7. Hand and Wrist MCQs

The scaphoid is at high risk for avascular necrosis following fracture due to its retrograde blood supply. Which vessel provides the primary blood supply to the proximal pole of the scaphoid?

A patient presents with an inability to form the 'OK' sign, demonstrating extended interphalangeal joints of the thumb and index finger. This deficit localizes to the anterior interosseous nerve (AIN). Which of the following muscles is innervated by this nerve?

A patient presents with ulnar nerve palsy secondary to a ganglion cyst compressing Guyon's canal. What structure forms the floor of Guyon's canal?

Which of the following describes the correct origin and innervation of the 3rd lumbrical muscle in the hand?

The Arcade of Frohse is a frequent site of compression for the posterior interosseous nerve (PIN). This structure represents the proximal fibrous edge of which muscle?

Which of the following tendons does NOT pass through the primary compartment of the carpal tunnel?

A 45-year-old woman undergoes an open carpal tunnel release. Postoperatively, she reports a new inability to palmar abduct her thumb, despite intact sensation over the thenar eminence and volar digits. An iatrogenic injury to the recurrent motor branch of the median nerve is suspected. According to the most common anatomical variation (extraligamentous type), how does this branch course to innervate the thenar muscles?

A 40-year-old male falls on an outstretched hand, sustaining a volar Barton's fracture of the distal radius. What is the pathognomonic feature of this fracture?

A 22-year-old athlete sustains a proximal pole scaphoid fracture. What is the primary reason for the high rate of avascular necrosis in this specific fracture pattern?

A 65-year-old female presents with an inability to extend her thumb at the interphalangeal joint 6 weeks after sustaining a nondisplaced distal radius fracture treated with cast immobilization. She reports a sudden, painless loss of motion while grasping a jar. What is the most likely etiology of this complication?

A 22-year-old athlete sustains a proximal pole scaphoid fracture. The treating orthopedic surgeon counsels the patient on the high risk of nonunion and avascular necrosis. This risk is primarily due to the blood supply originating from which of the following vessels?

A 32-year-old man sustains a Galeazzi fracture-dislocation. Following anatomic open reduction and internal fixation of the radial shaft, intraoperative evaluation reveals that the distal radioulnar joint (DRUJ) remains unstable in supination. What is the most appropriate next step in management?

Eight weeks following nonoperative management of a nondisplaced distal radius fracture in a short arm cast, a 60-year-old woman reports the sudden inability to actively extend her thumb interphalangeal joint. What is the most likely etiology of her new deficit?

A 55-year-old woman undergoes volar plate fixation for a distal radius fracture. Six months later, she suddenly loses the ability to actively flex the interphalangeal joint of her thumb. What is the most likely cause of this complication?

A 45-year-old female treated non-operatively for a nondisplaced distal radius fracture presents 6 weeks later unable to actively extend her thumb interphalangeal joint. Tenodesis effect is absent. What is the most appropriate and reliable surgical treatment?

Four months after undergoing open reduction and internal fixation of a distal radius fracture with a volar locking plate, a patient reports a sudden inability to flex the interphalangeal (IP) joint of the thumb. There is no history of new trauma. What is the most likely cause of this complication?

Six months after undergoing volar locked plating for a distal radius fracture, a 55-year-old woman reports sudden inability to actively flex the interphalangeal joint of her thumb. Radiographs reveal the plate was placed distal to the watershed line. What is the most likely cause of her current symptoms?

Following volar locked plating of a comminuted distal radius fracture, the patient develops attrition rupture of a tendon due to prominent screws penetrating the dorsal cortex. Which tendon is at greatest risk?

A 62-year-old female presents with a distal radius fracture following a fall. Closed reduction and splinting are performed in the emergency department. Which of the following radiographic parameters present on the initial injury films is most predictive of instability and secondary loss of reduction?

A newborn is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra at T8. What screening test is most critical to perform during the initial evaluation of this patient?