Slipped capital femoral epiphysis

etiology, clinical features, investigations to be done and management

1. Slipped capital femoral epiphysis Presenter- Dr.Madhukar

2. INTRODUCTION The capital femoral epiphysis is unique. It is one of the few epiphysis in the body that is inside the joint capsule.

3. Definition SCFE term refers to slippage of the overlying epiphysis of proximal femur posteriorly and inferiorly due to weakness of the growth plate in relation to metaphysis . Although this disorder is termed slipped capital femoral epiphysis(SCFE), this is a misnomer. The femoral epiphysis maintains its normal relationship within the acetabulum , and it is the femoral neck and the shaft that displace upwards and anteriorly relative to the femoral epiphysis and acetabulum .

4. Epidemiology Incidence is 2-3 per 100,000 population. Most common in adolescent period with rapid growth plate (boys 10-16yrs; girls 12-14yrs) Very early onset <10yrs and very late onset >16yrs should be evaluated for endocrine disorders. Males have 2.4 times the risk as females. Obesity is a risk factor because it places more shear forces around the proximal growth plate in the hip. Bilateral slippage is common of which 2 nd slip is about 12-18 months later to the 1 st (left is effected 1 st before right)

5. Etiology Local trauma Obesity Endocrine disorders (like primary or secondary hupoparthyroidism , adiposogenital dystrophy( hypogonodal male) Growth hormone deficiency Atypical SCFE is associated with renal failure, radiation therapy.

6. Pathology The epiphysis slowly displaces inferiorly and posteriorly with the femoral neck shifting upward and rotating anteriorly to the anterverted position thus resulting in varus deformity, adduction and external rotation of the femur. The displacement takes place through the layer of hypertrophied mature cartilage cells adjacent to the calcified cartilage zone The interval produced by separation becomes filled with fibrous tissue, embryonic cartilage and callus particularly at the posterior and inferior angle

7. Abduction and internal rotation of the hip are greatly limited by 2 factors - large hump formed by the fibrous cartilage overgrowth about the anterior exposed portion of the neck impinges against the anterior and superior margins of the acetabulum -The capital epiphysis is fixed posterior and inferior where further outward movement is limited by its impingement against capsule

8. Classification Based on symptoms -acute -chronic -acute on chronic Functional classification -stable -unstable Depending on head shaft angle -mild -moderate -severe

9. Acute slip: sudden onset of usually severe symptoms that have been present for less than 2 weeks.x -ray shows displacement without any bone healing Chronic slips –gradual onset and symptoms of more than 2weeks duration some bony healing and remodeling along the medial femoral neck usually seen on x -rays

10. Acute on chronic—symptoms lasting longer than one month and a recent sudden exacerbation of pain after a relatively trivial injury Pre-slip– essentially an x-ray finding manifested by irregularity widening and indistinctness of the epiphyseal plate

11. Depending on head shaft angle

12. Mild slipping – exist when the neck is displaced less than 1/3 rd of the diameter of the femoral head or when the head shaft angle deviates from normal by 30 degrees or less on both a,p and lateral views Moderate slipping—when neck is displaced between 1/3 rd and ½ the diameter of femoral head or angle deviation between30-60 degrees Severe slipping: when the neck is displaced more than half the diameter of the head or deviation of the head shaft angle of more than 60 degrees than normal

13. Loders classification stable unstable Wt bearing possible with or without crutches Less severe slips Effusion absent Good prognosis Less chances for avn Wt bearing is not possible even with crutches Slip is more severe Effusion is almost always present Bad or worst prognosis More chances for avn

14. Clinical features The onset is insidious Course is slowly progressive Symptoms:- Pain in the groin and around the hip Antalgic limp Sortening of the affected limb Limb may be in external rotation Flexion, abduction, internal rotation are limited. External rotation, adduction are increased. Axis deviation( pathognomic ) – when hip is flexed, the limb goes into external rotaion .

