Advanced Musculoskeletal Pathology Quiz

1. What is a potential complication of a humerus midshaft fracture?

In damage of MEDIAN nerve (Pronator teres syndrome)

In damage of AXILLARY nerve (Loss of sensation over deltoid)

In damage of ULNAR nerve (Cubital tunnel syndrome)

Humerus midshaft fracture is most likely to result in damage of DEEP branch of Brachial artery, leading to complications.

Explanation

Humerus midshaft fracture is most likely to result in damage of DEEP branch of Brachial artery, leading to complications.

2. Contrast defects in collagen synthesis of OI and EDS...

OI is caused by autosomal recessive inheritance pattern.

In EDS, the defect is in the formation of Type TWO collagen.

Characteristic finding in OI is hyperextensible skin.

The correct answer provides a detailed explanation of the defects in collagen synthesis in both OI and EDS. The incorrect answers fall short as they provide inaccurate information about the inheritance pattern of OI, the type of collagen affected in EDS, and the characteristic finding in OI.

Explanation

The correct answer provides a detailed explanation of the defects in collagen synthesis in both OI and EDS. The incorrect answers fall short as they provide inaccurate information about the inheritance pattern of OI, the type of collagen affected in EDS, and the characteristic finding in OI.

3. Damage to the region of ribs (from 9-11) on the left side could damage?

1)Most likely Spleen(Overlied by 9-11 ribs)2)Most likely liver.3)Most likely left kidney

Gallbladder

Pancreas

Stomach

The spleen is located beneath the 9-11 ribs on the left side.

Explanation

The spleen is located beneath the 9-11 ribs on the left side.

4. Osteoporosis risk factors include high/low body fat?

High body fat increases your risk of osteoporosis.

Body fat percentage does not affect the risk of osteoporosis.

Both high and low body fat can increase the risk of osteoporosis.

Low body fat, which is associated with lower estrogen levels, increases the risk of osteoporosis as estrogen helps protect bone density. In contrast, high body fat may provide some cushioning effect for bones, reducing the risk of osteoporosis. It is essential to manage body fat levels to maintain bone health.

Explanation

Low body fat, which is associated with lower estrogen levels, increases the risk of osteoporosis as estrogen helps protect bone density. In contrast, high body fat may provide some cushioning effect for bones, reducing the risk of osteoporosis. It is essential to manage body fat levels to maintain bone health.

5. Which of the following is a characteristic presentation of Vitamin D deficiency?

Formation of pseudofractures in long bones

Increased secretion of PTH leading to hypercalcemia

Decreased ALP activity in osteoblasts

Vitamin D deficiency leads to defective mineralization of the matrix in growing bones causing weight-bearing bones to bow laterally. This presentation is characteristic of rickets in children and osteomalacia in adults.

Explanation

Vitamin D deficiency leads to defective mineralization of the matrix in growing bones causing weight-bearing bones to bow laterally. This presentation is characteristic of rickets in children and osteomalacia in adults.

6. What is the function of T-tubules in muscle cells?

Membrane proteins involved in regulating cell division in muscle tissue.

A form of energy storage within muscles.

Specialized organelles responsible for protein synthesis in muscle cells.

7. Which malignancy should a patient with the following symptoms be screened for? Malar rash, erythomatous periorbital rash, pink/purple Gottron patches on knuckles, muscle weakness, increased CK levels, Anti-Jo1 antibody +, Anti-SRP antibody +, Anti-Mi2 antibody +, biopsy shows perimysial atrophy with CD4+T cell infiltrate.

Lung cancer

Prostate cancer

Breast cancer

Patients with dermatomyositis are at an increased risk for occult malignancies, with gastric carcinoma being a commonly associated cancer.

Explanation

Patients with dermatomyositis are at an increased risk for occult malignancies, with gastric carcinoma being a commonly associated cancer.

8. A 65 year-old female is admitted with acute back pain, loss of height, and kyphosis. Her bone mineral density scan (DEXA scan) shows a T score of exactly -2.5. What fractures is she at increased risk for? What are likely PO4 (3-) and Ca(2+) levels in her serum?

Her Calcium and Phosphate levels would be elevated.

She is at increased risk for pelvic fractures, skull fractures, and shoulder fractures.

The recommended treatment is only Bisphosphonates.

