ACL RECONSTRUCTION- GRAFT

OPTIONS, TUNNEL PLACEMENT &

FIXATION

DR SHEKHAR SRIVASTAV

SR. CONSULTANT- Knee & Shoulder Arthroscopy Delhi Institute of Trauma & Orthopedics, Sant Parmanand Hospital, Delhi

ACL Surgery

ACL Tear-

No repair

Only Recontruction

Graft -

Autograft - common

Allograft

ACL RECONSTRUCTION

SUCCESS Quality of the

Graft Appropriate

Tunnel Placement Strong Graft

Fixation

Graft Options

Autograft BPTB Hamstring Quadriceps

Allograft

Bone-Patellar Tendon Graft

Considered GOLD standard

Middle third of patellar

tendon harvested(10-

11mm)

Incision

-Medial Vertical

-Transverse

10 mm wide graft

harvested

2.5 mm bone plug from

patella & Tibial tuberosity

Skin incision

Take the central slip of 10

mm

Mark bone tendon junction

BPTB Graft

Advantages-

Ease of harvest

Consistent size & shape

Strong bone-tendon interface

Strong Bone to Bone fixaton

Good healing

BPTB Graft

Dis-advantages-

Risk of patellar #

Patellar tendonitis

Patello-femoral pain

Donor site tenderness on

kneeling

Bigger incision scar

Loss of sensation lat.to scar

Hamstring Grafts

Quadrupled Semi-T / Doubled STG graft

4 strands of Hamstrings = 250% strength of

native ACL

Advantages Ȃ

Stronger graft

Smaller Incision- Cosmesis

Can be used in skeletally immature

GRAFT HARVEST

GRAFT HARVEST

GRAFT HARVEST

GRAFT HARVEST

GRAFT PREPARATION

GRAFT PREPARATION

Hamstring Grafts

Disadvantages-

Soft tissue to bone

healing

Tunnel widening

Technically difficult than

BPTB

Loss of Hamstring

strength( apprx 10%)

Quadriceps Tendon Graft

Bony end on one side

and soft tissue strip on

other

Cross-sectional area

thicker than BPTB

Disadvantages-

Donor site risks

Quadriceps tendon graft

INCISION: Anterior midline

Tendon exposure: central third

Harvested with a bone plug

Quadriceps tendon

Advantage

Comparatively less harvest site morbidity

Larger cross sectional area of graft

Disadvantage

Bone block at only one end of graft

Allografts

Advantages-

No graft site mobidity

Available off the shelf

Boon- Multiligamentous Injuries

Disadvantages-

Risk of disease transmission

Weak graft

Delayed incorporation

Not universally available,Expensive

Which Graft Better?

Both grafts give excellent results

- Clinically

- Functionally

- Instrumented Examinations

Choose Graft

- Experience & Training

- Comfort level

FAILURE OF ACL

Single Most Common

Cause

INCORRECT TUNNEL

PLACEMENT

TUNNELS FOR ACL

LENGTH

DIAMETER

POSITION

TIBIAL TUNNEL

ENTRY POINT

Tibial jig- set at an

angle of 45-550

300 medial to mid

sagital axis

Apprx. 4 cms below

joint line

Anatomic Tibial Tunnel

EXIT (INTRA ARTICULAR)

LANDMARKS-

(A) ACL Footprint

Center of ACL

footprint

(B) LATERAL Meniscus

Post. Border of Ant.

Horn

FEMORAL TUNNEL

Access for tunnel placement

-Through the Tibial Tunnel

- Through medial instrument portal

ANATOMICAL POSITION

-Over the top position

- Right Knee-9 Ȃ 10pm

- Left Knee- 2 - 3 am

12

6 3 9

Anatomic Femoral Tunnel

Anatomic Tibial Tunnel

Graft Passage

Graft Fixation

Graft fixation

Secure graft fixation is paramount to a successful

reconstruction

ACL rehab emphasizes on immediate movement

and weight bearing

High demand on initial graft fixation

Ultimate long term success of an ACL

reconstruction depends on healing of the graft

fixation sites and biological healing

Ideal fixation

Strong enough to avoid failure

Stiff enough to restore knee stabilty

Secure enough to avoid slippage

Ideal Graft fixation

Anatomic

Biocompatible

Safe and reproducible

MRI compatible

Allow easy revision

Graft Fixation Choice of graft fixation depends on

-Surgeon preference

-Choice of graft

-Surgical technique

Fixation Options

Femoral Ȃ Interference screws/Intrafix

- Cross pin fixation- Rigidfix/ Tranfix

- Endobutton Fixation

Tibial - Intererference Screws/ Intrafix

- Suture discs, Post with washer

Types of Fixation

Aperture Fixation: at the level of joint

Interference screws

Suspensory Fixation:

