residency days

1. Slipped Capital
Femoral Epiphysis
Dr Sijan Bhattachan
2nd year resident, Orthopedic & Trauma Surgery
Civil Hospital, NAMS

2. Introduction
• Disorder of proximal femoral physis that leads to slippage
of metaphysis anteriorly and superiorly relative to
epiphysis, which remains anatomically positioned in the
acetabulum.
• Most common disorder affecting adolescent hips (about 10
per 100000)
• Children going through pubertal growth spurt.
• Boys (14-16 yrs) are affected
• Left hip ; B/L in approx 25%.

3. Aetiology
• Slip occurs through hypertrophic zone of cartilaginous growth plate
• Most of patients are either fat and sexually immature or excessively
tall and thin
Hormonal imbalance
• Normally pituitary hormone activity, which stimulates rapid growth
and increased physeal hypertrophy during puberty is balanced by
increasing gonadal hormone activity, which promotes physeal,
maturation and epiphyseal fusion.
• Disparity between these two processes may result in the physis
being unable to resist the shearing stresses imposed by the
increase in body weight

4. • Perichondrial ring (the retaining collar around the
physis) is relatively thinned in this age group and
provides less support for the increased load
transmitted through the physis during the growth
spurt
• Trauma plays a part, especially in the 30% of the
cases with an acute slip

5. Pathology
• In slipped epiphysis, femoral shaft rolls into external rotation and
the femoral neck is displaced forwards while the epiphysis
remains seated in the acetabulum.
• Epiphysis slips posteriorly on the femoral neck.
• Periosteum is stripped from anterior and inferior surface of femoral
neck. If slip is severe, the anterior reticular vessels are torn
• At the back of femoral neck, the periosteum is lifted from the bone
with the vessels intact; this may be the main or the only source of
blood supply to femoral head and damage to these vessels by
manipulation or operation may result in avascular necrosis

6. • Area between femoral neck and posterior
periosteum fills with callus which ossifies and
becomes progressively dense.
• Anterior and superior portion of the neck forms a
hump or ridge that can impinge on the rim of
acetabulum.
• Normally, this ridge will remodel with anterior
portion of neck contouring into smoother surface

7. • Similar to Salter Harris type 1 fracture, but may
differ by
-antecedent epiphysiolysis.
-slower displacement
-periosteum remains intact (chronic SCFE); In acute
cases. periosteum can be partially torn anteriorly over
the prominent metaphysis

8. Associated conditions
• Endocrine disorders
-Hypothyroidism
-Renal osteodystrophy
-Growth hormone deficiency
-Panhypopituitarism
• Down syndrome

9. Presentation
Symptoms
• Groin and thigh pain
• Limping
• Knee pain (15-50%; can lead to misdiagnosis)
• Symptoms are usually present for weeks to several
months before diagnosis is made.

10. Physical examination
• Abnormal gait; Antalgic, waddling, Trendelenburg gait
• Decreased hip motion; Loss of hip internal rotation,
abduction and flexion; Obligatory external rotation
during passive flexion of hip (Drehmann sign)
• Abnormal leg alignment; externally rotated foot
progression angle
• Thigh atrophy

12. D/d
• Perthes disease
• Fracture of proximal femur
• Septic arthritis/ Osteomyelitis
• Adductor muscle strain
• Stress fracture

14. Imaging
XRay
• AP view; epiphyseal plate seems to be too wide and too woolly;
Ephiphyseolysis.
• A line drawn along the superior surface of the femoral neck
should normally intersect the epiphysis. In the early slip, the
epiphysis may be flush with or even below this line
(TRETHOWAN’s sign)/ Klein’s line

15. • Blurring of proximal femoral
metaphysis.(Metaphyseal blanch sign of Steel);
seen on AP due to overlapping of the metaphysis
and posteriorly displaced epiphysis.

