PART 1 of 5
This is Part 1 of the Orthopedic Surgery
Fundamentals 6th Edition Comprehensive
Test Bank by Postma, Delahay, and Wiesel.
TABLE OF CONTENTS — PART 1 of 5
Chapter 1: Basic Science of Bone and Cartilage Metabolism — Questions 1–20
Chapter 2: Biomechanics and Biomaterials — Questions 21–40
Chapter 3: Imaging of the Musculoskeletal System — Questions 41–60
Chapter 4: Skeletal Trauma — Questions 61–80
Chapter 5: Orthopedic Infections — Questions 81–100
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Q1. A 45-year-old man sustains a tibial shaft fracture. During the inflammatory phase of fracture
healing, which cell type is primarily responsible for initiating the repair process?
A. Osteoblast
B. Osteoclast
C. Macrophage
D. Chondrocyte
Correct Answer: Macrophage ✅
Rationale: Macrophages are the primary cells responsible for initiating the repair process
during the inflammatory phase of fracture healing. They arrive at the fracture site within hours of
injury, phagocytose debris and bacteria, and release cytokines such as platelet-derived growth factor
and transforming growth factor-beta that recruit mesenchymal stem cells and promote angiogenesis.
Osteoblasts are responsible for bone formation and appear later during the reparative phase.
,Osteoclasts are responsible for bone resorption and remodeling, not initiation of repair.
Chondrocytes form the cartilaginous callus during the reparative phase but are not the initiating
cells. Understanding the sequence of cellular events in fracture healing helps clinicians optimize
conditions for union and recognize factors that may delay healing.
Q2. A 60-year-old woman with osteoporosis is being counseled on bone metabolism. Which cell type
is derived from the monocyte-macrophage lineage and is responsible for bone resorption?
A. Osteoblast
B. Osteocyte
C. Osteoclast
D. Chondroblast
Correct Answer: Osteoclast ✅
Rationale: Osteoclasts are derived from the monocyte-macrophage lineage and are
responsible for bone resorption. They are multinucleated cells that secrete hydrochloric acid and
proteolytic enzymes to dissolve the mineral and organic components of bone. Osteoblasts are
derived from mesenchymal stem cells and are responsible for bone formation. Osteocytes are
mature osteoblasts trapped within the bone matrix and function in mechanosensation and mineral
homeostasis. Chondroblasts form cartilage, not bone. Understanding the origin and function of
osteoclasts is essential for understanding conditions such as osteoporosis, where increased
osteoclast activity leads to net bone loss, and for selecting appropriate antiresorptive therapies.
Q3. A 30-year-old man is evaluated for a suspected stress fracture of the metatarsal. Which imaging
modality is most sensitive for detecting early stress fractures?
A. Plain radiography
B. Computed tomography
C. Magnetic resonance imaging
D. Ultrasound
Correct Answer: Magnetic resonance imaging ✅
,Rationale: Magnetic resonance imaging (MRI) is the most sensitive imaging modality for
detecting early stress fractures because it can visualize bone marrow edema and periosteal reaction
before radiographic changes become apparent. Plain radiography may be normal for the first 2 to 4
weeks after injury and typically shows periosteal reaction or a fracture line only after significant bone
resorption has occurred. Computed tomography is better for assessing cortical bone detail and
complex fractures but is less sensitive for early stress injuries. Ultrasound can detect periosteal fluid
and soft tissue changes but is operator-dependent and less sensitive than MRI. Understanding the
imaging modalities available for stress fractures helps clinicians make an early diagnosis and prevent
progression to complete fracture.
Q4. A 55-year-old woman undergoes dual-energy x-ray absorptiometry (DEXA) testing. Which T-score
value is diagnostic of osteoporosis?
A. -1.0
B. -1.5
C. -2.0
D. -2.5
Correct Answer: -2.5 ✅
Rationale: A T-score of -2.5 or lower is diagnostic of osteoporosis according to the World
Health Organization criteria. A T-score between -1.0 and -2.5 indicates osteopenia (low bone mass). A
T-score of -1.0 or higher is considered normal. The T-score compares the patient's bone mineral
density to that of a young healthy adult of the same sex. The Z-score, by contrast, compares the
patient to age-matched peers and is used in children and young adults. Understanding DEXA
interpretation helps clinicians diagnose osteoporosis, assess fracture risk, and initiate appropriate
treatment to prevent fragility fractures.