9. Why do postmenopausal women have an increased risk of Type 1 osteoporosis?

As a result of an overproduction of Calcium in the body leading to bone weakening.

Because postmenopausal women are more likely to engage in high-impact exercises that weaken bone structure.

Due to a lack of Vitamin C in the diet leading to decreased bone density.

Postmenopausal women have an increased risk of Type 1 osteoporosis due to the impact of estrogen on bone formation and resorption, leading to decreased bone density and increased bone resorption. This imbalance is a key factor in the development of osteoporosis in this population.

Explanation

Postmenopausal women have an increased risk of Type 1 osteoporosis due to the impact of estrogen on bone formation and resorption, leading to decreased bone density and increased bone resorption. This imbalance is a key factor in the development of osteoporosis in this population.

10. In osteitis fibrosa cystica due to primary hyperparathyroidism, levels of : Ca2+, PO43-, ALP, and PTH levels?

Ca2+ and PTH levels increase while PO43- and ALP decrease

Ca2+ and PO43- increase while ALP and PTH levels decrease

PO43- and ALP increase while Ca2+ and PTH levels decrease

Osteitis fibrosa cystica due to primary hyperparathyroidism is characterized by specific changes in the levels of PTH, calcium, phosphate, and ALP. Understanding these changes is crucial for proper diagnosis and treatment.

Explanation

Osteitis fibrosa cystica due to primary hyperparathyroidism is characterized by specific changes in the levels of PTH, calcium, phosphate, and ALP. Understanding these changes is crucial for proper diagnosis and treatment.

11. Contrast lab values in primary and secondary hyperparathyroidism.

High Ca2+, high PO43-, low ALP, low PTH

Low Ca2+, low PO43-, high ALP, low PTH

High Ca2+, low PO43-, normal ALP, low PTH

Primary hyperparathyroidism is characterized by increased levels of calcium, low phosphate, high alkaline phosphatase, and high levels of parathyroid hormone (PTH) due to overproduction. In contrast, secondary hyperparathyroidism presents with low calcium levels, high phosphate, high alkaline phosphatase, and high PTH due to response to compromised excretion of phosphate and excess excretion of calcium in chronic kidney disease (CKD).

Explanation

Primary hyperparathyroidism is characterized by increased levels of calcium, low phosphate, high alkaline phosphatase, and high levels of parathyroid hormone (PTH) due to overproduction. In contrast, secondary hyperparathyroidism presents with low calcium levels, high phosphate, high alkaline phosphatase, and high PTH due to response to compromised excretion of phosphate and excess excretion of calcium in chronic kidney disease (CKD).

12. A 34 year-old female presents with a visible mass in the knee region. X-ray reveals a 'Soap bubble' appearance and biopsy shows spindle-shaped cells with multinucleated giant cells. Is the tumor benign or malignant, and where is it located?

Ewing's sarcoma is a benign tumor that commonly affects older individuals in the age group of 50 and above.

Osteosarcoma is a malignant tumor that usually arises in the epiphysis of long bones.

Chondrosarcoma is a benign tumor that involves the metaphysis of long bones.

13. 22 year old man presents to clinic with painLESS, hard mass which doesn't move on left leg (which appears to be shorter than right one). Piece of mature bone with cartilage cap, in metaphysis of bone is detected. Is it a benign/malignant tumor?

14. What is the most likely tumor suppressor loss of function in a 16 year-old boy with osteosarcoma, who has a family history of Breast cancer and Soft tissue sarcoma?

Loss of function of PTEN tumor suppressor

Loss of function of BRCA1 tumor suppressor

Loss of function of Rb1 tumor suppressor

15. Name conditions that can affect diaphysis.

Osteoporosis

Fibrous dysplasia

Rheumatoid arthritis

Diaphysis can be affected by conditions such as Ewing sarcoma and Multiple Myeloma, but not by Osteoporosis, Rheumatoid arthritis, or Fibrous dysplasia.

Explanation

Diaphysis can be affected by conditions such as Ewing sarcoma and Multiple Myeloma, but not by Osteoporosis, Rheumatoid arthritis, or Fibrous dysplasia.

16. Patient complains of nighttime pain in leg, xray shows 1.5 cm mass in diaphysis of the bone. What is the most likely diagnosis?

