Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Osteonecrosis of the Knee
Updated: Oct 4 2016

Microfracture of the Knee

Preoperative Patient Care
Operative Techniques
E

Preoperative Plan

1

Determine pathology using MRI

  • radial tear
  • horizontal cleavage tear
  • displaced bucket handle tear
  • meniscal root tear
  • discoid meniscus

2

Execute surgical walkthrough

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

Room Preparation

1

Surgical Instrumentation

  • standard arthroscopy pump
  • motorized meniscal shaver
  • toothed grasper
  • double loaded 2-0 or 0 nonabsorbable sutures with long flexible needles

2

Room setup and Equipment

  • standard OR table with leg holder

3

Patient Positioning

  • supine
  • leg holders
  • place leg holder 5 to 8 cm proximal to the superior pole of the patella to maximize control of the limb
  • contralateral leg is placed in a well leg holder
  • for the diagnostic portion of the procedure is placed at the foot of the bed
  • for the remainder of the procedure, the foot of the bed is dropped
G

Scope Insertion

1

Mark out the anatomy of the knee

  • draw out the patella, patellar tendon, medial and lateral joint lines and the posterior contours of the medial and lateral femoral condyles

2

Place anterolateral portal

  • use 22 gauge needle on syringe and bury the needle
  • make wheal at skin and then 11 blade in same direction as the needle
  • place scope in same direction as needle and blade
  • hug the patellar tendon

3

Place anteromedial portal

  • place knee in 30 degrees of flexion with valgus moment applied
  • use a spinal needle to assess direction and appropriate superior/inferior direction.
  • visualize with lateral portal
H

Diagnostic Arthroscopy

1

Visualize

  • suprapatellar pouch
  • patellofemoral joint (take picture)
  • place bump under heel prn
  • lateral gutter
  • look for loose bodies and peripheral tears of LM
  • get MFC in view
  • bring knee into slight flexion and valgus as you go into medial compartment.
  • foot goes on to opposite hip and use standee to stabilize your foot
  • medial meniscus (take picture)
  • drop leg to flexion (bump should be under knee)

2

Establish far anteromedial portal

  • use 18-gauge needle to make sure that you clear the MFC and can get to the 2 o’clock (LEFT) or 10 o’clock (RIGHT) knee

3

Visualize

  • medial compartment - probe medial meniscus, articular cartilage
  • intercondylar notch – ACL/PCL (take picture)
  • lateral compartment – probe lateral meniscus, articular cartilage (take picture)
  • assess the full thickness articular lesion
I

Initial Preparation

1

Debride all unstable cartilage

  • debride all of the exposed bone of all remaining unstable cartilage
  • use a hand held curved curette and a full thickness radius resector to debride the cartilage
  • it is critical to debride all loose or marginally attached tissue from the surrounding rim of the lesion

2

Remove the calcified cartilage layer

  • remove the calcified cartilage layer that remains as a cap to many lesions
  • this is preferabely done with a curette
  • thorough and complete removal of the calcified cartilage layer is extremely important

3

Maintain the integrity of the subchondral plate

  • do not debride to deeply
  • the prepared lesion with a stable perpendicular edge of healthy well attached viable cartilage surrounding the defect provides a pool that helps hold the marrow clot (super clot) as it forms
J

Microfracture

1

Make multiple holes

  • these are microfractures in the exposed subchondral bone plate
  • use an awl with an angle that permits the tip to be perpendicular to the bone as it is advanced
  • typically this is 30 or 45 degrees
  • use a 90 degree awl on the patella or other soft bone
  • this should only be advanced manually

2

Position the holes appropriately

  • make the holes close together but not so close that one breaks into another IE breaking the subchondral plate between them
  • this usually results in microfracture holes that are approximately 3 to 4 mm apart

3

Determine the appropriate depth of the holes

  • when fat droplets can be seen coming from the marrow cavity, the appropriate depth of 2-4 mm has been reached

4

Drill holes in the appropriate order

  • microfracture holes around the periphery of the defect should be made first
  • these holes should be made immediately adjacent to the healthy stable cartilage rim
  • complete the process by making the microfracture holes towards the center of the defect
K

Wound Closure

1

Use 3-0 and 4-0 biosyn for closure

  • Apply steristrips

2

Cover with tegaderm and occlusive dressings

Postoperative Patient Care
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options