Hands-on Activity: Repairing Broken Bones
Educational Standards :
Pre-Req Knowledge (Return to Contents)
A basic understanding of bones, how they work and what they are made of. See the Our Amazing Skeleton lesson.
Learning Objectives (Return to Contents)
After this activity, students should be able to:
Materials List (Return to Contents)
For the teacher's introductory presentation:
Each group needs:
For the entire class to share:
[Note: These supplies depend on student designs, so wait to purchase them after designs are finalized.]
[Use any of these items that are accessible; a machine shop may have some items]
Introduction/Motivation (Return to Contents)
(Have ready to show to the class the attached Bone Repair Challenge PowerPoint presentation.)
Who has ever broken a bone? How did you repair it? When a bone breaks, it immediately begins healing itself. Usually, a doctor can assist a minor bone fracture by "immobilizing" the broken region with a cast or a sling to minimize its movement while healing. However, when severe fractures occur, sometimes more intense measures must be taken. For severe fractures, doctors must consider the risk of infection, the length of time needed to heal the break, and how to best heal the bone correctly to restore function and mobility.
For severe fractures, biomedical and materials engineers assist doctors by developing various devices used to help heal bones. Two categories of bone repair are internal and external fixation. Internal fixation is a temporary or permanent fixture that directly attaches to the bone under the skin for alignment and support. These include pins, rods, plates, screws, wires and bone grafting. External fixation is a temporary repair support outside of the skin that stabilizes and aligns the bone while the body heals. These devices include screws, metal braces and casts. External fixation devices can be adjusted outside of the bone. In some cases, internal fixation methods are chosen because they can provide increased patient mobility and quicker healing time.
Biomedical and materials engineers must consider the strength and biocompatibility of the device as well as ease of implantation and minimal invasiveness for the patient. Over the next few class periods, we will break turkey femurs and then work in groups to engineer ways to repair the bones. Let's see if you can make the bone stronger than before it was broken!
(Show the class the attached Bone Repair Challenge PowerPoint presentation to introduce or review the kinds of broken bones and the current medical internal fixation approaches to repair them [pins, rods, plates, screws, etc.]. The presentation includes medical illustration and x-ray examples, and concludes with the activity design challenge on one slide.)
Vocabulary/Definitions (Return to Contents)
Procedure (Return to Contents)
Before the Activity
Day 1: Bone Breaking
Days 2-4: Bone Repair
Day 5: Bone Testing
Attachments (Return to Contents)
Safety Issues (Return to Contents)
Troubleshooting Tips (Return to Contents)
Experiment with bone breaking in advance of the activity to make sure your method works well.
Have on hand one or two extra bones in case students have problem when fixing their original bone or with which students can practice drilling.
Assessment (Return to Contents)
Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." Respectfully listen to all ideas. Ask the students:
Activity Embedded Assessment
Design Presentations: After creating two or three design solutions for fixing the broken bone, have each group present their best design and answer the following questions:
Final Presentations and Project Reflection: After testing their devices, have students consider again the questions from the activity-embedded assessment, as well as the following:
Activity Extensions (Return to Contents)
Have students, individually or in groups, draw final designs based on what they learned from the testing and presentations.
Activity Scaling (Return to Contents)
References (Return to Contents)
Bone fracture repair-series, Procedure. Last updated September 21, 2009. MedlinePlus Medical Encyclopedia, US National Library of Medicine, National Institutes of Health. Accessed October 29, 2009. http://www.nlm.nih.gov/medlineplus/ency/presentations/100077_3.htm
Prototype. The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company. Accessed November 2, 2009, from Dictionary.com website. http://dictionary.reference.com/browse/Prototype
ContributorsTodd Curtis, Malinda Schaefer Zarske, Janet Yowell, Denise W. Carlson
Copyright© 2008 by Regents of the University of Colorado.
Supporting Program (Return to Contents)Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder
Acknowledgements (Return to Contents)
This digital library content was developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.