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Preoperative Patient Care
Operative Techniques
E

Preoperative Plan

1

Template osteotomy

  • this includes desired location of the implant, along with implant choice with regard to size, length, offset and angle

2

Execute surgical walkthrough

  • describe key steps of the operation verbally to attending prior to beginning of case.
  • describe potential complications and the steps to avoid them
F

Room Preparation

1

Surgical instrumentation

  • blade plate system
  • small or large fragment screws, depending on implant size
  • periosteal elevators
  • oscillating saw

2

Room setup and equipment

  • set up OR with radiolucent operating table
  • c-arm comes in from opposite side of patient
  • monitor is in surgeon direct line of sight at foot of OR table
  • flex the hip 90 degrees and abduct 45 degrees to obtain lateral views

3

Patient positioning

  • supine with a bump under the sacrum
  • bone holding clamps
G

Lateral Approach

1

Identify the vastus ridge

  • palpate the vastus ridge on the proximal lateral thigh (typically a few centimeters distal to the tip of the greater trochanter)

2

Make the skin incision

  • make the incision from the vastus ridge and extend distally in line with the femoral shaft
  • the incision should be slightly longer than the length of the templated blade plate
  • dissect down to fascia lata (Figure 2)
H

Deep Dissection

1

Split the fascia lata

  • split the fascia lata in line with the skin incision

2

Retract the vastus lateralis anteriorly

  • incise the vastus lateralis in L-fashion (off the vastus ridge and along the posterior aspect of the vastus lateralis; Figure 3)
  • Incising just anterior to the linea aspera facilitates subperiosteal dissection of the femur
  • if the dissection is as per above, the subperiosteal dissection will be just distal to the greater trochanteric apophysis
  • use fluoroscopy to identify the level of the greater trochanter apophysis

3

Perform subperiosteal dissection

  • subperiosteal dissection is carried out circumferentially with curved elevators (such as Crego elevators)
I

Pin Placement and Blade Plate Measurement

P

1

Identify pin placement

  • use fluoroscopy to identify the appropriate starting point on the proximal lateral femoral metaphysis for the guide pin

2

Place the guide pin

  • insert a 1.6 or 2.0mm guide pin in the femoral neck to a point short of the physis (Figure 4)
  • the pin starting point should be located so the chisel can be inserted easily up the femoral neck without exiting the neck inferiorly.
  • insert the pin at an angle that will allow for the amount of varus correction needed
  • for example, if a 90 degree blade plate is used and 40 degrees of varus correction is desired , then the pin should be inserted so that the angle between the guide pin and the femoral shaft is 130 degrees (130 minus 90 degrees = 40 degrees of varus)
  • in order to ensure correct placement of the proximal pin in the transverse plane, prior to pin insertion the hip is rotated internally until the greater troachenter is in its most lateral position.
  • this results in the femoral neck being parallel to the floor, so the pin is inserted parallel to the floor (in the transverse plane)
  • a 1.6 or 2.0mm smooth Kirschner wire is inserted

3

Check the pin placement with imaging

  • check the placement of the pin in AP and lateral views
  • the pin should be in the center of the femoral neck on the lateral view and in the inferior half of the femoral neck on the AP view

4

Measure the depth of the pin in the proximal femur

  • the depth of the pin in the femur is confirmed by placing a second k-wire next to the inserted pin and using a ruler to measure the difference in their inserted depths (Figure 5)
Pearls
  • The pin should be inserted to a depth equal to the length of the blade for the chosen blade plate
J

Blade Plate Chisel Placement

P

1

Place the blade plate chisel

  • insert the blade plate chisel under fluoroscopic control (Figure 6)
  • the chisel is inserted just cephalad to the guide pin
  • mallet the chisel into the femoral neck while the guide pin is used to help direct the insertion
  • make sure to keep the face of the chisel perpendicular to the femoral shaft in order to avoid inserting the chisel (and then the blade plate) in flexion or extension
  • for children with hard bone, the slotted hammer should be used to back out the chisel after every few hits with the mallet to advance the chisel (in order to avoid having the chisel become incarcerated in patients with strong bone)
Pearls
  • If the guide pin was inserted to the depth of the blade plate, advance the chisel just to the tip of the pin.

