Can You Pass This CPC Certification Exam?

1. This image is from a 30-year-old female patient with past history of trauma to her arm. The photograph shows the patient's hand trying to make a tight fist. What is the most likely nerve that has been damaged?

Radial

Median

Brachial

Axial

Ulnar

When making a fist, the ring and small fingers flex while the long and index tend to stay straight. In low median nerve injuries, the fingers are still able to flex, but thumb opposition is often lost.

Explanation

When making a fist, the ring and small fingers flex while the long and index tend to stay straight. In low median nerve injuries, the fingers are still able to flex, but thumb opposition is often lost.

2. This image is from a 20-year-old female patient with a past history of trauma to her arm. What is the most likely nerve that has been damaged?

Radial

Median

Brachial

Axial

Ulnar

Photograph of typical ulnar nerve palsy. Note the clawing of the ulnar two fingers and the wasting of the hypothenar muscles.

Explanation

Photograph of typical ulnar nerve palsy. Note the clawing of the ulnar two fingers and the wasting of the hypothenar muscles.

3. This image is from a 35 year old male patient with a past history of trauma to his arm. What is the most likely nerve that has been damaged?

Radial

Median

Brachial

Axial

Ulnar

The long extensors of the forearm are paralyzed and this will result in a "wrist drop". There is a small loss of sensation over the dorsal surface of the hand and the dorsal surfaces of the roots of the lateral three.

Explanation

The long extensors of the forearm are paralyzed and this will result in a "wrist drop". There is a small loss of sensation over the dorsal surface of the hand and the dorsal surfaces of the roots of the lateral three.

4. A 13-year-old boy complains of pain in his left lower leg for the past month. On examination, there is tenderness to palpation on the site, and the circumference of his left leg is more than the right leg. A radiograph of the leg shows a 6 cm expansile mass in the diaphyseal region of the left lower femur, with the characteristic "onion peel" appearance. A biopsy of the mass shows sheets of closely packed primitive cells with small relatively uniform nuclei and only scant cytoplasm. Karyotype analysis of the tumor shows a t(11;22) translocation. Which of the following is the most likely diagnosis?

Chondrosarcoma

Ewing's sarcoma

Enchondroma

Giant cell tumour

Fibrous dysplasia

The diaphyseal location, histologic appearance and translocation are characteristic of Ewing’s sarcoma. Because a common genetic locus is responsible for a large percentage of Ewing's sarcoma and primitive neuroectodermal tumours, these are sometimes grouped together in a category known as the Ewing family of tumours.

Explanation

The diaphyseal location, histologic appearance and translocation are characteristic of Ewing’s sarcoma. Because a common genetic locus is responsible for a large percentage of Ewing's sarcoma and primitive neuroectodermal tumours, these are sometimes grouped together in a category known as the Ewing family of tumours.

5. A 10-year-old boy has pain in the right hip for the past three weeks. On physical examination, his temperature is 38.2°C. There is swelling with marked tenderness to palpation in the region and reduced range of movement. Radiographs of the pelvis show areas of osteolysis and cortical erosion involving the femoral metaphysis with adjacent soft tissue swelling in the sub-periosteal region, and apparent abscess formation. Which of the following organisms is most likely to produce these findings?

Staphylococcus aureus

Haemophilus influenzae

Salmonella enteritidis

Group B Streptococcus

Neisseria gonorrhoeae

Staphylococcus aureus is the most likely organism to produce these findings. The presence of swelling, tenderness, reduced range of movement, and radiographic findings of osteolysis, cortical erosion, and soft tissue swelling with abscess formation suggest an infectious process. Staphylococcus aureus is a common cause of osteomyelitis, particularly in children. It is known to cause bone destruction and abscess formation, which are consistent with the findings described in the question. The other organisms listed are less commonly associated with osteomyelitis and do not typically produce the same radiographic findings.

Explanation

Staphylococcus aureus is the most likely organism to produce these findings. The presence of swelling, tenderness, reduced range of movement, and radiographic findings of osteolysis, cortical erosion, and soft tissue swelling with abscess formation suggest an infectious process. Staphylococcus aureus is a common cause of osteomyelitis, particularly in children. It is known to cause bone destruction and abscess formation, which are consistent with the findings described in the question. The other organisms listed are less commonly associated with osteomyelitis and do not typically produce the same radiographic findings.

6. A 16-year-old male complains of pain around his knee joint for 3 months. Physical examination shows no findings except local pain around knee joint over the area of the distal end of the femur. Radiograph shows an ill-defined mass involving the distal end of the femur along with the elevation of periosteum. A biopsy shows pleomorphic and mitotically active osteoblasts associated with osteoid. Which of the following is the most likely diagnosis?

