7. Hand and Wrist MCQs

A 65-year-old female sustains a nondisplaced distal radius fracture and is treated non-operatively in a cast. Six weeks post-injury, she experiences a sudden, painless inability to actively extend her thumb at the interphalangeal joint. What is the primary pathophysiological mechanism of this specific complication?

A 42-year-old male sustains a comminuted radial head fracture. He also complains of severe ipsilateral wrist pain, and wrist radiographs demonstrate positive ulnar variance. If the radial head is simply resected without prosthetic replacement, which of the following biomechanical consequences is most likely to occur?

A 50-year-old female undergoes an anterior subcutaneous transposition of the ulnar nerve for severe cubital tunnel syndrome. Postoperatively, she reports worsened ulnar neuropathy symptoms. Surgical exploration reveals a new site of compression. If the initial surgeon failed to release all potential sites of tethering during the transposition, what is the most likely anatomic structure causing this new compression?

A 35-year-old carpenter presents with aching pain in the proximal volar forearm and numbness in the radial three-and-a-half digits. Sensation over the thenar eminence is decreased. Electromyography reveals normal conduction at the wrist. Compression of the median nerve is suspected. Which anatomical structure is most likely responsible for this specific sensory deficit?

During a single-incision anterior approach for the repair of a retracted distal biceps tendon rupture, the surgeon places Hohmann retractors around the radial neck to facilitate visualization of the radial tuberosity. Which nerve is at the highest risk of injury with this maneuver?

A 35-year-old male sustains a severely comminuted, irreparable radial head fracture and reports right wrist pain after falling on an outstretched hand. Examination reveals instability of the distal radioulnar joint (DRUJ) and wrist radiographs demonstrate proximal migration of the radius. To restore longitudinal stability of the forearm and prevent chronic wrist pain, what is the most critical surgical intervention?

During an open in situ decompression of the ulnar nerve at the elbow, the surgeon must release a tough fascial band that bridges the two heads of the flexor carpi ulnaris (FCU) muscle to prevent entrapment. What is the name of this anatomic structure?

A 55-year-old diabetic woman presents with triggering and locking of her middle finger. Non-operative management has failed, and surgical release of the stenosing tenosynovitis is planned. Which annular pulley must be completely incised to reliably resolve this condition?

The median nerve provides motor innervation to the majority of the thenar musculature via its recurrent motor branch. Which of the following intrinsic thumb muscles is typically innervated by the deep branch of the ulnar nerve?

During a fasciectomy for severe Dupuytren's contracture involving the proximal interphalangeal (PIP) joint, the surgeon notes that the digital neurovascular bundle is displaced toward the midline and superficially. Which pathologic structure is primarily responsible for this displacement?

A 24-year-old male is struck on the posterior distal humerus and presents with an inability to extend his thumb, MCP joints, or wrist. However, wrist extension is accompanied by radial deviation. There is no sensory deficit in the forearm or hand. The site of nerve entrapment or injury is most likely at the:

During open reduction and internal fixation of a highly comminuted, intra-articular distal radius fracture utilizing a volar locking plate, the surgeon identifies a 'die-punch' fragment comprising the volar margin of the lunate fossa. Failure to adequately capture and buttress this specific fragment is most likely to result in:

A 32-year-old man falls on an outstretched hand and presents with severe wrist pain. Radiographs demonstrate a perilunate dislocation. When assessing the injury on a PA radiograph, disruption of Gilula's lines is noted. The most commonly expected direction of dislocation for the distal carpal row relative to the lunate is:

A 50-year-old male undergoes in situ ulnar nerve decompression for cubital tunnel syndrome. To ensure complete decompression, the surgeon must check for several potential sites of entrapment. Which of the following is the most distal structure that commonly compresses the ulnar nerve in this region?

During the volar approach (modified Henry) for plating a distal radius fracture, the surgeon must avoid placing the plate distal to the 'watershed line' to prevent which of the following complications?