This practice set contains high-yield board review questions covering key concepts in Upper Extremity Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 41
Topic: Upper Extremity Trauma
In a patient presenting with a terrible triad of the elbow, which of the following physical exam findings is most indicative of an associated Essex-Lopresti injury?
Correct Answer & Explanation
. Distal radioulnar joint (DRUJ) instability and wrist pain
Explanation
An Essex-Lopresti lesion involves a radial head fracture, rupture of the interosseous membrane, and DRUJ disruption. Concomitant wrist pain and DRUJ instability in the setting of a terrible triad strongly suggest this injury, strictly contraindicating radial head excision.
Question 42
Topic: Upper Extremity Trauma
The 'terrible triad' of the elbow is classically caused by a fall on an outstretched hand resulting in a specific cascade of forces. Which of the following biomechanical mechanisms best describes this injury?
Correct Answer & Explanation
. Valgus, supination, and axial load
Explanation
The terrible triad of the elbow typically results from an axial load applied to a supinated forearm combined with a valgus posterolateral rotatory force. This causes failure progressing circularly from the lateral side to the anterior side, and finally to the medial side.
Question 43
Topic: Upper Extremity Trauma
A patient successfully undergoes ORIF for a terrible triad injury with rigid fixation of the coronoid and radial head, and a robust LCL repair. What is the most appropriate early postoperative rehabilitation protocol to prevent stiffness while maintaining stability?
Correct Answer & Explanation
. Active-assisted range of motion in full pronation
Explanation
Early active-assisted range of motion is critical to prevent elbow stiffness. Exercises are typically performed with the forearm in pronation, which uses the crossed intact radius and ulna to protect the repaired lateral collateral ligament complex from varus stress.
Question 44
Topic: Upper Extremity Trauma
A 24-year-old rugby player falls directly onto his shoulder and sustains an acute acromioclavicular (AC) joint separation. Radiographs reveal 150% superior displacement of the distal clavicle relative to the acromion. Which ligaments are completely disrupted in this Type III injury?
Correct Answer & Explanation
. Acromioclavicular and coracoclavicular ligaments
Explanation
In a Type III AC joint separation, both the acromioclavicular (AC) ligaments and the coracoclavicular (CC) ligaments (conoid and trapezoid) are completely torn, allowing the clavicle to displace superiorly by 100-250%.
Question 45
Topic: Upper Extremity Trauma
According to recent quantitative anatomic studies regarding the proximal humerus, which vessel provides the predominant blood supply to the humeral head, challenging historical teachings?
Correct Answer & Explanation
. Posterior humeral circumflex artery
Explanation
While historically the arcuate branch of the anterior humeral circumflex artery was believed to be the main supply, modern studies (e.g., Hettrich et al.) demonstrate that the posterior humeral circumflex artery provides over 60% of the blood supply to the humeral head.
Question 46
Topic: Upper Extremity Trauma
A 28-year-old collegiate baseball pitcher presents with deep shoulder pain, mechanical clicking, and decreased throwing velocity. The pain is strongly reproduced with resisted forearm supination while the shoulder is flexed to 90 degrees. Which structure is most likely injured?
Correct Answer & Explanation
. Long head of the biceps anchor
Explanation
The patient's presentation and positive O'Brien's or Yergason's test are consistent with a SLAP (Superior Labrum Anterior and Posterior) tear. These lesions involve the superior labrum and the origin of the long head of the biceps tendon.
Question 47
Topic: Upper Extremity Trauma
A 25-year-old mountain biker falls directly onto the point of his shoulder. Radiographs demonstrate a 150% superior displacement of the distal clavicle relative to the acromion with an increased coracoclavicular distance. Which classification and typical management strategy correspond to this injury?
Correct Answer & Explanation
. Type V, operative reconstruction
Explanation
A Type V acromioclavicular (AC) joint injury is characterized by 100-300% superior displacement of the clavicle due to disruption of the CC ligaments and deltotrapezial fascia. Operative reconstruction is generally recommended for young, active patients to restore normal shoulder mechanics.
Question 48
Topic: Upper Extremity Trauma
A 25-year-old cyclist falls directly onto his right shoulder. Clinical examination reveals profound superior prominence of the distal clavicle. Radiographs demonstrate the distal clavicle displaced superiorly by 150% relative to the acromion. Which of the following describes the injured structures in a Type V acromioclavicular (AC) joint separation?
Correct Answer & Explanation
. Tear of the AC and CC ligaments with stripping of the deltotrapezial fascia
Explanation
A Type V AC joint separation involves severe superior displacement (>100-300%) due to disruption of both the AC and CC ligaments, along with extensive stripping or tearing of the deltotrapezial fascia. This degree of instability generally warrants surgical reconstruction.
