Biomechanics & Biomaterials MCQs

Ligaments and tendons possess viscoelastic properties that affect their biomechanical behavior under load. The biomechanical phenomenon where the internal stress within a tissue progressively decreases over time while it is held at a constant length (strain) is defined as:

An orthopedic surgeon revises a failed femoral neck fracture fixation by substituting a stainless steel side plate with a titanium plate, but leaves the original stainless steel lag screw in place. Several months later, rapid implant failure occurs with surrounding metallic debris. This phenomenon is primarily an example of:

Bone provides profound structural support primarily due to its dense inorganic matrix. Which of the following represents the predominant mature inorganic mineral constituent of healthy human cortical bone?

A physical therapist applies a constant load to a patient's contracted Achilles tendon, resulting in a gradual increase in tendon length over time. This phenomenon is a demonstration of which viscoelastic property?

In total hip arthroplasty, the use of highly cross-linked polyethylene (HXLPE) has significantly reduced wear rates compared to conventional polyethylene. What is the primary mechanical trade-off associated with increasing the radiation dose to increase cross-linking?

A new orthopedic implant material is being biomechanically tested. The total area under the stress-strain curve up to the point of fracture represents which of the following material properties?

During a revision open reduction and internal fixation of a nonunion, a surgeon uses a stainless steel screw through a titanium alloy plate. Several months later, rapid degradation is noted at the screw-plate interface. This is primarily an example of which type of corrosion?

In orthopedic biomechanics, when a constant load is applied to a viscoelastic tissue such as a ligament or tendon over an extended period, the tissue will slowly continue to elongate. This time-dependent deformation is known as:

During ACL reconstruction rehabilitation, what biomechanical property is responsible for the gradual elongation of a tendon graft over time when subjected to a constant continuous load?

A patient with a stainless steel dynamic compression plate subsequently has a titanium screw inserted into the plate. What type of corrosion is most likely to occur at the screw-plate interface?

Which of the following modifications to a cortical screw will most significantly increase its pullout strength in diaphyseal bone?

Which type of corrosion occurs primarily when a stainless steel screw is used in direct mechanical combination with a titanium plate in an orthopedic construct?

A 19-year-old female collegiate soccer player sustains a noncontact twisting injury to her knee, resulting in an ACL tear. Which of the following factors is considered the most significant modifiable contributor to the higher incidence of ACL tears in female athletes compared to males?

When preparing an articulating polymethylmethacrylate (PMMA) antibiotic spacer for a two-stage revision of an infected total knee arthroplasty, which specific characteristic of the chosen antibiotic is most crucial to ensure effective local elution and efficacy?

Regarding the surgical treatment of a large, symptomatic chondromyxoid fibroma of the proximal tibia in a young adult, what is the most appropriate definitive management?

A 55-year-old male presents with severe acute monoarticular pain, erythema, and swelling in his first metatarsophalangeal joint. Joint aspiration reveals negatively birefringent, needle-shaped crystals under polarized light microscopy. Which of the following is the composition of these crystals?

A 9-year-old boy with a history of juvenile dermatomyositis presents with hard, painful nodules under the skin over his elbows and knees.

What is the primary composition of these deposits?

A 10-year-old girl with a history of juvenile dermatomyositis develops widespread, firm subcutaneous nodules around her elbows, knees, and pelvis. Some of these nodules have ulcerated and express a chalky white substance.

What is the primary mineral composition of these deposits?