Deck 12: Joints

Question 1

A 31-year-old woman has a history of poliomyelitis affecting the anterior horn cells of the lower thoracic and lumbar segments of the spinal cord on the left side. On examination, she has severe right lateral flexion deformity of the vertebral column.

-The following statements are true about this case except which?

A) The virus of poliomyelitis attacks and destroys the motor anterior horn cells of the spinal cord.
B) The disease resulted in the paralysis of the muscles that normally laterally flex the vertebral column on the left side.
C) The muscles on the right side of the vertebral column are unapposed.
D) The right lateral flexion deformity is caused by the slow degeneration of the sensory nerve fibers originating from the vertebral muscles on the right side.

Answer 1

The right lateral flexion deformity is caused by the slow degeneration of the sensory nerve fibers originating from the vertebral muscles on the right side.

Question 2

A 20-year-old woman severely sprains her left ankle while playing tennis. When she tries to move the foot so that the sole faces medially, she experiences severe pain.

-What is the correct anatomic term for the movement of the foot that produces the pain?

A) Pronation
B) Inversion
C) Supination
D) Eversion

Answer 2

Inversion

Question 3

An exhausted medical student decided to brush up on gross anatomy by attending a lecture given by an old and revered visiting professor. After 45 minutes the lecture began to bore him, and his mind began to wander. He could not forget the attractive brunette nurse in the surgical clinic whom he had dated the previous evening. After 5 more minutes he found he just could not keep his eyes open. When would this lecture end? Just then, he involuntarily opened his mouth wide and yawned. To his great consternation he could not close his mouth. His jaw was stuck in the open position. What is your diagnosis?

Answer 3

The student had dislocated his temporomandibular joints on both sides. When he yawned, his lateral pterygoid muscles reflexly contracted forcibly and pulled the head of the mandible and the articular disc forward over the summit of the articular tubercle in each joint. Reduction is easily performed by pressing gloved thumbs downward and backward on the last molar teeth. The lateral pterygoid, the temporalis, and the masseter muscle tension is overcome and the head of the mandible snaps back over the articular tubercle to assume its normal anatomical position.

Question 4

An 11-year-old boy was showing off in front of friends by diving into the shallow end of a swimming pool. After one particularly daring dive, he surfaced quickly and climbed out of the pool, holding his head between his hands. He said that he had hit the bottom of the pool with his head and now had severe pain in the root of the neck, which was made worse when he tried to move his neck. A lateral radiograph revealed that the right inferior articular process of the fifth cervical vertebra was forced over the anterior margin of the right superior articular process of the sixth cervical vertebra, producing a unilateral dislocation with nipping of the right sixth cervical nerve.

-The following symptoms and signs confirmed the diagnosis except which?

A) The head was rotated to the right.
B) There was spasm of the deep neck muscles on the right side of the neck, which were tender to touch.
C) The patient complained of severe pain in the region of the back of the neck and right shoulder.
D) The slightest movement produced severe pain in the right sixth cervical dermatome.
E) The large size of the vertebral canal in the cervical region permitted the spinal cord to escape injury.

Question 5

A 50-year-old coal miner was crouching at the mine face when a large rock suddenly became dislodged from the roof of the mine shaft and struck him on the upper part of his back. The emergency department physician suspected a displacement of the upper thoracic spines on the sixth thoracic spine.

-The following physical signs confirmed a diagnosis of fracture dislocation between the fifth and sixth thoracic vertebrae except which?

A) A lateral radiograph revealed fractures involving the superior articular processes of the sixth thoracic vertebra and the inferior articular processes of the fifth thoracic vertebra.
B) Considerable forward displacement of the body of the fifth thoracic vertebra on the sixth thoracic vertebra occurred.
C) The patient had signs and symptoms of spinal shock.
D) The large size of the vertebral canal in the thoracic region leaves plenty of space around the spinal cord for bony displacement.
E) The patient later showed signs and symptoms of paraplegia.

Question 6

A 66-year-old woman was seen in the emergency department complaining of a burning pain over the upper part of her right arm. The pain had started 2 days previously and had progressively worsened. Physical examination revealed weakness and wasting of the right deltoid and biceps brachii muscles. The patient also had hyperesthesia in the skin over the lower part of the right deltoid and down the lateral side of the arm. Radiologic examination showed extensive spur formation on the bodies of the fourth, fifth, and sixth cervical vertebrae. These signs and symptoms suggested severe osteoarthritis of the cervical vertebral column.