Ewing’s sarcoma

Chondrosarcoma

Giant cell tumor

Osteosarcoma

Paget’s disease of bone

Osteoid production by a sarcoma is diagnostic of osteosarcoma. The metaphyseal location in a long bone is cosisitent with the tumor along with presentation in young persoon.

Explanation

Osteoid production by a sarcoma is diagnostic of osteosarcoma. The metaphyseal location in a long bone is cosisitent with the tumor along with presentation in young persoon.

7. A 42-year-old man on holiday is involved in an accident in which he sustains a right tibial diaphyseal fracture. The fracture is set with open reduction and internal fixation for proper alignment. One week later there are more osteoclasts in the region of the fracture. Which of the following is the most likely function of these osteoclasts?

Form collagen

Resorb bone

Synthesise osteoid

Elaborate cytokines

Divide

After sustaining a fracture, the body initiates a process called bone remodeling to repair the damaged bone. Osteoclasts are responsible for resorbing or breaking down the old or damaged bone tissue. This allows for the removal of the damaged bone and the subsequent formation of new bone by osteoblasts. Therefore, in this case, the increased presence of osteoclasts one week after the fracture suggests that their primary function is to resorb or break down the bone in the region of the fracture.

Explanation

After sustaining a fracture, the body initiates a process called bone remodeling to repair the damaged bone. Osteoclasts are responsible for resorbing or breaking down the old or damaged bone tissue. This allows for the removal of the damaged bone and the subsequent formation of new bone by osteoblasts. Therefore, in this case, the increased presence of osteoclasts one week after the fracture suggests that their primary function is to resorb or break down the bone in the region of the fracture.

8. A 62-year-old male previously healthy male, non-smoker, presented 6 months following a road traffic accident with a non-healing fracture. His X-ray image is shown below. What is the most likely cause of this complication?

Excess callus formation due to improper immobilization

Osteomyelitis causing excess callus formation & non healing

Bone necrosis & involucrum formation

Pseudoarthrosis formation

Osteosarcoma developing in a fracture

The most likely cause of the non-healing fracture in this 62-year-old male is osteomyelitis. Osteomyelitis is an infection of the bone that can lead to excessive callus formation and hinder the healing process. The presence of excess callus formation on the X-ray image supports this explanation. Other possible causes, such as improper immobilization, bone necrosis, pseudoarthrosis, or osteosarcoma, are less likely based on the given information.

Explanation

The most likely cause of the non-healing fracture in this 62-year-old male is osteomyelitis. Osteomyelitis is an infection of the bone that can lead to excessive callus formation and hinder the healing process. The presence of excess callus formation on the X-ray image supports this explanation. Other possible causes, such as improper immobilization, bone necrosis, pseudoarthrosis, or osteosarcoma, are less likely based on the given information.

9. A 19-year-old man is brought into the Emergency Department following a motorcycle accident in which he was thrown 20 feet. Vital signs on admission to the Emergency Department are blood pressure 90/60, pulse 140, respirations 24 and noisy. He is unconscious, has a bruise over his forehead, there is fresh blood flowing from a laceration in his right groin, and his left leg is twisted in a deformed angle. What type of shock does this patient appear to be in?

Cardiogenic shock

Neurogenic shock

Hypovolemic shock

Vaso-Vagal shock

Coma due to brain damage

Increased pulse rate and respiratory rate suggest hypovolemic shock.

Explanation

Increased pulse rate and respiratory rate suggest hypovolemic shock.

10. A 28-year-old male comes to his GP because of persistent pain in the area around his right knee. The area is firm, no erythema but tender on palpation. X–ray exam shows a 6 cm mass in his distal femoral epiphyseal area, with a soap bubble appearance. A bone biopsy shows multinucleated cell in a stroma composed of spindle shaped mononuclear cells. Which of the following is the most likely diagnosis?

Ewing’s sarcoma

Osteoblastoma

Enchondrooma

Giant cell tumour

Fibrous dysplasia

The most likely diagnosis in this case is a giant cell tumor. This is supported by the presence of a 6 cm mass in the distal femoral epiphyseal area with a soap bubble appearance on x-ray. Additionally, the bone biopsy shows multinucleated cells in a stroma composed of spindle-shaped mononuclear cells, which is characteristic of giant cell tumors. Ewing's sarcoma, osteoblastoma, enchondroma, and fibrous dysplasia would not typically present with these findings.

Explanation

The most likely diagnosis in this case is a giant cell tumor. This is supported by the presence of a 6 cm mass in the distal femoral epiphyseal area with a soap bubble appearance on x-ray. Additionally, the bone biopsy shows multinucleated cells in a stroma composed of spindle-shaped mononuclear cells, which is characteristic of giant cell tumors. Ewing's sarcoma, osteoblastoma, enchondroma, and fibrous dysplasia would not typically present with these findings.