Q5. A 25-year-old athlete sustains an anterior cruciate ligament (ACL) tear. Which structure provides
the greatest anterior stabilization of the knee joint?
A. Posterior cruciate ligament
B. Medial collateral ligament
C. Quadriceps muscle and tendon
D. Anterior cruciate ligament
, Correct Answer: Anterior cruciate ligament ✅
Rationale: The anterior cruciate ligament (ACL) provides the greatest anterior stabilization of
the knee joint by preventing anterior translation of the tibia on the femur. The posterior cruciate
ligament (PCL) prevents posterior translation. The medial collateral ligament resists valgus stress, and
the lateral collateral ligament resists varus stress. The quadriceps muscle and tendon contribute to
knee extension and dynamic stability but are not the primary static restraint against anterior
translation. Understanding the function of the ACL is essential for diagnosing ACL injuries, selecting
appropriate treatment (reconstruction versus rehabilitation), and counseling patients on return to
sport.
Q6. A 70-year-old man sustains a displaced femoral neck fracture. Why does this fracture have a high
risk of avascular necrosis?
A. The femoral neck lacks periosteum
B. The blood supply to the femoral head is disrupted
C. The fracture is intracapsular
D. The femoral neck has poor cancellous bone
Correct Answer: The blood supply to the femoral head is disrupted ✅
Rationale: Femoral neck fractures have a high risk of avascular necrosis because the blood
supply to the femoral head, primarily from the medial circumflex femoral artery, is disrupted by the
fracture. The blood vessels travel along the femoral neck and are vulnerable to injury with displaced
fractures. The femoral neck does lack a true periosteum and has poor cancellous bone in the elderly,
but these are not the primary reasons for avascular necrosis. The intracapsular location contributes
to the risk because the fracture hematoma is contained within the capsule, increasing intracapsular
pressure and further compromising blood flow. Understanding the vascular anatomy of the femoral
head helps clinicians counsel patients on the risks of avascular necrosis and select appropriate
treatment, such as arthroplasty in older patients.
Q7. A 12-year-old boy is diagnosed with osteosarcoma. Which site is the most common location for
osteosarcoma?
A. Distal femur
B. Proximal tibia
This is Part 1 of the Orthopedic Surgery
Fundamentals 6th Edition Comprehensive
Test Bank by Postma, Delahay, and Wiesel.
TABLE OF CONTENTS — PART 1 of 5
Chapter 1: Basic Science of Bone and Cartilage Metabolism — Questions 1–20
Chapter 2: Biomechanics and Biomaterials — Questions 21–40
Chapter 3: Imaging of the Musculoskeletal System — Questions 41–60
Chapter 4: Skeletal Trauma — Questions 61–80
Chapter 5: Orthopedic Infections — Questions 81–100
---
Q1. A 45-year-old man sustains a tibial shaft fracture. During the inflammatory phase of fracture
healing, which cell type is primarily responsible for initiating the repair process?
A. Osteoblast
B. Osteoclast
C. Macrophage
D. Chondrocyte
Correct Answer: Macrophage ✅
Rationale: Macrophages are the primary cells responsible for initiating the repair process
during the inflammatory phase of fracture healing. They arrive at the fracture site within hours of
injury, phagocytose debris and bacteria, and release cytokines such as platelet-derived growth factor
and transforming growth factor-beta that recruit mesenchymal stem cells and promote angiogenesis.
Osteoblasts are responsible for bone formation and appear later during the reparative phase.
,Osteoclasts are responsible for bone resorption and remodeling, not initiation of repair.
Chondrocytes form the cartilaginous callus during the reparative phase but are not the initiating
cells. Understanding the sequence of cellular events in fracture healing helps clinicians optimize
conditions for union and recognize factors that may delay healing.
Q2. A 60-year-old woman with osteoporosis is being counseled on bone metabolism. Which cell type
is derived from the monocyte-macrophage lineage and is responsible for bone resorption?
A. Osteoblast
B. Osteocyte
C. Osteoclast
D. Chondroblast
Correct Answer: Osteoclast ✅
Rationale: Osteoclasts are derived from the monocyte-macrophage lineage and are
responsible for bone resorption. They are multinucleated cells that secrete hydrochloric acid and
proteolytic enzymes to dissolve the mineral and organic components of bone. Osteoblasts are
derived from mesenchymal stem cells and are responsible for bone formation. Osteocytes are
mature osteoblasts trapped within the bone matrix and function in mechanosensation and mineral
homeostasis. Chondroblasts form cartilage, not bone. Understanding the origin and function of
osteoclasts is essential for understanding conditions such as osteoporosis, where increased
osteoclast activity leads to net bone loss, and for selecting appropriate antiresorptive therapies.
