The Hamstring ACL: Success and Understnding How and Why! Orthopedic - - PowerPoint PPT Presentation

The Hamstring ACL: Success and Understnding How and Why! Orthopedic Summit 2017 Mark E. Steiner, MD New England Baptist Hospital Boston

Disclosures

• Royalties

Stryker

• Fellowship Support

Arthre Don Joy Mitek Smith & Nephew Con Med

• Research Support

Don Joy Stryker

Good and Bad of Hamstring Grafts

• Easy access
• Doubled G + ST

> 4000 N strength > 700 N/mm stiffness

• hamstring strength
• Minimal donor site morbidity
• Sensory nerve injury
• Incomplete graft harvest
• Hemorrhage
• hamstring weakness

Good Bad

Patinent Perspective on Graft Options

• Internet Information
• Good in HS & College athletes
• Offer all Options
• Hamstring Graft concerns:

Retears Muscle weakness Infection Small Graft Anxiety Poor fixation

Revisions Years

Retears Scandinavian Registries

• 60,000 ACL reconstructions (85% hamstring grafts)

Revisions Hamstrings 2.7 % PT 2.3 %

Gifstad AJSM ’14 Rahr AJSM ’13

Surgical Technique ? Patient Selection?

“Ham grafts increased the risk of revision compared with PT”

Allografts in Athletes ?

• MARS group 2014 1205 Revisions, mean age 26
• 1. “an autograft decreased risk rerupture”
• 2. “No differences between soft tissue and B-T-B grafts”
• MOON group 2801 ACL all ages
• 1. Allograft in young athletes increased risk for graft tear
• 2. No differences between soft tissue and B-T-B grafts
• Daruwalla 184 Division I College football players

Autograft was associated with a greater RTP

HSS ACL Graft Registry 2009 - 2013

• PT auto

47%

• Ham auto

30%

• Allograft

23%

• No Allograft in < 18 y.o.
• Overall revision 5.1%
• Failure: No association with graft type (BTB vs Ham)

Kaiser San Diego <18y.o. KSST 2016

• PT auto

10 %

• Ham auto

73 %

• Allograft

17 %

• Revision PT

5.5%

• Revision Ham

7.5%

• Revision Allograft 13.2%

Infection Ham vs PT (> 7000 cases)

• Ham .6 %

(20 in 3257 cases)

Maletis AJSM ’13

PT .06% ( 2 in 2965 cases)

• Ham 2 in 118

Katz Arth’08

PT 0 in 52 Katz Arthroscopy ’08

Graft Irrigation May Prevent Infections

No Hamstring irrigation 1.7% infection (1095 cases) Vancomycine Hamstring irrigation 0% infection (2034 cases)

Phegan ‘16 Perez ‘16

Graft Size and Graft Strength

• Graft size related to height, weight and sex
• 4 strand grafts < 8 mm increased failures

Spragg ’16 Magnussen ’11 Mariscalco ’13

• ? Tensioning vs Size

Hamner ‘99 7 mm Hamner ‘99

Hamstring Tensioning Equal on All Limbs

• Manual tension

2831 N

• Equally tension

4590 N = PT Hamner JBJS ‘99

NO YES

Making Hamstring Grafts Larger 5 vs 4 strands

• Add allograft to make 9 mm Ham = poor results

Burrus ’15, McCarty ‘17 ?

• Make 5 strand graft =

good results Lee ’14

Lavery ‘14

Interference Screw Fixation with Osteoporotic Bone

Domnick J Arth ‘17

• Low Fixation Strength with osteoporotic

bone

• Consider BTB graft with older patients
• Consider staple or sutures to a post

Hamstring Weakness with hamstring ACL ? Related to Pain or Regeneration

• Normal flexion torque @ 2yr

Karlson ‘94

• All tendons regenerated = Normal

Flexion and Int Rot Strength

Ahlen ‘12

• 11% No Tendon regeneration

Less Strength & Agility

Choi ‘12

Set Up and Incision

• Done in 90° flexion
• Vertical Incision near tibial tubercle

Graft Preparation

• Circumferential Ligate
• Equal tensioning sutures

Locating an “Anatomic” Femoral Tunnel

• Remnants
• Clock face
• Ridges
• Measurements 

Measurements in 90° flexion

Height and Depth Guidelines for Anatomic Femoral Tunnels in Anterior Cruciate Ligament Reconstruction: A Cadaveric Study

• A. David Davis, M.D. J. Arthroscopy 2016

Measurements to the ACL Center at 90° flexion

• 8.5 mm up lateral wall
• 1.5 mm deep to the low point

Radiographic Grid Validation of Measurements

• ACL height ≈ Prior Measurements
• ACL depth: ? Slightly shallow to Prior Measurements

Prior measurements

AM Aimer at Height of ACL → Point close to ACL center

• 7 mm offset aimer
• Elevated 8.5 mm

View Pilot Hole from Medial Portal Medial Portal View Lateral Portal View

Aimer Placed Through AM Portal Pin Positioned in Starter Hole

Guidepin Placement

• Pin Exits in safe zone on lateral thigh

Advance Flexible Reamer Over Pin

Tunnel low at 90° = Tunnel posterior at 20°

V

90° extended

Tibial Tunnel Placed Relative to Notch

• Normal ACL “bundles” into the notch
• ACL graft is a cylinder

Tibial Tunnel Placed Medial

Passage of the Graft

• One suture tensions all 4 limbs equally

Interference Screw Fixation with Rigid Screwdriver no hyperflexion place pin first to prevent graft / screw wrapping

Tibial Fixation

• Equally Tension
• Knee in full extension
• Fixation with IS = or 1 mm larger than tunnel

Tibial Tunnel Placed Medial

Graft Placement > Graft Type = Stable Knee

V

90° extended

8.5 mm

Hamstring Graft for Whom

• Patient requests
• Pain and motion concerns
• recreational athletes
• Senior athletes who don’t want an allograft