what is new in crcl surgery in humans · double bundle - guidelines •measurement of the acl...

What is new in CrCl surgery in humans

ESVOT meeting, Lodi, Italy September 12, 2015

Stephen Bresina, Sc.D.

Kyon & Scyon Orthpoaedics

Failure Mechansim

• 30 % in USA due to contact (American Football)

• Non-contact failure - weight bearing foot is fixed on ground and upper body pivot causes rotation at knee joint

ESVOT, Lodi, Italy, Sept. 2015

Epidemiology of ACL injuries

ACL injuries per year ACL reconstructions per year

Sweden 5’000

England

30 per 100’000

USA > 550’000 (US Bancorp)

100’000-200’000 (journals)

≈200’000

Europe > 500’000 (Giesink, Kyon Symposium) > 180’000

New Zealand

36.9 per 100’000



ACL reconstruction Options

– Autograft

– Allograft

– Synthetic/prosthetic ligaments

– Ligament regeneration

Autografts – possible sources


• Patellar tendon, Referred to as BPTB • from the hamstring attachment to

the tibia – semitendenosus and gracilis tendons

• Quadriceps tendon • Iliotibial band • Tensor fascia lata • Achilles tendon

Graft Requirements

• Match the strength and stiffness of the natural ACL as close as possible

• Immediate rigid fixation

• Healing of the graft fixation sites are optimal

• Accesible for harvesting and to minimize damage or weakness of the donor site

No single graft source meets all of these requirements

No consesus in literature on the optimal choice


Graft Fixation

Match the strength and stiffness of the natural ACL as close as possible Immediate rigid fixation Healing of the graft fixation sites are optimal Accesible for harvesting and to minimize damage or weakness of the donor site • Graft Slippage is problem of fixation • Graft Elongation is a property of the graft material • Both can lead to late instability


Autograft - Bone-Patellar Tendon-Bone (BPTB)

• patellar tendon grafts use the middle third of the tendon

• plugs of bone from the kneecap above and the tibia below.


(BPTB) Graft – Gold Standard

• bone blocks pressed against tunnel with interference screws give good initial stability and ingrowth


Autograft - Hamstring tendons • hamstring tendons (semitendinosus and gracilis) are

taken as tendon only (no bone plugs) • incision is made along the inside edge of the knee, just

over where the hamstring tendons attach to the tibia • the center part of the semitendinosus and gracilis

tendons are removed. (sometimes only ST)


Autograft – Hamstring Tendons • the tendons are arranged into

three or four strips. • the strips are prepared to the

correct length and stitched together to hold them in place


Accufix GraftMaster from Smith and Nephew for graft preparation

Graft Strength

(D. Gulick, J Sport Science & Med. 2002) ESVOT, Lodi, Italy, Sept. 2015

Graft Stiffness

(D. Gulick, J Sport Science & Med. 2002)


Allografts

• Cadaveric source • most common allografts used include the

hamstring, patellar, and Achilles tendons • no pain or scaring from a donor site • shorter surgery time • the tendon reconstruction is performed identical to

that of the autografts • autograft is considered to be more desirable during

the first reconstruction • allografts used more for ACL reconstruction revision • risk of infection, or viral transmission (HIV, AIDS, etc)


Surgical Procedure • Prepare knee for graft placement

• remnants of the original ligament are removed. • intercondylar notch is enlarged so that nothing will rub

on the graft (notchplasty) • holes are drilled in the tibia and the femur to place the

graft • holes (tunnels) are

placed so that the graft will run between the tibia and femur in the same direction as the original ACL


Surgical Procedure

• graft placement • the graft is then pulled into position through the

tunnels • interference screws or staples are used to hold

the graft inside the tunnels


Functional outcomes


(Lohmander, )

OA • 5 Year Post op follow-up report Sweden

– 50% of ACL reconstructions could be avoided and replaced by physiotherapy

– no increased risk of osteoarthritis or meniscal surgery if the ACL injury was treated with physiotherapy alone compared with surgical treatment

– no difference in patients’ experiences of function, activity level, quality of life, pain, symptoms or general health

– no difference in any outcome between those who were operated on straight away, those who were operated on later and those who did not have an operation at all

Richard Frobell, Harald Roos, Ewa Roos, Frank W Roemer, Jonas Ranstam and Stefan Lohmander. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial BMJ 2013; 346


OA cont.

• 10 year follow-up study, 50 high level athletes (Meuffels, Br J Spor Med 2009)

– 48% radiographic OA in treated with ACL reconstruction

– 28% radiographic OA in knees treated without reconstruction

– No significant difference between groups

• 15 year follow-up randomised study, 100 patients (Meunier, Scand J Med Sci Sports, 2007)

– No differences in percentage of radiographic OA between surgical and non-surgical treatment


Improved techniques

• Single Bundle vs. Double Bundle


(S. Kohl, CH Zeitschrift Sportmed, 2013)

Double Bundle • Reproduces physiological structure

– smaller Anteromedial bundle tight in flexion

– larger posterolateral bundle tight in extension


(www.performanceorthosports.com)

Double Bundle - Guidelines

• Measurement of the ACL insertion on the tibia > 18 mm requires DB to sufficiently restore ACL insertion site

< 14 mm may not allow 2 tunnels to be drilled


(Murawski, Cartilage, 2013)

Clinical Relevance - Double Bundle

• DB has theoretical advantages

• increased surgical complexity

• DB reconstruction does not result in clinically significant differences in KT-1000 arthrometer or pivot shift testing.Source: Meta analysis resulted in 9 studies

included from 97 MEDLINE references(Meredick, AJSM, 2008)

• mixed results presented in literature with some showing superior knee stability with DB and others showing no difference (Murawski, Cartilage,

2013)


Synthetic Ligaments

• GoreTex, Leeds-Keio, historical

• Ligament Augmentation Reinforcement System - LARS

• Tricomponent graft

• Dynamic Anchoring Technique - Ligamys


Synthetic Ligaments


Mascarenhas, MJM_2008

Synthetic Ligaments


Gore Tex

Leeds Keio

Synthetic Ligaments - LARS • Ligament Augmentation Reinforcement

System

– two bundles orientated clockwise or anti-clockwise for right and left knees to mimic the natural ligament

– High strength UHMWPE fibers (Dyneema)

• 1’500 N for 30 fibers




Synthetic Ligaments – Ligamys (Mathys)


• the Ligamys implant provides a tight but elastic connection between the thighbone and the shinbone

• tunnels in the bones ensure that the polyethylene thread follows the natural path of the anterior cruciate ligament inside the joint

• the polyethylene thread is retained on the femur by the metal platelet and on the tibia by the monobloc with spring system





• the polyethylene thread is anchored in the monobloc with a precisely predetermined tension

• the tension is calculated to provide the cruciate ligament with the relief required for the rupture to heal

• at the same time the spring system gives enough free play to dynamically (elastically) respond to varying loads

Synthetic ligaments – Tricomponent Graft

ESVOT, Lodi, Italy, Sept. 2015 (E.J. Cheng, Jtissue Eng. 2014)

Regeneration of Ligament

• Collagen gels or scaffold

• Loaded with stem cells


Regeneration of Ligament

• 4 week tensile testing


Future: improvements are certainly coming

• Long term results with surgical improvements still to come

– Arthroscopic approach

– Instrumentation (aiming devices, tensioning)

– Interference screw material (resorbable, bone inducing)

– Graft fixation improvements

– Graft location improvements

– High strength synthetic material with proper fixation


what is new in crcl surgery in humans · double bundle - guidelines •measurement of the acl...

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