Question 49
Topic: Upper Extremity Trauma
A 28-year-old male rugby player sustains a direct blow to the superior aspect of his right shoulder with his arm adducted during a tackle. He presents with significant pain and a visible deformity. Radiographs show superior displacement of the distal clavicle, with the coracoclavicular distance measured at 20 mm on the injured side compared to 10 mm on the contralateral uninjured side. The deltotrapezial fascia appears intact. Which Rockwood classification best describes this injury?
Correct Answer & Explanation
. Type III
Explanation
The case describes a Rockwood Type III injury. According to the Rockwood classification system, a Type III injury involves complete tears of both the acromioclavicular and coracoclavicular ligaments. The clavicle is significantly displaced superiorly, typically demonstrating a 25 to 100 percent increased coracoclavicular distance. In this patient, the coracoclavicular distance increased from 10 mm to 20 mm, representing a 100% increase, which falls within the Type III criteria. Furthermore, the deltotrapezial fascia remaining intact is a key distinguishing feature of Type III compared to Type V, where it is extensively stripped. Type II involves a complete tear of the acromioclavicular ligaments with intact coracoclavicular ligaments and less than 25% increase in coracoclavicular distance. Type IV involves posterior displacement of the clavicle into the trapezius, requiring an axillary lateral radiograph for diagnosis, which is not indicated here. Type V involves severe superior displacement exceeding 100% of the normal coracoclavicular distance and extensive stripping of the deltoid and trapezius fascia, which is not described as stripped in this case.
Question 50
Topic: Upper Extremity Trauma
A surgeon is performing an open reduction and internal fixation of a chronic acromioclavicular joint separation. During the procedure, they note significant horizontal instability of the clavicle on the acromion, even after initial reduction. Based on the provided case, which ligamentous structure is the primary restraint to this specific type of instability?
Correct Answer & Explanation
. Superior acromioclavicular ligament
Explanation
Correct Answer: CThe case explicitly states under the 'Static Stabilizers' section: 'Biomechanically, the acromioclavicular ligaments provide the primary restraint to anterior-posterior horizontal translation of the clavicle on the acromion. Sectioning the superior acromioclavicular ligament results in profound horizontal instability.' The conoid and trapezoid ligaments (coracoclavicular ligaments) are crucial for vertical stability. The coracoacromial ligament is not a primary stabilizer of the AC joint itself, and the articular disc's role in stability is minimal, especially given its degeneration with age.
Question 51
Topic: Upper Extremity Trauma
A 35-year-old construction worker presents with a Rockwood Type III acromioclavicular joint injury after a fall from scaffolding. He reports significant pain and difficulty performing overhead tasks required for his job. On physical exam, he has dynamic overriding of the clavicle on the acromion during cross-body adduction. Based on the ISAKOS guidelines mentioned in the case, what is the most appropriate management strategy?
Correct Answer & Explanation
. Surgical stabilization with an acute suspensory cortical button fixation.
Explanation
Correct Answer: B. The case highlights the ISAKOS Upper Extremity Committee's subclassification of Type III injuries into Type IIIA (vertically unstable but horizontally stable) and Type IIIB (vertically and horizontally unstable). The consensus suggests that Type IIIA injuries are best managed non-operatively, while Type IIIB injuries, characterized by dynamic overriding of the clavicle on the acromion during cross-body adduction, often experience poor functional outcomes with conservative care and may benefit from early surgical stabilization. This patient is a manual laborer and presents with dynamic overriding during cross-body adduction, which is characteristic of a Type IIIB injury. Since the injury is acute, acute suspensory cortical button fixation is the appropriate surgical technique. Chronic biologic reconstruction is for injuries presenting after six weeks. Distal clavicle excision is typically for chronic osteolysis or arthrosis, not acute instability.
Question 52
Topic: Upper Extremity Trauma
The ISAKOS Upper Extremity Committee has provided consensus guidelines for the management of Rockwood Type III acromioclavicular joint injuries. According to these guidelines, which of the following patient presentations would most likely benefit from early surgical stabilization?
Correct Answer & Explanation
. A 40-year-old manual laborer with a Type IIIB injury, demonstrating dynamic overriding of the clavicle on the acromion during cross-body adduction.
Explanation
Correct Answer: C. The ISAKOS consensus guidelines subclassified Type III injuries into Type IIIA (vertically unstable but horizontally stable) and Type IIIB (vertically and horizontally unstable). The current consensus suggests that Type IIIA injuries are best managed non-operatively, while Type IIIB injuries, characterized by dynamic overriding of the clavicle on the acromion during cross-body adduction, often experience poor functional outcomes with conservative care and may benefit from early surgical stabilization. Option C describes a manual laborer with a Type IIIB injury, which is the specific indication for early surgical stabilization.
