|

Periacetabular Osteotomy

Planning

B

Preoperative Plan

1

Template osteotomy

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
C

Room Preparation

1

Surgical instrumentation

  • forked, angled osteotomes

2

Room setup and equipment

  • setup OR with radiolucent operating table
  • c-arm in from contralateral side
  • Monitor at foot of bed

3

Patient positioning

  • supine
  • ipsilateral arm abducted on arm board or placed across the chest
  • operative extremity prepped and draped free
  • proximally to costal margin
  • posteriorly to at least the posterior third of the ilium
  • medially to the umbilicus

Technique

D

The Modified Smith Peterson Approach

1

Mark the incision

  • start the incision 3 cm proximal to the ASIS and extend distally 10 cm
  • the incision should curve medially

2

Raise subcutaneous flaps

3

Identify the fascia over the TFL muscle belly

  • incise the fascia in line with the muscle fibers
  • bluntly elevate TFL off intermuscular septum

4

Reflect the external oblique aponeurosis

  • identify the plane between the external oblique and the gluteus medius and develop it to expose the periosteum over the iliac crest
  • divide periosteum is sharply over the iliac crest and carry subperiosteal dissection out over the inner table of the ilium.
E

Iliac Spine Osteotomy

1

Start the iliac spine osteotomy

  • osteotomize the anterior superior iliac spine, preserving the origin of the sartorius and the inguinal ligament
  • incise the periosteum on the medial edge of the iliac crest and reflect medially with the origin of the iliacus muscle
  • elevate direct head of the rectus from the anterior inferior iliac spine and reflect distally (may not be necessary if rectus sparing approach is utilized)
  • leave a stump of the tendon on the AIIS for later repair

2

Expose the hip capsule

  • psoas sheath is opened longitudinally and the psoas tendon is retracted medially
  • expose the hip capsule anteriorly and inferomedially
  • facilitate exposure by hip flexion and adduction
  • alternatively, the psoas may be retracted by subperiosteal release of its sheath from the pubic ramus and separating the sheath from the capsule in an effort to avoid scarring of the tendon within the sheath
F

Ischial Osteotomy

1

Deep dissection for osteotomy

  • interval between the medial joint capsule and the iliopsoas tendon is developed and sequentially dilated
  • use the tip of a long handled Mayo scissor and Lane bone levers, with the tips of each palpating the anterior ischium at the infracotyloid groove and the medial and lateral aspects of the ischium

2

Place the osteotome through interval between medial hip capsule and psoas tendon

  • place tip in contact with the superior portion of the infracotyloid groove of the anterior ischium just superior to the obturator externus tendon

3

Check placement with radiographs

  • start the infra-acetabular osteotomy just distal to the inferior lip of the acetabulum and aim towards the middle of the ischial spine

4

Impact the osteotome

  • osteotome is impacted in a posterior direction 15-20mm deep through first the medial cortex
  • impact the osteotome through the central part of the ischium
  • impact the osteotome to the lateral cortex
  • abduct the leg during this step to protect the sciatic nerve
G

Pubic, Iliac and Posterior Column Cuts

1

Facilitate exposure to the pubic ramus

  • flex and adduct the hip to increase the exposure to the hip
  • psoas tendon and medial structures are gently retracted medially

2

Prepare the pubic ramus cut

  • incise the periosteum along the axis of the superior pubic ramus
  • continue careful circumferential subperiosteal dissection
  • place a pair of narrow curved retractors subperiosteally around the anterior and posterior aspects of the pubic ramus
  • protect the obturator nerve
  • impact a third spike retractor into the superior cortex at least 1 cm medial to the medial most extent of the iliopectineal eminence
  • retract the iliopsoas and the femoral neurovascular bundle medially

3

Perform the pubic ramus cut

  • orient the pubic cut from anterosuperior and lateral to posteroinferior and medial
  • avoid creating a bony spike in the mobile fragment
  • two options for osteotomy
  • osteotomy can be performed by passing a Gigli saw around the ramus using a Satinsky vascular clamp and sawing upward away from the retractors
  • can also be performed by impacting a straight osteotome just lateral to the spike Hohman

4

Prepare the iliac cuts

  • release the periosteum on the inner surface of the ilium
  • clear the subperiosteal surface of the ilium and the quadrilateral surface
  • identify the sciatic notch with a large Hohmann retractor

5

Assess the lateral cortex of the ilium

6

Protect the abductors

  • A 1.5- to 2-mm subperiosteal window is created beneath the anterior abductors just distal to the ASIS without disturbing the abductor origin
  • narrow, long, spiked Hohmannn retractor is placed in this window and the tip of the Hohman should point toward the apex of the sciatic notch

7

Make the supra-acetabular cut

  • use the Hohman retractor as a guide, confirm planned level and orientation of the iliac osteotomy with the image intensifier on the lateral projection view
  • make the iliac cut with an oscillating saw in line with the narrow Hohmann retractor, until reaching a point about 1cm above the iliopectineal line (well anterior to the notch)
  • first cut the medial cortex
  • abduct the leg lower extremity to protect the sciatic nerve
  • cut the lateral cortex

8

Make the posterior column cuts

  • flex and adduct the leg to faciltate retraction of medial structures
  • reverse blunt Hohmann retractor is placed medially with its tip on the ischial spine to expose the posterior column
  • osteotomy is performed through the medial cortex with long straight 1.5cm osteotome
  • osteotomy extends from posterior end of the iliac saw cut, passing over the iliopectineal line, through the medial quadrilateral plate, parallel to the anterior edge of the sciatic notch on the lateral projection of the image intensifier, and is direct toward the ischial spine
  • osteotomy must extend at least 4 cm below the iliopectineal line to avoid entry into the acetabulum when completing the final posteroinferior osteotomy
  • the posterior cut is made first through the medial, then second through the lateral wall of the ischium