Cortical: Endobutton, Staples, Screw posts

Cancellous: Transfixation pins

Femoral Fixation

Graft properties- Strength Stiffness Slippage

Graft Tunnel Motion- Bungee Effect Windshield Wiper Effect

Bio-Interference Screw Fixation

Aperture Fixation

Compaction drilling

Dependent upon cancellous

bone

Post wall blowout

- Concern- Graft

maceration & failure at

physiological loading

Cross pin fixation

Impacted transversely into

lateral cortex

Implant passed under

looped graft

Implant perpendicular to

graft

Highest ultimate load

failure and stiffness

Concern- tunnel widening

and windshield wiper effect

Endobuttton Fixation Fixation at lateral femoral

cortex

No wear or abration of graft

Advantages- Osteoporotic

bones & femoral tunnel

blowout

Problems- fixation away

from aperture- tunnel

widening & bungee effect

Tibial Fixation

Interference screw/ Intrafix

Suture post

Dual fixation

POST-OP

Complications

Pre-op consideration

Patient selection- Non compliant/

Apprehensive

Timing of the operation

Immature Athlete

Med. Comp OA with ACL insufficiency

Complication- Graft

Graft harvest

Graft cut short

Small size

Prevent

careful harvest technique

Cut all band attached before using stripper

Dropped graft

Careful passing of graft

Another graft harvest

Complications

femoral tunnel

Improper tunnel placement-Anterior femoral tunnel

Residents ridge

Use femoral tunnel guides

Solution

Notchplasty

Posterior wall blow-out

Endobutton or transfix

Complications

Tibial Tunnel Improper tibial tunnel- anterior

tunnel placement

Intra-articular landmarks

Check guide wire impingement

before drilling

Solution

Notchplasty

Chamfering of the tunnel

IMPINGEMENT TEST

Complications

Neurovascular Ȃ most

serious complication

Vessel behind Post. Horn

Lat. meniscus

Early recognition and

prompt repair

Careful handling of

shaver and burr in

posterior compartment

Complication Recurrent Effusions

-Debris during surgery

-Reaction to bioabsorbable implants

-Vigourous physio

Management- Repeated aspirations

Infection - < 1%

Management- antibiotics & arthroscopic deb.

Stiffness Ȃ

- Improper tunnels

- Post-op arthrofibrosis

- Cyclops lesion

- Inadequate physio/ non-compliant patient

Management- Gentle MUA / Arthr. Adesiolysis

To Summarise

Autografts are better option than allograft

Both BPTB & Hamstring grafts work equally

well

Appropriate tunnel placement is essential to

prevent failure

Fixation method should be biological,

reproducible & should have sufficient strength

to allow early mobilisation & rehab

USE IT OR LOSE IT

THANK YOU Visit

www.delhiarthroscopy.

com

ARTHROSCOPY KNEE

Commonest surgery performed in UK

Treatment Ȃ Ligamentous and soft tissue injury of knee

> precise and accurate than open method

Less morbidity and early rehab

ARTHROSCOPIC ACL RECONSTRUCTION

Cruciate Ligaments

Anterior (ACL) Ȃ resists

anterior translation

Posterior (PCL) Ȃ resists

posterior translation

Collateral Ligaments

Medial (MCL) Ȃ resists

medially directed force

Lateral (LCL) Ȃ resists

laterally directed force

Ligaments of the Knee

Mechanism of Injury

ACL injury mechanism of injury

Twisting on fixed foot

Blow to the knee

Hyperextension

78% are non- contact

injuries (Noyes et al)

Examining the Patient

History

Pain & Instability

Examination

Motion of knee and degree of

swelling

Ligament specific tests of the

knee

Lachman test

Anterior and Posterior Drawer

MANAGEMENT

1/3 - No symptoms, Normal life

1/3 - Occasional instability,no strenuos activity

1/3 - Constant instability and pain

ACL deficient- little higher rate of future medial

meniscus tearing and arthritis.

ACL Reconstruction We’ll walk through an ACL reconstruction using the patient’s own grafts

Bony Tunnels are very precisely drilled in the tibia and femur to recreat

the normal anatomic position of the ACL . The graft is passed and

secured in bones.

SCORECARD

ENDOSCOPIC OPEN

Small incision x

Less pain x

Less morbidity x

Accuracy x

Early function x

Cosmesis x