MCQs – Hand 7

Modern Study Review (AI-Generated)

High-Yield Summary

Carpal tunnel release after distal radius fracture is a staple of orthopaedic exams, focusing heavily on symptom severity, timing, and fracture anatomy. The critical clinical decision hinges on whether median nerve symptoms are severe and progressive versus mild and stable, with fracture shortening as the key surgical indication. Acute Boutonniere injury diagnosis depends on PIP extension with MCP flexion, a classic exam maneuver. Understanding deformities like quadriga and lumbrical plus is essential for post-amputation finger function restoration. Radial nerve recovery sequence and proximal nerve compression sites are frequently tested, with ECU recovering first and EPL last, and the leash of Henry compressing the radial nerve specifically.

High-Yield Decision Matrix

Active Recall Q&A

Carpal Tunnel Release Indications

Q: What are the indications for performing carpal tunnel release after a distal radius fracture?
A: Severe and increasing median nerve symptoms warrant decompression; mild, chronic symptoms can be observed for 3-4 months.
Related Pearl: Early surgery is not indicated for mild symptoms within the first 10 days post-injury, as spontaneous improvement is common.

Q: Is mild median nerve symptomatology at 10 days post-distal radius fracture an indication for carpal tunnel release?
A: No, mild symptoms at 10 days do not indicate immediate surgery. Observation is preferred.
Related Pearl: Median nerve symptoms often improve as swelling subsides; premature surgery risks unnecessary morbidity.

Q: What is the main surgical indication for carpal tunnel release after distal radius fracture?
A: Shortening of the distal radius fracture is the primary indication for surgery.
Related Pearl: Shortening alters carpal tunnel anatomy, increasing median nerve compression risk.

Boutonniere Injury

Q: How do you test for an acute Boutonniere injury?
A: Ask the patient to actively extend the PIP joint while the MCP joint is flexed.
Related Pearl: Flexing the MCP isolates the central slip function, making Boutonniere deformity easier to detect.

Quadriga and Lumbrical Plus Deformities

Q: What causes quadriga deformity after finger amputation?
A: Excessive tension of the FDP muscle belly limits flexion of adjacent fingers due to early maximal flexion of the affected finger.
Related Pearl: Quadriga results from the common FDP muscle belly’s limited excursion; releasing FDP tension restores balanced finger flexion.

Q: How is lumbrical plus deformity characterized and treated?
A: It occurs when the FDP is relatively long after middle phalanx amputation, causing PIP extension during attempted flexion; treatment is lumbrical tendon release.
Related Pearl: The lumbrical tendon’s abnormal pull converts FDP force into PIP extension, impairing finger flexion.

Radial Nerve Recovery

Q: Which muscle is usually the first to recover after radial nerve injury?
A: Extensor carpi ulnaris (ECU) is typically the first to recover.
Related Pearl: Early ECU recovery can help localize lesion level and predict functional return.

Q: Which muscle is usually the last to recover after radial nerve injury?
A: Extensor pollicis longus (EPL) is usually the last to recover.
Related Pearl: EPL’s long course and distal innervation delay recovery compared to other radial nerve muscles.

Anterior Elbow Anatomy

Q: What is the order of structures from medial to lateral in front of the elbow?
A: Median nerve (most medial), brachial artery (middle), biceps tendon (most lateral).
Related Pearl: This anatomical relationship guides safe surgical approaches and vascular access.

Nerve Compression Sites

Q: What structures compress the median nerve in compressive neuropathies?
A: Ligament of Struthers, pronator teres, lacertus fibrosis, and arch of the flexor digitorum superficialis (FDS).
Related Pearl: Compression sites are key targets for surgical decompression in pronator syndrome.

Q: What compresses the radial nerve in the proximal forearm?
A: The recurrent radial artery (leash of Henry) compresses the radial nerve, not the median nerve.
Related Pearl: Vascular leashes are important but often overlooked causes of radial nerve entrapment.

Classic Clinical Notes

• Indications for doing carpal tunnel release after distal radius fracture: if symptoms are severe and increasing, decompression is warranted. For mild, chronic median neuropathy, observation may be employed for 3-4 months. Ie. the patient that arrives 10 days out with mild median nerve symptoms is not an indication for operation. The main indication for an operation is SHORTENING.

• Again: to test for an acute Boutonniere injury: look for ACTIVE PIP joint extension with the MCP joint FLEXED.

• Quadriga and lumbrical plus are sort of opposite anatomic problems. Both can occur after amputations of the fingers. In quadriga, the tension of the FDP is too tight (if it is sutured over the stump or attached to the extensor hood to drape over the tip of the amputation) so that when that finger is flexed, it reaches its maximal flexion before the others. Because FDP is a common muscle belly, the rest cannot flex any further. The treatment is to release the FDP. On the other hand, the lumbrical plus deformity can occur when the middle phalanx is amputated and the FDP is relatively LONG – the pull of FDP is then more through the lumbrical, thereby EXTENDING the PIP joint when the patient tries to flex it. The treatment is release of the lumbrical tendon.

• The last to return after radial nerve injury is debatable, but probably EPL. The first to recover is ECU.

• In front of the elbow, the most medial structure is the MEDIAN nerve, the most lateral structure is the biceps tendon (heading down to the radial tuberosity). Therefore, the artery is in between.

• When talking about compressive lesions of the median nerve, the nerve is compressed by ligament of Struthers, pronator teres, lacertus fibrosis, and the arch of FDS. The vascular leash (recurrent radial artery – leash of Henry) compresses the radial nerve and not the median nerve.

Last Updated on January 25, 2026 by Christian Veillette