Biomechanics & Biomaterials MCQs

The progressive deformation of a polyethylene tibial insert over time under a constant static load is an example of which biomechanical principle?

When adding antibiotics to polymethylmethacrylate (PMMA) bone cement, which of the following characteristics is essential for the antibiotic to be effective?

A viscoelastic orthopedic implant is subjected to a constant, sustained load over several years, resulting in a slow, progressive deformation of the material. This biomechanical phenomenon is best described as:

Combining a 316L stainless steel screw with a titanium alloy plate in a fracture construct increases the risk of implant failure due to which specific type of corrosion?

When incorporating an antibiotic into polymethylmethacrylate (PMMA) bone cement for an infected arthroplasty spacer, which specific property of the antimicrobial agent is most vital to ensure it remains active after the cement cures?

When applying a locked plate to a highly comminuted diaphyseal fracture, what is its primary biomechanical advantage over a standard, non-locked dynamic compression plate?

Stress shielding around a femoral stem is primarily caused by a mismatch in stiffness between the implant and the surrounding bone. Which of the following sequences represents the correct order of Young's modulus of elasticity from greatest to least?

A patellar tendon graft is used for ACL reconstruction and is tensioned on the back table. Over time, while held at a constant tension, the graft gradually elongates. Which biomechanical property does this describe?

Mixing stainless steel and titanium implants within the same surgical construct can lead to galvanic corrosion. In this scenario, what happens to the stainless steel component?

A researcher is studying the mechanical properties of different orthopedic materials compared to human cortical bone. Which of the following implant materials possesses a Young's modulus (modulus of elasticity) that is closest to that of cortical bone?

During an anterior cruciate ligament reconstruction, the surgeon pulls the soft-tissue graft under a constant load for several minutes before final fixation. The graft gradually lengthens during this period. Which viscoelastic property does this demonstrate?

A patient presents with a symptomatic nonunion of a femoral shaft fracture initially treated with a stainless steel plate. The surgeon plans to revise the fixation using a titanium plate and the existing stainless steel screws. Why is this construct contraindicated?

When preparing antibiotic-loaded polymethylmethacrylate (PMMA) bone cement for a two-stage revision of an infected total hip arthroplasty, which of the following antibiotics is best suited for incorporation due to its thermal stability and elution profile?

In a standard stress-strain curve for a metallic orthopedic implant, what does the slope of the curve in the linear elastic region represent?

During an ACL reconstruction, a hamstring tendon graft is tensioned and secured at a constant length. Over the first few minutes, the tension within the graft decreases. This viscoelastic phenomenon is known as:

On a standard stress-strain curve for a structural material such as metal or bone, the point at which the material transitions from completely reversible elastic deformation to permanent plastic deformation is known as the:

Galvanic corrosion occurs when two dissimilar metals are in contact within a conductive fluid environment. Which factor primarily dictates the severity and direction of this corrosive process?