Research Phase

• Background Research• Market Analysis• First Level Quality Functional Deployment Diagram• Decided to pursue implantable device• Determined likely materials for implant

Design Phase

• Determined shapes of implants to test• Determined locations within hip to test• Completed ANSYS simulations of impact on hip tissue

with multiple implant shapes (Figures 2 and 3)• Created testing device design (Figure 4)• Created CAD schematic of testing device

Testing Phase

• Constructed testing device (Figure 5)• Molded implant device materials• Created phantom hip tissue and greater trochanter• Characterized available implant materials (Figure 6)• Completed preliminary foam testing (Figure 7)

Device to Prevent Hip Fracture in the ElderlyDiana Rudz, BS; Emily Bauer, BS; Matthew Mitchell, BS; Brandon Cropley, BS; Jingxian Tan,

BS.Faculty Advisor: Jack Thompson, M. Eng.

Faculty Co- Advisor: Newton de Faria, PhDDepartment of Biomedical Engineering, Cornell University

AbstractThe rate of hip fracture in the United States is among the highest in the world (1). It has been estimated that there are at least 250,000 hospital admissions annually for hip fracture in the United States for people age 65 or older (2). Falling causes more than 95 percent of hip fractures (2). One in five elderly hip fracture patients die within a year of their hip fracture injury (2). Some of the characteristics that increase an elderly person’s risk of hip fracture are poor vision, medical conditions and medications that cause fragile bones, lack of coordination, physical inactivity, tobacco use, and alcohol consumption (3). Osteoporosis is a disease that causes bone structure to become porous, which decreases bone strength (4). Osteoporosis is a main contributor to between 70 and 90 percent of all hip fractures (4). While the fracture itself may occur as a result of a fall or injury, osteoporosis often contributes to the weakening of the bone that allows the fracture.

Currently the methods of hip fracture prevention are exercise, healthy eating, avoiding drugs and alcohol, maintaining a safe BMI, balance training, annual physical exams, and taking vitamin D and calcium supplements. There are also some external prevention devices such as hip protectors, but these have proven to be cumbersome and irritating for patients to deal with for daily use. There is a clear need for an inexpensive, convenient, and effective osteoporotic hip fracture prevention device. It is our goal to design a device for at-risk patients for preventative measures.

Project PurposeWe aim to design a device that could be safely and easily implemented to protect the greater trochanter area to prevent hip fracture during falls. This product would be significantly less threatening to the health of the patient in comparison to a hip fracture. It would also be cheaper than undergoing a hip replacement procedure. Ideally this device would be minimally invasive and would allow the patient to return home the same day.

Project Progress

BackgroundOne of the most serious and common injuries from a fall are hip fracture injuries. There are approximately 34 billion dollars spent as a result of hip fractures every year (2). The three main types of hip fractures are: femoral neck (intracapsular), intertrochanteric, and subtrochanteric fractures (Figure 1).

Future Work

References[1] Dhanwal, Dinesh, Elaine Dennison, Nick Harvey, and Cyrus Cooper. "Epidemiology of Hip Fracture: Worldwide Geographic Variation." Indian Journal of Orthopaedics. Medknow Publications, 1 Mar. 2011. Web. 29 Sept. 2015http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3004072/[2] "Hip Fractures Among Older Adults." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 21 Sept. 2015. Web. 29 Sept. 2015. http://www.cdc.gov/homeandrecreationalsafety/falls/adulthipfx.html[3] "Hip Fracture." Mayo Clinical Staff. Risk Factors. 11 Mar. 2015. Web. 29 Sept. 2015. http://www.mayoclinic.org/diseases-conditions/hip-fracture/basics/risk-factors/con-20021033 [4] "Osteoporosis Facts & Statistics." Osteoporosis Facts & Statistics. Web. 29 Sept. 2015. http://www.osteoporosis.ca/osteoporosis-and-you/osteoporosis-facts-and-statistics/[5] NICE CG124 Hip fracture: slide set. March 30, 2012. http://www.nice.org.uk/nicemedia/live/13489/54925/54925.ppt.[6] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1730160/[7] http://www.uptodate.com/contents/total-hip-replacement-arthroplasty-beyond-the-basics

Acknowledgements

Figure 1: Hip Fracture Classifications [5]

Part of the reason that hip fractures are so expensive is the lengthy process that patients who have had hip fractures must go through:• The hip fracture must be diagnosed, usually with X-Ray or MRI Imaging• The hip fracture must be fixed through a surgical procedure. These procedures include

the use of screws to fix the hip, a partial hip replacement surgery, or a total hip replacement surgery.

• Rehabilitation is necessary to improve the patient’s mobility/independence. Physical therapy is often needed to improve the patient’s range of motion as well as strengthening of muscle to return to pre-surgery levels. This process takes months and even up to a year.

Oftentimes, the surgery alone is not enough to ensure a recurrent hip fracture, with around 20% of people having a second hip fracture within two years of the first [2]. Bone-strengthening medicine such as bisphosphonates are used in increase bone density. Even after an extensive surgery, months of physical therapy, and work to improve the patient’s standard of living, many patients do not regain full mobility, and around 20% of patients die within a year of hip fractures [2].

Robert Karpman, MD, MBA, GeriSafe Founder and CEOTimothy Bond, Technical Services Manager of the Civil Infrastructure Laboratory Complex

Current Testing Progress

Figure 3: Implant Shape Designs Tested in ANSYS Simulation Software

Figure 2: Hip Model in ANSYS Simulation Software

Figure 4: CAD Drawing of Testing Device

Implant Shapes- U shaped- X shaped- O shaped

Tissue Depth- Under Skin

- Under IT Band- Directly on Bone

Data Analysis

0.000 0.050 0.100 0.150 0.200 0.250-0.010

0.010

0.030

0.050

0.070

0.090

0.110f(x) = 0.526196743424741 x − 0.00460244141995451R² = 0.981276678203404

OOMOO 25 LSR Characterization

Strain

Stre

ss (M

Pa)

Figure 6: Material Characterization Curve

Figure 5: Constructed Testing Device

0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55-50

150

350

550

750

950

1150

1350Blank Foam Impact Test

Time (s)

Impa

ct F

orce

(lbs

)

After we complete testing we will be able to determine the shape and depth that an implanted device would require to significantly decrease the force that impacts the greater trochanter during a fall. We will also determine how the implanted device would need to be attached to the surrounding tissue to stay in place.

Figure 7: Testing Device Impact Curve on Blank Polyethylene Foam