15. Hip flexion and external rotation are limited and with flexion of the affected hip, the limb rotates externally.

16. Preslipping stage : At first slight discomfort develops about the groin usually after activity and it subsides by rest this may be associated with slight stiffness and an occasional limp The pain may radiate along antero -medial thigh and to the inner aspect of the knee

17. Chronic slipping stage: An antalagic limp becomes pronounced and persistent . The findings include tenderness about the hip and limitation of motion abduction and internal rotation the limb gradually develops an adduction and external rotation deformity when hip is flexed the external rotation deformity is accentuated

18. Stage of fixed deformity -Pain and muscle spasm disappear but the limp,external rotation, adduction and shortening persists Signs: -The patient is likely to be a boy between age of 10-17 years or a girl between 11 and 13 in whom menstruation has not at started

19. The radiographic abnormalities that may be seen in SCFE depend on the degree of displacement of the capital epiphysis. The AP radiograph of the hip, supplemented by a frog-lateral view, is usually sufficient to make a correct diagnosis. Several diagnostic indicators of SCFE have been identified on the anteroposterior projection of the hip

20. The TRIANGLE SIGN OF CAPENER may be of value in recognizing early SCFE. On a plain film of the normal adolescent hip, an intracapsular area at the medial aspect of the femoral neck is seen overlapping the posterior wall of the acetabulum , creating a dense triangular shadow-triangle of capener In most cases of SCFE, this triangle is lost.

21. In a later stage, periarticular osteoporosis becomes apparent, as do widening and blurring of the physis and a decrease in height of the epiphysis Moreover, as the disease progresses, slippage of the capital epiphysis can be identified by the absence of an intersection of the epiphysis with a line drawn tangent to the lateral cortex of the femoral neck

22. Metaphyseal blanch sign of steel In Ap view- crescent shaped area of increased density overlying the metaphysis adjacent to the physis . This increased density is due to the overlapping of the femoral neck and the posteriorly displaced capital epiphysis.

23. Chronic stages of this disorder exhibit reactive bone formation along the superolateral aspect of the femoral neck, along with remodeling ; this creates a protuberance and broadening of the femoral neck, which gives it a “pistol-grip” appearance known as a HERNDON HUMP.

24. Radiological appearances - Preslipping stage -indicated by the absence of the normal shoulder on the upper aspect of the neck and head [TRETHOWAN’S SIGN] in which a line called KLEINS LINE ,drawn along the superior surface of the neck will pass above the femoral head rather than through the head -The head is more or less sickle shaped instead of hemispherical and its height is diminished -The epiphyseal is widened and rarefaction or even streaks of sclerosis may be seen underneath it

25. Early stage -The head of the femur lies in the acetabulum but it is rotated so that its lower and laterally. -The head is slightly displaced in relation to the neck

26. Advanced stage: -The femoral head is atrophic especially in its projecting lower half and it has now become so rotated and displaced that only a small anterior portion is actually in the acetabulum -The projecting lower edge of the head is now curved laterally and upwards and is in contact with the lower border of the neck

27. -The head is often completely separated from the neck and lies loose in the acetabulum except for the displacement, the contour of the bones is normal but the joint margins and the joint space may be hazy from the extravasation of blood.

28. CT SCANS Are valuable in visualizing early slipping.CT provides the most accurate measurement of the extent of epiphyseal displacement and angulation

29. Diagnosis Diagnosis is a combination of clinical suspicion plus radiological investigations. 20-50% cases of scfe are misdiagnosed on their 1 st presentation to a medical facility. This is because the common symptom is knee pain. This is a referred pain from the hip. The symptom complex consist of- A limp of spontaneous onset(without apparent cause) Pain referred to the knee in obese adolescent. Characteristic radiographic appearance.

30. Differential diagnosis 1. Tuberculosis of hip -Attitude- adducted and medially roated -Movements-restricted in all directions atrophy is greater -Hip is more sensitive and painful even at rest radiographs show extensive demineralization of the femoral head and acetabulum without any epiphyseal displacement

31. 2. Perthes disease -History : limitations of movement slight atrophy and shortening are identical with those of mild epiphyseal coxa vara the chief points of difference -age: perthes diseases rarely begins after the tenth year while slipped capital femoral epiphysis begins before it -X-ray: in perthes the head is not displaced but actually deformed

32. Difference between SCFE and PERTHE’S SCFE PERSTHE’S age - 10-14 yrs Late onset 14-16 yrs 4-7 yrs Late onset 7-10 yrs Thin and tall adolscent or short obese individuals Occurs in normal child Presents as pain with slippage and limping nated later satge Initially child limps and then at later stages complaints of pain Limb may externally roated but no fixed flexion deformity Fixed flexion deformity is noted

33. 3. Congenital dislocation of hip -Usually present since birth. -Head of the femur may be palpated outside the acetabulum . - Telescopy present in majority of the case.