2

Confirm chisel location

  • check fluoroscopically that the chisel is well-positioned in the femoral neck in all views
K

Femoral Osteotomy

P

1

Insert derotation pins

  • insert derotation pins proximal and distal to the osteotomy sites. (Figure 7)
  • the pins allow the amount of rotation performed to be measured with a sterile goniometer
Pearls
  • Mark the sites for the osteotomies prior to inserting derotation pins.
  • Insert the proximal pin close to the chisel, to allow room for the angled (varus) proximal cut.

2

Perform the femoral osteotomy

  • make the first osteotomy cut distal to the chisel at a distance that is equal to the distance between the blade of the plate and the location where the plate angles medially (10mm for an infant plate, 12mm for a toddler plate and 15mm for child and adolescent plates)
  • this first osteotomy should be perpendicular to the long axis of the femoral shaft (Figure 8)
  • a second cut is made distal and parallel to this cut if the femur is to be shortened.
  • the final osteotomy is made in the proximal fragment and is parallel to the chisel if a 90 degree blade plate is going to be used. (Figure 9)
  • this cut starts halfway across the femur in order to avoid cutting into the femoral neck

3

Remove the medial bone wedge

  • the medial wedge of bone created by this final cut is removed
  • the psoas tendon is freed from this fragment with electrocautery and/or elevators since this fragment includes the lesser trochanter
  • a separate psoas lengthening is rarely needed for these patients
  • this also facilitates femoral head reduction
L

Reduction

P

1

Places the blade plate onto the inserter

  • place the blade on the insertion device before removing the chisel
  • make sure the head of screw on the inserter will be facing toward the ceiling once the plate is inserted (so the screw can be loosened and the inserter removed from the plate)

2

Place the blade plate

  • while controlling the position of the proximal femoral fragment, remove the chisel with a slotted hammer
  • gently insert the blade plate into the tract created by the chisel
  • ideally, at least the initial part of this can be done manually, but a mallet isused to gently tap the plate into place, as needed (Figure 10)

3

Check placement of the plate

  • when the plate is only partially inserted, positioning and direction are checked fluoroscopically to ensure satisfactory placement
  • when the blade plate inserter is contacting bone, it is removed and the plate is inserted to its final position using the impactor and mallet.
Pearls
  • When checking a lateral view, rotate the leg gently in order to minimize the risk of blade plate cutout proximally.

4

Reduction of the osteotomy and plate placement

  • with the hip flexed, the osteotomy is reduced
  • a bone holding clamp (such as a Verbrugge) holds the plate to the femur and maintains reduction
  • rotation is checked and adjusted, if needed
  • the reduction is checked clinically and fluroscopically

5

Place cortical screws

  • bicortical screws are used to attach the plate to the distal fragment (Figure 11)
  • at least one compression screw is used, whenever possible

6

Confirm placement of the blade plate with imaging

  • final fluoroscopic imaging confirms the femoral head is reduced, the blade plate is in the correct position and the screws are the appropriate length
N

Wound Closure

1

Irrigation

  • irrigate the wound copiously
  • this irrigation can be done with or without antibiotics added to the irrigant

2

Deep closure

  • reattach the vastus lateralis to the vastus ridge with a large (size 0 or 1) absorbable suture.
  • close the posterior margin of the vastus lateralis with a running stitch of the same size absorbable suture
  • close the fascia lata with a running suture of the same suture material and size
  • take care to keep the layers of the vastus lateralis and fascia lata separate (i.e. do not suture the fascia lata to the vastus lateralis)

3

Superficial closure

  • a 2-0 absorbable suture is used for the subcutaneous layer
  • a 3-0 absorbable, undyed monofilament is used for the subcuticular layer

4

Dressings

  • place a soft dressing on the incision

5

Immobilization

  • spastic CP
  • apply A-frame or spica cast for small children.
  • use a hip abduction pillow or hip abduction brace for larger children.
  • typically developing children
  • use a hip abduction pillow for young children (up to approximately 8 years).
  • make older children non-weightbearing with crutches or a walker
Postoperative Patient Care
Private Note