Deck 11: Bones and Cartilage

Question 1

A 19-year-old boy was suspected of having leukemia. It was decided to confirm the diagnosis by performing a bone marrow biopsy.

-The following statements concerning this procedure are correct except which?

A) The biopsy was taken from the lower end of the tibia.
B) Red bone marrow specimens can be obtained from the sternum or the iliac crests.
C) At birth, the marrow of all bones of the body is red and hematopoietic.
D) The blood-forming activity of bone marrow in many long bones gradually lessens with age, and the red marrow is gradually replaced by yellow marrow.

Answer 1

The biopsy was taken from the lower end of the tibia.

Question 2

A 45-year-old man with extensive maxillofacial injuries after an automobile accident was brought to the emergency department. Evaluation of the airway revealed partial obstruction. Despite an obvious fractured mandible, an attempt was made to move the tongue forward from the posterior pharyngeal wall by pushing the angles of the mandible forward. This maneuver failed to move the tongue, and it became necessary to hold the tongue forward directly to pull it away from the posterior pharyngeal wall.

-The most likely reason the physician was unable to pull the tongue forward in this patient is which?

A) The hypoglossal nerves were damaged on both sides of the neck.
B) Spasm of the styloglossus muscles
C) The mandibular origin of the genioglossus muscles was floating because of bilateral fractures of the body of the mandible.
D) The presence of a blood clot in the mouth
E) The resistance of the patient

Answer 2

The mandibular origin of the genioglossus muscles was floating because of bilateral fractures of the body of the mandible.

Question 3

A 46-year-old man was seen in the emergency department after being knocked down in a street brawl. He had received a blow on the head with an empty bottle. On examination, the patient was conscious and had a large dough-like swelling over the back of the head that was restricted to the area over the occipital bone. The skin was intact, and the swelling fluctuated on palpation.

-The following statements concerning this patient are correct except which?

A) The hematoma, although large, did not extend forward to the orbital margins and did not extend laterally as far as the temporal lines.
B) The hematoma was located just beneath the scalp and was superficial to the periosteum of the occipital bone.
C) The swelling did not occupy the subcutaneous tissue of the scalp.
D) The hematoma was restricted to one skull bone and was situated beneath the periosteum.

Answer 3

The hematoma was located just beneath the scalp and was superficial to the periosteum of the occipital bone.

Question 4

A 45-year-old woman visited her physician because of a low back pain of 3 months' duration. She was otherwise very fit. On examination of her back, nothing abnormal was discovered. The physician then listened to her chest, examined her thyroid gland, and finally examined both breasts. A large, hard mass was found in the left breast.

-The following facts supported the diagnosis of carcinoma of the left breast with secondaries in the vertebral column except which?

A) The lump in the breast was painless and the patient had noticed it while showering 6 months previously.
B) Several large, hard, pectoral lymph nodes were found in the left axilla.
C) A lateral radiograph of the lumbar vertebral column showed extensive metastases in the bodies of the second and third lumbar vertebrae.
D) The lump was situated in the upper outer quadrant of the left breast and was fixed to surrounding tissues.
E) Although the cancer had spread by the lymph vessels, no evidence of spread via the bloodstream was present.

Question 5

A 65 -year-old man and a 10-year-old boy were involved in a severe automobile accident. In both patients the thorax had been badly crushed. Radiographic examination revealed that the man had five fractured ribs but the boy had no fractures.

-What is the most likely explanation for this difference in medical findings?

A) The patients were in different seats in the vehicle.
B) The boy was wearing his seat belt and the man was not.
C) The chest wall of a child is very elastic, and fractures of ribs in children are rare.
D) The man anticipated the impact and tensed his muscles, including those of the shoulder girdle and abdomen.

Question 6

An 18-year-old woman was thrown from a horse while attempting to jump a fence. She landed heavily on the ground, striking the lower part of her chest on the left side. On examination in the emergency department she was conscious but breathless. The lower left side of her chest was badly bruised, and the ninth and tenth ribs were extremely tender to touch. She had severe tachycardia, and her systolic blood pressure was low.

-The following statements are possibly correct except which?

A) There was evidence of tenderness and muscle spasm in the left upper quadrant of the anterior abdominal wall.
B) A posteroanterior radiograph of the chest revealed fractures of the left ninth and tenth ribs near their angles.
C) The blunt trauma to the ribs could not result in injury to the underlying spleen.
D) The presence of blood in the peritoneal cavity had irritated the parietal peritoneum, producing reflex spasm of the upper abdominal muscles.
E) The muscles of the anterior abdominal wall are supplied by thoracic spinal nerves.

Question 7

A 15-year-old girl, while demonstrating to her friends her proficiency at standing on her hands, suddenly went off balance and put all her body weight on her left outstretched hand. A distinctive cracking noise was heard, and she felt a sudden pain in her left shoulder region. On examination in the emergency department, the smooth contour of her left shoulder was absent. The clavicle was obviously fractured, and the edges of the bony fragments could be palpated.

-The following statements concerning this case are correct except which?

A) The clavicle is one of the most common bones in the body to be fractured.
B) Anatomically, the weakest part of the clavicle is the junction of the medial and middle thirds, and this is where the fracture commonly occurs.
C) The lateral bony fragment is depressed downward by the weight of the arm.
D) The lateral fragment is pulled forward and medially by the pectoral muscles.
E) The medial fragment is elevated by the sternocleidomastoid muscle.
F) The supraclavicular nerves or a communicating vein between the cephalic and internal jugular vein may be damaged by the bone fragments.

