Three-Segment Thoraco Lumbar Sacral Orthotic Brace

Dave HowerAnjani RavindraJessica Schaberl

Kimberly Zawrotny

Project Mentor: Bob MawhinneyHanger Orthopedic Group

Overview

• Thoraco Lumbar Sacral Orthotic Braces are used to stabilize the spine following:• Spinal injuries such as compression or burst

fractures: 11,000 new incidences per year in United States

• Surgical procedures such as spinal fusions, decompressions, or treatment for ankylosing spondylitis: ~2 million per year in the United States

• Traditional bi-valve TLSO braces are difficult to put on correctly, leading to improper brace placement procedures which can cause pain or ill-fit.

Project Objectives

• Redesign the TLSO brace so as to improve ease and speed of correct placement without significantly increasing the cost of the brace.

• Convince potential customers, such as physicians who prescribe TLSO braces for their patients, that the Three-Segment TLSO brace is an improvement over traditional bi-valve designs.

• Prove that Three-Segment brace is easier to put on by demonstrating faster placement procedure and reduced rolling requirements

Customer Requirements

• The brace should…• Immobilize the spine • Provide the same level of spinal support as current

bi-valve TLSO brace designs• Be easy to put on while prostrate, with minimal rolling

required for correct placement• Fasten securely• Be designed to promote patient comfort• Be the same size and weight as a bi-valve brace of

same prescription• Cost the same as prescribed bi-valve brace, in the

range of $250.00 (excluding service charges).

Competitive Analysis

• Front Closing Brace with Hip Extension

• Aspen TLSO Bracing System

• Cybertech Medical TLSO Brace

http://www.aspenmp.com/products/tlso/instructions.html http://www.cybertechmedical.com/TLSO.htmlhttp://www.bostonbrace.com/cf_boston_tlso.html

Design Alternatives• TLSO Brace Placement Assist Device

• Rejected because did not allow for proper support of spine during placement

• Consulted with MD in rehabilitation services

• Shape Memory Material • Rejected because of costs and insurmountable

technology barriers• Consulted with materials science professor

• Redesign Current TLSO Brace• Chosen because most feasible economically and in

regards to time constraints• Working from established design• Consulted with Orthotics Specialist

Three-Segment TLSO Description

• Custom-molded brace composed of three segments: front, left side, right side

• Hinges join front to side segments• Side segments meet in back• Connected by three straps• Covers torso from pelvis to sternum in front, and

hips to shoulder blades in back

Comparison to Competition

Strengths

• Much less complex design

• Can be placed without assistance if needed

• Ease of manufacture

• No part of brace needs to be slid under patient

Weaknesses

• Still requires rolling to place

• Difficult to tighten straps

• Current model does not include Hip Extension

Features and Benefits of the Redesign

• Split Back Segment• Brace does not need to be forced

underneath patient• Contributes to easy placement

procedure

• Three Connections• Faster to fasten than bi-valve

design with 6 connections

• Hinged Design• Easier to manipulate brace during

placement

Features and Benefits of Redesign

• Non-Velcro Straps

• Easier to manipulate brace during placement

• Will not snag or damage clothing or furniture

• Ease of Production

• Faster molding process• Offsets costs of hinges, so Three-

Segment brace does not cost more than bi-valve design

Engineering Technology: Producing Prototype

• Mold and Prototype Development Process• Apply multiple layers of wet plaster bandages around

patient

• Allow to dry and then remove, maintaining shape of body

• Fill cast with molding plaster to obtain positive mold

• Vacuum fold plastic on the outside

• Add AliPlast foam on inner side

Quality Systems Considerations

Risk Analysis

• Connection, Hinge, or Material Failure

• Material selection and frequent inspection

• Improper brace placement

• Written and verbal instructions

• Skin Irritations

• Warning labels

Regulatory Considerations

• Searched FDA Device Classification Panels to determine device classification• In accordance with 21 CFR 890.3490, the Three-

Segment TLSO brace is a Class 1 Device

• Searched FDA 510(k) Database for Predicate Devices:• Orthomedic Lumbar Flexion Brace• Vertebrace Spinal Supports

• Followed 21 CFR 820.30 standards for medical device quality management systems

Project Management: Initial Schedule

Presentation

Second Prototype

First Prototype

Project Selection

Project Selection

First Prototype

Second Prototype

Specialist Test

Presentation

Project Management: Actual Schedule

Experimental Design and Results

• Orthotics Specialist Test

• Time comparison for Orthotics Specialist to place bi-valve brace and three-segment brace on patient

Brace Type Trial Time (sec)

Bi-Valve

1  83

2 105 

3 80 

Three-Segment

1 40 

2 45 

3 50 

Experimental Design and Results

• Self Placement Test

• Time comparison for self-placement of bi-valve brace and three-segment brace

• Quantification of rolling required for self-placement of bi-valve brace and three-segment brace

Brace Type Trial Time (sec) Number Rolls

Bi-Valve

1 130 3.5

2 111 2.5

3 109 2.5

Three-Segment

1 103 1.5

2 99 1.5

3 95 1.5

Conclusions

• Three-segment brace offers viable alternative to current brace designs

• Provides same level of support with easier placement than other TLSO designs

• Does not significantly increase cost• Approved by orthotic and rehabilitation specialists

• Would prescribe for patients

Acknowledgements

Thanks to… • The generous gift of Drs. Hal Wrigley and Linda

Baker

• Department of Bioengineering

• Bob Mawhinney and Hanger Orthopedic Group Staff

• Drs. Boninger and Fulay

• Andy Holmes