16. • Capener’s sign;In 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

17. • In lateral view, the femoral epiphysis is tilted backwards.
Minor abnormalities can be detected by measuring the
angle subtended by the epiphyseal base and the femoral
neck; this is normally a right angle; anything less than 87
degree means that the epiphysis is tilted posteriorly

18. • Decreased epiphyseal height, physeal widening,
lesser trochanter prominence due to increased
external rotation of femur and new bone formation
in the posterior femoral metaphysis, with anterior
remodelling, are also useful signs in diagnosis

19. • USG may detect a hip effusion associated with an acute event
and may also show metaphyseal remodelling in a chronic slip
• MRI has been used
-To diagnose preslip condition when radiographs are negative
-To detect and stage AVN of femoral head

20. • CT useful in preoperative planning of realignment
procedures for complex proximal femoral
deformities

21. Grading
Based on timing of onset (Temporal classification)
Preslip;
• Groin or knee pain, particularly on exertion ; Limp
• Examination is often normal, but may demonstrate
reduced internal rotation.
• XRay may show widening or irregularity of physis

22. Acute slip
• Symptoms present for less than 3 weeks
• Painful hip movements with an external rotation
deformity, shortening and marked limitation of
rotation

23. Chronic slip
• Symptoms lasting for more than 3 weeks
• Episodes of deterioration and remission
• Loss of internal rotation, abduction and flexion of
hip
• Limb shortening

24. Acute on chronic slip
• Long prodromal history and an acute, severe
exacerbation.
• This classification does not corelate to the risk of
avascular necrosis or predict the outcome in the
longer term

25. Loder et al (1993) ; Based on ability to bear weight.
• Stable; Child can walk with or without crutches;
Minimal risk of AVN (<10%)
• Unstable; Walking not possible; 47% risk of AVN
• Provides prognostic information.

26. Radiological grading based on measurement of magnitude of slip
relative to width of femoral neck or the angle of arc of slip
On frog lateral xray,
• Mild; Displacement is less than one third of the width of femoral neck
• Moderate; Displacement is between one third and a half
• Severe; Displacement is greater than half of the femoral neck width

27. Southwick Slip angle classification; Based on
femoral epiphyseal-diaphyseal angle difference
between affected and unaffected hip (On both AP and
frog lateral pelvis radiograph;
• Mild; <30 degree
• Moderate; 30-50 degree
• Severe; >50 degree

29. • Kullio et al classified based on USG findings.
-Acute; Effusion without metaphyseal remodelling
-Chronic; No effusion with metaphyseal remodelling.

30. Treatment
Aims of treatment;
• To preserve the epiphyseal blood supply
• To stabilize the physis
• To correct any residual deformity.
• Manipulative reduction of slip carries a high risk of
avascular necrosis and should be avoided.

31. Operative modalities
• Percutaneous insitu fixation
• Contralateral hip prophylactic fixation (B/L insitu
fixation)
• Open epiphyseal reduction and fixation
• Osteochondroplasty
• Proximal femoral osteotomy

32. • The choice of treatment depends on the degree of
slip
Minor slip;
• Deformity is minimal and needs no correction
• Position is accepted and the physis is stabilised by
inserting one or two screws or threaded pins along
the femoral neck and into the epiphysis, under
fluoroscopic control

33. Moderate slip
• Deformity, though noticeable, is often tempered by
gradual bone modelling and may in the end cause little
disability.
• One can therefore accept the position, fix the epiphysis
insitu and then wait.
• If after a year or two, there is a noticeable deformity, a
corrective osteotomy is performed below the femoral
neck

35. Severe slip
• Causes marked deformity which untreated, will
predispose to secondary OA.
• Closed reduction by manipulation is dangerous and
should not be attempted.
• Open reduction by Dunn’s method gives good
results but should be reserved for specialist

36. • Alternative method recommended for less
experienced surgeon- is to fix the epiphysis as for a
moderate slip and then, as soon as the fusion is
complete, to perform a compensatory
intertrochanteric osteotomy.
• Easiest is Triplane osteotomy with simultaneous
repositioning of the proximal femur in valgus, flexion
and medial rotation

38. Percutaneous insitu fixation
Goal; To stablize the epiphysis from further slippage and promote
closure of the proximal femoral physis.
Technique;
• Single cannulated screw is sufficient and decreases risk of
osteonecrosis (compared to multiple pins).; starting position being
anterior of femoral neck and not lateral cortex.
• Screw should be perpendicular to physis, and enter into the central
portion of femoral head on both AP and lateral views (center-
center).
• Advance until 5 threads cross physis; should be at least 5 mm from
subchondral bone in all views

39. • One versus two cannulated screws is controversial
• 2 screws constructs have greater bimechanical stability
than a single screw construct.
• Benefit of 2 screws needs to be considered in the face of
greater risk of screw related complications

40. Postoperative;
• Stable slips are able to bear weight after fixation
• Unstable slips are kept touch down weight bearing for 6 weeks
Outcome;
• Does not treat deformity at head neck junction
• Unsatisfactory outcomes in 10-20 % have resulted in advocacy of
other techniques to correct the deformity and mitigate long term risk
of chondral damage