11. A 28-year-old college student presented with bony growth over the lower end of femur following a slip and fall 12 weeks ago. What is tissue labeled B?

Fibroblasts in granulation tissue

Mature bone tissue

Osteoid in woven bone

Calcification in fracture tissue

Haemorrhage

Note irregular pink material of osteoid lined by osteoblasts of a woven bone in fracture healing.

Explanation

Note irregular pink material of osteoid lined by osteoblasts of a woven bone in fracture healing.

12. A 10-year-old boy has complained of sudden onset of nocturnal pain in his left leg around the knee. The pain is relieved dramatically by aspirin. Nothing remarkable is seen on physical examination. The radiograph shows a well defined 1 cm lucent area surrounded by a thin rim of bony sclerosis located in the proximal tibia cortex. He undergoes curettage and the pain doesn't return. Which of the following is the most likely diagnosis?

Enchondroma

Osteoid osteoma

Giant cell tumour

Osteoblastoma

Osteosarcoma

The most likely diagnosis for the 10-year-old boy's condition is osteoid osteoma. This is supported by the sudden onset of nocturnal pain in the left leg around the knee, which is relieved dramatically by aspirin. The radiograph shows a well-defined lucent area surrounded by a thin rim of bony sclerosis in the proximal tibia cortex, which is consistent with the characteristics of an osteoid osteoma. The fact that the pain does not return after curettage further supports this diagnosis.

Explanation

The most likely diagnosis for the 10-year-old boy's condition is osteoid osteoma. This is supported by the sudden onset of nocturnal pain in the left leg around the knee, which is relieved dramatically by aspirin. The radiograph shows a well-defined lucent area surrounded by a thin rim of bony sclerosis in the proximal tibia cortex, which is consistent with the characteristics of an osteoid osteoma. The fact that the pain does not return after curettage further supports this diagnosis.

13. A 26-year-old man sustained a stab wound to the left chest just below the mid-clavicle. His blood pressure is 70/50. He is cyanotic. His neck veins are markedly distended and there is minimal external bleeding. What is the most likely diagnosis?

Lung collapse

Circulatory shock

Hypovolemic shock

Cardiac shock

Cardiac tamponade

The most likely diagnosis in this case is lung collapse. The patient's symptoms, including a stab wound to the left chest, cyanosis, and distended neck veins, suggest a tension pneumothorax, which is a type of lung collapse. The minimal external bleeding and low blood pressure are also consistent with this diagnosis. Tension pneumothorax occurs when air accumulates in the pleural space, causing the lung to collapse and putting pressure on the heart and great vessels, leading to circulatory compromise.

Explanation

The most likely diagnosis in this case is lung collapse. The patient's symptoms, including a stab wound to the left chest, cyanosis, and distended neck veins, suggest a tension pneumothorax, which is a type of lung collapse. The minimal external bleeding and low blood pressure are also consistent with this diagnosis. Tension pneumothorax occurs when air accumulates in the pleural space, causing the lung to collapse and putting pressure on the heart and great vessels, leading to circulatory compromise.

14. A 75-year-old man complains of pain in his right hip and thigh for the past several months. His range of motion is reduced in the hip but there is no tenderness or swelling. Radiographs show thickened cortical bone with a narrowed joint space. A bone biopsy shows a mosaic pattern of the lamellar bone with the appearance shown. Which of the following is the most likely diagnosis?

Osteochondroma

Osteoarthritis

Paget’s disease of bone

Hyperparathyroidism

Fibrous dysplasia

The most likely diagnosis in this case is Paget's disease of bone. Paget's disease is a chronic disorder characterized by abnormal bone remodeling, resulting in thickened and enlarged bones. The radiographs showing thickened cortical bone and narrowed joint space are consistent with Paget's disease. Additionally, the mosaic pattern of the lamellar bone seen on the bone biopsy is a characteristic finding of Paget's disease. Osteochondroma, osteoarthritis, hyperparathyroidism, and fibrous dysplasia do not typically present with these specific findings.

Explanation

The most likely diagnosis in this case is Paget's disease of bone. Paget's disease is a chronic disorder characterized by abnormal bone remodeling, resulting in thickened and enlarged bones. The radiographs showing thickened cortical bone and narrowed joint space are consistent with Paget's disease. Additionally, the mosaic pattern of the lamellar bone seen on the bone biopsy is a characteristic finding of Paget's disease. Osteochondroma, osteoarthritis, hyperparathyroidism, and fibrous dysplasia do not typically present with these specific findings.