Biomechanics & Biomaterials MCQs

A surgeon places a titanium screw through a stainless steel plate during fracture fixation. Which of the following modes of corrosion is most likely to occur at the interface of these two implants?

A resident is tensioning a hamstring autograft for an ACL reconstruction. They apply a constant load to the graft for 5 minutes and observe that the graft gradually lengthens. Which viscoelastic property does this describe?

Which characteristic is essential for an antibiotic to be effective and safe when mixed into polymethylmethacrylate (PMMA) bone cement for a joint spacer?

A viscoelastic material subjected to a constant deformation will demonstrate a gradual decrease in the stress required to maintain that deformation. This mechanical phenomenon is known as:

Which of the following scenarios describes galvanic corrosion in orthopedic implants?

Which type of corrosion is primarily mechanically driven and occurs at the microscopic contact points between modular junctions, such as the head-neck taper in a total hip arthroplasty?

On a stress-strain curve for a typical orthopaedic metallic implant, the point at which the material transitions from elastic deformation to plastic deformation is known as the:

In the stress-strain curve of a ductile orthopedic implant material, the point at which the material undergoes non-reversible plastic deformation but has not yet fractured is best described by which of the following terms?

A surgeon contemplates using a pure titanium plate with 316L stainless steel screws for a fracture fixation. What is the expected electrochemical consequence of mixing these metals?

During the correction of a severe scoliotic curve, a surgeon applies an initial distractive force across a pedicle screw construct. Over the next hour, while the displacement remains constant, the tension in the rods gradually decreases. This biomechanical phenomenon is known as:

When analyzing the stress-strain curve of a normal human anterior cruciate ligament undergoing tensile testing, what structural event is represented by the initial, non-linear 'toe region'?

In orthopedic biomechanics, the pullout strength of a cortical screw is most directly proportional to which of the following design variables?

Which type of corrosion is most likely to occur at the modular head-neck junction of a total hip arthroplasty system, potentially leading to adverse local tissue reactions (ALTR)?

In the typical stress-strain curve of a normal ligament, the initial non-linear 'toe region' is anatomically represented by which of the following microstructural phenomena?

When selecting materials for a fracture fixation plate, the surgeon must consider the modulus of elasticity to minimize stress shielding. Which of the following implant materials has a modulus of elasticity closest to that of cortical bone?

A surgeon removes a fractured stainless steel plate that was previously fixed with titanium screws. There is significant dark discoloration and pitting at the specific screw-hole interfaces. Which type of corrosion is predominantly responsible for this finding?

A patient undergoes joint aspiration for an acutely painful, swollen ankle. Microscopic analysis of the synovial fluid under polarized light reveals rhomboid-shaped crystals with weakly positive birefringence. What is the composition of these crystals?