Biomechanics & Biomaterials MCQs

Cortical bone exhibits viscoelastic properties, meaning its biomechanical behavior changes depending on the rate of loading. During a high-speed motor vehicle collision, a femur is loaded at a very high strain rate. Compared to a low-energy fall, how does the bone behave?

An orthopaedic implant engineer is comparing the fatigue properties of different orthopaedic biomaterials. Which of the following materials has a Young's Modulus of Elasticity closest to that of human cortical bone, thereby theoretically reducing stress shielding?

During a revision total hip arthroplasty, the surgeon notices significant corrosion at the modular head-neck junction. The femoral stem is made of a titanium alloy, while the modular head is cobalt-chromium. Which type of corrosion is most directly caused by the pairing of these dissimilar metals?

A mechanical test is performed on an anterior cruciate ligament (ACL) graft. The stress-strain curve initially demonstrates a non-linear 'toe region' before becoming linear. What microstructural event is responsible for this toe region?

Nine months following open reduction and internal fixation of a diaphyseal femur fracture, a patient returns with sudden thigh pain. Radiographs reveal a broken plate and persistent nonunion. The plate failure occurred despite no single load exceeding the material's ultimate tensile strength. This failure mechanism is termed:

When preparing polymethylmethacrylate (PMMA) bone cement for fixing a pathological fracture, the surgeon must understand its mechanical limitations. PMMA is strongest under which of the following mechanical forces?

Cortical bone is described as an 'anisotropic' material. Which of the following statements best defines this property in the context of orthopaedic biomechanics?

A researcher is developing a novel polyethylene component for a total knee arthroplasty. They note that under a constant, unchanging compressive load over several years, the material slowly undergoes increasing plastic deformation. This specific time-dependent property is called:

To minimize stress shielding around a non-cemented femoral stem, the implant material should ideally have an elastic (Young's) modulus close to that of cortical bone. Among the following orthopedic metals, which has the lowest elastic modulus?

Cortical bone exhibits viscoelastic properties. When loaded at a very high strain rate, such as during a high-velocity trauma, how do the mechanical properties of the bone change compared to a low strain rate?

A surgeon accidentally uses a stainless steel screw through a titanium plate during fracture fixation. This mixed-metal construct places the patient at highest risk for which type of corrosion?

Which of the following statements correctly describes the inherent mechanical properties of polymethylmethacrylate (PMMA) bone cement?

On the stress-strain curve for an orthopedic alloy, the exact point at which the material transitions from elastic (recoverable) deformation to plastic (permanent) deformation is known as the:

Cortical bone exhibits different mechanical properties (e.g., strength, stiffness) depending on the direction of the applied load. This fundamental biomechanical property is termed:

In orthopedic biomechanics, what term describes the phenomenon where a viscoelastic material undergoes increasing deformation over time under a constant applied load?

In orthopedic biomechanics, the gradual and progressive deformation of a viscoelastic material over time when subjected to a constant, sustained load is defined as what?

A surgeon is choosing an intramedullary nail for a young, active patient with a tibia fracture. They are considering two options: one made of stainless steel and another of titanium alloy. From a biomechanical perspective, which material property is most relevant to minimizing long-term stress shielding of the bone?

A surgeon is fixing a pediatric forearm fracture and wants to minimize the need for future hardware removal. Which screw material would be most appropriate, considering biocompatibility and biomechanics?

A 42-year-old patient requires internal fixation for a long bone fracture. The surgeon is debating between a 316L stainless steel plate and a Ti-6Al-4V titanium alloy plate. From a long-term biological and biomechanical perspective, what is a distinct advantage of the titanium alloy plate?