MCQs – Hand 1

Modern Study Review (AI-Generated)

High-Yield Summary

This topic is a staple of the Royal College exam, focusing heavily on distal radius fractures, rheumatoid hand deformities, and common hand/wrist ligament injuries. The single most important trade-off in distal radius fractures is radial shortening versus dorsal angulation, with radial shortening being the worst prognostic factor for long-term function and arthrosis risk. While the exam favors rigid numeric thresholds (e.g., >10° dorsal angulation), modern practice increasingly emphasizes individualized functional outcomes and early motion protocols. Recognition of soft tissue injuries such as Stener lesions and central slip disruptions remains critical for timely surgical intervention.

High-Yield Decision Matrix

Active Recall Q&A

Ulnar Tunnel Syndrome

Q: What is the most common cause of ulnar tunnel syndrome?
A: A ganglion cyst.
Related Pearl: Soft tissue masses like ganglia compress the ulnar nerve in Guyon’s canal more frequently than fractures or vascular causes.

Colles Fracture

Q: In Colles fractures, which factor is the worst prognostic indicator: radial shortening or dorsal angulation?
A: Radial shortening is worse than dorsal angulation.
Related Pearl: Shortening alters wrist biomechanics more significantly, increasing the risk of arthrosis and functional impairment.

Q: At what degree of dorsal angulation in a distal radius fracture does pain and decreased motion become clinically significant?
A: Above 10 degrees of dorsal angulation.
Related Pearl: Excessive dorsal tilt reduces articular congruity, leading to pain and limited wrist motion.

Q: How much radial shortening increases the risk of radiocarpal arthrosis, and by what percentage?
A: 2 mm of shortening increases the risk by 20%.
Related Pearl: Even minimal shortening disrupts load distribution across the wrist joint, accelerating degenerative changes.

Q: What effect does dorsal angulation of the distal radius fracture have on the articular contact area?
A: It decreases the contact area between the distal radius and the scaphoid and lunate.
Related Pearl: Reduced contact area predisposes to joint incongruity and early arthritis.

Q: What biomechanical consequence does radial shortening have on wrist loading?
A: It causes increased ulnar loading, leading to ulnocarpal impingement and arthrosis.
Related Pearl: Ulnar variance changes shift load to the ulnar side, stressing the TFCC and ulnar carpus.

Q: Which deformity is associated with decreased grip strength: radial shortening or dorsal angulation?
A: Radial shortening and shift.
Related Pearl: Grip strength depends on stable wrist length and alignment; shortening compromises this.

Q: Which deformity is more associated with decreased wrist range of motion: radial shortening or dorsal angulation?
A: Dorsal angulation.
Related Pearl: Angular deformities limit joint excursion more than shortening alone.

Rheumatoid Hand

Q: For MCP joint involvement in rheumatoid arthritis, which surgical option is preferred: silicone arthroplasty or fusion?
A: Silicone arthroplasty is preferred.
Related Pearl: Arthroplasty preserves motion and function, critical in MCP joints for hand dexterity.

Q: Which joints in the rheumatoid hand are more amenable to fusion due to their role in strong lateral pinch?
A: PIP joints of the long and index fingers, and the thumb MCP and IP joints.
Related Pearl: Stability in these joints is prioritized over motion to maintain pinch strength.

Q: Which joints should fusion be avoided in rheumatoid arthritis due to their importance in hand dexterity?
A: PIP joints of the ring and small fingers, and the thumb CMC joint.
Related Pearl: Preserving motion in these joints is essential for fine motor tasks.

Boutonniere Deformity

Q: What is the key clinical test to rule out acute Boutonniere deformity?
A: Assess active PIP extension with the wrist and MP joint fully flexed.
Related Pearl: Flexing wrist and MP joints isolates the central slip function, revealing subtle extension deficits.

Q: What degree of loss of active PIP extension suggests central slip disruption in Boutonniere deformity?
A: A loss of 15 to 20 degrees or greater.
Related Pearl: Even mild extension lag can indicate central slip injury requiring early intervention.

Q: What does weak PIP extension against resistance indicate in the context of Boutonniere deformity?
A: It is suggestive of central slip disruption.
Related Pearl: Weakness under resistance confirms functional impairment of the extensor mechanism.

Q: What diagnostic sign is seen with extravasation of intra-articular dye in Boutonniere deformity?
A: Dye extravasation dorsal and distal to the PIP joint confirms central slip disruption.
Related Pearl: Imaging can be used to confirm clinical suspicion when physical exam is equivocal.

Condylar Fractures

Q: How should condylar fractures of the metacarpals and phalanges be managed if closed reduction is inadequate?
A: Open reduction and internal fixation (ORIF) or closed reduction with pinning is required.
Related Pearl: These fractures are inherently unstable and rarely heal well without fixation.

Traumatic Finger Amputation

Q: What is the quadriga effect in traumatic finger amputations?
A: When the FDP tendon is sewn to the extensor tendon or over the tip, that finger flexes fully but limits flexion of other fingers.
Related Pearl: The common muscle belly of FDP causes limited excursion in adjacent fingers if one finger’s tendon is tethered.

Q: How is the quadriga effect treated?
A: Release the FDP tendon to the affected finger.
Related Pearl: Tendon release restores independent finger flexion and prevents global flexion loss.

Lumbrical Plus Phenomenon

Q: What is the lumbrical plus phenomenon?
A: A finger that extends at the PIP and DIP joints during attempted flexion due to FDP pull transmitted via the lumbrical.
Related Pearl: Seen after FDP grafts or amputations through the middle phalanx, it impairs finger flexion mechanics.

