A 45-year-old construction worker presents to the emergency department after falling from scaffolding and landing on his outstretched right arm. He reports severe shoulder pain and inability to move his arm. Which assessment finding would be most indicative of an anterior shoulder dislocation?
1Flattened deltoid muscle contour with the arm held in internal rotation and adduction
2Prominent acromion process with the arm positioned in external rotation
3Loss of normal rounded shoulder contour with the arm held in slight abduction and external rotation✓ 정답
4Visible deformity at the acromioclavicular joint with arm adducted against the body
해설
Anterior shoulder dislocation typically presents with loss of normal rounded shoulder contour and the arm held in slight abduction and external rotation. Other findings like flattened deltoid or acromioclavicular deformity are more characteristic of other injuries.
Core Nursing ExplanationKey Concept Analysis: This question tests your ability to differentiate the classic physical presentation of an Anterior shoulder dislocation from other shoulder injuries. The mechanism of injury—a fall on an outstretched arm—is a classic cause. In an anterior dislocation, the humeral head is forced out of the glenoid fossa and comes to rest anteriorly and inferiorly to the coracoid process. This displacement causes the characteristic deformity and arm position.
Answer Rationale: Key Point! The correct answer is ③ Loss of normal rounded shoulder contour with the arm held in slight abduction and external rotation. This is the hallmark sign. The "loss of rounded contour" is due to the empty glenoid fossa, creating a "squared-off" appearance. The arm is held in a protective, slightly abducted and externally rotated position because any attempt at internal rotation or adduction would be extremely painful, as it would engage the dislocated humeral head against the anterior structures.
Distractor Analysis:
① Flattened deltoid muscle contour with the arm held in internal rotation and adduction: This description is more suggestive of a Watch out for confusion!Posterior shoulder dislocation, a much rarer injury often caused by seizures or electric shock, where the arm is held fixed in internal rotation and adduction.
② Prominent acromion process with the arm positioned in external rotation: A prominent acromion can be seen in both anterior and posterior dislocations due to the loss of the humeral head beneath it. However, the arm in external rotation is specific to anterior dislocation. This option is partially correct but incomplete; it misses the key feature of the "loss of normal rounded contour," which is a more definitive visual indicator.
④ Visible deformity at the acromioclavicular (AC) joint with arm adducted against the body: This is the classic presentation of an Watch out for confusion!Acromioclavicular joint separation (often called a "shoulder separation"), not a glenohumeral (shoulder) dislocation. The deformity is a "step-off" at the AC joint, and the arm is often held adducted to relieve tension on the torn ligaments.
Related Concepts: Always assess neurovascular status (sensation, capillary refill, radial pulse) distal to any dislocation before and after reduction, as the axillary nerve and brachial plexus are at risk in anterior dislocations. The mechanism of injury (fall on outstretched hand - FOOSH) is also common for fractures like the Colles' fracture of the wrist.
Concept Summary
Injury
Mechanism
Key Physical Finding
Arm Position
Anterior Shoulder Dislocation
Fall on outstretched arm (FOOSH), forced abduction/external rotation
Loss of rounded contour ("squared-off" shoulder), palpable hollow under acromion
Slight abduction, external rotation
Posterior Shoulder Dislocation
Seizure, electric shock, direct blow to front of shoulder
Flattened anterior deltoid, prominent coracoid process
Adducted, internally rotated (fixed)
AC Joint Separation
Fall directly onto point of shoulder
"Step-off" deformity at AC joint, piano key sign
Arm held adducted against body for support
Side-by-Side Comparison!
Assessment Focus
Anterior Dislocation
Posterior Dislocation
AC Joint Separation
Visual Clue
Squared-off shoulder
Flattened anterior deltoid
Bump/step at top of shoulder
Arm Position
Abducted, Externally Rotated
Adducted, Internally Rotated
Adducted (arm cradled)
Common Cause
FOOSH, sports injury
Seizure, electrocution
Direct fall on shoulder
Joint Involved
Glenohumeral joint
Glenohumeral joint
Acromioclavicular joint
Anatomy, Physiology & Pharmacology Points
Anatomy: The shoulder is a ball-and-socket joint (glenohumeral joint) with great mobility but inherent instability. The humeral head (ball) sits in the shallow glenoid fossa (socket). Anterior dislocations often involve damage to the Bankart lesion (tear of the labrum) and the Hill-Sachs lesion (impaction fracture of the humeral head).
Neurovascular Risk: The Axillary nerve wraps around the surgical neck of the humerus and is the most commonly injured nerve. Assess sensation over the "regimental badge" area (lateral deltoid).
Pharmacology: Reduction (putting the joint back in place) often requires procedural sedation and analgesia (e.g., midazolam and fentanyl) or intra-articular local anesthetic.
Memory Tips
Anterior Dislocation A-B-E: Arm is held in Abduction and External rotation. The shoulder looks Boxy (squared-off).
Posterior Dislocation from a Seizure: Think "P" for Posterior and "P" for seizure (from the French "mal de Parkinson" is a mnemonic, but the link is "P"). The arm is locked in adduction and internal rotation.
AC Separation: Think of a "separated" shirt seam at the shoulder. The bump is visible at the very top where the collarbone meets the shoulder blade.
