Biomechanics & Biomaterials MCQs

A patient presents with acute monoarticular knee swelling. A joint aspirate reveals 65,000 white blood cells/hpf, predominantly polymorphonuclear leukocytes, and negatively birefringent needle-shaped crystals. Which of the following crystals is present?

Viscoelastic materials such as ligaments and tendons exhibit which of the following properties when subjected to a constant physiological load over an extended period of time?

Which of the following biomaterial combinations poses the highest risk for galvanic corrosion when used together in orthopedic internal fixation?

In the flexor tendon pulley system of the fingers, which two annular pulleys are considered most critical to preserve or reconstruct during surgery to prevent tendon bowstringing?

A 45-year-old active male feels a 'pop' in his posterior knee while squatting. MRI demonstrates a complete radial tear of the posterior horn of the medial meniscus exactly at its tibial attachment. Biomechanically, this injury is equivalent to which of the following?

A 52-year-old woman experiences a sharp pop in her posterior knee while squatting. MRI reveals a complete posterior root tear of the medial meniscus with 4 mm of radial meniscal extrusion. Which of the following best describes the biomechanical consequence of this injury if left untreated?

Highly cross-linked polyethylene (HXLPE) is utilized in THA to substantially reduce wear rates. What is a known mechanical consequence of the post-irradiation melting or annealing process used to eliminate free radicals?

Which of the following manufacturing processes in highly cross-linked polyethylene (HXLPE) primarily contributes to the reduction of its mechanical yield strength and fatigue resistance compared to conventional polyethylene?

In orthopedic implant metallurgy, mixing components made of 316L stainless steel and titanium alloys is generally avoided. Which of the following best explains the risk of combining these two different metals in vivo?

When analyzing the stress-strain curve of an orthopedic implant material, the area under the curve strictly within the elastic region represents which mechanical property?

A 60-year-old man presents with an acutely swollen knee. Aspiration yields cloudy synovial fluid that demonstrates positively birefringent, rhomboid-shaped crystals under compensated polarized light microscopy. What specific material constitutes these crystals?

When designing an orthopedic implant for diaphyseal fracture fixation, minimizing stress shielding is a primary goal. Which of the following implant materials possesses a Young's modulus most closely approximating that of human cortical bone?

In fracture fixation, utilizing a stainless steel screw through a titanium plate in a saline-rich environment can lead to accelerated degradation of the implant. This process is best described as which type of corrosion?