34. Prognosis The second hip becomes affected in about 1 in 4 cases The end result depends to a certain extent on the degree of displacement of the head In early case where there is minimal slipping the end result is completely satisfied Good results can be achieved with good reduction provided avascular necrosis avoided

35. Good results can be achieved even with up to 50% displacement of the head if good reduction is followed by corrective osteotomy Some patients with a displaced epiphysis after treatment develop avascular necrosis cartilage necrosis and arthritic changes during adult life

36. Management Conservative management- rest and traction Closed manupulative reduction Operative management insitu pinning -open instiu pinning -Bone peg Epiphysiodesis - Osteotomies -

37. Closed reduction Manipulative reduction has been reported for acute and acute on chronic slips with moderate and sever displacement. An association of avascular necrosis with manipulative reduction has been reported.

38. -The development of avascular necrosis may be related to severity of the slip rather than to the manipulative reduction provided that only a very gentle reduction is performed. This is performed with the patient on a fracture table and internal rotation alone usually is sufficient to obtain adequate reduction

39. - Longitudinal traction is applied to counteract the muscle spasm straight longitudinal traction especially when combined with medial rotation will effectively reduce the displacement of an acute slip and this can be followed by internal fixation

40. The aim of surgery are To prevent further slip To reduce the displacement To effect early closure of the epiphyseal plate

41. Internal fixation In situ pin or screw fixation Percutaneous in situ pinning is currently the most often used treatment for mild moderate and some severe acute on chronic slipped capital femoral epiphysis Open in situ pinning may be indicated for more severe acute or acute on chronic slipping

42. Percutaneous in-situ pinning Although earlier reports indicated that two or three pins were necessary for stability and results of multiple pinning generally have been satisfactory Reports now recommend the use of a single larger diameter central pin or screw because single pin insertion is technically simpler than insertion of multiple pins but this is still surgeon dependent

43. Whether pins or cannulated hip screws are used, they should not be removed for at least 12 months or until the physis closes. Persistent pin penetration has been the most serious disadvantage of in situ pinning. Adverse effects attributed to unrecognized pin penetration include joint stiffness.

44. The pins should be placed in the femoral neck and into the centre of the head in the safe zone to avoid pin penetration. Lehman et al and Shaw recommended the use of cannulated hip screw with injection of radio opaque dye to detect pin penetration. The pin tip is to be advanced to 8mm or1/3 rd of the radius of the femoral head from the sub chondral bone. This places the actual tip 7 to 18 mm from the subchondral bone, leaving a safe margin.

45. Open in situ pinning Technique ( Morrissy ): Place the patient on the fracture table with the affected leg abducted 10 to 15 degrees and internally rotated as for as possible without force. This brings the femoral neck as close as possible parallel to the floor to assist in obtaining true anterior and lateral image views after standard preparation and draping under image control insert a k-wire

46. Through the antero -lateral area of the thigh down to the femoral neck, adjusting the guide wire on the antero -posterior projection to determine the axis of the femoral neck and obtain a lateral view to determine the amount of posterior inclination needed. When the starting point and the posterior inclination have been estimated, insert the guide through a small puncture wound.

47. Advance the guide wire to the physis and confirm placement in the central axis of the femoral head by intensification. If the position is correct advance the guide assembly across the plate until the proper depth is reached determine the correct screw length by passing a guide wire of identical length advance correct length screw over the guide pin and then remove the pin.

48. Use both anteroposterior and lateral views to conform that the screws do not penetrate the joint and close the stab wound with a single subcuticular suture . If two screws are deemed necessary for an acute slip the first screw should lie in the central axis of the femoral head and the second below it avoiding the superolateral quadrant . The second screw should stop at least 8mm from the subchondral bone

49. After treatment Range of motion exercises are to begin the day after surgery . Partial weight bearing is allowed for most of the patients on first day using crutches. Crutches are used until all signs of synovitis are gone and motion is free and painless .all vigorous activities are forbidden until the physis have closed . The screws are removed after physeal closure has been demonstrated.

