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University of Pittsburgh Senior Design – BioE 1160/1161. Baby Bootie: Clubfoot Orthotic Device. Erika J. Franzen William L. Porter Alexis C. Wickwire April 13, 2004 Mentor: Morey S. Moreland, MD. Overall Goal. - PowerPoint PPT Presentation
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Baby Bootie: Clubfoot Orthotic Device
University of PittsburghSenior Design – BioE 1160/1161
Erika J. FranzenWilliam L. Porter
Alexis C. Wickwire
April 13, 2004
Mentor: Morey S. Moreland, MD
Overall Goal
• To create an improved device design as a means of treatment of corrective therapy for clubfoot deformity
Overview• Background
Prevalence Treatments and Methods
• Specific Objectives• Design
Considerations Development
• Results• Milestones• Future
Background: Clubfoot
• Congenital, idiopathic foot deformity
• Affects bones, joints, muscles, and blood vessels
• Ankle equinus, heel varus, midfoot cavus, and forefoot adduction
Foot position is pointing downwards and twisted inwards
Anterior view of infant’s left foot
http://www.drfoot.co.uk/pictures/clubfootrepair.jpgFaulks et al. 2005
Prevalence• Prevalence
~1/1,000 births in the US 100,000 cases annually 5-7 times greater in
developing countries• 80% of all cases
• Up to 50% bilateral cases
• Family history in 24% patients (familial)
• Twice as prevalent in males than females 3-Day Infant w/ bilateral clubfoot
http://www.drfoot.co.uk/pictures/clubfootrepair.jpgFaulks et al. 2005
Current Treatment• Surgical
Soft-tissue
Bone
Combination
• Non-surgical Soft-tissue manipulation
Cont. passive motion
Strapping
Casting
Normal Clubfoot
http://www.mgh.harvard.edu/ortho/ClubFoot.htm
Non-Surgical Methods
Plaster Casts
• Achieve proper position of foot Dorsiflexion, ER, eversion
• Normal quality of life can be achieved with correction
• Most popularly use a combo. of casts, braces US$200 - $300 / brace US$3,000 for 12 months
Ponseti Method
Corrective Braces
http://www.orthoseek.com/articles/img/club2.gifhttp://www.mgh.harvard.edu/ortho/ClubFoot.htm
Ponseti Method
1. Brief manual manipulation
2. Casting @ maximum correction
3. Percutaneous heel cord release
4. Final cast (3 weeks)
5. Maintain correction with brace
• Full time: 3 months
• 14-16 hours/nightwear: up to 4 y/o
~5 times
(1 week each)
Need for Improvement
• Costly Complexity Production
• Knee immobility
• Foot-to-foot constraint
• Parental misuse Placement
Removal
Objective
3 Primary Design Requirements:
1. Low production cost
2. Improve comfort and effectiveness during wear/use Improve foot-brace interface Unilateral
3. Adaptable Simplistic design Economic considerations
Economic Considerations
Significantly lower price wrt US competitive standards
• Materials
• Labor
• Simple design
• Available resources
• Unilateral
• Hazard Risk
• Resilience/Wearability
• Material cost, availability
• No mechanical parts
• No plastic molded components
Initial Design Considerations
Prototype Development
V 1.0
(Lateral View)
V 2.0
(Anterior View)
V 1.0 Concerns
V 1.0
(Lateral View)
• Knee constraint Comfort
Muscle, tendon atrophy and shortening
• How to maintain position of thigh unit?
Prototype Version 2
V 2.1 V 2.2 V 2.3
V 2.0
(Anterior View)
(Lateral View)
Proposed Solution
V 2.4
• Longer gauntlet
• Removed sole
• Removed ankle strap
• Material buckling
• Strap attachment points
(Lateral View)
Fabrication Limitations
• Inaccessibility to patients
• Mold adult foot Non-representative casting size
Reduced ankle flexibility, rotation
Healthy foot (no clubfoot)
Prototype
Anterior
Posterior
Lateral
Medial
Materials: Gauntlet
•Outside - Calfskin (light weight) tanned black
•Inside - Horsehide (lightweight) pearl tanned
•Padding – polyethylene foam closed cell Moisture barrier
•Nylon laces through brass eyelets
•Polyethylene stay
•Stainless steel bone
Materials: Strapping
•1” Velcro straps backed with light polyester Dacron webbing
•Z69 bonded nylon thread
•AA eyelets
•Big double headed rapid rivet nickel plated brass
Posture Correction
DorsiflexionExternal Rotation
Validation: Independent Evaluation
• Feedback Pediatric Orthopedic Surgeons
O&P manufacturer
• Initial Reaction: FAVORABLE
• Wearability
• Ease of use
• Positioning
• Concern: scalability
Cost Analysis
• Custom to patient: US $160
• Mass produced: US $80
Wearability
• Unilateral
• Knee mobility
• Open heel, toe Growth and development
Verify correct wear/placement
• Ankle lace-up Provides intimate fit
Adaptability
US $200-300
US $12 http://www.mgh.harvard.edu/ortho/ClubFoot.htm
Competitive Analysis
• Denis-Browne Bar Bilateral US $200-$300 Adaptable
• Wheaton Brace Unilateral Knee constraint US $200-$300 Not adaptable
http://www.mgh.harvard.edu/ortho/ClubFoot.htm http://www.orthoseek.com/articles/img/club2.gif
Competitive Analysis
DBB Wheaton Our Design
Low Cost XUnilateral X XAdaptable X X
Ease of Use X XMobility X
Project Milestones
• Contacted project mentor @ Children’s Hospital (Dr. Moreland)
• Prototype designs• Contacted potential manufacturer at Hanger
Prosthetics and Orthotics, Inc. (Bob Mawhinney)
• Fabricated 2 prototypes Evaluation/Validation
• Submitted business proposal to the Enterprize Business Competition
• Compiled Design History File
Future
• Fabricate properly scaled brace• Establish standardized sizes• Adapt parallel design for in developing
countries• Further evaluation
Patients Clinicians
Acknowledgements
• Generous gift of Drs. Hal Wrigley and Linda Baker
• Dr. Moreland
• Dr. Mendelson
• Bob Mawhinney
• Department of Bioengineering, University of Pittsburgh
Thank You!