Sports Knee Surgery What’s New

& What’s Coming

Dr Jonathan Mulfordmyorthopod.com.au

Who am I?

ACL Surgery

• What do you think of the LARS?

What Are you asking me?

• What is the best graft?

Graft Choice

• Autograft – Patients own tissue

• Allograft – someone else's tissue

• Synthetic - Artificial

Which Graft• Leo P – Hamstrings

• Merv C – Patella tendon

• Americans Allograft

• Koreans Quads Tendon

• Footy show says Synthetic Graft

• ????????

Media

• LARS option: Fisher aims for fast return• David Rodan back on training track two

weeks after knee surgery• Miracle op to melt down surgeons' phones• Rodan surgery to become the norm• Covell's career on knife's edge• Moltzen plays it safe

WHICH GRAFT WOULD YOU HAVE?

• Autograft

• Allograft

• Synthetic

Lets look at some evidence

Allograft

Allograft significantly lower normal stability rates than autograft

Allograft abnormal stability rate 3 times greater than autograft.

Autograft

Hamstrings

• Good Things

• Bad Things

Hamstrings

• Pros– Quick harvest– Reliable– Can use for double bundle– Small incisions

Hamstring Graft

• Cons– Subtle hamstring discomfort

– Graft gets weaker intially as revascularises

– Fixation to bone can takes longer than BTB

– Stretches a little more than BTB

– Graft size not predictable

Patella Tendon

• Good Things

• Bad Things

Patella Tendon

• Pros– Bone heals to bone quickly– Stiffer graft (doesn’t seem to stretch

as much)– No hamstring problems– Better if • larger heavier patients and• collision sports• ligament lax individuals• Known Hamstring problems

BTB graft

• Cons– Arguably anterior knee

pain (Bone graft)– Longer to harvest graft– Larger incisions– uncomfortable initially– Risk of patella fracture and

tendinopathy

Quads Tendon

• Good Things

• Bad Things

Quads Tendon

• Pros– Strong graft– Good for revision graft – May be useful for double bundle– May have less morbidity then Patella and hamstrings

• Cons– Quads weakness– Anterior knee pain– Not commonly used

Great

• What does the literature tell us.

• Remember there is a lot of poor literature.

Patella vs Hamstrings

What about Quads?

• Currently performing Systematic review.

• No difference to BTB• Quads strength? / • less anterior knee pain ? /

Patient Specific Approach

• Choose graft that matches the patients needs.

• Discuss the pros and cons of each graft.

Artificial Graft

• Have been used for over 30years

• Avoids the donor site morbidity, quicker recovery, cheat biology.

• Problem has been their durability – they have not matched autograft in this regard.

As a result Long rehab that

• Lion opts for LARS 11/5/2010

LARS

• What’s good?

• What’s bad?

History Artificial Grafts

• 1918 silk sutures – failed 3 months

• First graft 1973 - Proplast made of polytetrafluoroethylene (PTFE)

• Results with this system yielded an average time to breakage of just over 1 year.

Classification of Synthetic Grafts

– Ligament Augmentation Devices • (polypropylene, polyester) • initial strength until revascularisation, • stress shielding of autogenous tissue and

prevented adequate strength.

– Total Prosthetics • permanent replacement with no

revascularisation. • Excellent short-term results, long-term

efficacy results were poor due to wear and ensuing rupture of the prosthesis.

CARBON FIBRE PROSTHETICS

• Began late 70s• carbon wear particles • coated with collagen and absorbable polymers

• Good Early results• longer term - unacceptable stretching and

complete rupture as major complications.

DACRON

• tightly woven polyester strips.

• Early results were good

• however by 4 years about 50% had failed due to stretching of the graft.

LEEDS-KEIO ARTIFICIAL LIGAMENT

• a polyester mesh• intended as a scaffold for soft

tissue ingrowth• Good early results.

• a large number of long-term graft ruptures despite excellent early results

KENNEDY LIGAMENT AUGMENTATION DEVICE (LAD) – 1980

• Ligament Augmentation Device (LAD) in 1980.• Idea - protect the autogenous tissue graft

early

• Problem - Stress shielding resulted.

• Later - effusion and synovitis.

LIGAMENT ADVANCEDREINFORCEMENT SYSTEM (LARS) ARTIFICIAL LIGAMENT

• polyethylene terephthalate (PET).

• intra-articular segment– Twist– PET Encourage ingrowth

• wear resistance of 22 million of cycles = 10 years of straining use.

Literature on LARS

• One case synovitis reported short term.

• Short term results in a handful of papers are good.

• Fast recovery and return to sport/activity.

• risk of rupture remain and must be addressed through long-term follow-up studies.

• 3 ruptures of 159• 1 synovitis

Longest Follow-up LARS• ACL Reconstruction Using Artificial Ligament:

Five Years Follow Up

• S.I.O.T. 2007; 33(suppl.1) : 8238-8242G. Cerulli et at.

