Can You Pass This CPC Certification Exam?

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.

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

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.

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.

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.

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.

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.

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.

Increased pulse rate and respiratory rate suggest hypovolemic shock.

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.

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

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.

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.

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.