41. Osteotomy in SCFE
• Because moderately or severely displaced chronic slips
produce permanent irregularities in the femoral head and
acetabulum, some form of realignment procedure often
is indicated to restore the normal relationship of femoral
head and neck and possibly delay the onset of
degenerative joint disease.
• Two basic types of osteotomies
-Closing wedge osteotomy through the femoral neck,
usually near the physis to correct the deformity.
-Compensatory osteotomy through the trochanteric
region to produce a deformity in the opposite direction

42. Closing wedge osteotomy (femoral neck)
• Subcapital cuneiform osteotomy (FISH / Dunn)
• Base of neck osteotomy (Kramer / Barmada)
Compensatory osteotomy (Trochanter)
• Imhauser osteotomy
• Southwick osteotomy

43. • The nearer to the physis, the greater power of
correction but with higher risks of AVN

44. Dunn procedure
• 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 capital femoral epiphysis on the femoral neck by
resecting a portion of the superior femoral neck
• Advantage; the deformity itself is corrected
• High risk of AVN and chondrolysis.

45. • Dunn osteotomy for severe chronic slips in children with
open physics is based on two well known facts;
-Slip of femoral head strips the periosteum from the back of
femoral neck and a beak of new bone is laid down beneath it
-the main reticular blood supply runs up the back of the
femoral neck.
• A lateral approach allows stripping of periosteum and its
contained vessels under direct vision to avoid damaging
the blood supply to femoral head.

46. • Greater trochanter is elevated and the femoral neck
exposed.
• By gentle subperiosteal dissection, the posterior
retinacular vessels are preserved while mobilising the
epiphysis.
• A small segment of femoral neck is then removed, so
that the epiphysis can be repositioned without tension
on the posterior structures
• Once reduced, it is held by two or three pins.

48. Modified Dunn Procedure
• Surgical hip dislocation, Open capital realignment and fixation
• Goal; To correct the acute proximal femoral deformity, protect
femoral head blood supply and stabilise the epiphysis.
Technique
• Surgical hip dislocation via Gibson approach (Between Gluteus
maximus and medius)
• Develop retinacular soft tissue flaps (anteriorly and posteriorly)
• Mobilize epiphysis (remains attached to posterior reticular flap)

50. • Debride metaphysis (Prominent reactive callus along
the posterior metaphysis, needs to be removed to
permit proper epiphyseal reduction and avoid kinking of
reticular vessels)
• Reduce epiphysis to metaphysis
• Fixation with 2-3, 3.0 mm K wires
• Postoperative; Touch down weight bearing for 6 weeks
• Complication rate of 37%

52. Base of Neck Osteotomy
• Indicated to correct residual deformity after closure of
physis.
• Corrects varus and retroversion components of
moderate or severe chronic SCFE.
• Pose less risk to interruption of blood supply to femoral
head in comparision to Dunn procedure
• Osteotomy is held with threaded steinmann pins, which
extends into the capital epiphysis if the physics is still
open.

53. • Kramer et al described an extra capsular basal neck
osteotomy in an attempt to decrease risk of AVN.
• AVN and chondrolysis have still been reported.

54. Intetrochanteric osteotomy
• Southwick described an osteotomy at the
level of lesser trochanter which corrects varus
and extension deformity with no derotation to
avoid abductor weakness.
• Biplane wedge osteotomy.
• Indicated for chronic or healed slips with head
shaft deformities between 30 and 70 degrees

55. Imhauser osteotomy
Goal; To correct symptomatic proximal femoral deformity in moderate to
severe chronic SCFE deformity.
Technique
• Lateral approach
• Transverse osteotomy just proximal to lesser trochanter
• Correction;
-flexion through osteotomy
-internal rotation of distal shaft
-Mild valgus correction

56. Imhauser osteotomy
• It primarily corrects posterior angulation with
secondary correction of external rotation and varus

58. Osteochondroplasty
• Goal; To address pain and loss of motion related to hip impingement from
prominent metaphyseal bump in mild to moderate chronic SCFE deformity.
• Indications;
-symptomatic femoroacetabular impingement (FAI) of true cam lesion from
metaphysical bump
-Mild to moderate SCFE deformity (slip angle<30 degree)
• Technique
-Arthroscopy; Remove metaphyseal bump with arthroscopic burr
-Limited anterior arthrotomy (Modified Smith Peterson approach)
-Surgical hip dislocation

59. Complications
Slipping at the opposite hip;
• In 20% of cases
• Asymptomatic hip should be checked by
xray and at the least sign of abnormality,
the epiphysis should be pinned.
• Risk factors; Male, obesity, young age of
initial slip (<10 yrs;open triradiate cartilage),
endocrine disorders
• Posterior sloping angle of more than 12
degree has been described as a predictive
of development of contralateral slip.
• Weight loss programs.