Question 8

A 22-year-old medical student fell off her bicycle onto her outstretched hand. She thought she had sprained her right wrist joint and treated herself by binding her wrist with an elastic bandage. Three weeks later, however, she was still experiencing pain on moving her wrist and so decided to visit the emergency department. On examination of the dorsal surfaces of both hands, with the fingers and thumbs fully extended, a localized tenderness could be felt in the anatomic snuffbox of her right hand. A diagnosis of fracture of the right scaphoid bone was made.

-The following statements concerning this patient are correct except which?

A) The fracture line on the scaphoid bone may deprive the proximal fragment of its arterial supply.
B) A bony fragment deprived of its blood supply may undergo ischemic necrosis.
C) Because the scaphoid bone articulates with other bones, the fracture line may enter a joint cavity and become bathed in synovial fluid, which would inhibit repair.
D) The scaphoid bone is an easy bone to immobilize because of its small size.
E) Fractures of the scaphoid bone have a high incidence of nonunion.

Question 9

A heavily built, middle-aged man running down a flight of stone steps misjudged the position of one of the steps and fell suddenly onto his buttocks. Following the fall, he complained of severe bruising of the area of the cleft between the buttocks and persistent pain in this area.

-The following statements concerning this patient are correct except which?

A) The lower end of the vertebral column was traumatized by the stone step.
B) The coccyx can be palpated beneath the skin in the natal cleft.
C) The anterior surface of the coccyx cannot be felt clinically.
D) The coccyx is usually severely bruised or fractured.
E) The pain is felt in the distribution of dermatomes $\mathrm{S} 4$ and $\mathrm{S} 5$ .

Question 10

An elderly woman was run over by an automobile as she was crossing the road. Radiographic examination of the pelvis in the emergency department of the local hospital revealed a fracture of the ilium and iliac crest on the left side.

-The following statements about fractures of the pelvis are correct except which?

A) Fractures of the ilium have little displacement.
B) Displacement is prevented by the presence of the iliacus and the gluteal muscles on the inner and outer surfaces of this bone, respectively.
C) If two fractures occur in the ring forming the true pelvis, the fracture will be unstable and displacement will occur.
D) Fractures of the true pelvis do not cause injury to the pelvic viscera.
E) The postvertebral and abdominal muscles are responsible for elevating the lateral part of the pelvis should two fractures occur.
F) A heavy fall on the greater trochanter of the femur may drive the head of the femur through the floor of the acetabulum and into the pelvic cavity.

Question 11

A pregnant woman visited an antenatal clinic. A vaginal examination revealed that the sacral promontory could be easily palpated and that the diagonal conjugate measured less than 4 in. $(10 \mathrm{~cm})$ .

-The following statements concerning this examination are correct except which?

A) Normally it is difficult or impossible to feel the sacral promontory by means of a vaginal examination.
B) The normal diagonal conjugate measures about 10 in. $(25 \mathrm{~cm})$ .
C) This patient's pelvis was flattened anteroposteriorly, and the sacral promontory projected too far forward.
D) It is likely that this patient would have an obstructed labor.
E) This patient was advised to have a cesarean section.

Question 12

On a routine anteroposterior radiographic examination of a patient's right hip joint, the long axis of the neck of the femur was found to be at an angle of $160^{\circ}$ with the long axis of the femoral shaft.
-Is this angle normal in a 5-year-old child? In a 35-yearold man? What is the clinical condition called in which the angle is smaller than normal? Which movement of the hip joint is limited by this condition?

Question 13

Fracture of the neck of the femur in the adult commonly results in avascular necrosis of part of the femoral head. Can you explain this on anatomic grounds? Trochanteric fractures are never accompanied by avascular necrosis. Why?

Question 14

A 37-year-old woman was involved in a light plane accident. She and her husband were flying home from a business trip when they had to make a forced landing in a field due to fog. On landing, the plane hit a tree and came to rest on its nose. Her husband was killed on impact and she was thrown from the cockpit. She was evaluated in the emergency department with multiple injuries. Radiographic examination of her pelvis showed a fracture of her left ilium and iliac crest.
-From your knowledge of anatomy, would you expect much displacement of the bony fragments?

Question 15

A 25 -year-old man was running across a field when he caught his right foot in a rabbit hole. As he fell, the right foot was violently rotated laterally and overeverted. On attempting to stand, he could place no weight on his right foot. On examination by a physician, the right ankle was considerably swollen, especially on the lateral side. After further examination, including a radiograph of the ankle, a diagnosis of severe fracture dislocation of the ankle joint was made.

-The following statements concerning this patient are correct except which?

A) This type of fracture dislocation is caused by forced external rotation and overeversion of the foot.
B) The talus is externally rotated against the lateral malleolus of the fibula, causing it to fracture.
C) The torsion effect on the lateral malleolus produces a spiral fracture.
D) The medial ligament of the ankle joint is strong and never ruptures.
E) If the talus is forced to move farther laterally and continues to rotate, the posterior inferior margin of the tibia will be sheared off.

Question 16

A 32-year-old woman was rock climbing when she decided to jump from a ledge down to a flat rock some five feet below. On landing she maintained her balance but experienced a severe pain in her right foot in the region of the heel. On examination later in the emergency department of the local hospital, the physician's assistant noted the extreme tenderness felt over the sides and inferior surface of the right calcaneum. She also noted that the right calcaneum appeared wider than the one on the left. Using your knowledge of anatomy, make the diagnosis.