AC Joint Separation
Widening or displacement at the acromioclavicular joint after shoulder trauma
AC joint separation means the acromioclavicular joint alignment is disrupted, usually after trauma to the shoulder.
An AC joint separation is an injury where the end of the collarbone and the acromion no longer line up normally. It often happens after a direct fall onto the shoulder.
Representative X-ray
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What it is
- This is a traumatic injury of the acromioclavicular and related supporting ligaments
- The severity can range from mild widening to major superior displacement of the clavicle
How it appears on chest X-ray
- On X-ray, the AC joint may look widened, the clavicle may sit higher than expected, and the coracoclavicular distance may increase in more severe injuries
What radiologists look for
- Radiologists assess joint widening, clavicle displacement, coracoclavicular distance, and whether there are associated fractures or other shoulder injuries
How X-ray helps
- X-ray helps confirm the alignment change and can support injury grading and orthopedic planning
Common causes
- The usual cause is a direct blow or fall onto the shoulder, including sports injury, bicycle crashes, and other trauma
Symptoms / associated symptoms
- Symptoms usually include shoulder pain, swelling, tenderness over the top of the shoulder, and pain with arm movement
Risk factors
- Risk factors include contact sports, falls, cycling trauma, prior shoulder injury, and high-impact activity
Why it can matter clinically
- Complications can include persistent pain, cosmetic deformity, chronic instability, arthritis, and reduced shoulder function
When to seek medical care
- Shoulder deformity, severe pain, reduced arm movement, or trauma with swelling should be evaluated promptly
Evaluation and diagnosis
- Evaluation includes trauma history, shoulder examination, radiographs, and in some cases orthopedic review for grading and management
Treatment approaches
- Treatment may include sling support, ice, pain control, rehabilitation, and orthopedic management, with surgery in selected severe cases
Medication classes clinicians may use
Medication supports pain control rather than correcting the joint alignment.
Treatment modalities commonly paired with medication decisions
- Sling immobilization
- Pain control
- Rehabilitation
- Orthopedic evaluation for higher-grade injury
Analgesics
Used for pain control after AC joint injury.
- acetaminophen
- ibuprofen
FAQ
Can X-ray confirm AC joint separation?
Yes. X-ray is commonly used to assess AC joint alignment and compare it with normal expected positioning.
Does every AC joint separation need surgery?
No. Many lower-grade injuries are treated without surgery, while higher-grade injuries may need orthopedic review for possible operative repair.