50. Prophylactic pinning of the contra-lateral hip is performed in rare instances such as In high risk non complaint patients or patients with epiphysio-lysis from irradiation therapy or renal failure .

51. Bone peg epiphysiodesis - Described by Ferguson and Howorth in 1931 -Reported complications after pin or screw penentration into the joint increased its popularity -There is rapid physeal closure and low incidence of complications especially in chondro-lysis

52. Disadvantages Graft insufficency leading to increase in severity of slip and failure of physeal fusion Longer opreating time Increased blood loss Longer hospitalization Longer rehabilitation

53. Spica cast immobilization may be necessary to present further slip Post operative complication - avascularnecrosis - chondro-lysis -infection -lengthy immobilization - heterotopic ossification

54. Technique of bone peg epiphysiodesis through anterolateral apporach ( wenier etal ) -Make a mid lateral incision beginning 4 to 5 inches below the level of the greater trochanter in the lateral mid line of the upper portion of the thigh,proceeding proximally to the greater trochanter and then angling obliquely to the antero -superior iliac spine

55. - Muscles are split and retracted capsule of the hip joint is exposed and opened in an H shape fashion - If bony hump present on the antero -lateral meta- physeal region resulting from slip remove it with an osteotome - Make a square or rectangular window in the anterior surface of femoral neck insert a large hollow drill through the window and drill it across the physis into the epiphysis under image intensifier

56. -Remove a cylindrical core consisting of metaphyseal bone physis and a portion of the epiphyseal bone there by guaranting passage of the drill across the physis and into the epiphysis enlarge the cylindrical tunnel with a curret and remove more of the physis remove sections of cortico-cancellous bone from the outer layer of ilium and sand witch them together and drive this composite bone peg across the physis into epiphysis

57. After treatment Spica cast applied in acute slips for six weeks and then touch down wait bearing is allowed Chronic slips are ambulated on crutches after 48 to 96 hrs of bed rest Weight bearing can be started at approximately 10 weeks

58. -In an effort to simplify bone peg epiphysiodes schmidt et al developed a percutaneuos fluoroscopically guided technique using cortical allograft inserted through a hole drilled in the lateral femoral cortex passed through the femoral neck and across the physis -Procedure is similar to the percutaneous pin fixation except that rather than cannulated screw a 10mm reamer is inserted over the guide pin and a tunnel is reamed -Reamed tunnels is filled with a cortical strut allograft. -operative time the and morbedity similar to single screw fixiation

59. Osteotomy -Chronic slips with moderate or severe displacement produce perment irregularities in the femoral head and acetabulum and some form of reconstructive procedure often is indicated the goals of any osteotomy are- Restoration of the normal relationship of the femoral head and neck Dealy of the onset of degenerative joint disease

60. There are two basic types of osteotomy Closing wedge osteotomy through the femoral neck usually near the physis to correct the deformity and Compensetory osteotomy through the trochanteric region to the produce deformity in the opposite direction

61. Four femoral neck osteotomies are described The technique of fish The technique of dunn just distal to the slip( subcapital ). The base of neck technique of kramar et al. The technique of abraham et al. The itertrochantric osteotomy by southwick . Compensatory osteotomies in the trochanteric region as well as partial cheilectomy to reduce deformity

62. Cuneiform osteotomy of the femoral neck(fish) -Reduction by a cuneiform osteotomy made just distal to the physis and internal fixation may be necessary for a severe chronic or acute on chronic slip. -The reported incidence of avascular necrosis and chondrolysis after this procedure have been exceptionally high

63. Technique -Place the patient supine make an anterolateral approach to the hip -Open the capsule longitudinally determine the size of the wedge to be removed by noting the degree of slip and the position of the epiphysis make the base of the wedge anteriorly and superiorly for correct positioning of the epiphsysis after removing sufficient bone -Reduce the epiphsysis by flexion abduction and internal rotation of the limb after reduction fix the epiphysis to the neck with 3 or 4 pins

