AC Joint Injury Overview
An injury to the acromioclavicular (AC), commonly known as a separated shoulder or a shoulder separation is quite common and is usually caused from direct trauma to the shoulder, such as a hard fall or blunt force during sports. An AC joint injury can result in a shoulder separation or any level of shoulder sprain, all leading to AC joint pain. Sports medicine specialist and orthopedic surgeon, Dr. Nikhil Verma, shoulder specialist, can help patients living in the Chicago, Westchester, Oak Brook and Hinsdale, Illinois communities remain active after experiencing an injury to the AC joint.
The AC joint is the location where the clavicle (collarbone) meets the highest point of the shoulder blade (acromion). The joint is held together by multiple ligaments and the ends of the bone are wrapped in cartilage to allow joint movement.
AC joint injuries cause damage to the ligaments and cartilage at some level. An AC joint injury is measured in multiple grades, Grade 1 through Grade 6. Grade 1 represents mild shoulder pain with no shoulder deformity. Grade 6 represents a complete disruption of the ligament, such as a separated shoulder where the clavicle is completely severed inferiorly. Grades 4, 5 and 6 AC shoulder separations are very rare and may cause extreme AC joint pain, deformity and shoulder instability.
Symptoms of an AC Joint Injury
An AC joint injury is marked by AC joint pain following injury, ranging from mild tenderness to intense, sharp pain. This is typically felt on top of the shoulder and bruising may occur. In many higher grade cases, patients may experience a popping sensation, visible deformity, swelling and bruising.
Diagnosis of a Separated Shoulder
A separated shoulder can be easy to diagnose when it causes deformity to the joint. When there is less deformity in the lower grade cases, a physical examination must be performed by Dr. Verma to locate the area of AC joint pain and discomfort. X-rays and an MRI may be utilized to determine the grade of injury, assess what ligaments are damaged and ensure there is no shoulder fracture.