Osteosarcoma

Osteochondroma

Osteoporosis

Osteoid osteoma is a benign tumor of OsteoBlasts which produces osteoid, surrounded by a rim of reactive bone. It arises in the cortex in the diaphysis of a long bone, characterized by nighttime pain and a mass in the diaphysis.

Explanation

Osteoid osteoma is a benign tumor of OsteoBlasts which produces osteoid, surrounded by a rim of reactive bone. It arises in the cortex in the diaphysis of a long bone, characterized by nighttime pain and a mass in the diaphysis.

17. What joint findings are you likely to find in a patient with rheumatoid arthritis?

Metacarpal Bossing, joint hypermobility, presence of Heberden nodes, normal joint space width, no soft tissue swelling

Cubital deviation of fingers, boutonniere deformity, sparing of PIP joints, saucerization of bone, periarticular osteophytes

RADIAL deviation of fingers, sparing of Heberden nodes, joint space widening, absence of erosions, increased joint flexibility

These are all characteristic joint findings of rheumatoid arthritis, indicating inflammation, joint space narrowing, erosions, and other changes associated with the disease.

Explanation

These are all characteristic joint findings of rheumatoid arthritis, indicating inflammation, joint space narrowing, erosions, and other changes associated with the disease.

18. Why do patients with Achondroplasia have a larger head compared to limbs?

Due to excessive growth hormone secretion

As a result of maternal age effects

Because of a mutation in the IGF1 gene

Achondroplasia is characterized by specific mechanisms affecting bone growth, leading to disproportion between the head and limbs. Problems with growth hormones or IGF1 mutations do not specifically correlate with the unique features of Achondroplasia. Additionally, paternal age is a known risk factor for the condition, not maternal age.

Explanation

Achondroplasia is characterized by specific mechanisms affecting bone growth, leading to disproportion between the head and limbs. Problems with growth hormones or IGF1 mutations do not specifically correlate with the unique features of Achondroplasia. Additionally, paternal age is a known risk factor for the condition, not maternal age.

19. Contrast Cancellous bone=trabecular (Spongy) bone with Compact bone(CORTICAL Bone) by locations/Diseases affecting them?

C. Osteoporosis mainly involves compact bone whereas hyperparathyroidism mainly affects cancellous bone.

B. Cancellous bone is primarily affected by osteomalacia. Compact bone is primarily affected by rickets.

A. Cancellous bone is found in the skull bones. Compact bone is found in the ribs.

Cancellous bone, also known as trabecular or spongy bone, is typically found in locations such as vertebral bodies and ends of long bones. On the other hand, compact bone (cortical bone) is mostly found in the appendicular skeleton, providing support and muscle attachment sites. Diseases like hyperparathyroidism usually result in subperiosteal thinning in compact bone, while osteoporosis mainly affects spongy bone. Therefore, options A and B are incorrect as they provide inaccurate information regarding the locations and diseases affecting cancellous and compact bone. Option C is also incorrect as it fails to correctly contrast the locations and diseases affecting the two types of bones.

Explanation

Cancellous bone, also known as trabecular or spongy bone, is typically found in locations such as vertebral bodies and ends of long bones. On the other hand, compact bone (cortical bone) is mostly found in the appendicular skeleton, providing support and muscle attachment sites. Diseases like hyperparathyroidism usually result in subperiosteal thinning in compact bone, while osteoporosis mainly affects spongy bone. Therefore, options A and B are incorrect as they provide inaccurate information regarding the locations and diseases affecting cancellous and compact bone. Option C is also incorrect as it fails to correctly contrast the locations and diseases affecting the two types of bones.

20. Why do we have histologic findings of primary unmineralized spongiosa in medullary canals in osteopetrosis?

In osteopetrosis, there is an excess production of OsteoCLASTS leading to accumulation of unmineralized spongiosa in medullary canals.

The defect in osteopetrosis lies in OsteoBLASTS, which fail to create new bone matrix leading to unmineralized spongiosa.

Osteopetrosis is characterized by decreased Calcitonin levels, which results in accumulation of unmineralized spongiosa in medullary canals.

In osteopetrosis, the primary defect lies in OsteoCLASTS, not OsteoBLASTS, resulting in the inability to resorb bone properly. This leads to the accumulation of unmineralized spongiosa in medullary canals.