Q: How is the lumbrical plus phenomenon treated?
A: Transect the involved lumbrical tendon through a longitudinal incision in the webspace on the radial side.
Related Pearl: Surgical release restores normal flexion mechanics by eliminating aberrant lumbrical tension.

PIP Joint Volar Dislocation

Q: What injury is associated with volar dislocations of the PIP joint?
A: Central slip avulsion.
Related Pearl: Volar dislocation disrupts the extensor mechanism, leading to Boutonniere deformity if untreated.

Wrist Arthrodesis

Q: What is the optimal wrist fusion position in wrist arthrodesis?
A: 10-20° dorsiflexion, 5-10° ulnar deviation, with the 3rd metacarpal aligned with the radius.
Related Pearl: This position balances functional hand positioning and grip strength post-fusion.

Trigger Finger

Q: Where is the stenosis located in trigger finger?
A: At the A1 pulley, located just at the MCP joint.
Related Pearl: A1 pulley thickening causes tendon catching during finger flexion and extension.

Gamekeeper’s Thumb (UCL Injury)

Q: How is the ulnar collateral ligament (UCL) of the thumb tested clinically?
A: With the thumb in 30° of flexion.
Related Pearl: This position isolates the UCL, avoiding confounding by accessory ligaments.

Q: What is a Stener lesion in Gamekeeper’s thumb injuries?
A: Interposition of the adductor aponeurosis between the torn UCL and its insertion, preventing healing.
Related Pearl: Stener lesions require early surgical repair to restore thumb stability.

Q: In UCL injuries, from which bone is the avulsed fragment typically pulled off?
A: The proximal phalanx, not the metacarpal.
Related Pearl: Recognizing the fragment location aids accurate diagnosis and surgical planning.

Classic Clinical Notes

• The most common cause of ulnar tunnel syndrome is a ganglion; other soft tissue masses can occur. Beware fractures of the wrist or hook of hamate, repetitive trauma, ulnar artery thrombosis, pseudoaneurysms.

• Radial shortening in a Colles fracture is particularly bad for rotation. In general, shortening on the MCQ exam seems to be the worst prognosistic factor in Colles fractures; worse than abit of angulation. Dorsal articular angulation decreases motion, but above 10 degrees of dorsal angulation is also painful. Shortening of 2 mm increases the risk of radiocarpal arthrosis by 20%.

• Dorsal angulation of the distal radius fracture decreases the contact area of the distal articular surface for the scaphoid and lunate. This and shortening can lead to arthritis. Shortening of the radius tends to cause more ulnar loading and can lead to ulnocarpal impingement and subsequent arthrosis.

• Radial shortening and shift is associated with decreased grip strength, while dorsal angulation is more associated with decreased ROM.

• Silicone arthroplasty is preferred over fusion for MCP involvement in the rheumatoid hand.

• Joints that must be stable to provide strong lateral pinch are more amenable to fusion in the rheumatoid hand – eg: PIP joints of long and index fingers, and the thumb MCP and IP.

• Joints that have motion which is important for hand function/dexterity do poorly with fusion – eg: PIP of ring and small fingers, and the CMC joint of the thumb. Ie. Try to avoid fusing the PIP joints of 4 and 5.

• Active extension of the PIP joint is the key test to perform when ruling out acute Boutonniere deformity. A 15 to 20 degree or greater loss of active PIP extension when the wrist and MP joint are fully flexed is a sign of potential central slip disruption. Weak PIP extension against resistance is also suggestive. Extravasation of intra-articular dye dorsal and distal to the PIP joint is also diagnostic.

• Condylar fractures of the metacarpals and phalanges require closed reduction and pinning or open reduction and internal fixation if the closed reduction is inadequate. They are not stable if left alone, even if undisplaced.

• Beware quadriga effect in traumatic amputations of the finger – if the FDP tendon is sewed down or over the tip to the extensor tendon, that finger may flex fully, but it will reach the end of its flexion before the other fingers have fully flexed. Because there is no more flexion possible in that finger, and because they all come from one muscle belly, the rest of the fingers now will not achieve full flexion. If you see this in the amputated finger, go in and release the FDP tendon to that finger.

• A finger that goes out straight when attempting to flex it is demonstrating the “lumbrical plus” phenomenon. It occurs when the pull of FDP is applied through the lumbrical, so that the MCP joint is flexed, but the DIP and PIP joints are extended when a forceful flexion is attempted. This is seen in FDP tendon grafts, and in amputations through the middle phalanx. Treatment is to transect the involved lumbrical tendon through a longitudinal incision in the webspace, on the radial side of the finger.

• Volar dislocations of the PIP joint cause central slip avulsions.

• Wrist arthrodesis – best fusion position: 10-20 of dorsiflexion, 5-10 of ulnar deviation, with 3rd metacarpal lined up with the radius.

• Triggering of the finger occurs with stenosis at the A1 pulley – located just at the MCP joint.

• Gameskeeper thumb injuries (ulnar collateral ligament) – interposition of the adductor aponeurosis (Stener lesion) is the reason to explore and fix these injuries early.

• Test the UCL of the thumb in 30 of flexion – tests the main collateral ligaments.

• In UCL injuries, the fragment of bone that may get pulled off is from the proximal phalanx, not the metacarpal.

Last Updated on January 25, 2026 by Christian Veillette