A noticeable bump on the shoulder often signals an acromioclavicular (AC) joint separation, commonly called a shoulder separation. This joint is where the collarbone (clavicle) meets the highest point of the shoulder blade (acromion). A separation occurs when the stabilizing ligaments are stretched or torn, allowing the clavicle to push upward. This creates the characteristic bulge, and its visibility relates directly to the severity of the underlying ligament damage.
Conservative Management of the AC Joint Injury
The initial approach to managing an AC joint injury focuses on reducing pain and inflammation while allowing damaged ligaments to heal. For the majority of AC separations, non-surgical treatment is the preferred method. This approach aims to restore full shoulder function, even if a minor bump remains.
Immediate care involves rest and immobilization, typically using a sling to support the arm and take pressure off the injured joint. Applying ice to the area for 15 to 20 minutes several times a day helps manage acute pain and swelling. Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen are frequently recommended to reduce discomfort and inflammation.
Once the initial acute pain subsides (which can take several weeks), the focus shifts to a structured physical therapy (PT) program. PT is crucial for conservative management, ensuring the shoulder regains its full range of motion and strength. The rehabilitation program begins with gentle, passive exercises to prevent stiffness, gradually progressing to active exercises that strengthen surrounding muscles.
The goal of this phase is to stabilize the shoulder girdle through muscle conditioning, compensating for any remaining ligamentous laxity. Patients are advised to avoid heavy lifting and activities that stress the joint until they achieve a pain-free range of motion. Depending on the injury’s grade, a full return to activity can take anywhere from two weeks to three months.
Factors Determining If the Bump Remains
Whether the physical bump disappears or persists depends on the extent of ligamentous damage sustained during the initial injury. Medical professionals classify AC joint separations using a grading system to describe the severity of the trauma. The key ligaments involved are the acromioclavicular (AC) ligaments and the stronger coracoclavicular (CC) ligaments, which anchor the collarbone to the coracoid process.
In a Grade I separation, the AC ligaments are only stretched or mildly sprained, and the joint remains aligned. The initial bump is usually temporary swelling that resolves as inflammation subsides, allowing the joint to return to its normal appearance. A Grade II separation involves a complete tear of the AC ligaments and a sprain or partial tear of the CC ligaments.
With a Grade II injury, the clavicle is slightly displaced upward, and a small, noticeable bump often remains permanently, though it may lessen as surrounding tissues heal. The displacement causes the shoulder blade and arm to drop slightly, making the clavicle’s end appear more prominent. This permanent visual change rarely affects the long-term function of the shoulder.
Grade III separations and higher grades involve a complete tear of both the AC and CC ligaments, leading to significant upward displacement of the clavicle. This loss of ligamentous support results in a permanent, pronounced bump or deformity on the shoulder. Even with successful conservative treatment, the clavicle stabilizes in this elevated position, and the aesthetic appearance does not change. For Grades IV, V, and VI, which involve extreme displacement, the large bump is a permanent fixture unless surgical intervention is pursued.
Surgical Options for Joint Reshaping
For injuries resulting in a significant, permanent bump or causing persistent pain and instability after conservative treatment, surgical intervention may be considered. Surgery is typically indicated for high-grade injuries (Grades IV through VI) and sometimes for Grade III injuries in highly active individuals or those who perform heavy overhead work. The primary goal is to stabilize the joint and anatomically reduce the clavicle’s displacement, directly addressing the visual bump.
One common surgical approach involves fixation, where hardware like plates, screws, or strong sutures temporarily hold the clavicle in its correct position. A frequently employed technique is coracoclavicular (CC) fixation, which uses a suture loop or button device to secure the clavicle to the coracoid process. This fixation holds the joint in place while surrounding ligaments heal or while a more permanent reconstruction is performed.
Another option is ligament reconstruction, which uses a graft or synthetic materials to replace the completely torn CC ligaments. This approach is often paired with a distal clavicle resection, where a small portion of the clavicle’s end is removed to prevent bone-on-bone contact and reduce the risk of future arthritis. These reconstructive procedures aim to provide long-term stability and restore the shoulder’s natural contour by pulling the clavicle back into alignment, significantly reducing the visual prominence of the bump.