25 patients older than 40 - Lars® artificial ligaments at a five-years follow-up with very good results.

Dr Nicolas Duval using LARS since 1993

• Best results are in early ACL repair augmented by LARS

In older patients (more than 50) I use the LARS in any condition because of the low morbidity and easy rehab.

Why is rehab “Faster”

• No Donor site Morbidity

• Graft not going to weaken early.

LARS Indications

• Sportsmen who have acute injury require fast recovery for particular target time AND prepared to take the risks possible long term failure.

• Older patients with less demands however functional instability and want less involved rehab.

• LARS concept is good but not quite right

The future – Scaffolds and Growth Factors with Repair.

• tissue engineering techniques

– Grafts that regenerate a mechanically robust and natural ACL

– cell-specific growth factors that influencing the maturation and healing response of ligament tissue will also be available.

Platelet Rich Plamsa - Injections

Other ACL controversy

Graft Tunnel Placement

• Many papers recently.• Femur – medial portal better than trans-tibial.

• Tibia – place posterior aspect foot print.

Double bundle – double trouble?

Meta-analysis – No significant difference clinically between double bundle and single bundle.

ACL Navigation

• Has been available since 1995.

• Overall gives more reliable positioning of the tunnels

• No clinical benefit shown

• there is still debate over positioning of the tunnels.

Patellofemoral Joint

• Instability• MPFL

Trochlea Dysplasia

Trochleoplasty

CARTILAGE LESIONS

Bottom Line – at present no technique has clinically shown to be superior than another.

Emerging Options for Treatment Articular Cartilage Injury in the Athlete• Very controversial!!!

• Treatment articular cartilage injuries is a therapeutic challenge.

• Cartilage not good at repairing due to avascular surroundings and unique matrix organisation

Non Surgical

• Chondrotin Sulphate• Synvisc One

Surgical Options

• Options– Marrow stimulation techniques– Osteochondral transplant techniques– Cell based repair techniques

Future - Use of Stem Cells and Growth Factors

Marrow Stimulation Techniques• Microfracture – Minimally invasive, low morbidity,

relative short rehab.– Micropenetration of subchondral

plate creates blood clot containing pluripotent marrow derived mesenchymal stem cells.

– MSC produce fibro-cartilage repair tissue.

– Time from injury to micro-fracture is important

– Best lesion size <200mm sq

• Enhanced Microfracture– Try to enhance chondrogenic differentiation– Addition growth factors (TGF-B3, BMP-7)– Still in the lab

Osteochondral

• OATS

Cell based repair techniques

• MACI• Cartilage taken – grown in lab and then

reinserted.

Stem Cells

• “The Regenexx™ procedure as an alternative to traditional knee surgery is non-invasive, resulting in faster healing and less recovery time. Read more about our knee surgery alternative, or fill out our form below to find out right now if you are a candidate.”

• Banking Stem Cells

Mesenchymal Stem Cells

• MSC found in bone marrow, skeletal muscle, synovial membrane, adipose tissue and umbilical cord blood.

Problems MSC

• Selection Cell• Delivery to site• 3D Scaffold ideal (synthetic or polymer)– Synthetic issues retention and degradation– Biological – disease transmission, immunological

reaction, precision.

Tissue Engineered Construct - TEC • Synovial tissue cultured

with ascorbic acid – sheet collagen produced

• 3D tissue is produced with cartilage cells interwoven in extracellular matrix

• Culture in medium with growth factors known to stimulate cartilage and type II collagen

• More Fibrous than Hyaline

• Testing with different GF and gene modification with viruses.

Additional Surgery

Meniscus

Partial ResectionRepair

Replacement -

Meniscal Lesions• Different populations

• Young high energy sports injury.

• Middle aged sports injury with previous recon

• Low energy associated with OA

Meniscal Repair

Meniscus Replacement• Partial menisectomy• Replacement with a Collagen Meniscal

Implant (CMI) is an option.• CMI is approved in Europe for medial

meniscus.• CMI is a collagen-based implant that

acts as a scaffold for tissue infiltration.• They are like a sponge made from

bovine achilles tendons, GAGs are added, they are deg\hydrated and orietated in a mold then chemically crosslinked with formaldehyde.

Meniscus replacement - Allograft

• Problems are availability, logistics, costs, and varying results

Future - Stem Cell Therapy

• Goats – MSC injected into knees that where OA due to ACL deficiency,

• A new meniscus like regenerative type tissue formed

CONCLUSION• Lots of exciting advances happening in sports

knee injuries.

• Many advances are still some way off clinical application.

• Balance of biology, synthetics, growth factors and gene manipulation.

• Watch this space!

Thankyou

• Jonathan Mulford• Myorthopod.com.au