6th Annual Wichita Sports Medicine Symposium June 6th 2009

KNEE LIGAMENT INJURIES: EXAM AND TREATMENT Daniel J. Prohaska, MD www.drprohaska.com danprohaska@gmail.com June 6, 2009

Talk available: www.drprohaska.com

Knee Ligaments Why do we need a knee lecture Everything is pretty much sorted out in regard to the knee isn’t it? Just when you think you have it all down….

It's not just the ACL

It's the whole knee Cartilage Insertion site Graft healing Meniscus Neurovascular ingrowth bone Muscle

ACL 48% MCL 29% ACL/MCL 13% PCL 7% LCL 3% Ligament Injury Miyasaka, 1989

200,000 ACL Injuries Per Year?

Different Grafts Biological graft materials: autograft: BPTB, Hamstrings, Quad-tendon allograft: Achilles, BPTB, ACL, peroneal Synthetic graft materials have not been successful Engineered biological ACL scaffolds: still experimental

Use of different grafts 1980- BPTB 1983- Extraarticular 1985- Allografts BPTB-Auto 1992- Hamstrings

Who Uses What? Hamstrings + BPTB: equal. 62% use multiple grafts Education of graft choices leads to best graft More than one graft may work for each patient

Global Perspective on ACL Reconstruction > 20 different techniques > 5 different grafts different rehab protocols different outcome assessments overall clinical / functional results are good or excellent

How perfect are current operative techniques? Need for improvement?

20 years ago less knowledge about graft options

Graft Comparison Advantages Disadvantages BPTB Consistent size and shape Bone to bone healing Consistent fixation Donor site morbidity HAMSTRINGS Various fixations Tendon-Bone-Healing Greater stiffness No interference with extensor mechanism

Graft Comparison Advantages Disadvantages Quadriceps tendon Higher stiffness Bone to bone healing at one side Donor site morbidity Allograft Decrease in tensile strength Prolonged healing response Disease transmission Better cosmesis No donor site morbidity Less postoperative pain

Does not yet exist Perfect Graft Reproduces insertion and biomechanics Biological incorporation Resumes neuromuscular control Does not yet exist

Biomechanical research Single bundle ACL (BPTB and hamstrings) AP stability restored rotational stability not restored Pivot shift not restored

Where we are: Development of Reconstructive Knee Surgery has made advancements largely due to the use of the arthroscope. Patients and physicians now take for granted that procedures can be done with arthroscopic assist.

Literature Suggests it is possible to obtain stability 90-95% with variety of graft sources Not all surgeons can obtain this level of stability with single tunnel technique Doing a double bundle does not make the procedure technically easier and may in fact lead to further instability ?

Are WeFailing Our patients Changes in ACL surgery/rehab need to focus on where we are failing patients Are we failing with the single tunnel technique?

Where are we failing? Recent studies have found that patients with ACL reconstruction have a high incidence of arthritic changes in the long-term We want to prevent arthritic changes, but do we really know why they occur?

Where are we failing? Is it the meniscus, bone bruise, the cartilage, the graft? Do we need double bundles? The theory is that arthritic changes are occuring because adequate stability is not being achieved with single-bundle

Where are we failing? ACL deficient knee alone does not cause arthritic changes It is the meniscus tears and chondral damage that occurs with additional giving way episodes that causes the problem If a person with an ACL-deficient knee can prevent instability, arthritic changes may not occur

Where are we failing? Patients who have some knee laxity with full ROM are better off long-term than patients with stability and less than full ROM “Stable” knees may be bad knees in the future if we don’t also consider all factors that make knees symmetrical

Where are we failing? Goals of ACL surgery is to obtain knee symmetry for Stability ROM Strength FUNCTION

Don’t change into a technicians We seem to always seek a surgical answer to problems Most solvable problems are related to rehabilitation, not surgery Cannot control meniscus tears or chondral damage

Changing Surgical Technique Why “fix” a problem that we have not really found Why Ignore other big problems, ie chondral and meniscus damage

Biomechanical Research need for in situ forces in vivo data For ACL and PCL !

