Dr Varun Sapra

SCFE –

Femoral neck and shaft displace relative to the femoral epiphysis and the acetabulum

Misnomer as neck displaces relative to the epiphysis

Usually, upward & anterior

Head remains posterior and downward in the acetabulum.

INTRODUCTION

Femoral epiphysis displacing relative femoral neck:-

i) Posterior-a varus relation M.C

ii) Forward (anteriorly)

iii) Laterally (into a valgus position)

DISPLACEMENTS

Dispalcement

THE PHYSIS

PATHO-ANATOMY

1 Reserve Zone-

Composed of chondrocytes

Type II collagen is present in its highest amount

Oxygen tension is low

2 Proliferative Zone.

Chondrocytes form matrix

Oxygen tension is high

Rich vascular supply.

The majority of the longitudinal growth of the growth plate occurs in this zone.

Growth plate

The zone is avascular,

low oxygen tension (similar to the reserve zone).

Chondrocytes prepare matrix for mineralization and

calcification.

Slip occurs through the weakest structural area of the plate, the hypertrophic zone.

3 Hypertrophic Zone

Varies according to race, sex, geography

Estimated 2 per 100,000

Males > females (male to female ratio is 2:1)

left > right

During adolescence, max skeletal growth

boys 13-15 years, avg 14

girls 11-13 years, avg 12

associated with puberty

Bilateral - 20-25 %

When bilateral slips occur, the second slip usually occurs within 12 to 18 months of the initial slip.

Incidence/Epidemiology

Often unknown

Majority are normal by current endocrine work-up

Etiologic –

Altering the strength of the zone of hypertrophy

Affecting the shear stress to the plate

1)Endocrine

2)Mechanical

ETIOLOGY

Predisposing features:

-thinning of perichondral ring complex

-retroversion of femoral neck

-change in inclination of prox femoral physis relative to femoral neck/shaft

Mechanical Factors

Fibrous band that encircles physis at cartilage-bone interface

Acts as limiting membrane,

mechanical support to physis

Thins rapidly with maturation strength

1) Perichondral Ring Thinning

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

Increased obliquity

Patients with a slipped epiphysis have a slope 11 degrees more

on the affected side and 5 degrees more on the unaffected side

1) Obesity,

2) Hypogonadal males (adiposogenital syndrome)

3) Growth spurt

4) Hypothyroidism (treated or not)

5) GH administration

6) CRF

Growth hormone - stimulate growth of the physis converting cartilage to bone. too much un-ossified cartilage unable to resist stress imposed by increased body weight

No screening unless clinical suspicion

Endocrine Factors

Periosteum stripped from ant/inf surface of femoral neck

Area btw neck & post periosteum fills with callus & ossifies

Anterosuperior neck forms “hump”(remodel)

Acute slips will have hemarthrosis

PATHOLOGY-GROSS

-Edematous synovial membrane,periosteum,capsule

Light microscopic - physis is widened and irregular

Resting zone -60 to 70% of the width of the physis, Hypertrophic zone -15 to 30%.

SCFE, the hypertrophic zone may constitute up to 80% of the physis width.

Microscopic

A,Slipping hypertrophied zone of the physis

B The zone of hypertrophy is widened

C The chondrocytes of the hypertrophied zone at the cleft

Temporally, according to onsetacuteacute-on-chronicchronic

Functionally, according to ability to WB(weight bear)stable

unstable

Morphologically, according to extent of displacement

CLASSIFICATION

CLASSIFICATION

Based on Duration of slip

STABLE UNSTABLE

Weight bearing Possible Not possible

Severity of slip Less severe More severe

Effusion Absent Present

Good prognosis 96% 47%

AVN 0% 50%

Preslip phase-

i)Weakness in the leg

ii) limping on exertion;

iii)On physical examination,

Lack of medial rotation of hip , hip in extension.

