Biomechanics & Biomaterials MCQs

During biomechanical testing of a human anterior cruciate ligament (ACL) graft, the tissue is subjected to a constant deformation (length is held constant) over a period of time. The researchers note that the load required to maintain this constant deformation gradually decreases. Which viscoelastic property is being demonstrated?

An orthopedic surgeon utilizes a stainless steel screw to secure a titanium plate during open reduction internal fixation of a diaphyseal fracture. Postoperatively, the patient develops localized failure and rapid degradation at the screw-plate interface. This failure is primarily due to which phenomenon?

A 65-year-old male undergoes a total hip arthroplasty using a highly cross-linked polyethylene liner. Which of the following best describes the primary mechanism by which highly cross-linked polyethylene reduces wear compared to conventional polyethylene?

A patient presents with pain and a sterile effusion 5 years after receiving a modular total hip arthroplasty with a cobalt-chromium head and a titanium femoral stem. Aspirate reveals dark fluid and metal debris. What type of corrosion is most likely occurring at the head-neck junction?

A surgeon plans to use a stainless steel plate with titanium screws for fracture fixation. Which of the following types of corrosion is most likely to occur at the screw-plate interface?

A 55-year-old female undergoes a revision total hip arthroplasty. During the procedure, the surgeon utilizes a stainless steel cerclage wire around a titanium femoral stem. Which type of corrosion is most likely to occur at the interface of these two different metals?

Which of the following common orthopedic implant metals has a modulus of elasticity that most closely approximates that of cortical bone?

Galvanic corrosion in orthopedic implants is most likely to occur under which of the following circumstances?

Which of the following statements best describes the primary biomechanical advantage of utilizing a titanium alloy (Ti-6Al-4V) instead of a cobalt-chromium (Co-Cr) alloy for a femoral intramedullary nail?

Galvanic corrosion represents a significant mechanism of implant degradation and failure in orthopedic surgery. This phenomenon is most likely to occur under which of the following clinical scenarios?

A surgeon plans to revise a failed internal fixation using a combination of existing 316L stainless steel hardware and new titanium alloy implants. Which of the following mechanisms of material failure is most likely to be accelerated by placing these two dissimilar metals in direct contact in vivo?

When analyzing the mechanical properties of an orthopedic implant on a stress-strain curve, which of the following points indicates the transition from reversible elastic deformation to irreversible plastic deformation?

Articular cartilage exhibits complex biomechanical behavior under load. Which of the following statements provides the best definition of the viscoelastic property known as 'stress relaxation'?

Viscoelastic materials exhibit time-dependent deformation. A surgeon applies a dynamic splint to a contracted joint, keeping the force constant while the tissue slowly lengthens. What viscoelastic property does this demonstrate?

Mixing dissimilar metals in an orthopedic implant construct, such as utilizing a stainless steel screw through a titanium plate, primarily increases the risk of which type of corrosion?

In the stress-strain curve of a given orthopaedic implant material, what term describes the specific point where plastic deformation begins and the material will no longer return to its original shape upon load removal?

When comparing Titanium alloy (Ti-6Al-4V) to Stainless Steel (316L) for use in orthopedic fracture fixation plates, Titanium is characterized by which of the following mechanical properties?

In biomechanics, which of the following terms describes the phenomenon where a viscoelastic material experiences a decrease in stress over time when held at a constant strain?