ACL Single bundle ACL currently the gold standard 10-35% poor results based on continued pain and instability Long term follow-up (7 years) shows indicates a high proportion of patients develop DJD Biau, Corr, 2007 Freedman et al.,AJSM, 2003 Fithian DC et al, AJSM 2005

Single Bundle ACL Single bundle ACL reconstruction does not recreate the normal knee kinematics Evidence points to double bundle recreating kinematics Does it matter?

ACL Anatomy PL and AM parallel in extension Both bundles have tension

ACL Anatomy In flexion AM stays tight, PL loosens

ACL Histologically the insertions are distinct

ACL Right knee Standard lateral portal Only bifurcate ridge and part of posterolateral bundle insertion are visualized

ACL Anatomy Right Knee Viewing through medial portal

ACL Anatomy

3-D ACL reconstruction Tunnel

3-D ACL reconstruction Tunnel

$ ACL Factory?

? ACL double-bundle What does it take to do double? ACL graft: 2 bundles What does it take to do double?

PCL injuries treatment controversial conservative treatment for isolated injuries ? clinical results of PCL reconstruction: 80% satisfaction

PCL Anatomy - Components anterolateral (AL) taut in flexion posteromedial (PM) taut in extension meniscofemoral (MFL)

PCL Biomechanics Tensile testing: AL - stiffer, stronger than PM and MFL Function of different bundles of PCL can not be restored with single drill hole replacement

PCL Reconstruction 1999 Current approaches tunnel placement: AL graft fixation / tension: knee in flexion Newer considerations double bundle

PCL Reconstruction – 2009 Double Bundle 1. AL 10 mm Achilles tendon Fix at 90° with anterior drawer 2. PM 7-8 mm doubled ST Fix at full extension

PCL Reconstruction Double-bundle technique AL PM

PCL Reconstruction Tibial Onlay technique

GRAFT HEALING Goal is to reproduce the insertion site of the native ACL Different healing for different grafts

ACL insertion bone mineralized cartilage non-mineralized ligament subchondral bone mineralized cartilage non-mineralized cartilage ligament “tide mark” mineralized cartilage non-mineralized bone ligament

Animal studies for tendon to bone fixation (hamstring) Sharpey's fibers Single collagen fibers attaching to bone Rodeo et al, 1993 Extra-articular model Intra-articular model Grana et al. 1994

Factor of Rehabilitation Tailor Made ! Rehab depending on graft fixation slow rehabilitation fast

Different Fixations

Fixation with bioscrew But ... Weiler et al. 1998

Fixation - Failures single side fixation FAILED HEALING ? ACL reconstruction with hamstrings, fixation with PLLA interference screw 15 mo after ACL surgery single side fixation FAILED HEALING ?

Fixation - Failures New Bio-Screws with TCP to incorporate faster Allograft Screws: $$$$ Two screws more than surgeon reimbursement for procedure Billed to insurance as allograft: ethics of this practice?

Biological Incorporation No graft can completely reproduce insertion sites! Improve healing? Improve remodeling?

Biological solutions Decorin BMP-2 IGF-1 bFGF NEAR FUTURE ?

Immobilization Not the answer to gain graft incorporation. Graft incorporation enhanced by stress loads below the threshold of fixation

Problems with Motion Post Op Some reasons patients have problems with extension post op could be cyclops lesion, scar tissue, or malposition of graft. Surgeon needs to be sure of graft placement and check motion before secures the graft in place

Scar tissue Scar tissue around the patella femoral joint will severely limit flexion. This needs to be addressed early in PT with aggressive treatment for patellar mobilization. Stiffness rate should not exceed 3-5%.

Biological solutions Cell therapy Gene therapy Tissue engineering

GENE THERAPY

Why Improve? Too Much Morbidity from injuries and the surgery! Preventive Training unable to prevent injury.

What can we do to become better? Understand anatomy Recreate anatomy as closely as possible Use of technology? Need for more accurate way to measure reproducibly rotational control achieved with ACL reconstructions

Thank You!! www.drprohaska.com