DFT-EMREE-ORTHO-09/10/2025-MAXEMO

22 Y/O M, a university football player, presents to the clinic after an acute knee injury during a match. He states he was running, planted his R foot to change direction, and felt a loud “pop” in his knee, followed by immediate severe pain and inability to continue playing. O/E, his R knee is significantly swollen and tender. There is a large effusion. Which of the following physical examination findings is most specific for this patient's likely injury?

• Positive posterior drawer test

• Positive McMurray test with a painful click

• Laxity with valgus stress at 30° flexion

• Positive Lachman test with a soft endpoint

• Tenderness over the lateral joint line

Answer explanation

The vignette describes a classic mechanism for an Anterior Cruciate Ligament (ACL) tear—the most commonly injured knee ligament. The Lachman test, which assesses anterior translation of the tibia on the femur with the knee in 20-30° of flexion, is the most sensitive and specific clinical test for an acute ACL rupture. A positive test is indicated by increased forward movement without a firm endpoint ("soft endpoint").

A 34 Y/O F, who delivered her first child 2 months ago, c/o R wrist pain x3 weeks. The pain is localized over the radial styloid and is exacerbated when she lifts her baby. O/E: There is tenderness to palpation over the first dorsal compartment. No swelling or erythema is noted. Which of the following physical examination maneuvers is most specific for confirming the suspected diagnosis?

• Phalen's test

• Finkelstein's test

• Allen's test

• Grind test

• Tinel's sign at the carpal tunnel

Answer explanation

Finkelstein's test involves having the patient make a fist with the thumb inside the fingers, followed by passive ulnar deviation of the wrist. This maneuver stretches the tendons of the first dorsal compartment (abductor pollicis longus and extensor pollicis brevis), eliciting sharp pain in patients with De Quervain's tenosynovitis. It is the classic and most specific provocative test for this condition.

72 Y/O F trips and falls onto her outstretched right hand. She presents to the ED with severe wrist pain, swelling, and a visible deformity. O/E: Marked dorsal displacement of the distal radius, tenderness over the radiocarpal joint, and limited range of motion. Distal neurovascular status is intact. An X-ray confirms a transverse fracture of the distal radius with dorsal angulation. What is the most likely eponym for this fracture pattern?

• Smith's fracture

• Colles' fracture

• Barton's fracture

• Chauffeur's fracture

• Galeazzi fracture

Answer explanation

A Colles' fracture is defined as a fracture of the distal radius, typically within 2-3 cm of the radiocarpal joint, with dorsal displacement and angulation of the distal fragment. This "dinner fork" deformity is classically caused by a fall on an outstretched hand with the wrist in extension, fitting the vignette perfectly.

A 34 Y/O M is brought to the ED after a fall onto his outstretched R arm. He c/o severe arm pain and inability to "lift his hand up." O/E, there is marked tenderness and deformity over the mid-shaft of his humerus. Neurological exam reveals weakness of wrist and finger extension (wrist drop) and ↓ sensation over the dorsal first web space. An X-ray confirms a closed, displaced fracture of the humeral shaft. Injury to which of the following nerves is the most likely cause of this patient's neurological findings?

• Median nerve

• Ulnar nerve

• Radial nerve

• Axillary nerve

• Musculocutaneous nerve

Answer explanation

The radial nerve runs in the spiral groove on the posterior aspect of the humerus, making it highly susceptible to injury with mid-shaft humeral fractures. Its motor function includes extension of the wrist and fingers, and its sensory distribution includes the dorsal first web space. The patient's presentation of "wrist drop" is classic for radial nerve palsy.

A 35 Y/O M graphic designer presents with a 6-week Hx of intermittent R wrist pain and tingling in his thumb and index finger. Symptoms are exacerbated after long hours of using a computer mouse and frequently awaken him from sleep. O/E, sensation is mildly reduced in the median nerve distribution. There is no thenar atrophy. His symptoms are reproduced by wrist flexion (Phalen's test). What is the most appropriate initial management for this patient?

• Surgical carpal tunnel release

• Oral gabapentin

• Referral for physiotherapy

• Wrist splinting in a neutral position, especially at night

• Intra-articular corticosteroid injection

Answer explanation

For mild to moderate carpal tunnel syndrome, the most appropriate and evidence-based initial management is conservative. Wrist splinting, particularly at night, maintains the wrist in a neutral position, which minimizes pressure on the median nerve within the carpal tunnel, thereby alleviating symptoms like nocturnal paresthesia.

A 28 Y/O M sustains a closed, comminuted fracture of the radial shaft in a motor vehicle accident. Following successful closed reduction and splinting, he is admitted for observation. Four hours later, he c/o escalating 10/10 pain in his forearm, which is poorly responsive to IV opioids. O/E, the forearm is visibly swollen and feels tense and "woody" on palpation. He has excruciating pain on passive extension of his fingers. A weak radial pulse is palpable. Sensation to light touch is diminished over the dorsum of the hand. What is the most likely diagnosis?