Explanation

In osteopetrosis, the primary defect lies in OsteoCLASTS, not OsteoBLASTS, resulting in the inability to resorb bone properly. This leads to the accumulation of unmineralized spongiosa in medullary canals.

21. What cells communicate through GAP junctions allowing calcium and cAMP to pass between them and are also responsible for laying down bone?

Chondrocytes

Osteoclasts

*OsteoBLASTS(Can lay down bone)

Adipocytes

Osteoblasts are responsible for bone formation, while osteoclasts are responsible for bone resorption. Chondrocytes are cartilage cells, and adipocytes are fat cells, neither of which communicate through GAP junctions in the same way osteocytes do.

Explanation

Osteoblasts are responsible for bone formation, while osteoclasts are responsible for bone resorption. Chondrocytes are cartilage cells, and adipocytes are fat cells, neither of which communicate through GAP junctions in the same way osteocytes do.

22. Which muscles are needed for complete shoulder abduction?

Infraspinatus, teres minor, latissimus dorsi

Pectoralis major, rhomboids, trapezius

Biceps brachii, brachialis, brachioradialis

The correct answer includes the supraspinatus for the first 15 degrees, deltoid from 15 degrees to horizontal, and serratus anterior after the horizontal position.

Explanation

The correct answer includes the supraspinatus for the first 15 degrees, deltoid from 15 degrees to horizontal, and serratus anterior after the horizontal position.

23. A male patient with Nocturia and frequency complains of back pain which is NOT relieved by rest or changing position. What should you consider as a possible diagnosis?

Urinary tract infection as a cause of back pain

Muscle strain from physical activity as a cause of back pain

Dehydration leading to muscle cramps as a cause of back pain

Back pain that is not relieved by rest or changing position is concerning for neoplastic bone disease, particularly in older males. Prostate cancer and breast cancer are known to metastasize to bone, presenting with similar symptoms.

Explanation

Back pain that is not relieved by rest or changing position is concerning for neoplastic bone disease, particularly in older males. Prostate cancer and breast cancer are known to metastasize to bone, presenting with similar symptoms.

24. What are some key features of metabolic abnormality of bone?

Increased thickness of cortical and trabecular bone, dark appearance on radiograph (osteoporosis), excess production of both osteoid and mineralized bone.

Normal thickness of cortical and trabecular bone, normal appearance on radiograph, no change in osteoid or mineralized bone.

Fluctuating thickness of cortical and trabecular bone, mixed appearance on radiograph, increased production of osteoid but decreased mineralized bone.

*Decreased thickness of cortical and trabecular bone.*Radiograph:washed-out appearance(Osteopenia)*Loss of Both Osteoid(Organic bone matrix) and Mineralized bone.

25. Normally, osteopetrosis is characterized by normal calcium values. What happens if calcium values are decreased?

*It indicates poor prognosis,Malignant,severe form of the disease.

Decreased calcium values indicate a benign, less severe form of osteopetrosis.

Hypocalcemia is not related to osteopetrosis.

Low calcium levels suggest a temporary fluctuation in the disease but not necessarily a poor prognosis.

In osteopetrosis, a decrease in calcium values indicates a more severe and aggressive form of the disease with a poor prognosis.

Explanation

In osteopetrosis, a decrease in calcium values indicates a more severe and aggressive form of the disease with a poor prognosis.

26. A 56 year-old male presents with SOB, cough, morning joint stiffness, tender swollen MCP and PIP joints, rheumatoid nodules, fever, weight loss, pleuritic chest pain, and diffuse chest pain. What labs are most likely to show?

Anti-DNA Antibody and ANA

Hepatitis B Surface Antigen and H. pylori IgG Antibody

Thyroid Peroxidase Antibodies and Cyclic Citrullinated Peptide

27. Male Patient with an increasing hat size, LION like face and progressive hearing loss (auditory foramen narrowing) suffers multiple long bone fractures. Labs show only elevated ALP levels, everything else is normal. Most likely cause of death?

Acute kidney failure due to chronic ALP elevation and subsequent renal damage.

Respiratory failure due to compression of the airways by an enlarged skull and facial bones.

Metabolic acidosis caused by an overproduction of alkaline phosphatase leading to systemic pH imbalance.