High-Frequency NCLEX Topics
The NCLEX loves to test differentiation of musculoskeletal injuries based on mechanism and presentation. Anterior shoulder dislocation is a classic. Be prepared for questions that ask for the priority nursing action (e.g., "assess neurovascular status") or the patient education after reduction (e.g., immobilization, avoiding certain movements, signs of complications).
Watch Out for Question Variations!
Priority Assessment: "The nurse's priority assessment for a patient with a suspected anterior shoulder dislocation is:" Answer: Neurovascular status of the affected limb.
Post-Reduction Care: "Following a closed reduction of an anterior shoulder dislocation, the nurse should instruct the patient to:" Answer: Wear the immobilizer/sling as directed, avoid external rotation and abduction, and report numbness or tingling immediately.
Complication Identification: "A patient with a reduced anterior shoulder dislocation reports numbness over the lateral upper arm. The nurse suspects injury to which nerve?" Answer: Axillary nerve.
Nursing Clinical Practice GuideClinical Scenario: You are the triage nurse in the ED. A 45-year-old male, John, is brought in by co-workers. He fell approximately 10 feet from scaffolding, landing on his right outstretched hand. He is cradling his right arm with his left, his face is pale and sweaty, and he reports 10/10 pain in his right shoulder. You observe an obvious deformity—his right shoulder looks "squared off" compared to the left.
Nursing Intervention Strategy:
Immediate Assessment (ABCs first, then focused): Ensure airway, breathing, and circulation are stable. Then, perform a focused musculoskeletal and neurovascular assessment.
Inspection: Note the squared-off contour, compare bilaterally.
Neurovascular Checks (Priority!):
Sensation: Lightly touch the skin over the lateral deltoid ("regimental badge area") to assess axillary nerve function. Check sensation in the entire hand (radial, median, ulnar nerve distributions).
Motor: Ask patient to gently wiggle his fingers. Do NOT ask him to move his shoulder or elbow.
Circulation: Palpate the radial pulse. Assess capillary refill in the fingernails. Check skin color and temperature.
Pain Management: Administer prescribed analgesics (often IV opioids) as ordered. Anticipate the need for sedation prior to reduction.
Immobilization & Preparation: Support the arm in its current position of comfort (slight abduction/external rotation) with pillows or a sling. Assist with obtaining X-rays (usually AP and Y-view or axillary lateral) to confirm dislocation and rule out associated fractures.
Post-Reduction Care: After the physician performs the reduction (e.g., using traction-countertraction or Stimson technique), re-assess neurovascular status. Apply a shoulder immobilizer or sling. Provide discharge education.
Patient Safety and Precautions:
Never attempt to reduce the dislocation yourself. This is a physician/advanced practitioner procedure.
Continuous monitoring of neurovascular status is critical before and after reduction. Compromise can occur from the injury itself or from the reduction maneuver.
Post-reduction, the shoulder is unstable. Educate the patient to avoid movements that could cause re-dislocation, particularly abduction and external rotation.
Nursing Procedure & Medication FlowPre-Reduction:
Establish IV access.
Administer procedural sedation/analgesia as ordered (e.g., midazolam for sedation, fentanyl for pain). Monitor respiratory status and oxygen saturation closely with pulse oximetry.
Position patient as directed for the reduction technique (often supine).
Post-Reduction & Discharge:
Apply immobilizer (sling and swath or shoulder immobilizer) to maintain the arm in internal rotation and adduction.
Reinforce education: Wear immobilizer at all times as prescribed (typically 1-4 weeks), ice the shoulder for 15-20 minutes several times a day for swelling/pain, follow-up with orthopedics, begin gentle pendulum exercises only when cleared, and report signs of complications (increased pain, numbness, tingling, coolness, or discoloration of the hand) immediately.
A Word from Your Senior Nurse
"Musculoskeletal injuries like this are painful and scary for the patient. Your calm, systematic assessment is key. That neurovascular check isn't just a box to tick—it's how you catch a nerve or vascular injury early, which can prevent long-term disability. Remember, you're assessing the limb distal to the injury. And when you see that classic 'squared-off' shoulder, you can be confident in your assessment while providing compassionate care. In clinicals and on the NCLEX, always link the mechanism (FOOSH) to the likely injury, and let your nursing priorities (like neurovascular assessment) guide your actions."
Anterior Shoulder Dislocation — Displacement of the humeral head anteriorly out of the glenoid fossa, presenting with a squared-off shoulder and the arm held in slight abduction/external rotation.
Neurovascular Assessment — A priority nursing assessment checking circulation (pulse, color, temperature, capillary refill), sensation, and motor function distal to an injury or surgical site.
Axillary Nerve — A nerve susceptible to injury in anterior shoulder dislocations; assessed by checking sensation over the lateral deltoid muscle ("regimental badge area").
Acromioclavicular (AC) Joint Separation — A sprain or tear of the ligaments connecting the acromion and clavicle, causing a visible "step-off" deformity at the top of the shoulder.
Posterior Shoulder Dislocation — A rare dislocation where the humeral head is displaced posteriorly, often from seizures, presenting with a flattened deltoid and the arm fixed in adduction/internal rotation.