Affected leg is fixed, the thigh goes into abduction and external rotation

CLINICAL FEATURES

i)The clinical criterion- acute onset of symptoms < 2 weeks

ii)Prodromal symptoms - weakness, limp, and intermittent groin,

medial thigh, or knee pain

Uable to weight bear.

iii) Antalgic gait

iv) An external rotation deformity

v) Shortening

vi) limitation of motion.

The greater the amount of slip, the greater is the restriction of

motion.

Unstable Acute or Acute-on-Chronic Slipped

Capital Femoral Epiphysis

i)Groin or medial thigh/knee pain for months to years.

ii)Exacerbations and remissions of the pain or limp

iii)Limitation of motion(particularly medial rotation) the leg fixed external rotation

iv) Increased- hip extension

external rotation

adduction

Decreased

flexion , internal rotation ,abduction

CHRONIC SLIP/ STABLE SLIP

v) Antalgic limp

vi)Local tenderness over the hip joint

vii)Shortening

viii)Thigh or calf atrophy.

ix) Hip flexion contracture -Chondrolysis.

Stable, Chronic Slipped Capital Femoral Epiphysis

DISORDER AGE SEX BILATERAL

DDH 0-2yrs FEMALES1:4

20%

PERTHES DISEASE

4-6yrs MALES5:1

10%

SCFE 10-15yrs MALES2:1

25-40%

Causes of Limp & Hip, Thigh or Knee Pain in

Children

1)X-RAY-

Frog-leg lateral accentuate the deformity

Lateral view the best to detect the slip - head is posterior in relation to the neck

DIAGNOSIS

PRE-SLIP The earliest radiographic change widening and

irregularity of the physis

Klein's line

A crescent-shaped area of increased density over the metaphysis of the femoral neck

This density is produced by

overlapping of femoral neck

and the posteriorly displaced

capital epiphysis

Metaphyseal blanch sign-Steel sign

SCHAM SIGN- A) Normal hip, the inferomedial femoral neck

overlaps the posterior wall of the acetabulum-triangular radiographic density

B) Displacement of the capital epiphysis - dense triangle is lost

Capeners sign AP view in the normal hip the posterior acetabular margin cuts across the medial corner of the upper femoral metaphysis. With slipping the entire metaphysis is lateral to the posterior acetabular margin

Acute- little or no of the femoral neck

Chronic-remodeling of the femoral neck

Remodeling

Southwick Classification

lateral epiphyseal-shaft angle (LESA).

mild slips- <30 degree

moderate slips -30 - 60 degrees

severe slips- >60 degrees

Normal values 145 degrees - AP

10 degrees posterior on the frog-leg lateral

Epiphysis relative to the metaphyseal

width

More accurate in the measurement of the head–neck angle

Demonstrating penetration of the hip joint by fixation devices

Confirm closure of the proximal femoral physis

Assess the severity of residual deformity of the upper femur

II) CT SCAN

Measurement of the head–neck angle on computed tomography (CT) scan

3)Technetium-99 Bone Scan

Increased uptake -involved hip,

Decreased uptake -AVN,

Increased uptake in the joint space - chondrolysis.

4) Ultrasonography

5) Magnetic Resonance Imaging

Goals in treatment

1)To prevent further displacement of the epiphysis

2)To promote closure of the physeal plate.

Long-term goals of treatment include

1)Restoration of a functional range of motion

2)Freedom from pain

3) Avoidance of aseptic necrosis and chondrolysis

TREATMENT

1. Absolute Bed Rest

2. Traction

3. Hip Spica Cast

1)NON OPERATIVE TREATMENT

• Bilateral BK cast

• Holding the hips in Abd & IR

• Weight bearing not allowed usually for 3 - 4 months

Spica Cast immobilization

i)Percutaneous and open in situ pinning

ii)Open reduction and internal fixation

iii) Epiphysiodesis

iv)Osteotomy

v)Reconstruction by arthroplasty, arthrodesis, or cheilectomy

2)OPERATIVE TREATMENT

Single

Central pin- the screw in the center of the femoral head

DISADVANTAGE

Persistent pin penetration

.

