Biomechanics & Biomaterials MCQs

When a stainless steel screw is placed through a titanium plate in a fracture fixation construct, which specific type of corrosion is most likely to accelerate device failure?

To avoid galvanic corrosion in orthopedic implants, dissimilar metals should generally not be mixed. Which of the following combinations is most likely to result in significant galvanic corrosion?

A surgeon uses a stainless steel cerclage wire in combination with a titanium plate for a femoral fracture fixation. Months later, localized bone resorption and implant failure are noted at the junction of the two metals. Which type of corrosion is most likely responsible for this failure?

Which of the following orthopedic implant materials has an elastic (Young's) modulus most closely resembling that of human cortical bone?

On a stress-strain curve of a metallic orthopedic implant, what point represents the maximum stress a material can withstand before permanent deformation occurs?

A 45-year-old male undergoes revision internal fixation for a femoral shaft nonunion. The surgeon plans to use a stainless steel plate with the retained titanium screws from the index procedure. Which of the following best describes the primary type of corrosion that is likely to occur?

Which of the following factors is most strongly associated with increased volumetric wear of highly cross-linked polyethylene in total hip arthroplasty?

During the application of a halo vest, the pins are initially torqued to 8 in-lbs. After 48 hours, the torque on the pins is measured and found to have decreased, despite the pins not visibly moving. Which of the following viscoelastic properties best explains this phenomenon?

Which of the following orthopedic implant materials possesses a modulus of elasticity that most closely matches that of normal human cortical bone, thereby minimizing stress shielding?

When a stainless steel plate is fixed with titanium screws in an orthopedic construct, accelerated localized corrosion may occur at the screw-plate interface over time. Which specific type of corrosion is primarily responsible for this degradation?

A 45-year-old male undergoes revision ORIF for a nonunion of the femur. The surgeon uses a stainless steel plate and titanium screws. Which of the following best describes the likely consequence of mixing these metals in vivo?

A new titanium alloy is undergoing biomechanical testing for intramedullary nail fabrication. The material deforms under an applied load and returns precisely to its original shape once the load is removed. The maximum stress this material can withstand before permanently deforming is known as which of the following?

During the correction of a severe knee flexion contracture, a physical therapist applies a static, constant force splint. Over several weeks, the soft tissues progressively lengthen despite the force remaining unchanged. This viscoelastic property is termed:

When analyzing the stress-strain curve of a normal articular cartilage specimen loaded in tension, an initial non-linear 'toe region' is observed before the curve becomes linear. What microscopic structural change corresponds to this toe region?

In the stress-strain curve of orthopedic biomaterials, the slope of the linear elastic region represents which of the following properties?

Polymethylmethacrylate (PMMA) bone cement is frequently used in joint arthroplasty. The addition of barium sulfate to PMMA serves which of the following purposes?