Transcript Slipped Capital Femoral Epiphysis

Slipped Capital Femoral
Epiphysis
Introduction

SCFE = misnomer
neck displaces relative to the epiphysis
 Usually, upward & anterior of neck
 Rapid growth, weakening of physis, shearing
stresses

Femoral head in contact
with acetabulum
 Femoral shaft and neck
rotate externally
 Head moves posteriorly
 Neck moves cephalad
Historical Perspective

? Pare 1572 first described SCFE
 ? Muller 1889
Schenkelhalsverbiegungen im Jungesalter
“bending of the femoral neck in adolescence”

Whitman 1909 osteotomies
 Boyd 1949 stabilization with pins
Incidence/Epidemiology

Varies according to race, sex, geography
 Estimated 2 per 100,000
 Males > females
left > right
 During adolescence, @ max skeletal growth
boys 13-15 years, avg 14
girls 11-13 years, avg 12

Bilateral 17-80% reported
most studies show 20-25%
Classification

Temporally, according to onset
acute, acute-on-chronic, chronic

Functionally, according to ability to WB
stable, unstable
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Morphologically, according to extent of displacement
Temporal Classification
Acute

Sudden, dramatic, fracture-like episode
 Prodromal symptoms for 3 weeks or less
 Trauma too trivial to cause SH1
 X-rays- little or no neck remodeling
 AVN frequent, 17-47%
**R/O true Salter-Harris Type 1**
Temporal Classification
Chronic

Most frequent form
 Few months of vague groin/thigh pain, limp
 X-rays- remodeling of neck
 Can be missed as symptoms as often minor
Temporal Classification
Acute-on-chronic

Prodrome for > 3 months with sudden
exacerbation of pain
 X-rays- displacement beyond remodeling
Functional Classification

Stable
able to WB on presentation
 Unstable
not able to WB
 Preferred classification
 Clinically meaningful
different prognosis
Morphologic Classification
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
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Degree of displacement of epiphysis on neck
Southwick femoral head-shaft angle
mild < 30°
moderate 30-60°
severe > 60°
(normal 145° on AP)
CT more accurate, not routinely used
Etiology

Often unknown
 Majority are normal by current endocrine
work-up

Endocrine
 Mechanical
Etiology
Mechanical Factors

Predisposing features:
-thinning of perichondral ring complex
-retroversion of femoral neck
-change in inclination of prox femoral
physis relative to femoral neck/shaft

Blount’s disease, peroneal spastic flatfoot, LeggCalve-Perthes disease
Etiology
Mechanical Factors
1) Perichondral Ring Thinning

Fibrous band that encircles physis at cartilagebone interface
 Acts as limiting membrane, mechanical
support to physis
 Thins rapidly with maturation  strength
Etiology
Mechanical Factors
2) Retroversion of Femoral Neck

Relative or femoral retroversion
 ? Physis more susceptible to AP shearing
forces
3) Inclination

Increased slope of proximal femoral physis on
both affected and non-affected sides
Etiology
Endocrine Factors

Long suspected
 Obesity, hypogonadal males (adiposogenital
syndrome), growth spurt
 No screening unless clinical suspicion
 Known association with:
-hypothyroidism (treated or not)
-conditions with GH administration
-CRF

Prev pelvic XRT, Rubinstein-Taybi syndrome,
Klinefelter’s syndrome, 1° hyperparathyroidism,
panhypopituitism assoc with intrancranial tumours
Etiology
Endocrine Factors

Hypothyroidism
prior to or during Rx
 GH deficiency
during or after Rx

Bilateral slips….prophylactic pinning should
be strongly considered
Endocrine Factors
CRF


Thought to be due to uncontrolled 2°
hyperparathyroidism
Goal of Rx: control hyperparathyroidism
within 2/12 of slip sx
If not successful  surgical Rx
 Monitor until skeletal maturity due to high
incidence of slip progression
Pathology

Do not support or exclude endocrine or
mechanical etiologic actors
 ? Changes 2° physeal disruption or endocrine
influence
Weiss & Sponseller 1990
Normal iliac crest physeal Bx in pts with SCFE
Pathology
Gross

Periosteum stripped from ant/inf surface of
femoral neck
 Area btw neck & post periosteum fills with
callus & ossifies
 Anterosuperior neck forms “hump”, can
impinge on acetabular rim (remodel)
Acute slips will have hemarthrosis
Pathology
Microscopic

Howorth 1949 169 slips treated open
“Preslip” stage
-widened physis without displacement
-edematous synovial membrane,
periosteum, capsule
 Thicker proliferative & hypertrophic zones
- chondrocytes, organized in clumps
Clinical Picture
Stable SCFE
History
 vague or dull pain (groin, anteromedial thigh, knee)
 Exacerbated by activity
 Weeks to months
Physical Exam
 Antalgic limp with  ER
 Thigh atrophy
  hip ROM- loss of IR,ABD, flexion
 Obligate ER with flexion, pain at extreme IR
 Hip flexion contracture (chondrolysis)
 No strenuous maneuvers, i.e. hopping/squatting
Clinical Picture
Unstable SCFE
History
 Sudden onset of severe pain
 Minor fall or twisting injury
Physical Exam
 Held in ER
 Refusal to move hip
 Moderate shortening
**Always examine hips in any child with knee pain
 Matava et al. (1999) 106 slips
15% knee/distal thigh pain only

