A 52-year-old man comes to the hospital following 4 weeks of vague back and abdominal pain.  He also has experienced episodic fever, anorexia, and a 2-kg (4.4-lb) weight loss.  The patient was recently diagnosed with HIV and has not yet begun taking antiretroviral therapy.  He has a history of intravenous drug use.  A CT scan of the abdomen reveals an infection involving the structure indicated by the arrow in the image below.

Which of the following structures is involved by this patient’s infectious process?

A 12-year-old girl is brought to the emergency department following a sports injury involving the right lower extremity.  The patient was playing soccer when she jumped and turned to the right to avoid being kicked by another player.  She landed on her right foot with her foot internally rotated and her knee extended.  Since the injury, the patient has been able to bear weight but says the knee feels unstable and she is afraid that it may give way, causing her to fall.  Physical examination shows swelling of the right knee.  Stability testing shows excessive anterior translation of the tibia relative to the femur.  Which of the following ligaments is most likely injured?

 65-year-old man comes to the office due to right lower abdominal pain that radiates to his groin and difficulty walking for the past week.  Climbing stairs has been particularly hard for the patient, and he has fallen several times due to knee buckling.  Medical history is significant for type 2 diabetes mellitus, hypertension, and atrial fibrillation.  The patient takes apixaban for chronic anticoagulation therapy.  On physical examination, the right patellar reflex is decreased compared to the left.  Abdominal CT scan is shown below:

Which of the following additional findings is most likely to be seen in this patient?

A 53-year-old man comes to the office with a dull ache in his right shoulder.  The pain is worse with movement and often interferes with his sleep.  The patient cannot recall any traumatic events prior to the start of the pain but did experience increased discomfort after helping his daughter move into her college dorm room a week ago.  His past medical history includes dyslipidemia and hypertension, for which he takes the appropriate medications.  Physical examination reveals localized tenderness just below the acromion.  The physician asks the patient to abduct his arms 90 degrees to the side and flex them 30 degrees forward with his thumbs pointing to the floor.  She then applies downward force to his arms.  This maneuver elicits pain in the patient’s right shoulder and reveals right-sided weakness as compared to the left side.  A tendon of which of the following muscles is most likely injured in this patient?

A 6-year-old girl is brought to the emergency department after falling from a chair onto her outstretched right arm.  Physical examination shows swelling of the right elbow and tenderness to palpation over the distal humerus.  Radial pulse is slightly diminished in the right upper extremity compared to the left.  The patient cannot cooperate with neurologic examination of the right hand due to significant pain.  A peripheral intravenous line is placed, and analgesics are administered for pain control.  X-ray reveals a supracondylar humeral fracture with anteromedial displacement of the proximal fracture fragment.  Which of the following structures is most likely to be injured in this patient?

A 54-year-old woman comes to the office due to right upper arm weakness and fatigue.  She has no difficulty during most activities but has trouble when attempting to raise her arm overhead.  The patient first noticed the symptoms after a recent hospitalization.  On examination, there is no sensory loss in the upper extremities, but she has difficulty abducting her right arm past the horizontal position.  The patient is instructed to stretch her arms forward and press her hands against a wall; when she does, the medial border of the right scapula lifts off the thoracic wall and becomes prominent.  This patient was most likely hospitalized for which of the following?

A 52-year-old man comes to the office due to right shoulder pain.  He is an avid golfer but has been unable to play for the past 3 months due to the pain.  Lately, it has started to interfere with his daily activities, such as getting dressed.  An MRI shows thickening and calcification of the supraspinatus tendon.  Which of the following shoulder actions is most likely to provoke pain in this patient?

A 72-year-old man comes to the primary care clinic with a 6-month history of back and bilateral thigh pain provoked by walking.  He normally can walk only 2-3 blocks before having to stop due to pain.  However, when he is out walking with his grandchild, leaning on the stroller seems to provide pain relief.  The patient also notices an occasional tingling sensation in his lower extremities.  He has no prior trauma or history of rheumatologic disorders.  On physical examination, muscular strength is normal and the sensory findings are unremarkable.  Peripheral pulses are full and symmetric.  Thickening of which of the following ligaments is most likely contributing to this patient’s current presentation?

A 30-year-old man is evaluated for 6 months of persistent pain in his right buttock and posterior thigh.  He is a construction worker and has difficulty lifting heavy objects or climbing stairs.  He has no history of back injury and no associated back pain.  Past medical history is unremarkable.  The patient does not use tobacco and drinks only moderate quantities of alcohol.  On examination, the patient develops pain with forced adduction of the flexed thigh and internal rotation of the extended thigh against resistance.  Further evaluation reveals possible entrapment of the sciatic nerve in the greater sciatic foramen.  Which of the following structures passes through the foramen and occupies most of its volume?

A 15-year-old boy comes to the office due to right arm numbness.  He plays on his high school baseball team and has been intensively practicing his pitching for an upcoming game.  For the past several weeks, the patient has had fluctuating tingling and numbness involving the right shoulder, arm, and hand.  He also has recently developed dull pain in the right little finger and hand.  The symptoms worsen with overhead activities and when throwing a baseball.  The patient has no medical problems other than being told that he has an extra rib.  On examination, there is right-sided weakness of the intrinsic hand muscles.  Which of the following muscles is most likely contributing to this patient’s condition?

A 56-year-old man comes to the emergency department due to persistent left wrist pain.  While walking his dog 5 hours ago, he fell forward onto the ground and landed on his outstretched hand.  Examination shows mild left wrist swelling with preserved range of motion.  There is point tenderness over the dorsolateral aspect of the wrist between the tendons of the extensor pollicis longus and extensor pollicis brevis.  An x-ray of the left wrist is shown in the image below:

This patient is at greatest risk for developing which of the following complications?

A 44-year-old woman comes to the office due to increasing right hip pain for the past several days.  The pain is exacerbated by walking and by sitting with the right leg crossed over the left leg.  The patient has a history of plantar fasciitis.  Vital signs are within normal limits.  BMI is 30 kg/m2.  On examination, right hip abduction and internal rotation against resistance when the hip is flexed reproduce the pain.  The cause of this patient’s symptoms is suspected to be pathology at a tendon insertion site.  The tendon of which of the following muscles is most likely involved?

A 56-year-old man comes to the office for evaluation of right leg pain and numbness.  The pain started 2 days ago during an 8-hour car ride during which the patient was a backseat passenger in a small car.  Midway through the car ride, he began to have numbness and burning pain over the lateral aspect of the right thigh.  The patient has tried stretching to relieve the pain, but it has only worsened and he is now unable to wear a belt due to the discomfort.  He has type 2 diabetes mellitus and has gained 11.3 kg (25 lb) over the past year.  BMI is 42 kg/m2.  On examination, lower extremity strength is 5/5 bilaterally.  The right leg has a large area of numbness over the upper lateral thigh.  Straight leg raise is negative.  Reflexes are symmetrical and intact.  Compression of which of the following nerves is the most likely cause of this patient’s presentation?