In Situ Pin or Screw Fixation

AFTER TREATMENT

Range-of-motion exercises - begun the day.

Unstable slips- partial weight bearing 6 to 8 weeks.

sports and other activities forbidden until physeshave closed.

The screws removed after physeal closure

A, Anterior approach to hip and H-shaped capsular

incision.

B, Use of hollow mill to create tunnel across physis

C, Sandwiched iliac bone grafts are driven across

physis.

Bone Peg Epiphysiodesis

A portion of the residual physis is removed and a dowel or “peg” of autologous bone graft (ipsilateraliliac crest) is inserted into the epiphysis.

In unstable slips, supplementary internal fixation, postoperative traction, or spica cast immobilization for 3 to 8 weeks until early stabilization has occurred

Disadvantages

1)Graft insufficiency

2)Increase in severity of slip

3)Failure of physeal fusion

4)longer operating time, increased blood loss, longer hospitalization, and longer rehabilitation.

AFTER TREATMENT

In acute slips - spica cast for 6 weeks

In chronic slips weight bearing started at approximately 10 weeks.

OSTEOTOMY

There are two basic types of osteotomy:

1)Closing wedge osteotomy through the femoral neck - correct the deformity.

2)Compensatory osteotomy through the trochantericregion - produce a deformity in the opposite direction

OSTEOTOMY

To restore the normal relationship of the femoral head and neck

Delay the onset of degenerative joint disease.

Prevent further slippage

Correct preexisting deformity .

INDICATIONS

1)Curetting the physis and securing the capital epiphysis to the neck

2) Fixing the capital epiphysis with a bone graft epiphysiodesis or metallic implant

2) Inducing fusion by reorienting the plane of the capital physis into a more horizontal position

The goal of preventing further slippage is achieved

Trapezoidal osteotomy of the femoral neck

Referred as “an open replacement of the displaced femoral head”

should not be done if the physis is closed.

Reduce the capital femoral epiphysis on the femoral neck by resecting a portion of the superior femoral neck.

Advantage - the deformity itself is correctedResults.

High risk of complications, AVN and chondrolysis.

1) Dunn Procedure

Indicated to correct residual deformity after closure of the physis.

corrects the varus and retroversion components of moderate or severe chronic SCFE.

Pose less risk to interruption of the blood supply to the femoral head than the Dunn procedure

Osteotomy held with threaded Steinmann pins, which extended into the capital epiphysis if the physis is still open

2)Base-of-Neck Osteotomy (Kramer and Barmada Procedures).

Barmada's group –

Extracapsular base-of-neck osteotomy performed slightly more distally

Recommended for moderate to severe chronic SCFE with a greater than 30-degree head–shaft angle on lateral radiographs.

Preferable method to correct deformity associated with SCFE

Southwick osteotomy –chronic or healed slips with head–shaft deformities between 30 and 70 degrees

Biplane osteotomy Performed at the level of the lesser trochanter.

Imhauser's procedure - Intertrochanteric

COMPLICATIONSI)Chondrolysis

2)Post operative narrowing of joint space

4)Intertrochanteric Osteotomy(Imhauser/Southwick Procedure).

Not performed routinely.

Symptomatic slipping of the contralateral slip after unilateral treatment - 12.5%

Asymptomatic slipping of the contralateral hip has -40%.

Prophylactic Pinning of Contralateral Slips

Indications-

High-risk

Noncompliant patients

Epiphysiolysis from irradiation therapy

Metabolic or endocrinopathic

Renal failure.

Children younger than 10 years at the time of

presentation

1)CHONDROLYSIS

Occasionally referred to as “acute cartilage necrosis”

NATURAL HISTORY

Symptoms develop between 6 weeks and 4 months after treatment,

Progressive joint space narrowing occurs, maximum reduction - 6 to 12 months of onset of symptoms.

