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Osteochondral Plug Allograft Transfer of the Knee

Planning

B

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
C

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

Technique

D

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
E

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
F

Lesion Evaluation and Preparation

1

Plan the best perpendicular approach

  • place a 16 gauge needle to plan the best perpendicular approach to both the defect and the donor sites

2

Prepare the defect

  • prepare the defect by removing loose debris
  • freshen the edges with a curette or an arthroscopic nife to create perpendicular chondral walls
  • clear the subchondral bone of any residual articular cartilage
  • avoid generalized bone bleeding
G

Determining the Number of Grafts

1

Measure the defect size and shape

  • use a probe to obtain a preliminary measurement of the defects shape and dimensions

2

Determine the number of grafts needed to fill the defect

  • when more than one graft is used, maintain a 2-3 mm bone bridge between the recipient sites to ensure a good press fit

3

Measure depths of the lesions

  • measure the depths of the lesion using a 2 mm mark on the harvester
  • 6 mm grafts hav been shown to fill the diameter of the defects the best
  • larger plug harvesters are available but may require an arthrotomy and are more likely to encroach on weightbearing areas at harvest sites

4

Place grafts in the appropriate order

  • place the grafts starting at the periphery of the defect so that the articular cartilage matches the adjacent chondral edge after transplantation

5

Measure the depth of the lesions

  • analyze the depth of the defect
  • in most cases a standard 10.5-12 mm harvester is sufficient
  • osteochondral lesions or lesions with significant bone loss may require the use of variable depth harvester and placement of grafts that have cancellous sections standing above the crater base
H

Defect Preparation

1

Debride the subchondral bone

  • remove any residual articular cartilage from the subchondral bone

2

Drill the recipient site

  • drill the recipient site before harvesting the donor autograft plugs
  • this allows the selection of the best match on the femoral surface between the donor grafts and the articular cartilage adjacent to the recipient sites
  • using the COR perpendicularity system reproducibly identifies the best orientation for drilling the recipient site
  • this also makes it feasible to drill the recipient site before harvesting the grafts

3

Insert the drill guide

  • insert the drill guide with the perpendicularity rod through the portal and into position at the recipient site

4

Disengage the drill guide

  • with the drill guide positioned in a perpendicular orientation, turn the perpendicularity rod counterclockwise until it disengages
  • remove the rod

5

Drill the recipient sites

  • drill the recipient sites with the corresponding COR drill bit under direct arthroscopi visualization
  • keep the drill perpendicular to the articular surface
  • the projecting tooth at the drill keeps the drill from walking
  • this allows precise recipient site placement by creating a starter hole

6

Drill to the appropriate depth

  • advance the drill to the appropriate depth using the markings 5 mm, 8mm,10 mm, 12 mm and 15 mm and 20 mm that is found on the side of the drill
  • compare this line to the adjacent articular cartilage
  • the fluted drills concave sides remove bone during drilling and reduce both friction and heat
  • in the cases of subchondral bone loss the depth should be used and the depth underdrilled to restore the contour and height of the articular surface
  • this is done by aligning the laser mark with the desired articular cartilage height
  • the recipient holes can be drilled at the same time or sequentially after autograft insertion

7

Maintain the bony bridge

  • care should be taken to maintain a bone bridge between the recipient sites 2 to 3 mm and avoid recipient site convergence

8

Insert the harvester into the disposable cutter

9

Remove the retropatellar fat pad

  • completely debride the retropatellar fat pad to improve visualization and to avoid soft tissue entrapment

10

Insert the perpendicularity rod

  • insert the perpendicularity rod into the harvest cutter assembly before the insertion into the joint
  • the perpendicularity rod will function as an obturator and minimize both soft tissue capture and fluid loss as the assembly is inserted into the knee

11

Prepare the graft harvest

  • position the harvester delivery guide/cutter/perpendicularity rod assembly on the donor site in preparation of the graft harvest
  • use the perpendicularity rod to confirm the perpendicular position of the cutter and then remove
  • rotate the arthroscope to confirm alignment from many angles

12

Cut to the desired depth

  • use a mallet to tap the harvester delivery guide/cutter to the desired depth

13

Remove the plug

  • remove the plug by gently twisting the T-Handle while withdrawing the plug
  • avoid toggling the donot hole

