Biomechanics & Biomaterials MCQs

The torsional rigidity of a solid intramedullary nail is proportional to its radius raised to which power?

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

In total joint arthroplasty, the phenomenon of "third-body wear" is best classified as which type of wear mechanism?

Which of the following biomechanical terms best describes the phenomenon where a ligament subjected to a constant, sustained load exhibits a progressive increase in deformation over time?

On a standard stress-strain curve for a given orthopaedic implant, the total area under the curve prior to the point of structural failure represents the material's:

The use of a stainless steel screw through a titanium plate in an internal fixation construct is generally avoided in orthopedic surgery due to the risk of which type of corrosion?

When analyzing the biomechanical properties of a hollow intramedullary nail, its torsional rigidity (polar moment of inertia) depends most heavily on which geometric parameter?

A 45-year-old woman reports an acute pop in the back of her knee while squatting. MRI reveals a medial meniscus posterior root tear with 3 mm of extrusion. Which of the following biomechanical changes occurs in the knee as a result of this injury?

Which historical sterilization method for ultra-high-molecular-weight polyethylene (UHMWPE) is most associated with subsequent severe oxidation, delamination, and rapid wear in THA?

Highly cross-linked polyethylene (HXLPE) is widely used in modern THA to reduce wear rates. What is the primary mechanical trade-off associated with increasing the radiation dose used to create cross-linking in polyethylene?

A 65-year-old active man undergoes a total hip arthroplasty using a highly cross-linked polyethylene liner. Which of the following mechanical properties is most significantly decreased in highly cross-linked polyethylene compared to conventional ultra-high-molecular-weight polyethylene (UHMWPE)?

Trunnionosis has emerged as a significant mode of failure in modern total hip arthroplasty, particularly involving modular head-neck junctions. This process is most accurately described by which of the following mechanisms?

In modern cementing techniques for total hip arthroplasty (third-generation cementing), vacuum mixing of the polymethylmethacrylate (PMMA) bone cement is standard practice. What is the primary biomechanical benefit of vacuum mixing?

A 35-year-old woman is 4 months postoperative from open reduction and internal fixation of an ankle fracture, which included placement of two 3.5mm trans-syndesmotic screws. She is completely asymptomatic and asks if the screws must be removed. Based on current orthopedic literature, what is the recommendation regarding routine removal of syndesmotic screws?

Which of the following manufacturing processes is most effective at reducing the wear rate of ultra-high-molecular-weight polyethylene (UHMWPE) while minimizing the risk of long-term in vivo oxidation?

A dynamic splint is applied to a patient's elbow to treat a flexion contracture. Over time, the tension in the elastic band of the splint decreases despite the elbow remaining locked in the exact same position. This viscoelastic phenomenon is best described as:

The combination of a titanium femoral stem and a cobalt-chromium femoral head in total hip arthroplasty relies on a passivation layer to resist corrosion. If this oxide layer is repeatedly breached by micromotion at the head-neck junction, the resulting degradation is most accurately termed:

Which of the following orthopedic implant materials possesses a modulus of elasticity most closely resembling that of human cortical bone?

Which of the following alterations occurs when a radiopacifier such as barium sulfate or zirconium dioxide is added to polymethylmethacrylate (PMMA) bone cement?

During tensile testing of a human anterior cruciate ligament, the initial non-linear 'toe region' of the load-deformation curve is primarily caused by: