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High Tibial Osteotomy
Updated: Oct 4 2016

High Tibial Osteotomy

Preoperative Patient Care
Operative Techniques
E

Preoperative Plan

1

Template the mechanical axis

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

  • plating system for HTO

2

Room setup and Equipment

  • standard OR table with leg in supine position

3

Patient Positioning

  • supine
G

Diagnostic Arthroscopy

1

Perform a diagnostic arthroscopy

  • check the status of the lateral compartment
  • if there is lateral compartment OA or chondral defects, off loading the knee into that compartment may be detrimental to the long term results of surgery
  • check the status of the patellofemoral joint
  • check for significant patellofemoral OA
  • significant OA of the lateral patellar facet and the lateral trochlea can be exacerbated with HTO

2

Identify any meniscal tears

  • debride any meniscal tears back to where they are stable
H

Initial Dissection

1

Locate the proper bony anatomic landmarks

  • identify the tibial tubercle, posteromedial tibia and the joint line with a skin marker

2

Mark and make the skin incision

  • mark the incision so that it lies 2 to 3 cm posterior to the tibial tubercle and 1 cm distal to the joint line
  • extend the incision distally for 5 to 6 cm
  • dissect through the subcutaneous fascia down to the Sartorius fascia

3

Identify the musculature of the knee

  • palpate the superior border of the gracilis hamstring tendon.
  • open the Sartorius fascia along the superior border of the gracilis tendon
  • release the Pes Bursa medially from the tibial tubercle in an inverted L fashion
  • elevate the pes bursa distally taking care to the develop the plane between the bursa and underlying medial collateral ligament
  • proximally incise the retinaculum and layer 1 of the knee to the approximate level of the joint line

4

Place Z retractors

  • identify the patellar tendon anteriorly
  • identify the plane posterior to the tendon
  • place a Z retractor under the tendon to protect it
  • posteriorly dissect the MCL subperiosteally using a Cobb elevator
  • this is taken back toward the posteromedial border of the tibia
  • use the Cobb elevator to dissect the muscles and tissues from the posterior tibia along the line of the osteotomy
  • make sure to stay directly posterior on the tibia to avoid any neuromuscular injury
  • pass a finger across the posterior tibia
  • place a Z retractor posteriorly to protect the pes bursa,MCL and posterior neurovascular structures
I

Placing Guidepins

1

Check the mechanical axis

  • take an intraoperative mechanical axis view using either a Bovie cord or the alignment rod in the osteotomy set
  • using fluoroscopy place the alignment rod at the center of the femoral head

2

Align with the ankle

  • place the rod at the center of the ankle joint

3

Identify the mechanical axis

  • the location of the alignment rod in the coronal view of the knee is the intraoperative location of the mechanical axis
  • save these images for later comparison

4

Place the guidepins

  • place a guide pin from medial to lateral across the proximal tibia 1 cm distal to the joint parallel to the joint surface
  • the tip of the guide pin should be just proximal to the level of the fibula
  • verify the location of the guidepin with fluoroscopy

5

Place the osteotomy guidepin assembly

  • insert the osteotomy guidepin assembly onto the guidepin
  • the guidepin assembly acts on the same concept as an ACL tibial aiming guide

6

Place guidepines at the joint line

  • place the subsequent guidepins at the proper angle and oriented to the tip of the previous guidepin placed parallel to the joint line

7

Place a parallel guide sleeve onto the guidepin osteotomy assembly

  • the osteotomy guidepin assembly determines the angle of the cut in the coronal plane and has the ability to rotate in the sagittal plane to reproduce the anterior-posterior tibial plateau slope accurately

8

Set the angle of the guidepin assembly

  • set the angle of the guide pin assembly in the coronal place so that the guide pins will enter the proximal tibia above the tibial tubercle

9

Place the medial and lateral guidepins

  • place 2 guidepins from medial to lateral along the orientation of the osteotomy cut
  • verify the position with fluoroscopy

10

Remove the components

  • remove the parallel guide sleeve, guide pin assembly and the initial guidewire parallel to the joint line
J

Cutting and Opening the Osteotomy

1

Place the cutting guide

  • an optional cutting guide is available for positioning over the guide pins
  • always position the saw on the inferior surface of the guide pins to avoid inadvertent maltracking of the saw towards the joint surface

2

Make the osteotomy cuts

  • use the oscillating saw to cut the tibial osteotomy to within 1 cm of the lateral cortex
  • use fluoroscopy frequently to verify the depth and angle of the osteotomy cut
  • pay careful attention to the posterior and anterior tibial cortex cuts to avoid cutting the neurovascular structures and the patellar tendon respectively

3

Complete the osteotomy cuts

  • use thin osteotomes to complete the osteotomy within 1 cm of the lateral cortex

4

Test the osteotomy for distraction

  • perform the VALGUS BOUNCE TEST to assess whether or not the osteotomy is ready fro distraction
  • this ensures that adequate cuts have been made anteriorly and posteriorly
  • this allows the peroneal nerve, popliteus and lateral inferior geniculate artery to fall posteriorly

5

Distract the osteotomy

  • insert an osteotomy wedge into the osteotomy site
  • open the osteotomy to the desired correction
  • use fluoroscopy to assess the status of the lateral cortex and the progression of the osteotomy
  • be aware of propagation of the osteotomy to the lateral cortex with disruption of the lateral hinge or propagation of the osteotomy intra-articularly
  • this can usually be felt by a sudden pop or give of the osteotomy wedge on insertion

6

Establish the proper alignment

  • the posterior tine of the wedge should be as posterior as possible to avoid inadvertent increase in tibial slope
  • because of the triangular shape of the proximal tibia, the millimeter reading of the posterior tine will be greater than that of the anterior tine if the osteotomy is in the proper sagittal alignment
  • the opening of the anterior half of the osteotomy should be one third the height of the posterior half
  • this will verify that the tibial slope has not been significantly altered
K

Plate Fixation

1

Remove the osteotomy wedge

  • remove the handle of the osteotomy wedge
  • leave the anterior and posterior tines

2

Place the plate

  • place the proper sized osteotomy plate into the osteotomy site
  • slope the wedge in the plate from anterior to posterior

3

Secure the plate

  • secure the plate with 2 6.5 mm fully threaded cancellous screws in the proximal fragment
  • secure the distal fragment with 2 4.5 mm bicortical screws
L

Bone Grafting

1

Place the appropriate type of grafting in the osteotomy site

N

Wound Closure

1

Reattach the soft tissues

  • reapproximate the pes bursa over the distal portion of the osteotomy plate to its anatomic location with no. 1 vicryl
  • the horizontal incision in the sartorius fascia is closed with the no.1 vicryl as is the proximal split into the medial retinaculum
  • close the wound in the standard fashion
  • place the leg in a hinged knee immobilizer that is locked in extension

2

Close the subcutaneous tissue with 3-0 vicryl

3

Close the skin 3-0 monocryl

Postoperative Patient Care
Private Note