-This disease produced the following changes in the vertebrae and related structures except which?

A) Repeated trauma and aging had resulted in degenerative changes at the articulating surfaces of the fourth, fifth, and sixth cervical vertebrae.
B) Extensive spur formation resulted in narrowing of the intervertebral foramina with pressure on the nerve roots.
C) The burning pain and hyperesthesia were caused by pressure on the third and fourth cervical posterior roots.
D) The weakness and wasting of the deltoid and biceps brachii muscles were caused by pressure on the fifth and sixth cervical anterior roots.
E) Movements of the neck intensified the symptoms by exerting further pressure on the nerve roots.
F) Coughing or sneezing raised the pressure within the vertebral canal and resulted in further pressure on the roots.

Question 7

A medical student offered to move a grand piano for his landlady. He had just finished his final examinations in anatomy and was in poor physical shape. He struggled with the antique monstrosity and suddenly experienced an acute pain in the back, which extended down the back and outer side of his left leg. On examination in the emergency department, he was found to have a slight scoliosis with the convexity on the right side. The deep muscles of the back in the left lumbar region felt firmer than normal. No evidence of muscle weakness was present, but the left ankle jerk was diminished.

-The symptoms and signs of this patient strongly suggest a diagnosis of prolapsed intervertebral disc except which?

A) The pain was the worst over the left lumbar region opposite the fifth lumbar spine.
B) The pain was accentuated by coughing.
C) With the patient supine, flexing the left hip joint with the knee extended caused a marked increase in the pain.
D) A lateral radiograph of the lumbar vertebral column revealed nothing abnormal.
E) A magnetic resonance imaging study revealed the presence of small fragments of the nucleus pulposus that had herniated outside the anulus in the disc between the fifth lumbar vertebra and the sacrum.
F) The pain occurred in the dermatomes of the third and fourth lumbar segments on the left side.

Question 8

A 22-year-old student was driving home from a party and crashed his car head on into a brick wall. On examination in the emergency department, he was found to have a fracture dislocation of the seventh thoracic vertebra, with signs and symptoms of severe damage to the spinal cord.

-On recovery from spinal shock, he was found to have the following signs and symptoms except which?

A) Fracture dislocation of the seventh thoracic vertebra, which would result in severe damage to the seventh thoracic segment of the spinal cord
B) A band of cutaneous hyperesthesia extending around the abdominal wall on the left side at the level of the umbilicus that was caused by the irritation of the cord immediately above the site of the lesion
C) On the right side, total analgesia, thermoanesthesia, and partial loss of tactile sense of the skin of the abdominal wall below the level of the umbilicus involving the whole of the right leg
D) Upper motor neuron paralysis of his left leg
E) Unequal sensory and motor losses on the two sides, which indicate a left hemisection of the spinal cord

Question 9

A 36-year-old woman went sailing with her husband and they were caught in a severe gale. While the husband at the helm desperately managed to keep the boat under control, the wife tried to get the sails down. Eventually the squall died down and they were able to return safely to port. The next morning, the woman woke up with severe pain over the left side of her chest. On being examined in the emergency department of the local hospital for a suspected myocardial infarction, the physician found that the patient was acutely tender over her left costal margin, which was made worse on taking a deep breath. What is the possible diagnosis?

Question 10

Separation of the acromioclavicular joint is common in football and soccer players. Explain why such separations are unstable after reduction.

Question 11

A father, seeing his 3-year-old son playing in the garden, ran up and picked him up by both hands and swung him around in a circle. The child's enjoyment suddenly turned to tears, and he said his left elbow hurt. On examination, the child held his left elbow joint semiflexed and his forearm pronated.

-The following statements concerning this case are consistent with the diagnosis of dislocation of the superior radioulnar joint except which?

