Grade 1 AC Joint Separation
A grade 1 separation is the mildest form of this injury and the one most likely to be shrugged off. The ligaments surrounding the acromioclavicular joint are stretched rather than torn, nothing has shifted out of position, and an X ray looks entirely normal. What the patient has is a sore shoulder after a fall, and in most cases that is exactly what it turns out to be.
Steven Struhl, MD is board certified in orthopedic surgery and separately in sports medicine and has practiced in New York since 1991. Most grade 1 injuries he sees need reassurance and a short period of rest rather than treatment, and saying so plainly is part of the job.
What Happens in a Grade 1 Separation
The AC ligaments, the small ligaments wrapping the joint itself, are stretched and microscopically damaged. The coracoclavicular ligaments running from the collarbone down to the shoulder blade are completely intact, which is why the collarbone stays exactly where it belongs and the joint remains stable.
- AC Ligaments: stretched and mildly damaged but not torn through.
- CC Ligaments: entirely intact, holding normal alignment.
- Displacement: none, with imaging appearing normal.
- Joint Stability: preserved, with no instability on examination.
Grade 1 AC Separation Symptoms
- Point Tenderness: soreness located precisely at the top of the shoulder over the joint.
- Mild Swelling: modest swelling without visible deformity or a bump.
- Pain With Reaching: discomfort bringing the arm across the body or overhead.
- Full Motion: range of motion is preserved, though the end of the range may be sore.
Grade 1 AC Separation Treatment and Recovery
- Short Sling Use: a few days of support for comfort, not for healing.
- Ice And Anti Inflammatories: managing the acute inflammation in the first week.
- Early Motion: gentle movement resumed quickly to prevent stiffness.
- Gradual Return: most patients resume normal activity within two to three weeks.
Grade 1 injuries do not require surgery and do not develop into higher grades on their own. The one thing worth watching is a shoulder that is not steadily improving, since a persistent ache past a few weeks sometimes means the original grade was underestimated on a single standard film.
Frequently Asked Questions About Grade 1 AC Separations
- Most resolve within two to three weeks, with the sharpest pain settling in the first week. A short period of sling use is for comfort rather than healing, and returning to gentle motion early helps rather than hurts.
- No. The visible bump associated with this injury comes from the collarbone displacing upward, which requires the coracoclavicular ligaments to tear. In a grade 1 those ligaments are intact, so the shoulder keeps its normal contour.
- Not by itself. Ligament damage does not progress without a new injury. What can change is the recorded grade, if the original assessment came from a single X ray that understated the displacement.
- Most patients return within two to three weeks once pain has settled and full strength has returned. Contact sport is worth delaying until the shoulder tolerates direct pressure comfortably, since a second impact on a healing joint can produce a more significant injury.
Schedule an AC Joint Evaluation in New York City
Most grade 1 separations need time rather than treatment, and hearing that from a surgeon who reconstructs the severe ones carries more weight than hearing it from a search result. Contact our office at (212) 207-1990 in New York City or (914) 328-4111 in Westchester if the shoulder is not improving as expected.