9

Complete the osteotomy of the posterior-inferior corner

  • may be completed directly with an angled chisel or may be completed by indirect fracture through manipulation of the fragment
H

Mobilization and Correction

1

Place a Schanz pin in the supra-acetabular region

  • 3.2mm drill hole is made parallel, and just distal to, iliac osteotomy
  • T-handle chuck is used to insert Schanz screw into acetabular fragment, well above the dome of the acetabulum

2

Test the mobility of the fragment

  • if there is lack of full mobility
  • check the
  • periosteum around the pubic ramus
  • the posterior cortex at the final cut
  • the ischial cut

3

Perform the correction in the desired plane

  • A 1-inch straight Lambotte chisel is placed into the supra-acetabular iliac saw cut to both confirm completion of the lateral cortex osteotomy and protect the cancellous bone above the acetabulum during displacement
  • A bone spreader is placed into the iliac osteotomy between the posterosuperior intact ilium and the Lambotte chisel anteriorly
  • the tines of a Weber bone clamp are placed onto the superior ramus portion of the aceabular fragment in such a way as to place its handle anterior to, and in contact with, the Schanz screw
  • while gently opening the bone spreader, the Schanz screw and Weber clamp are used to internally rotate the fragment and mobilize the acetabular fragment
  • most common corrective maneuver (to correct anterior and lateral deficiencies)
  • lift the acetabular fragment slightly toward the ceiling, creating initial displacement
  • followed by a three step movement of lateral, distal, and internal rotation
I

Fixation

1

Place provisional fixation

  • place provisional fixation with three or four smooth 2.4 mm K wires

2

Check correction with radiographs

  • check an AP radiograph of the pelvis that is centered over the symphysis pubis
  • the symphysis pubis should be in line with the saccroccoygeal joint
  • the obturator foramen should be symmetric
  • the pelvis should be horizontal

3

Evaluate correction with radiographs

  • evaluate the AP radiographs for
  • lateral center edge angle >20 deg
  • acetabular inclination (Tonnis angle) 0-10 deg
  • medial translation of the joint hip center
  • the position of the teardrop
  • the version of the acetabulum

4

Place final fixation

  • use three or four 3.5 or 4.5 mm cortical screws for final fixation

5

Confirm final reduction and fixation

  • use imaging to confirm acetabular correction and fixation placement

6

Assess range of motion

  • hip flexion must be greater than 90 degrees
  • Check for impingement on a lateral project image in 90 deg of flexion
  • assess joint stability by extension, abduction and external rotation
J

Wound Closure

1

Remove prominent acetabular fragment

  • trim the prominent acetabular fragment with an oscillating saw
  • use the trimmings to fill the iliac gap

2

Repair the hip capsule

  • approximate the anterior hip capsule with absorbable suture if capsulotomy was performed

3

Reattach soft tissue attachments

  • repair the rectus tendon origin with nonabsorbable suture
  • reposition and fix the ASIS fragment with nonabsorbable suture with drill holes in the ilium

4

Deep closure

  • repair oblique fascia to the abductor fascia over the iliac crest

5

Superficial closure

  • use 3-0 vicryl for subcutaneous tissue
  • use 3-0 monocryl for skin

Patient Care

K

Preoperative H & P

1

Obtains history and performs basic physical exam

  • perform neurovascular exam
  • location of , quality of and activities associated with hip pain are recorded
  • document gait pattern, leg length and range of motion

2

Order basic imaging studies

  • AP and false profile view, cross table view and functional views in abduction

3

Perform operative consent

  • describe complications of surgery including
  • technical complications
  • nerve palsy
  • bleeding
  • RSD
  • DVT
  • infection
L

Perioperative Inpatient Management

1

Write comprehensive admission orders

  • IV fluids
  • DVT prophylaxis
  • pain control
  • advance diet as tolerated
  • foley out when ambulating
  • check appropriate labs
  • wound care
  • remove dressings POD 2
  • appropriate medical management and medical consultation
  • inpatient physical therapy

2

Discharge patient appropriately

  • pain meds
  • partial weightbearing
  • monitor neurological and vascular status
  • schedule follow up in 6 weeks
M

Intermediate Evaluation and Management

1

Recognize vascular, nerve or other associated injuries

2

Appropriately interprets basic imaging studies and recognizes fracture patterns

  • interpret radiographs of the hip

3

Makes informed decision to proceed with operative treatment

  • describes accepted indications and contraindications for surgical intervention

4

Provides post-operative management and rehabilitation

  • postop: 6 week postoperative visit
  • check radiographs
  • diagnose and management of early complications
  • may begin to ween from crutches depending on healing
  • postop: 12 week postoperative visit
  • check radiographs
  • start resistance exercises
  • check radiographs yearly

5

Capable of diagnosis and early management of complications

N

Advanced Evaluation and Management

1

Recognizes factors that could predict difficult reduction and post-operative complication risk

  • abnormal vascular examination
  • neurological deficits

2

Appropriately orders and interprets advanced imaging studies

3

Completes comprehensive pre-operative planning with alternatives

4

Modifies and adjusts post-operative treatment plan as needed

  • recognize deviations from typical postoperative course
O

Complex Patient Care

1

Develops unique, complex post-operative management plans

 

Please rate topic.

Average 3.3 of 3 Ratings

Topic COMMENTS (0)
Private Note