TECHNIQUE VIDEO
TECHNIQUE STEPS
 
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TECHNIQUE STEPS
Preoperative Patient Care
Operative Techniques
E

Preoperative Plan

1

Radiographic templating

  • template implant size

2

Execute surgical walkthrough

  • describe the steps of the procedure to the attending prior to the start of the case
  • describe potential complications and steps to avoid them
F

Room Preparation

1

Surgical Instrumentation

  • endoprosthetic system of the distal femur

2

Room setup and Equipment

  • Standard radiolucent OR table
  • fluoroscopy (optional)

3

Patient Positioning

  • supine position with bump underneath the hip
G

Extensile Longitudinal Medial Approach

1

Mark the incision

  • make a longitudinal incision proximally along the sartious border and follow it distally towards the medial aspect of the tibial tubercle
  • Any previous biopsy tract should be kept in line with the incision and should be ellipsed

2

Identify the saphenous nerve

  • identify and protect the saphenous nerve

3

Create interval

  • open the interval between the sartorius and vastus medialis
  • expose the superficial femoral artery and vein along the saphenous nerve
H

Tumor Margins and Neurovascular Mobilization

1

Mobilize structures

  • dissect the vessels and the saphenous nerve from proximal to distal
  • reflect the structures posterior and medial with the sartorious

2

Tie off vessels

  • tie off all geniculate vessels with 2-0 or 3-0 silk ties as they course from the vessels towards the distal femur and tumor
  • be careful to not tie off the medial or lateral sural vessels that are found posteriorly and are the main blood supply to the respective gastrocnemius muscles
  • these vessels will be the base of the gastroc flap if needed
  • be careful at the canal of Hunter because these vessels are just deep to the adductor tendon

3

Dissect out the popliteal vessels

  • distal to the canal of Hunter, dissect the popliteal vessels and reflect posterior and medial
  • visualize the short head of the biceps proximal to distal joining the long head laterally

4

Identify and protect the sciatic nerve

5

Expose the tumor

  • reflect the quadriceps laterally off the femur by separating the junction between the adductors and the vastus medialis proximal and medial to the tumor

6

Ligate the appropriate vessels

  • ligate the terminal profunda artery and vein just deep the medial intermuscular septum

7

Dissect out neurovascular structures

  • dissect the superficial femoral vessels, saphenous nerve and popliteal vessels from the tumor throughout its length to below the joint line

8

Incise the medial gastrocneumius

  • be sure not to ligate the medial sural vessels

9

Expose the distal aspect of the tumor

  • with the femoral vessels dissected and reflected, reflect a portion of or entire quadriceps along with the patella and patellar tendon over the tumor
  • this leaves the vastus intermedialis as an oncologic margin

10

Open the joint capsule

  • cut the ACL, PCL, popliteus tendon and the collateral ligaments
  • cut the posterior capsule while the popliteal vessels are kept in direct view or under your finger to prevent injury

11

Reflect the quadriceps over the tumor

  • leave a cuff of muscle on top of the tumor as the tumor margin

12

Make cortical marks

  • before dislocating the knee, place marks proximally on the femur and tibia
  • mark the distance between the points
  • this distance should be the same after the prosthesis is implanted
  • the anterior cortex is marked on the proximal femur to help with rotary alignment during the femoral stem insertion
  • the linea aspera is also used to approximate rotary position

13

Dislocate the knee

  • cut the short head of the biceps and the rest of the posterior capsule
I

Femoral Resection

1

Cut the femur

  • cut the femur with a saw at the predetermined level
  • remove one centimeter more than the assembled length of the femur

2

Identify pathology

  • send a sample of proximal marrow to pathology for fresh frozen analysis and tumor margin

3

Prepare the femur

  • ream the femur to accept the largest stem possible
  • chamfer the cut end
  • clean the cut end with an irrigating brush
J

Tibia Cuts

1

Prepare the tibia

  • remove 7 mm of proximal tibia
  • osteotomize the tibia with an oscillating saw with a slightly posterior slope
K

Confirm Length, Rotation, And Trial Components

1

Place trial components

  • remove half of the undersurface of the patellar fat pad
  • remove and prepare the undersurface of the patella with a burr to receive the patellar component
  • resurfacing the patella is optional as some surgeons opt not to resurface for pediatric patients

2

Perform trial reduction

  • measure to make sure that the post-construction distance is the same as the pre-resection difference
  • passively range the knee to assess for rotation, length, and patellar traction
  • check the tension of the neurovascular structures
L

Final Implant Placement and Hinge Assembly

1

Cement in the appropriate order

  • cement the tibia component and the patella first

2

Insert the femoral component

  • insert the femoral component slowly

3

Confirm measurements

  • make a final measurement with the components in place
N

Wound Closure

1

Perform deep closure

  • close the joint capsular tissue to the remaining capsule around the proximal tibia
  • use 0-Vicryl for deep closure
  • suture the sartorius to the vastus medialis over a 10 mm flat drain with an 0-Vicryl suture

2

Perform superficial closure

  • place a 10 mm flat drain
  • use 2-0 vicryl for subcutaneous closure
  • use 3-0 monocryl or staples for skin

3

Place dressings

Postoperative Patient Care
 

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