64. Cuneiform osteotomy of femoral neck {fish}

65. After treatment -The patient should be free in bed with the involved limb supported on pillows -When comfortable he is allowed out of bed using crutches with only touch down weight bearing of the involved limb -Full weight bearing is permitted after x-rays show the osteotomy to be completely healed at approximately 5 months pins are removed full activity allowed 2 months later

66. Cuneiform osteotomy of femoral neck ( dunn ) -Dunn described an osteotomy for severe chronic slips in chidern with open physis he emphasized that this procedure should not be done if the physis is closed

67. The slip of the femoral head strips the periosteum from the back of the femoral neck and beak of new bone is laid down beneath it The main retincular blood supply runs of the femoral neck a lateral apporach allows stripping of the periosteum and its contained vessels under direct vision to avoid damaging the blood supply to the femoral head

68. Technique -Through a lateral approach make an incision in the periosteum and elevate the posterior vascular covering of the femoral neck make to osteotomy cuts one in the long axis of the neck to remove the bony beak and the second at right angles to the neck to shorten it by 3 to 4 mm. appose the surface of the osteotomy and insert three threaded pins up the femoral neck to its cut surface.

69. -Reduce the deformity and conform position on x ray. In the lateral view the head should appear to sit squarely on the neck but in AP view the head should be tilted into about 20 degrees of valgus when reduction is satisfactory drive the pins into the femoral head close the wound in layers

70. After treatment -A cast is applied from the nipple line to the toes on the affected side holding the extremity in the nuetral roatatoin and abduction and to above knee on the opposite side. -Cast is removed at 4 weeeks and active and passive motions are begun after two weeks crutch walking is allowed at 3 to 4 months after surgery partial weight bearing is permitted full weight -Bearing permitted only after x-ray evidence of union of osteotomy

71. Compensatory basilar osteotomy of femoral neck -Kramer et al described a compensatory osteotomy of the base of the femoral neck that corrects the varus and retoversion components of moderate or severe chronic slipped capital femoral epiphysis

72. -They suggested that it is safer than an Osteotomy made near or at the physis because the line of the osteotomy is distal to the major bloood supply in the posterior retinacuium . -Threaded pains are used for fixation of the osteotomy and the epiphysis not only is the anatomical relationship of the proximal femur restored but also futher slipping is prevented

73. Technique -Determine preoperatively the size of the wedge to be removed by measuring the head-neck angle on AP radiograph and confirmed at surgery by measuring the width of the callus by direct inspection.

74. -Part of wedge will be in line with the widest part of the slip in the anterior and superior aspects of the neck make the more distal osteotomy cut first perpendicular to the femoral neck and following the anterior intertrochanteric line from proximal to distal extended this osteotomy -Cut to the posterior cortex but leave this cortex intact (this will permit the greenstick fracture in the posterior cortex when closed)make the second osteotomy cut directed obliquely so that its cutting edge stays distal to the posterior retinacular blood supply.

75. -Drill one or two 5mm threaded steinmann pins into the femoral neck proximally to ensure that the proximal portion of the femur is kept under control before completing the osteotomy -Complete the osteotomy by medial rotation nd abduction of the distal segment. -Advance the threaded steinmann across the osteotomy site and physis to prevent for the slipping

76. After treatment Bed rest for 2 to 3 weeks followed by non weight bearing partial weight bearing is allowed depending on the stability of the osteotomy stienmenn pins should be removed only after physis has fused

77. Extra capsular base of neck osteotomy Extra capsular base of neck osteotomy Abraham et al recommended this osteotomy as safe and effective in preventing furthur slipping and improving hip range of motion in pts with severe chronic slip They noted that with severe slips the amount of correction of varus and posterior tilt of the femoral head is limited and complete restoration of normal head shaft angle may not be possible

78. Removal of a wedge larger than 20 mm compromises femoral neck length and may greately increase femoral antversion Also pinning across the osteotomy site becomes more difficult when correction of more than 55 degrees of varus or valgus is attempted These same restrictions also are applicable to intra capsular base of neck osteotomies and southwick procedure

