1. General Principles & Basic Science MCQs

Trunnionosis, or failure at the modular head-neck taper junction of a total hip arthroplasty, is best described as mechanically assisted:

The mechanical behavior of cortical bone varies depending on whether a load is applied longitudinally, transversely, or in shear. This characteristic is defined as:

Low-intensity pulsed ultrasound (LIPUS) is utilized to accelerate fracture healing. The primary cellular mechanism by which mechanical acoustic waves are transduced into a biologic response involves the upregulation of:

A surgeon inadvertently utilizes a stainless steel plate with a titanium screw. The direct contact between these dissimilar metals in an electrolytic physiological fluid primarily predisposes the construct to:

Romosozumab has recently been approved for the treatment of severe osteoporosis. What is the precise molecular target of this monoclonal antibody?

When analyzing the stress-strain curve of an orthopedic biomaterial, the total area under the curve prior to the point of material failure represents which biomechanical property?

During bone resorption, osteoclasts create an acidic microenvironment in Howship's lacunae by secreting protons via a vacuolar H+-ATPase. Which enzyme is then primarily responsible for the degradation of the organic type I collagen matrix?

In an experiment, a cadaveric anterior cruciate ligament is rapidly stretched to a constant, fixed length. Over the next several minutes, the force required to maintain this specific length gradually decreases. This viscoelastic phenomenon is known as:

Titanium alloy (Ti-6Al-4V) is frequently chosen over Cobalt-Chromium for the manufacturing of diaphyseal-engaging femoral stems in uncemented total hip arthroplasty. What is the primary biomechanical advantage of Titanium in this application?

An adult sustains a transverse radius fracture and undergoes open reduction and internal fixation with a dynamic compression plate. If absolute stability and rigid compression are achieved, the fracture will heal via which mechanism?

Polymethylmethacrylate (PMMA) bone cement is supplied as a powder and a liquid monomer. What is the specific function of Barium sulfate or Zirconium dioxide, which are added to the powder component?

Parathyroid hormone (PTH) plays a critical role in calcium homeostasis. At the cellular level within bone tissue, what is the primary direct action of PTH?

A nonunion of the tibia requires bone grafting. The surgeon desires a graft material that possesses osteoconductive, osteoinductive, and osteogenic properties simultaneously. Which of the following materials is the only one to fulfill all three criteria?

Articular cartilage is a highly specialized connective tissue adapted to withstand compressive loads. Which structural component of the extracellular matrix is primarily responsible for generating the tissue's swelling pressure and compressive stiffness?

Orthopedic stainless steel implants are commonly manufactured from 316L alloy. In this designation, the "L" indicates an important compositional alteration designed to prevent intergranular corrosion. What does the "L" stand for?

When two dissimilar metals are placed in physical contact within the electrolytic environment of the human body, galvanic corrosion may occur. Which of the following implant combinations represents the greatest risk for severe galvanic corrosion?

A ligament subjected to a constant, prolonged tensile load demonstrates a gradual increase in length over time. Which of the following terms best describes this biomechanical property?

A 45-year-old patient receives a cementless total hip arthroplasty. To minimize stress shielding of the proximal femur, the femoral stem should be manufactured from a material with a modulus of elasticity closest to that of cortical bone. Which of the following materials has the lowest modulus of elasticity?