Biology, Genetics & Bone Healing MCQs

A 75-year-old woman with severe osteoporosis presents with an acute, painful T12 compression fracture. She has failed 6 weeks of aggressive conservative management, including bracing and narcotic analgesics. Which of the following is the most appropriate next step?

Following a standard arthroscopic rotator cuff repair, by which histological mechanism does the tendon primarily heal to the greater tuberosity?

Which of the following molecules acts as an endogenous soluble decoy receptor to inhibit osteoclastogenesis by binding to RANK Ligand (RANKL)?

According to Perren's strain theory, what is the maximum interfragmentary strain that can be tolerated for primary (direct) bone healing to occur without the formation of an intermediate callus?

Romosozumab is a monoclonal antibody used in the treatment of severe osteoporosis. It exerts its primarily anabolic bone effect by targeting and inhibiting which of the following proteins?

Parathyroid hormone (PTH) helps maintain calcium homeostasis through its action on bone, intestines, and kidneys. In the kidney, PTH stimulates the production of the active form of Vitamin D by upregulating which enzyme?

Denosumab is an effective pharmacological treatment for osteoporosis and giant cell tumor of bone. What is its specific mechanism of action?

According to Perren's strain theory of fracture healing, what type of tissue forms first when the interfragmentary strain is between 2% and 10%?

Sclerostin, a protein product of the SOST gene, regulates bone mass primarily by acting as a negative regulator of which of the following pathways?

Bone morphogenetic proteins (BMPs) primarily exert their osteoinductive cellular effects by initiating intracellular signaling through which of the following molecules?

Nitrogen-containing bisphosphonates are frequently used to alter bone metabolism in orthopaedic patients. They achieve their effect primarily by which of the following mechanisms?

A 70-year-old woman with severe osteoporosis is started on denosumab. This medication improves bone density by directly targeting and neutralizing which of the following?

According to Perren strain theory, what is the maximum allowable interfragmentary strain that permits primary (direct) bone healing to occur?

A 65-year-old woman is prescribed teriparatide for severe osteoporosis. The anabolic effect of this medication on bone mass is primarily mediated by which of the following mechanisms?

Osteoclasts are responsible for bone resorption during remodeling. From which of the following cell lineages are mature osteoclasts derived?

A 70-year-old woman with severe osteoporosis is treated with romosozumab, a monoclonal antibody that targets sclerostin. By inhibiting sclerostin, this medication primarily enhances bone formation through which of the following cellular mechanisms?

Continuous hypersecretion of parathyroid hormone (PTH) leads to net bone resorption. However, once-daily subcutaneous administration of teriparatide results in net bone formation. This anabolic effect of intermittent PTH is primarily mediated by:

Which of the following cells is the primary source of osteoprotegerin (OPG), and what is its molecular mechanism of action in bone remodeling?

According to Perren's strain theory of fracture healing, primary (contact) bone healing with the direct formation of lamellar bone can only occur when the strain environment at the fracture gap is maintained below what threshold?

Osteocytes act as the primary mechanosensors within bone. Under conditions of decreased mechanical strain (unloading), osteocytes upregulate the secretion of which molecule to inhibit osteoblast differentiation?