COMPLICATIONS

EPIDEMIOLOGY

Spontaneously

Depends on mode of treatment

1.5% percutaneous in situ pinning

50% - spica cast.

Pin penetration of the joint

Intertrochanteric osteotomy.

Girls are more likely to be affected than boys.

CLINICAL FEATURES

Stiffness

Pain in the groin or upper thigh.

Walking affected.

The hip held in flexion, abduction, and external rotation.

There is substantial reduction in the arc of motion of the hip in all planes, and motion is usually painful.

Radiographically,

Loss of joint space.

The radiographic criterion - loss of more than 50% of the joint space

or an absolute measurement of 3 mm or less.(normal-4-6mm)

A technetium bone scan shows increased uptake in an affected joint space.

ETIOLOGY

Etiology is not known various theories-

1) Lack of synovial fluid production- failure of nutrition of articular cartilage

2) Autoimmune - Produce an antigen

3) Metallic implant penetration

4) Impingement - labrum and acetabulum by anterior “pistol grip” deformity of the femoral neck

1)CT of the hip to confirm that no implant encroachment is present.

2) Aspiration of the hip to rule out a low-grade infection.

3)If pin penetration has occurred, the implant must be removed or replaced if the physis is not fused.

4)Supportive care

5) Muscle releases or capsulotomy,

6) Arthrodesis or total joint arthroplasty.

TREATMENT

Generalized osteopenia

and narrowing of the cartilage space.

Axhausen in 1924 used the term aseptic necrosis

Without treatment

Acute displacement (unstable slip).

Closed or open reduction of unstable slips

Osteotomy of the femoral neck.

Intertrochanteric osteotomy.

lowest open epiphysiodesis or in situ pinning of stable slips

AVASCULAR NECROSIS

The blood supply to the femoral head is interrupted,

The lateral epiphyseal arterial system may be damaged

EPIDEMIOLOGY

RADIOGRAPHIC FINDINGS AND CLINICAL FEATURES

Two patterns of distribution are typically seen:

Total head necrosis

Partial (or segmental) necrosis

Affected epiphysis first fails to become osteopenic

Resorption of the necrotic bone

collapse of the affected portion of the epiphysis.

TREATMENT

1)prevention.

2)Implant removal

3) Joint arthroplasty (total or partial) or hip fusion

4)Hip arthrodesis

10% to 15% of patients with SCFE

Osteonecrosis is rare in untreated patients

Results from interruption of the retrograde blood supply by the original injury (superior retinacularartery of the medial circumfl ex femoral)

1) unstable (acute) slips,

2) forceful repetitive manipulations

3) open reduction, or

4) osteotomy of the femoral neck.

5) Superolateral placement of pins

3) OSTEONECROSIS

Anterior physeal separation. a sign indicating a high rise for avascular

necrosis

separation of the anterior lip of the epiphysis from the metaphysis

ETIOLOGY

i) Fixation of SCFE with multiple pins

ii) Unused drill holes

iii) After nail removal

iv) Thermal injury caused by reaming of the femoral neck

.

Femoral Neck Fracture

Subtrochanteric fracture,

Transverse fractures

Immediate ORIF with a hip screw and a long side plate

Femoral neck fracture

less common

spica casting

weight relief alone

Vascularized pedicle bone graft

The complication can be decreased by

avoiding drilling unnecessary holes in the bone

avoiding overzealous reaming of the femoral neck

Untreated Slipped Capital Femoral Epiphysis

i)Severe degree and that degenerative arthritis

ii)AVN

iii)Chondrolysis

The displacement is either superior and posterior

Increased femoral anteversion.

Clinical picture

In valgus slips there is a restriction of adduction as well as of flexion.

In anterior slips there is a limitation of extension and external rotation

Treatment

1)in situ pinning.

2)limited open approach for in situ pinning-valgus slip

2)Open bone graft epiphysiodesis -if percutaneous pinning is inadvisable or unsuccessful

ANTERIOR AND VALGUS SLIPS

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