1

Novel Design of an Anterior Cruciate Ligament (ACL) Injury Prevention Brace

Rachel Porter

Dan Greenshields

Justin Killewald

Lawrence Technological UniversityBME Senior Projects 1Dr. Mansoor Nasir, Fall 2013

Faculty Advisor: Dr. Eric Meyer, PhDTechnical Advisor: Ken Cook, P.E.

2Agenda

Problem

Need Statement

Background

Knee Anatomy

Knee Mechanics

Knee Injuries

ACL Injuries

ACL Injury Mechanisms

Objective

Current progress/Future plans

Research plan

Design Process

Patent

Testing

Cost & materials

Timeline

Tasks & responsibilities

3Problem

Knee injuries account for approximately 60% of all sports related injuries. Nearly half of those injuries occur to the ACL [1].

Extensive recovery time ~ 8-12 months

4Need Statement

An improved knee brace for ACL injury prevention could help lower the injury rate in athletes.

Short term benefits

In turn, this potentially could delay the onset of further knee complications later in life.

Long term benefits

5Design

ACL braces

Prevent hyperextension

Prevent valgus bending

Osteoarthritis braces

Unicompartmental loading

Include design characteristics of prevention braces

6Knee Anatomy

Bones

Ligaments

Menisci

Cartilage

Muscles/tendons

[2] http://www.webmd.com/pain-management/knee-pain/picture-of-the-knee

7Knee Motions

Sagittal

Flexion

Extension

Coronal/Frontal

Valgus bending

Varus bending

Axial Internal rotation

External rotation

8Knee Injuries Bone fracture

Torn ligament

ACL

PCL

MCL

LCL

Torn meniscus

Lateral

Medial

Osteoarthritis

[7]

9ACL Injuries

200,000 – 300,000 ACL injuries/year in the U.S. [3]

70% of injuries are non-contact [4]

Females are 3-10 times more likely to sustain injury [5]

Stop-jump landing and cutting [5]

Most common injury position: < 30° of flexion

http://bretcontreras.com/wp-content/uploads/q-angle-men-vs-women.jpg

10ACL Injury Mechanisms

Internal rotation

Foot planted as body twists

Anterior shear of tibia

Foot planted as knee is hit from the front

Axial Load

Compressive force causes tibial slipping (5500 N) [4]

Hyperextension

Tension on ACL causes tearing

Valgus bending

Knee is angled towards center of body

11Objective

Redesign OA brace hinge to prevent hyperextension, valgus bending, and axial loading on the knee joint to protect the ACL

Research plan

Hinge design

Patent filing

Human subject testing

12Current ACL Braces

Donjoy Defiance – clinically proven brace

Decreases ACL strain [6]

FourcePoint hinge

Protects against hyperextension and valgus bending

Worn by many college and NFL linemen

http://www.djoglobal.com/products/donjoy/defiance

13Osteoarthritis Braces

Commonly used by elderly population

Medial compartment most affected by OA. [8]

Offload medial compartment to even the distribution on compartments

Unicompartmental loading

Medial/lateral

14Modified Hinge Design

Polycentric gears Spider gears

Hypothesis

Lateral hinge = polycentric

Medial hinge = spider gear

Stainless Steel

Both hinges – prevent hyperextension

Medial hinge – shifts loading mechanism

Lateral hinge – prevent valgus bending

15Modified Hinge Design cont.

Polycentric normal action Compressive loading – flexed action

16Patent Filing Process

http://www.uspto.gov/patents/process/index.jsp

17Current Patent Search

Hundreds of knee brace patents

OA brace

ACL brace

Individual components patented

Hinge - consistent

Strap

Frame

18Future Patent Filing

Our design has not been patented

Two different hinges on our brace

Start process in January

Finish and file in May

Could take years to get full patent approval

19Institutional Review Board (IRB)

Department of Health and Human Services

Protect the rights and welfare of human subjects

Monitor research development, testing and evaluation methods

Submitted for IRB approval

Application

Consent form

Participant info sheet

http://www.irbservices.com/irbservices/Choose_IRBS_files/IRBS%20Master%20Logo.png

20Current Testing Techniques

3D motion capture

20 participants

Stop-jump landings

With and without brace

Measured

Knee flexion angle

Ground reaction forces

[5]

21Experimental Method 2 participants

Jump landing trials onto force plates

3 tests Without brace

With Donjoy Defiance brace

With redesigned brace

Measure

Ground reaction force

Segment acceleration

Joint reaction force

Moment

Materials

Vicon Nexus

Polygon

http://bjsm.bmj.com/content/early/2010/06/16/bjsm.2009.069351/F2.large.jpg

22Cost & Materials

Braces = $1000

Donjoy OA Defiance Brace

1 male and 1 female

Hinge redesign material = $500

Springs, screws, washers, stainless steel

Testing supplies = $300

Velcro, double sided tape

LESA foundation - $1000 granted

23Timeline

Month Milestone

January Assemble first prototype brace and begin human subject testing

February Continue testing prototype and adjust design

March Adjust design and continue testingData analysis

April Data analysis and interpretation

May Prepare final report and presentationFile provisional patent

24Anticipated Challenges

Not a significant decrease in compressive load forces

Time restrictions

Failed IRB approval

Patent filing

25Tasks & Responsibilities

Individual tasks

Rachel Porter

Institutional Review Board (IRB) filing

Dan Greenshields

Existing knee brace patent search

Patent application

Justin Killewald

Hinge design research

Materials used in braces

Shared tasks

Prototype design & fabrication

Testing

Data analysis

Presentation creation

Final report documentation

26References

[1] Rishiraj, Neetu, Jack E. Taunton, Robert Lloyd-Smith, Robert Woollard, William Regan, and D.B. Clement. "The Potential Role of Prophylactic/Functional Knee Bracing in Preventing Knee Ligament Injury." Sports Medicine 39.11 (2009): 937-60. Print.

[2] http://www.webmd.com/pain-management/knee-pain/picture-of-the-knee

[3]Teng, Phillis S.P., K.F. Leong, P.Y. Huang, and J. McLaren. "The Effect of a Knee-ankle Restraint on ACL Injury Risk Reduction during Jump-landing." Procedia Engineering60 (2013): 300-06. Print.

[4] Meyer, Eric G., and Roger C. Haut. "Excessive Compression of the Human Tibio-femoral Joint Causes ACL Rupture." Journal of Biomechanics 38.11 (2005): 2311-316. Print.

[5] Yu, B. "Immediate Effects of a Knee Brace With a Constraint to Knee Extension on Knee Kinematics and Ground Reaction Forces in a Stop-Jump Task." American Journal of Sports Medicine 32.5 (2004): 1136-143. Print.

[6] http://www.djoglobal.com/education/patient-education/acl-bracing

[7] Majewski, M., H. Susanne, and S. Klaus. "Epidemiology of Athletic Knee Injuries: A 10-year Study." The Knee 13.3 (2006): 184-88. Print.

[8] Gaasbeek, Robert D.A., Brenda E. Groen, Brieke Hampsink, Ronald J. Van Heerwaarden, and Jacques Duysens. "Valgus Bracing in Patients with Medial Compartment Osteoarthritis of the Knee A Gait Analysis Study of a New Brace." Gait & Posture26 (2007): 3-10. Print.

27Questions?