By: Iaian Cameron and Sam Donaldson

Cementing Bones

Whitefish High School

Mr. Spangler

Advanced Chemistry

Intro

Research Question: What kind of forces and how much force can bone cement withstand

Hypothesis: The bone cement will be more effective when not connected to bone marrow.

Background Info

The DePuy Medium Viscosity Bone Cement is used as a cement to adhere bone to metal during an orthopedic surgery. The cement sets in 10 minutes so you have limited time to work with it and it also costs approximately $100 a batch (6 batches). This test is to simulate how much raw force the cement can withstand in the human body so people who have underwent this surgery can better understand their physical limitations.

First We Tested an Epoxy

Procedure for Applying Cement

1) Put two surgical gloves on each hand2) Put all the powdered contents of the cement in the expendable cup3) Empty all the liquid material into the powder under the fume hood4) Mix for 30 seconds under the fume hood5) Let it settle under the fume hood for 3 minutes or until it does not adhere to

gloves (putty-like consistency)6) Apply in between the desired adhering area with hands7) Let it settle in the air duct for approximately 10 minutes

Warning: Cement sets very quickly and the fumes are toxic

Materials: Expendable Cup, DePuy Medium Viscosity Bone Cement expendable stirring rod, fume hood, two pairs of surgical gloves, and timer

Procedure for Testing Force

1) Tie both ends of the bone to the overhead bar using the straps2) Using the rope, hang weights in increasing increments from the exposed ends of the metal3) Repeat step two until the metal and the bone separate entirely4) Record max weight held

Caution: Be careful when the cement fails

Materials: Bone adhered to metal, two straps, varying weights, rope, strength, flat overhead bar.

T-Grip Test

Pull Test

Double Cantilever Beam Test

Testing

Data

• T-Grip test– Held 90

pounds

• Double cantilever beam test-Held 130

pounds

• Pull-Test-Held 125

pounds

• The Bone-cement bond is weaker than the metal-cement bond

Conclusion

• The Bone-cement is pretty strong as we showed in a variety of tests

• People that have this substance in their body shouldn’t be too worried about physical limitations

Improvements

• Testing more likely forces in a body• Use bones that are fresher and that are

constantly at body temperature• Use titanium instead of steel• More sterile environment

References

• "A Double Cantilever Beam Test for Characterizing Mode I Delamination of Composite Materials." A Double Cantilever Beam Test for Characterizing Mode I Delamination of Composite Materials. N.p., n.d. Web. 09 May 2013.

• "Depuy CMW." DePuy.com | Patient & Caregiver Resources For Back, Hip, Limb & Joint Pain From DePuy. N.p., n.d. Web.

• "DePuy.com | Patient & Caregiver Resources For Back, Hip, Limb & Joint Pain From DePuy." DePuy.com | Patient & Caregiver Resources For Back, Hip, Limb & Joint Pain From DePuy. N.p., n.d. Web. 09 May 2013.