Practice Set 604 of 789
This practice set contains high-yield board review questions covering key concepts in 1. General Principles & Basic Science. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Ultrasound therapy delivers superficial heat to the tissue and has a penetration depth of 5 mm.
. True
Haversian bone is composed of vascular channels surrounded circumferentially by lamellar bone. Which of the following terms is used to describe the unit of bone composed of a neurovascular channel surrounded by a cell-permeated layer of bone matrix:
. Bone remodeling unit
A 78-year-old woman has a history of chronic low back pain. She denies any extremity problems. Her pain is worse in the morning, and gets better, although it does not go away, as the day goes on. An MRI scan of the lumbar spine is shown in Figure
. She denies any acute worsening of her symptoms, although in general, her symptoms are slowly worsening. She takes nonsteroidal anti-inflammatory drugs as needed for her pain, but otherwise takes no other medications. What is the next most appropriate step in management?
The increased radiographiCbone density in osteonecrosis is most likely secondary to:
. Calcification of the necrotiCbone marrow
. Osteoclasts - synthesize organic matrix
The floor of the acetabular fossa touches the ilioischial line
. Figure 51a
Figure 26 is a radiograph of an 11-year-old boy with insidious-onset anterior knee pain.
. Plain radiographs
. Superficial zone (Zone I)
Demineralized bone matrix (DBM) is commonly used as a bone graft substitute in orthopedic procedures. Which of the following factors or pathways is primarily responsible for the unique osteoinductive properties of DBM?
. Vascular endothelial growth factor (VEGF) secretion
During a posterior (Kocher-Langenbeck) approach to the hip for a posterior wall acetabular fracture, the surgeon identifies the short external rotators. To avoid postoperative weakness in hip extension, an important nerve exiting the greater sciatic foramen immediately inferior to the piriformis muscle must be protected. What muscle does this nerve primarily supply?
. Gluteus medius
A 30-year-old female presents with progressive knee pain. Radiographs reveal an eccentric, lytic lesion in the distal femoral epiphysis extending to the subchondral bone without a sclerotic margin. A biopsy is obtained and the histology is shown below.
If medical therapy is considered, which of the following best describes the targeted mechanism of action?
. Targeting osteoclasts directly via bisphosphonates to induce apoptosis
When a diaphyseal fracture is treated with a perfectly applied lag screw and a neutralization plate (an absolute stability construct), bone healing primarily occurs through which of the following biological processes?
. Endochondral ossification
. Reparative phase; Type II transitioning to Type I collagen
A 65-year-old male is diagnosed with multiple myeloma and presents with hypercalcemia and extensive 'punched-out' lytic bone lesions. What is the primary molecular mechanism responsible for this accelerated osteolysis?
. Direct mechanical destruction of the bone matrix by myeloma cells
Bone morphogenetic proteins (BMPs) play a critical role in bone healing and formation by initiating an intracellular signaling cascade. Which of the following intracellular proteins directly mediate the canonical signaling pathway of BMPs to regulate gene transcription in osteoblasts?
. Beta-catenin
Articular cartilage is divided into distinct structural zones. Which zone contains the highest concentration of water, the lowest concentration of proteoglycans, and collagen fibers arranged parallel to the articular surface?
. Superficial (tangential) zone
A 35-year-old female presents with a destructive, expansile lytic lesion in her distal femur that extends to the subchondral bone. Biopsy confirms a Giant Cell Tumor (GCT) of bone. Denosumab therapy is initiated to reduce tumor size prior to intralesional curettage. Denosumab exerts its effect by directly binding to and inhibiting which of the following molecules?
. RANKL
. Type II
A 30-year-old female is diagnosed with an eccentric, lytic lesion in the distal femoral epiphysis. Biopsy reveals neoplastic mononuclear cells expressing RANKL and reactive multinucleated giant cells. Which targeted systemic therapy is indicated if the tumor is deemed surgically unresectable?
. Imatinib
In the context of bone metabolism and molecular biology, which of the following accurately describes the primary function of sclerostin?
. Stimulates osteoclast differentiation via direct RANKL activation