• Radial artery thrombosis

• Acute compartment syndrome

• Median nerve neuropraxia

• Complex regional pain syndrome (CRPS)

• Inadequate fracture reduction

Answer explanation

The clinical picture is classic for acute compartment syndrome. The key features are pain out of proportion to the injury, a tense or "woody" compartment on palpation, and severe pain on passive stretching of the muscles within that compartment (in this case, finger extensors). The presence of a palpable (even if weak) pulse is common in early compartment syndrome, as intracompartmental pressure often exceeds venous and capillary pressure before it exceeds arterial pressure.

A 6 Y/O M is brought to the ED after falling from a playground slide onto his outstretched left hand. O/E, there is marked swelling and tenderness over the lateral aspect of his left elbow. He has a restricted range of motion 2° to pain. Distal neurovascular examination is intact. An X-ray of the elbow reveals a Salter-Harris IV fracture of the lateral condyle with 3 mm of displacement, but the articular surface appears congruent. What is the most appropriate initial management for this patient?

• Long arm cast immobilization and close follow-up

• Open reduction and internal fixation (ORIF)

• Closed reduction and percutaneous pinning (CRPP)

• Analgesia and discharge with sling for comfort

• Immediate arthrocentesis to drain hemarthrosis

Answer explanation

The vignette describes a displaced lateral condyle fracture (3 mm), which is an indication for surgical stabilization to prevent further displacement, nonunion, or malunion. For fractures with 2-4 mm of displacement and an intact articular surface, closed reduction with percutaneous pinning is the preferred method. It is less invasive than open reduction while providing the necessary stability for healing.

An 8 Y/O F presents to the clinic 1 day after falling on her right arm. Her parents thought it was a sprain, but the pain has worsened. O/E, there is significant tenderness and swelling over the distal humerus. Sensation to light touch is intact in all nerve distributions, and a weak radial pulse is palpable. During the neurological exam, the patient is specifically asked to make an "OK" sign with her thumb and index finger. She is unable to flex the distal joint of her index finger and the interphalangeal joint of her thumb, resulting in a "pinch" gesture instead. This specific examination finding is most suggestive of an injury to which nerve?

• Ulnar nerve

• Radial nerve

• Musculocutaneous nerve

• Anterior interosseous nerve

• Posterior interosseous nerve

Answer explanation

The anterior interosseous nerve (AIN) is a pure motor branch of the median nerve. It innervates the flexor pollicis longus (flexes the thumb IP joint) and the flexor digitorum profundus to the index and middle fingers (flexes the DIP joints). The inability to make a proper "OK" sign, known as AIN palsy, is the classic presentation. The AIN is the most commonly injured nerve in extension-type supracondylar fractures due to its proximity to the fracture site.

A 45 Y/O F presents after falling down a flight of stairs, landing on her left side. She has isolated left arm pain. O/E: Significant angular deformity and ecchymosis of the mid-upper arm. The skin is intact. A comprehensive neurovascular exam is normal. Ix: X-ray reveals a closed, transverse fracture of the humeral diaphysis with 35 degrees of varus angulation and 4 cm of shortening. What is the most appropriate definitive management?

• Coaptation splint followed by a functional brace

• Closed reduction and hanging arm cast

• Open reduction and internal fixation (ORIF)

• Skeletal traction

• Shoulder immobilizer with analgesia and early mobilization

Answer explanation

While the majority of closed humeral shaft fractures can be managed non-operatively, this patient has unacceptable alignment that meets the criteria for surgical intervention. Absolute indications for ORIF include significant displacement, such as angulation >20-30 degrees (patient has 35 degrees) or shortening >3 cm (patient has 4 cm). ORIF with plate and screw fixation is required to achieve anatomical reduction, provide stable fixation, and allow for early functional recovery.

A 45 Y/O M with a known Hx of chronic lower back pain presents to the ED c/o acute worsening of pain radiating bilaterally down his legs x12 hrs. He also reports new-onset numbness in his groin and difficulty initiating urination. O/E: BP 140/85, HR 92, afebrile. Neurological exam reveals 3/5 power in ankle dorsiflexion bilaterally, ↓ sensation in the perineal "saddle" area, and ↓ anal tone on DRE. Patellar and Achilles reflexes are absent. What is the next best investigation to confirm the suspected diagnosis?

• Lumbar spine X-ray

• CT myelogram

• Urgent MRI of the lumbosacral spine

• Electromyography (EMG) and nerve conduction studies

• Blood tests including CRP and ESR

Answer explanation

The patient's presentation with bilateral sciatica, saddle anesthesia, urinary retention, and decreased anal tone is highly suggestive of Cauda Equina Syndrome (CES), a neurosurgical emergency. An urgent MRI of the lumbosacral spine is the gold standard and most critical next step to visualize the spinal cord, nerve roots, and the site of compression (likely a large central disc prolapse) to plan for immediate surgery.