Joseph Norris, MD
Orthopedic Surgeon Sports Medicine
Home Patient Info AC Separation

AC Separation

AC Separation (“Shoulder Separation”)

AC SeparationDefinition

  • An acromioclavicular (AC) joint separation is when the clavicle (collar bone) separates or dislocates from the acromion
  • This is commonly referred to as a "separated shoulder"


  • Most commonly occurs in younger patients (ages 12-25), especially males, but can occur in anyone
  • Most commonly results from a direct blow or fall on the shoulder
  • Patients that play contact sports like football, rugby, lacrosse are at higher risk


  • There are 6 types of AC separations, with I-III being the most common

AC SeparationType I – Minimal to no displacement (sprain), with pain to palpation (touch) over the AC joint (most common)

Type II- Partial separation with complete tear of the acromioclavicular (AC) ligament wit intact coracoclavicular ligaments

Type III- Complete tear of the AC ligament with partial tear or sprain of the coracoclavicular ligaments, a small defect or bump may be seen on physical exam

Type IV- Complete tear of the AC ligament with complete tear of the coracoclavicular ligaments and posterior displacement of clavicle

Type V- Complete tear of AC and coracoclavicular ligaments with 100% displacement superiorly just under the skin

Type VI- Complete tear of the AC and coracoclavicular ligaments with displacement inferiorly under the coracoids (not very common)


  • Treatment for an AC separation is usually non-surgical
  • For grades I-III, patient is usually in a sling for a few days to a week until pain subsides, anti-inflammatories and then start using the arm to gain function and motion
  • These patients usually return to sport when they are pain free and have regained full strength (2-4 weeks depending on severity)
  • Grades IV-VI which are less common, usually are treated surgically with a coracoclavicular reconstruction
  • Patients are usually immobilized for a period of 3-4 weeks and then begin therapy for range of motion which is 3-4 weeks and then strengthening which is another 3-4 weeks
  • Altogether, surgical repair is anywhere from a 3-6 month recovery
  • Patients who suffer a grade II or higher AC separation may notice a "bump" or prominence that usually will not go away, and that is normal
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