Baby Bootie: Clubfoot Orthotic Device

1. 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

2. Overall Goal • To create an improved device design as a means of treatment of corrective therapy for clubfoot deformity

3. Overview • Background • Prevalence • Treatments and Methods • Specific Objectives • Design • Considerations • Development • Results • Milestones • Future

4. 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 Faulks et al. 2005 http://www.drfoot.co.uk/pictures/clubfootrepair.jpg

5. 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 Faulks et al. 2005 http://www.drfoot.co.uk/pictures/clubfootrepair.jpg

6. 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

7. Non-Surgical Methods • 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 Plaster Casts Corrective Braces http://www.mgh.harvard.edu/ortho/ClubFoot.htm http://www.orthoseek.com/articles/img/club2.gif

8. Ponseti Method • Brief manual manipulation • Casting @ maximum correction • Percutaneous heel cord release • Final cast (3 weeks) • Maintain correction with brace • Full time: 3 months • 14-16 hours/nightwear: up to 4 y/o ~5 times (1 week each)

9. Need for Improvement • Costly • Complexity • Production • Knee immobility • Foot-to-foot constraint • Parental misuse • Placement • Removal

10. Objective 3 Primary Design Requirements: • Low production cost • Improve comfort and effectiveness during wear/use • Improve foot-brace interface • Unilateral • Adaptable • Simplistic design • Economic considerations

11. Economic Considerations Significantly lower price wrt US competitive standards • Materials • Labor • Simple design • Available resources

12. Initial Design Considerations • Unilateral • Hazard Risk • Resilience/Wearability • Material cost, availability • No mechanical parts • No plastic molded components

13. Prototype Development V 1.0 (Lateral View) V 2.0 (Anterior View)

14. V 1.0 Concerns • Knee constraint • Comfort • Muscle, tendon atrophy and shortening • How to maintain position of thigh unit? V 1.0 (Lateral View)

15. Prototype Version 2 V 2.0 (Anterior View) V 2.1 V 2.2 V 2.3 (Lateral View)

16. Proposed Solution • Longer gauntlet • Removed sole • Removed ankle strap • Material buckling • Strap attachment points V 2.4 (Lateral View)

17. Fabrication Limitations • Inaccessibility to patients • Mold adult foot • Non-representative casting size • Reduced ankle flexibility, rotation • Healthy foot (no clubfoot)

18. Prototype Lateral Anterior Posterior Medial

19. 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

20. 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

21. Posture Correction External Rotation Dorsiflexion

22. Validation: Independent Evaluation • Feedback • Pediatric Orthopedic Surgeons • O&P manufacturer • Initial Reaction: FAVORABLE • Wearability • Ease of use • Positioning • Concern: scalability

23. Cost Analysis • Custom to patient: US $160 • Mass produced: US $80

24. Wearability • Unilateral • Knee mobility • Open heel, toe • Growth and development • Verify correct wear/placement • Ankle lace-up • Provides intimate fit

25. Adaptability US $200-300 US $12 http://www.mgh.harvard.edu/ortho/ClubFoot.htm

26. Competitive Analysis • Wheaton Brace • Unilateral • Knee constraint • US $200-$300 • Not adaptable • Denis-Browne Bar • Bilateral • US $200-$300 • Adaptable http://www.mgh.harvard.edu/ortho/ClubFoot.htm http://www.orthoseek.com/articles/img/club2.gif

27. Competitive Analysis

28. 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

29. Future • Fabricate properly scaled brace • Establish standardized sizes • Adapt parallel design for in developing countries • Further evaluation • Patients • Clinicians

30. Acknowledgements • Generous gift of Drs. Hal Wrigley and Linda Baker • Dr. Moreland • Dr. Mendelson • Bob Mawhinney • Department of Bioengineering, University of Pittsburgh

31. Thank You!