60. Avascular necrosis; (4-6%)
• Mostly Iatrogenic ; Operative complication
(Hardware placement in posteriosuperior femoral
neck;disruption of vascular supply)
• May occur as result of initial trauma (Unstable slips)
• Minimized by avoiding forceful manipulation and
operations which might damage the posterior
retinacular vessels

61. • Tamponade effect due to acute hemorhhage within capsule
has been suggested as a cause of osteonecrosis but no
evidence has indicated that immediate aspiration of hip joint
is effective in preventing osteonecrosis.
• If a significant effusion is suspected, USG can be done to
determine amount of effusiion and necessity of capsulotomy.
• If immediate (within 24 hours) stabilisation of an acute slip
cannot be accomplished because of delayed presentation, a
delay of at least 7 days has been recommended to avoid the
“unsafe window” during which surgical intervention may
increase the risk of osteonecrosis.

62. • Physeal separation defined as the amount of
separation of anterior lip of epiphysis from the
metaphysis on a frog leg lateral radiograph.
• “Anterior physeal separation is associated with high
incidence of subsequent osteonecrosis after SCFE”
-Ballard and Cosgrove.

63. Articular chondrolysis; (0-2%)
• Probably results from vascular damage (often iatrogenic) .
• Associated with unrecognised implant penetration of
articular surface
• Progressive narrowing of the joint space and the hip
becomes stiff.
• Symptoms develop between 6 weeks and 4 months after
treatment

64. Clinical features
• Stiffness
• Pain in groin or upper thigh
• Walking affected
• Hip held in flexion, abduction and external rotation
• Substantial reduction in the arc of motion of hip in all
planes and motion is usually painful

65. • Radiographically, Loss of joint space; Either loss of
more than 50% of the joint space or an absolute
measurement of 3 mmm or less (Normal is 4-6 mm)
• A technetium bone scan shows increased uptake in an
affected joint space.
• CT of hip to confirm that no implant encroachment is
present
• If pin penetration has occurred, the implant must be
removed or replaced if the physis is not fused.

66. • In some cases , condition improves spontaneously
or with conservative management while in others it
leads to loss of mobility and OA.
• If severe joint space narrowing persists with
limitation of joint motion, arthrodesis or arthroplasty
should be considered

68. Coxa vara;
• Result of unnoticed or inadequately treated Slipped epiphysis.
• Except in most severe cases, this is more apparent than real;
the head slips backwards rather than downwards and the
deformity is essentially one of femoral neck retroversion
• Secondary effects are external rotation deformity of the hip,
possibly shortening of the femur and secondary OA
• Treatment is proximal femoral osteotomy (Intertrochanteric
osteotomy)

69. Femoral fracture
• Either femoral neck fracture or subtrochanteric
fracture following insitu fixation of SCFE
• Likelihood of this complication can be decreased by
avoiding drilling unnecessary holes in the bone
during surgery and by avoiding overzealous
reaming of femoral neck

71. FAI
• One of the cause of FAI is SCFE that has healed in less
than suitable anatomic position.
• Literature is unclear about how much posterior angulation
can be accepted during initial treatment or even how much
angulation later will cause FAI
• Anterior head-neck offset angle (Notzli alpha angle) has
been reported to correlate most strongly with FAI
• Greater the Notzli angle, the smaller the arc of motion
required to cause cam type impingement on the acetabular
rim.

73. • The cam effect in which the femoral head or screw head
abuts the acetabular labrum and the pincer effect in
which the acetabular rim impinges on the femoral neck
have both been described in adults who had treatment of
SCFE as adolescents.
• FAI can be identified by arthroscopy and MRI; plain
crosstable lateral radiographs
• Valgus osteotomy or the Imhauser procedure has been
recommended after insitu pinning to avoid acetabular
impingement.

75. References
• Apley’s system of orthopaedics and fractures, 9th
edition.
• Campbell operative orthopaedics,12th edition.
• orthobullets.com
• Internet sources