination there will be limp and abnormal gait( externally rotated or trendelenburg gait)
• Drehmanns sign- obligatory external rotation of the hip

Imaging and investigation

• X-ray hip in AP and Lateral view
  • klines line will intersect less of femoral head or not at all( Trethowans sign)
  • S sign
  • epiphysiolysis growth plate widening
  • decreased epiphyseal height
  • capers sign entire epiphysis id lateral to the posterior acetabular margin
  • Metaphysical blanch sign of steel – crescent shaped area of increased density overlying metaphysics adjacent to physics on ap xray due to superimposition of femoral neck and posteriorly displaced capital epiphysis
• USG 95% sensitive
• MRI gold standard. may help diagnose pre slip stage
• CT in case of severe deformity
• Blood investigation in case of pre-pubertal, short height, weight below 50th percentile and age <10
  • TSH
  • Free t4
  • urea
  • createnine

Classification

• Loders (JBJS Am 1993)
  • Stable – able to weight bear with or without crutch (AVN chances <10% , 96% good results with pinning)
  • Unstable – unable to weight bear at all( AVN chances 40-50%)
• Wilsons
  • 1- < 33% of metaphysics uncovered
  • 2- 33-50%
  • 3- > 50%
• Southwick
  • for grading of slip in frog leg lateral view by subtracting the normal side from abnormal side between shaft and epiphysis in AP and lateral view9 AP 145 normal, Lateral 10 normal)
  • mild ,30 degree
  • moderate 30-50 degree
  • severe > 50 degree

Management

• prevent progression f the slip and help promote further growth go hip.
• Pinning in situ
  • avoid forceful reduction as the AVN risk increases
  • Triangulation- trajectory in two planes
  • one 6.5 mm cannulated screw
  • perpendicular to epiphysis
  • 5 mm from subchondral bone
  • 3 to 5 threads into epiphysis
  • remove screw when epiphysis closes
  • toe touch weight bearing for 6 weeks
  • follow up until physical closure
• Severe acute slip Philip et al JBJS Br 2001
  • risk of AVN increases after 24 hrs of presentation so safer too convert to chronic slip and then manage after a period of traction
  • 2015 bone and joint J open reduction(AVN RISK 33%) has better outcome than closed reduction(AVN RISK 80)
  • Proximal femoral osteotomy
    • neck shortening osteotomy(DUNN)
    • CERVICO TROCHANTERIC FLEXION DEROTATION OSTEOTOMY(SOUTHWICK/IMHAUSTER).