Q3. A 30-year-old man is evaluated for a suspected stress fracture of the metatarsal. Which imaging
modality is most sensitive for detecting early stress fractures?
A. Plain radiography
B. Computed tomography
C. Magnetic resonance imaging
D. Ultrasound
Correct Answer: Magnetic resonance imaging ✅
,Rationale: Magnetic resonance imaging (MRI) is the most sensitive imaging modality for
detecting early stress fractures because it can visualize bone marrow edema and periosteal reaction
before radiographic changes become apparent. Plain radiography may be normal for the first 2 to 4
weeks after injury and typically shows periosteal reaction or a fracture line only after significant bone
resorption has occurred. Computed tomography is better for assessing cortical bone detail and
complex fractures but is less sensitive for early stress injuries. Ultrasound can detect periosteal fluid
and soft tissue changes but is operator-dependent and less sensitive than MRI. Understanding the
imaging modalities available for stress fractures helps clinicians make an early diagnosis and prevent
progression to complete fracture.
Q4. A 55-year-old woman undergoes dual-energy x-ray absorptiometry (DEXA) testing. Which T-score
value is diagnostic of osteoporosis?
A. -1.0
B. -1.5
C. -2.0
D. -2.5
Correct Answer: -2.5 ✅
Rationale: A T-score of -2.5 or lower is diagnostic of osteoporosis according to the World
Health Organization criteria. A T-score between -1.0 and -2.5 indicates osteopenia (low bone mass). A
T-score of -1.0 or higher is considered normal. The T-score compares the patient's bone mineral
density to that of a young healthy adult of the same sex. The Z-score, by contrast, compares the
patient to age-matched peers and is used in children and young adults. Understanding DEXA
interpretation helps clinicians diagnose osteoporosis, assess fracture risk, and initiate appropriate
treatment to prevent fragility fractures.
Q5. A 25-year-old athlete sustains an anterior cruciate ligament (ACL) tear. Which structure provides
the greatest anterior stabilization of the knee joint?
A. Posterior cruciate ligament
B. Medial collateral ligament
C. Quadriceps muscle and tendon
D. Anterior cruciate ligament
, Correct Answer: Anterior cruciate ligament ✅
Rationale: The anterior cruciate ligament (ACL) provides the greatest anterior stabilization of
the knee joint by preventing anterior translation of the tibia on the femur. The posterior cruciate
ligament (PCL) prevents posterior translation. The medial collateral ligament resists valgus stress, and
the lateral collateral ligament resists varus stress. The quadriceps muscle and tendon contribute to
knee extension and dynamic stability but are not the primary static restraint against anterior
translation. Understanding the function of the ACL is essential for diagnosing ACL injuries, selecting
appropriate treatment (reconstruction versus rehabilitation), and counseling patients on return to
sport.
Q6. A 70-year-old man sustains a displaced femoral neck fracture. Why does this fracture have a high
risk of avascular necrosis?
A. The femoral neck lacks periosteum
B. The blood supply to the femoral head is disrupted
C. The fracture is intracapsular
D. The femoral neck has poor cancellous bone
Correct Answer: The blood supply to the femoral head is disrupted ✅
Rationale: Femoral neck fractures have a high risk of avascular necrosis because the blood
supply to the femoral head, primarily from the medial circumflex femoral artery, is disrupted by the
fracture. The blood vessels travel along the femoral neck and are vulnerable to injury with displaced
fractures. The femoral neck does lack a true periosteum and has poor cancellous bone in the elderly,
but these are not the primary reasons for avascular necrosis. The intracapsular location contributes
to the risk because the fracture hematoma is contained within the capsule, increasing intracapsular
pressure and further compromising blood flow. Understanding the vascular anatomy of the femoral
head helps clinicians counsel patients on the risks of avascular necrosis and select appropriate
treatment, such as arthroplasty in older patients.
Q7. A 12-year-old boy is diagnosed with osteosarcoma. Which site is the most common location for
osteosarcoma?
A. Distal femur
B. Proximal tibia
