STABILIZATION OF LONG BONE FRACTURES Team Members: Robert - - PowerPoint PPT Presentation

▶
stabilization of long bone
SMART_READER_LITE
LIVE PREVIEW

STABILIZATION OF LONG BONE FRACTURES Team Members: Robert - - PowerPoint PPT Presentation

Jan 21, 2024 378 likes •597 views

TWO-PIN EXTERNAL FIXATOR FOR TEMPORARY STABILIZATION OF LONG BONE FRACTURES Team Members: Robert Bjerregaard- Communicator Cole Drifka- BSAC Marc Egeland- BWIG Derek Klavas- Team Leader Advisor: Client: Wan-Ju Li Ph.D. Ken Noonan M.D.

slide-1
SLIDE 1

Team Members: Robert Bjerregaard- Communicator Cole Drifka- BSAC Marc Egeland- BWIG Derek Klavas- Team Leader

TWO-PIN EXTERNAL FIXATOR FOR TEMPORARY STABILIZATION OF LONG BONE FRACTURES

Advisor: Wan-Ju Li Ph.D. Client: Ken Noonan M.D.

slide-2
SLIDE 2

Background Motivation: 4-Pin vs. 2-Pin Existing Devices Client Requirements This Semester’s Work External Fixator Bar Design Options Pin Support Design Options Future Work Acknowledgements

OVERVIEW

slide-3
SLIDE 3

 Multi-injury trauma patients often require temporary fixation of the femur  Temporary immobilization of the upper leg for up to 48 hours  Patient may undergo bed-to-bed transfer, femur should remain stabilized throughout

BACKGROUND

http://www.1-800-translate.com/TranslationBlog/wp- content/uploads/2010/06/emergencyroom.jpg

slide-4
SLIDE 4

4-Pin External Fixation

 4 terminally threaded pins

  • 2 proximal and 2 distal to

fracture site

 Procedure must be conducted in the Operating Room  Alignment of 4 pins is time consuming, requiring multiple physicians

2-Pin External Fixation

 2 terminally threaded pins

  • 1 proximal and 1 distal to

fracture site

 Procedure can be conducted immediately in the Emergency Room  Minimal time, only one physician necessary

MOTIVATION

slide-5
SLIDE 5

EXISTING DEVICES

http://www.fixus.nl/fixus99.html

Fixus 99 External Fixation System Monutube Triax External Fixation System

http://emedicine.medscape.com/article/1 270717-treatment http://www.osteosynthesis.stryker.com/me dias/pdf/triax_optech_50752504a2806.p df

  • There are currently no known two-pin fixation

devices on the market

Traction pin stabilization

slide-6
SLIDE 6

Implemented in ER by a single resident or staff physician Installation time must be at most twenty minutes A maximum of two fixation pins must be used Device must fit wide range of patients External bar must be radiolucent, and entire device must be MRI compatible

CLIENT REQUIREMENTS

slide-7
SLIDE 7

Implemented in ER by a single resident or staff physician Installation time must be at most twenty minutes A maximum of two fixation pins must be used Device must fit wide range of patients External bar must be radiolucent, and entire device must be MRI compatible

CLIENT REQUIREMENTS

Future Work

slide-8
SLIDE 8

Design a pin with increased rotational stability Construct a temporary external fixator that is easy to apply

THIS SEMESTER’S WORK

http://www.engr.wisc.edu/alumni/perspective/34.3/gi ft03PeterTong.html

slide-9
SLIDE 9

 External bar with no joints  Pros:

  • Easy to construct the bar
  • Streamlined design after

installed  Cons:

  • Requires complicated

clamp design

  • Fits a limited range of pin

locations

STANDARD FIXED BAR

slide-10
SLIDE 10

 Joint allows for rotation along long axis of bar  Pros:

  • Fits a wider range of pin
  • rientations
  • Extra degree of freedom
  • Less complicated clamp

design – easier installation  Cons:

  • More complicated design

SINGLE AXIS ROTATION

slide-11
SLIDE 11

 Dual ball-and-socket allows for  Pros:

  • Fits the widest range of pin

locations

  • Three degrees of freedom
  • Least complicated clamp

design – easy installation  Cons:

  • Bulky and complex design

BALL-AND-SOCKET

slide-12
SLIDE 12

Design gn Charact acter eristi stics cs Fix ixed Bar Sin ingl gle e Axis is Rota

  • tation

tion Ball ll-and nd-Soc Socket Ease of Installation (40) 20 35 40 Cost (10) 10 6 8 Ergonomics (20) 20 17 15 Manufacturability (10) 8 6 10 Adjustability (20) 10 18 20 Total (100) 68 82 93

Fixation Bar Design Matrix

slide-13
SLIDE 13

 Drill hole, slide in pin, screw to expand  Pros:

  • Greater stability than

standard pin  Cons:

  • Potential damage to bone
  • Could be difficult to

remove

  • Targets soft trabecular

bone

MOLLY BOLT

slide-14
SLIDE 14

 Insert pin, screw in central bore  4 expandable segments grip cortical bone to increase stability  Pros:

  • Greater stability than standard

pin

  • 30% higher pullout strength

than standard pin [2]  Cons:

  • Potential damage to bone and

surrounding tissue

  • More difficult to manufacture

EXPANSION PIN

slide-15
SLIDE 15

 Reverse threading combined with external sleeve  Loosening of inside pin causes external sleeve to drive deeper into cortical bone  Pros:

  • Exceptional stability

 Cons:

  • Bulky
  • Hard to manufacture

NEGATIVE FEEDBACK PIN

slide-16
SLIDE 16

PIN DESIGN MATRIX

Design gn Charact haracter eristi stics cs Moll lly Bolt lt Expansio nsion n Pin in Negati tive e fe feedbac back k Pin in Rotational Stability (40) 28 35 30 Ease of Installation (15) 12 12 10 Manufacturability (10) 5 9 7 Potential Damage to Tissue (25) 10 15 18 Cost (10) 7 7 7 Total (100) 62 78 72

Support Pin Design Matrix

slide-17
SLIDE 17

FINAL DESIGN

slide-18
SLIDE 18

Test stability of existing expansion pin in animal bone Construct pins and fixation bar Test stability of entire fixator Design entire fixator to be MRI compatible Design fixation bar to be radiolucent

FUTURE WORK

slide-19
SLIDE 19

Dr. Wan-Ju Li Dr. Ken Noonan

ACKNOWLEDGEMENTS

slide-20
SLIDE 20

 http://www.3dcontentcentral.com/Search.aspx?arg=femur  Cook et. al. “Lumbosacral fixation using expandable pedicle screws: an alternative in reoperation and osteoporosis”. The Spine Journal. Vol. 1, Issue 2. 2001.

REFERENCES

slide-21
SLIDE 21

QUESTIONS?