A) The head of the radius was pulled out of the anular ligament.
B) At age 3 years, the child's anular ligament has a large diameter and the head of the radius can easily be pulled out of the ligament by traction.
C) The incidence of this condition is equal in both sexes.
D) The pain from the joint caused reflex contraction of the surrounding muscles to protect the joint from further movement.
E) The subluxation of the joint can be treated by pulling downward on the forearm and at the same time performing the movement of pronation and supination. Finally, the elbow joint is flexed and held in that position.

Question 12

A 60-year-old woman fell down the stairs and was admitted to the emergency department with severe right shoulder pain. On examination, the patient was sitting up with her right arm by her side and her right elbow joint supported by the left hand. Inspection of the right shoulder showed loss of the normal rounded curvature and evidence of a slight swelling below the right clavicle. Any attempt at active or passive movement of the shoulder joint was stopped by severe pain in the shoulder. A diagnosis of dislocation of the right shoulder joint was made.

-The following statements concerning this patient are consistent with the diagnosis except which?

A) This patient had a subcoracoid dislocation of the right shoulder joint.
B) The head of the humerus was dislocated downward through the weakest part of the capsule of the joint.
C) The pull of the pectoralis major and subscapularis muscles had displaced the upper end of the humerus medially.
D) The greater tuberosity of the humerus no longer displaced the deltoid muscle laterally, and the curve of the shoulder was lost.
E) The integrity of the axillary nerve should always be tested by touching the skin over the upper half of the deltoid muscle.

Question 13

A 63-year-old man fell down a flight of stairs and sustained a fracture of the lower end of the left radius. On examination the distal end of the radius was displaced posteriorly. This patient had sustained a Colles' fracture.

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

A) Occasionally the styloid process of the ulna is also fractured.
B) The median nerve may be injured at the time of the fall.
C) When the fracture is reduced, the styloid process of the radius should come to lie about $0.75 \mathrm{in} .(1.9 \mathrm{~cm})$ proximal to that of the ulna.
D) The fracture produces posterior angulation of the distal fragment of the radius.
E) On reduction of the fracture the distal end of the radius should lie at an angle of $15^{\circ}$ anteriorly.
F) The hand should always be splinted in the position of function.

Question 14

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 scaphoid bone is an easy bone to immobilize because of its small size.
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 fracture line on the scaphoid bone may deprive the proximal fragment of its arterial supply.
E) Fractures of the scaphoid bone have a high incidence of nonunion.

Question 15

A 46-year-old woman slipped on a shiny floor and sustained a fracture of the fifth metacarpal bone on her left hand. What type of angulation of the fragments is commonly found in fractures at this site? When a splint is applied with the little finger flexed, in which direction should the little finger be pointing?

Question 16

A medical student, while playing football, collided with another player and fell to the ground. As he fell, the right knee, which was taking the weight of his body, was partially flexed; the femur was rotated medially; and the leg was abducted on the thigh. A sudden pain was felt in the right knee joint, and he was unable to extend it. The student was diagnosed as having a torn medial meniscus of the knee joint.

-The following statements concerning this case confirmed the diagnosis except which?

A) The right knee joint quickly became swollen.
B) Severe local tenderness was felt along the medial side of the joint line.
C) The medial meniscus split along part of its length, and the detached portion became jammed between the articular surfaces, limiting further extension.
D) The trauma stimulated the production of synovial fluid, which filled the joint cavity.
E) The distension of the suprapatellar bursa was responsible for the large amount of swelling above the injured knee.
F) The pain sensation from the injured knee was confined to the femoral nerve as it ascended to the central nervous system.

Question 17

A 27-year-old woman was found to have an unstable right knee joint following a severe automobile accident. On examination it was possible to pull the tibia excessively forward on the femur. A diagnosis of ruptured anterior cruciate ligament was made.

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

A) The anterior cruciate ligament is attached to the tibia in the anterior part of the intercondylar area.
B) The anterior cruciate ligament passes upward, backward, and laterally from its tibial attachment.
C) The anterior cruciate ligament is attached above to the posterior part of the medial surface of the lateral femoral condyle.
D) The anterior cruciate ligament is more commonly torn than is the posterior cruciate ligament.
E) Because the cruciate ligaments are located outside the synovial membrane, bleeding from a torn ligament does not enter the joint cavity.

Question 18

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 medial ligament of the ankle joint is strong and never ruptures.
D) The torsion effect on the lateral malleolus produces a spiral fracture.
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.