79. Before surgery the head shaft angle is measured on lateral films by measuring the angle formed by epiphyseal line and the femoral shaft in the affected limb and comparing it with normal limb The head shaft angle for posterior tilt or retroversion is measured on frog lateral view and compared with normal side The difference between normal and abnormal angles are used to determine the size of wedge removed during osteotomy

80. Make a standard anterolateral approach mark the anterior joint line or intertrochantric line Delineate a triangle on the anterior surface of the femoral neck to indicate the two plane wedge osteotomy Locate the proximal cut by placing a 3cm long k wire on the anterior surface of the femur from the lesser to greater trochanter at the base of the neck along the edge of the capsule confirm position by c-arm

81. Externally rotate the leg and drill a second K wire on the AP plane just distal to the guide wire Begin the second osteotomy line from the lesser trochanter to the growth plate of the greater trochanter Make a single osteotomy along the posterior cortex and completely remove the wedge and by maintaining traction internally rotate or abduct the leg to close the osteotomy . Use cannulated screws to hold the osteotomy , use only one screw to span the physis of the femoral head avoiding superolateral quadrant .

82. After treatment Partial weight bearing with cruches for 6 to 8 weeks than full weight bearing Malunited slipped capital femotal epiphysis A malunited slip differs from a chronic slip only in that with the former the epiphysis plate as fused and further slipping will not occur To correct a deformity consisting mainly of coxa vara but with some external rotation a closing wedge trochanteric osteotomu is sufficient with the base of wedge laterally

83. -Correcting a deformity consisting of coxavara hyperextension and moderate or severe external rotation is more difficult this triple de formity may be corrected by a ball and socket osteotomy made at the level of lesser trochanter or a biplanewedge osteotomy

84. Southwick’s intertrochantric osteotomy This is measured biplane intertrochanteric osteotomy in which degree of correction is accurately pre determined before surgery. Osteotomy through the trochanter is most useful when the head has slipped from 30-70d is considered minimum and is fixed insitu with threaded pins Initially the limitation of joint movement due to muscle is overcomed by longitudinal traction in mild abduction and an internal rotation strap for few days.

85. The X-ray measurements are made on both AP and frog leg lateral views. AP view gives the degree of varus deformity. Frog leg lateral view gives the measure of posterior tilting. Measurements are made by template models on X-ray prior to surgery.

86. Complications 1.Avascular necrosis : More common with moderate and severe slips and less common with mild slips. Avn is common following femoral neck osteotomy33%,Open reduction with knowles pin- 27%, less common with in situ fixation – 1.5% and after trochanteric osteotomy – 10%. AVN probably results from interruption of retrograde blood supply and is apparently influenced by the original injury. Forceful repetitive manipulatations , open reductions, osteotomies of femoral neck and superolateral placement of pins.

87. 2. Chondrolysis : Sometimes termed as ‘acute cartilaginous necrosis’ is an affection of the hip joint characterized pathologically by rapid loss of articular cartilage and clinically by development of continuous pain and severe restriction of motion.

88. A joint space that measured less than 3mm width and decreased range of motion are required for the diagnosis. Occurs more often in females and black. More common following trochanteric osteotomy - 59%, open reduction -55%. Femoral neck osteotomy – 37%, pin protruding into the joint – 51%. It is usually diagnosed within the first 6-9 months of observation

89. The joint space is rapidly lost and severe limitation of movement is present. Subsequently the width of the joint space usually increases slowly and range of motion also increases slightly. If severe joint space narrowing persists with limitation of joint motion arthrodesis or arthroplasty should be considered. Conservative treatment by bed rest , traction. Usually the joint goes to ankylosis

90. 3. Osteorthritis : Normally pressure forces of weight bearing are widely distributed over the femoral head. In coxa vara pressure forces are concentrated over a smaller area causing degeneration of cartilage and incongruous joint surfaces. The time required for these changes to develop was long and varied from 18 months to 4 years after onset.

91. 4. Fractures: Fractures can occur just distal to the knowles pins. So the pins should be removed after the epiphyseal plate has fused. Over reaming of the femoral neck also cause a stress fracture. 5. Continued slipping: In case of conservative treatment or in which pins were not placed far enough proximally or removed before the physis had completely fused.

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