Biomechanics & Biomaterials MCQs

When a constant force is applied to a ligament over time, the ligament will gradually undergo continuous elongation. This viscoelastic property is known as:

The non-Newtonian, shear-thinning behavior of normal synovial fluid, where viscosity decreases as the shear rate increases, is primarily conferred by which of the following molecules?

Which of the following physical characteristics must an antibiotic possess to be effectively mixed into and eluted from polymethylmethacrylate (PMMA) bone cement?

An orthopedic researcher evaluates the mechanical properties of a new implant material. The total area under the stress-strain curve up to the point of fracture is measured and found to be greatest for this new material compared to standard titanium. Which mechanical property does this specific area represent?

A 65-year-old man undergoes revision total hip arthroplasty for a painful, aseptic joint. Intraoperatively, significant black debris is noted around the modular head-neck junction of his cobalt-chrome head on a titanium stem. Which of the following mechanisms best explains the generation of this debris?

In total joint arthroplasty, highly cross-linked polyethylene (HXLPE) is irradiated to reduce wear rates. What is the primary biological or mechanical purpose of adding Vitamin E (alpha-tocopherol) to HXLPE during manufacturing?

A ligament is subjected to a constant physiological load. Over a period of 20 minutes, the ligament experiences a progressive, time-dependent increase in strain (elongation) despite the load remaining entirely unchanged. Which viscoelastic property does this phenomenon represent?

An orthopedic surgeon decides to use a titanium alloy (Ti-6Al-4V) femoral stem instead of a cobalt-chromium (Co-Cr) stem for a cementless total hip arthroplasty. Which of the following mechanical properties most accurately explains the reduced risk of proximal femoral stress shielding associated with titanium?

A patient with a modular cementless total hip arthroplasty presents with unexplained hip pain and rising serum cobalt levels. Radiographs show no loosening. What is the predominant mechanism of wear occurring at the head-neck taper junction (trunnionosis)?

Viscoelastic materials exhibit time-dependent mechanical properties. When a ligament is stretched to a constant length and held there over time, the tension within the ligament gradually decreases. What is this biomechanical phenomenon called?

An orthopedic surgeon decides to use a 316L stainless steel screw to fixate a titanium alloy plate for a complex fracture. Which specific type of implant degradation is most likely to occur due to this combination?

Cortical bone exhibits different mechanical properties depending on the direction of the applied load; for example, it is significantly stronger when loaded longitudinally in compression than when loaded transversely. What is this biomechanical property called?

When evaluating the mechanical behavior of a metallic orthopedic implant, the stiffness of the material is represented by the slope of the elastic region on a stress-strain curve. Which specific mechanical term describes this slope?

Surgeons often mix antibiotics into polymethylmethacrylate (PMMA) bone cement for local prophylaxis or treatment of periprosthetic joint infections. Which pharmacokinetic or physical characteristic is absolutely mandatory for an antibiotic to be effective in PMMA?

Various synthetic bone graft substitutes are utilized in orthopedic surgery to fill bone defects, acting purely as osteoconductive scaffolds. Among the following options, which material exhibits the most rapid rate of in vivo resorption?

A researcher applies a constant load to a human anterior cruciate ligament graft during biomechanical testing. Over several hours, the length of the graft progressively increases without any increase in the applied force. What viscoelastic property does this phenomenon represent?

A surgeon contemplates using a stainless steel screw to secure a titanium plate during fracture fixation. This combination is generally avoided due to the risk of galvanic corrosion. In this electrochemical process, which of the following accurately describes the interaction?

Retrieval analysis of a failed total hip arthroplasty shows microscopic scratches, plowing, and gouges on the cobalt-chromium femoral head caused by third-body bone cement particles. What specific type of wear does this represent?

When preparing antibiotic-loaded polymethylmethacrylate (PMMA) bone cement for a prosthetic joint infection spacer, which characteristic of the selected antibiotic is most crucial for successful incorporation, survival, and elution?