Carney (1991) 46% distal thigh/knee as only
presenting complaint
**Always examine/x-ray contralateral side
20% have evidence on initial presentation
Diagnostic Imaging
Plain Radiographs

Often only imaging needed
 Earliest sign = physeal widening/irregularity
 Klein’s Lien (AP)
- line tangential to superior femoral neck
will intersect lateralmost portion
- with SCFE,  overlap or none =Trethowan’s
sign
 Steel’s metaphyseal blanch sign (AP)
crescent-shaped area of density
Metaphyseal blanching
Diagnostic Imaging

CT
-useful in mgmt
-confirm physeal closure
-severity of deformity
 MRI
-detection of AVN
 Bone Scan
- uptake for AVN
- uptake both sides for chondrolysis
Treatment

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Goal: stabilize the epiphysis to the femoral neck to
prevent further slippage
In situ fixation/pinning
Bone graft epiphysiodesis
Primary osteotomy
Spica Cast
Treatment Choice depends on type pf slip, severity,
surgeon preference
Treatment
Initial Management

To radiology in wheelchair or stretcher
 **Identify unstable slips**
 Do not attempt frog-leg lateral in unstable
slips
 Admit with strict bedrest, until definitive Rx
Treatment
Stable SCFE
In Situ Pinning/Fixation
 Many different philosophies
number/type of implant, physeal closure, position
of screws
 Current standard: one cannulated screw into
femoral epiphysis from base of anterior neck for
stable slips.
Two screws considered for unstable slips
(additional stability, rotational control)
In Situ Fixation

Fracture table
 Avoid excessive IR & manipulation
 Guide-wire for screw placement
 Ideal placement of screw is as close to centre of
epiphysis & as  to physis as possible
**epiphysis is posterior, entry point must be at
base of neck and screw directed posteriorly into
centre
Avoid posterior femoral neck
In Situ Fixation
In Situ Fixation
Post-operative Management

Protected partial weight-bearing with
crutches for 6 weeks
 No sports for 3 months
 Clinical exam + x-rays every 3-6 months
until skeletal maturity
In Situ Fixation
Advantages
 Minimal scarring
 No need to manipulate limb during surgery
Disadvantages
 Difficult lateral view
 Difficult guidewire placement if obese
 Screw-related complications
perforation into joint, loss of fixation, failure,
Bone Graft Epiphysiodesis

Portion of residual physis is removed by drilling
and curettage
 Dowel or “peg” of autologous bone graft inserted
across femoral neck
 Supplementary internal fixation or cast for
unstable slips
Indications
 Stable slip that has progressed despite fixation
 Severe slip
Bone Graft Epiphysiodesis
Bone Graft Epiphysiodesis
Primary Osteotomy
Goals:
 Correct symptomatic loss of motion, esp.
flexion and IR
 Improve biomechanics for healing
 Improve longevity of the hip
Primary Osteotomy
Dunn Procedure

Anterosuperior wedge of superior femoral
neck, including residual physis
 Femoral epiphysis is reduced on neck
without tension
 Secured with screws or pins

Best anatomic restoration
 High risk of AVN
Primary Osteotomy
Base-of Neck


Kramer & Barmada
Expose neck intra or extracapsularly
Anterosuperiorly based wedge from base of neck
Apex of wedge may be extracapsular posteriorly
Reduction and punning as in Dunn

Lower AVN risk
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Primary Osteotomy
Intertrochanteric

Southwick
 Based on head-shaft angle
 Anterolaterally based intertrochanteric
wedge
 Corrects extension/varus deformity by
flexion/abduction of distal fragment,
IR as needed

Low AVN risk
 Chondrolysis 10-40%
Treatment
Spica Cast

Little indication for immobilization
alone
 Often used as adjunct to
surgical treatment
 May be used if surgery
contraindicated or other treatments
have failed
Anterior & Valgus Slips

Valgus slip = superior and posterior displacement
 Valgus  adduction, flexion
 Anterior  extension, ER

Same treatments
watch for femoral neurovascular bundle
with valgus slip
Prophylactic Pinning of
Contralateral Hip
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20% present with bilateral involvement
Additional 25% will have symptomatic
contralateral slip
Most develop within 6 months
Ongoing debate
Consider in CRF (95% bilateral), endocrinopathyrelated slips, younger patients
If not done, educate parents and monitor every 6
months
Complications
Chondrolysis

Incidence and etiology unknown (5-7%)
 Stiffness, persistent groin or thigh pain
 Painful ROM, flexion contracture
 RF: pins, cast immobilization, severe, chronic
 X-rays:  joint space
 50% loss or  3mm
 Usually 6 weeks to 4 months after Rx, max within 6-12
months of onset
Treatment
 Removal hardware
 Supportive – activity modification, physio, NSAIDs
(arthroplasty)
Complications
AVN

Most severe complication
 RF: unstable (47%), severe, iatrogenic
 Evident a few weeks to 1 year after slip
 Total or partial
 Poor long-term prognosis
Treatment
 Prevention
avoid reduction, manipulation, Rx delay
 Educate family & patient
 Delay osteotomy until healed
AVN
Long-term Outcomes

Risk of OA directly related to severity of
residual deformity
 Significant potential for remodeling
delay treatment until skeletal maturity
 Evidence that osteotomy alters the
development of OA is lacking