14

Place the harvest delivery system

  • insert the harvester delivery guide system/cutter into the graft loader
  • push down firmly until it makes contact with the bottom of the loader
  • push the harvest graft from the cancellous bone side of the graft plug upwards into the harvester/delivery system guide and out of the cutter section

15

Remove the harvester from the cutter

  • the graft plug will remain inside the harvester until it is transplanted
I

Graft Insertion and Backfilling

1

Disassemble the harvester tube from the cutter

2

Place the harvester tube in the clear plastic insertion tube with depth markings

  • place the plastic plunger in the harvester delivery system before insertion of the delivery into the joint

3

Place in the knee

  • insert the loaded harvester-clear plastic delivery guide system into the knee
  • the portal may need to be enlarged for passage of the delivery guide system
  • place the clear end of the delivery system with the graft tip slightly projecting perpendicularly at the recipient site outlet

4

Position the autograft

  • align the articular cartilage of the autograft with the adjacent articular cartilage
  • implant with gentle tapping until it is flush with the articular cartilage
  • the 8mm side is recommended for 4 mm and 6 mm grafts
  • the 12 mm side is recommended for 8 mm and 10 mm grafts
  • use a universal tamp to fine tune the graft placement

5

Fill the donor sites

  • especially for harvested plugs greater than 6 mm in diameter or if multiple plugs have been harvested from a single area
  • larger diameter and deep defects can cause excessive stress on the surrounding cartilage and degeneration
J

Wound Closure

1

Use 3-0 and 4-0 biosyn for closure

  • apply steristrips

2

Cover with tegaderm and occlusive dressings

Patient Care

K

Preoperative H & P

1

Obtain history and perform basic physical exam

  • history
  • Age
  • Gender
  • HPI
  • PMHx
  • identify medical co-morbidities that might impact surgical treatment
  • Social history
  • physical exam
  • ROM
  • joint effusion
  • joint tenderness
  • complete neurovascular exam of extremity.

2

Order basic imaging studies

  • order triplanar standing radiographs of the knee

3

Perform operative consent

  • describe complications of surgery including
  • pain
  • infection
  • gritty sensation of the joint
  • loss of motion
  • recurrent effusion
L

Perioperative Inpatient Management

1

Discharges patient appropriately

  • pain meds
  • schedule follow up in 2 weeks
  • outpatient physical therapy
  • immediate range of motion exercises without a brace are begun
  • non-weightbearing for 3 weeks
M

Outpatient Evaluation and Management

1

Obtains focused history and performs focused exam

  • concomitant and associated orthopaedic injuries
  • evaluate for
  • knee pain
  • mechanical symptoms
  • pain or swelling with ADLs and sports
  • joint line tenderness
  • knee effusion
  • associated with decreased quadriceps strength

2

Interprets basic imaging studies

  • standing radiographs
  • 30 degree flexion lateral
  • AP weightbearing in extension
  • 45 degree PA flexion weightbearing views

3

Prescribes and manages non-operative treatment

  • Injects/aspirates knee
  • guides trial of medical managment
  • NSAIDS
  • attempts trial of physical therapy
  • quad strength closed chain

4

Makes informed decision to proceed with operative treatment

  • documents failure of nonoperative management
  • describes accepted indications and contraindications for surgical intervention

5

Provides post-operative management and rehabilitation

  • postop: 2-3 week postoperative visit
  • wound check
  • remove sutures
  • diagnose and management of early complications
  • continue touchdown weightbearing
  • postop: 4-6 week postoperative visit
  • check range of motion
  • progressive weight bearing weeks 3-6 weeks after surgery
  • full weightbearing beginning at 6 weeks
  • progressive quadriceps strengthening
  • diagnosis and management of late complications
  • postop: 4 months year postoperative Visit
  • full athletic activity at 4 months
N

Advanced Evaluation and Management

1

Appropriately orders and interprets advanced imaging studies

  • MRI

2

Provides complex nonoperative treatment

  • concomitant injuries
  • ligament
  • fractures

3

Modifies and adjusts post-operative treatment plan as needed

  • knee arthrofibrosis
  • continued pain
O

Complex Patient Care

1

Treat complex complications

 

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