Question 53
Topic: Upper Extremity Trauma
During open reduction and internal fixation of a chronic acromioclavicular (AC) joint injury, the surgeon must address both vertical and horizontal instability. Which of the following native structures acts as the primary restraint to anteroposterior (horizontal) translation of the distal clavicle?
Correct Answer & Explanation
. Superior acromioclavicular ligament
Explanation
The superior acromioclavicular ligament is the thickest and most robust portion of the AC capsule, serving as the primary restraint to anteroposterior translation of the distal clavicle.
Question 54
Topic: Upper Extremity Trauma
A 42-year-old male falls directly onto his shoulder. Clinical examination reveals a prominent acromion, but the distal clavicle is non-palpable and appears displaced posteriorly. Radiographs confirm posterior displacement of the clavicle through the trapezius muscle. What is the correct Rockwood classification for this injury?
Correct Answer & Explanation
. Rockwood Type IV
Explanation
A Rockwood Type IV acromioclavicular injury involves posterior displacement of the distal clavicle into or completely through the deltotrapezial fascia, typically requiring surgical intervention.
Question 55
Topic: Upper Extremity Trauma
In evaluating the stability of the acromioclavicular (AC) joint, a surgeon considers the primary anatomical restraints. Which of the following accurately describes the primary ligamentous restraint to superior translation of the distal clavicle?
Correct Answer & Explanation
. The conoid and trapezoid ligaments
Explanation
The coracoclavicular (CC) ligaments, comprising the conoid and trapezoid, are the primary restraints to superior and inferior translation of the clavicle. The AC capsular ligaments primarily resist anterior-posterior (horizontal) translation.
Question 56
Topic: Upper Extremity Trauma
A patient is evaluated for an AC joint injury after a fall. Examination shows severe inferior displacement of the distal clavicle, resting underneath the coracoid process, posterior to the conjoint tendon. What is the Rockwood classification for this injury?
Correct Answer & Explanation
. Type VI
Explanation
A Rockwood Type VI AC joint injury involves inferior displacement of the distal clavicle into a subcoracoid or subacromial position. This is a severe, high-energy injury that invariably requires surgical reduction.
Question 57
Topic: Upper Extremity Trauma
An orthopedic surgeon is performing an anatomic coracoclavicular (CC) ligament reconstruction for a chronic Type V acromioclavicular joint separation. To accurately reproduce the native anatomy and optimize biomechanical stability, where should the surgeon place the clavicular drill tunnel for the conoid ligament?
Correct Answer & Explanation
. 4.5 cm medial to the distal clavicle articular surface and posteriorly
Explanation
The conoid ligament inserts approximately 4.5 cm medial to the distal articular end of the clavicle and slightly posterior to the midline. The trapezoid ligament inserts approximately 3.0 cm medial to the distal clavicle and anteriorly.
Question 58
Topic: Upper Extremity Trauma
A 30-year-old cyclist falls directly onto the point of his shoulder. Clinical examination reveals an irreducible, posteriorly displaced clavicle that is firmly palpable within the trapezius muscle belly. Radiographs, including an axillary lateral view, confirm the distal clavicle is displaced posteriorly relative to the acromion. Which Rockwood classification type does this injury represent?
Correct Answer & Explanation
. Type IV
Explanation
A Rockwood Type IV injury is characterized by posterior displacement of the distal clavicle into or through the deltotrapezial fascia. This is an absolute indication for operative reduction and fixation, as closed reduction is generally unsuccessful.
Question 59
Topic: Upper Extremity Trauma
A 50-year-old male presents with an intra-articular distal humerus fracture. The surgeon elects to perform an olecranon osteotomy for maximal articular exposure. Which type of olecranon osteotomy provides the highest inherent biomechanical stability upon repair?
Correct Answer & Explanation
. Chevron osteotomy with the apex pointing distally
Explanation
A chevron osteotomy with the apex pointing distally is preferred for olecranon osteotomies because it provides excellent inherent rotational and translational stability upon reduction. This osteotomy is typically performed at the bare area of the greater sigmoid notch.
Question 60
Topic: Upper Extremity Trauma
When performing a paratricipital (Alonso-Llames) approach for a distal humerus extra-articular fracture, which of the following best describes the management of the triceps mechanism?
Correct Answer & Explanation
. The triceps is elevated off the posterior humerus and retracted medially and laterally
Explanation
The paratricipital approach leaves the triceps insertion intact while creating windows on the medial and lateral borders of the triceps. The triceps muscle belly is elevated off the posterior humerus, allowing visualization of the extra-articular distal humerus.
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