A “separated shoulder” is a common injury, particularly among physically active people, resulting from trauma to the upper shoulder structure. This injury is fundamentally different from a dislocated shoulder, which involves the ball-and-socket joint. A separation affects a different joint entirely, requiring distinct treatment protocols. Understanding the specific nature of a separated shoulder is the first step toward effective treatment and recovery.
Understanding the AC Joint and Separation
A separated shoulder refers specifically to damage involving the acromioclavicular (AC) joint, located at the very top of the shoulder. This joint connects the clavicle (collarbone) to the acromion, a bony projection of the scapula (shoulder blade). The AC joint is stabilized by two sets of ligaments that hold these bones in alignment.
The acromioclavicular ligaments span the joint directly. The stronger coracoclavicular (CC) ligaments connect the clavicle to the coracoid process, another part of the shoulder blade. The AC joint provides stability to the entire shoulder complex, allowing for a wide range of motion, especially when lifting the arm overhead.
A “separation” occurs when these stabilizing ligaments are stretched or torn, causing the clavicle to move out of its normal position relative to the acromion. The severity depends on which ligaments are damaged and the extent of the tear. This disruption can significantly limit movement and cause pain.
Common Causes and Immediate Symptoms
The most frequent cause of an AC joint separation is a traumatic event, most commonly a direct blow to the top of the shoulder. This often occurs during a fall onto the “point” of the shoulder, especially when the arm is tucked in, such as falling from a bicycle, being tackled in contact sports, or slipping on ice.
Immediate and acute pain at the top of the shoulder is the primary symptom following the injury. This pain is often accompanied by swelling and bruising around the AC joint area. Tenderness is felt when pressing directly on the joint itself.
A visible deformity signals a more severe separation, where the end of the collarbone appears raised. This “bump” occurs because the damaged ligaments allow the clavicle to displace upward. The affected arm may also be held close to the side to prevent painful outward movement.
Classifying the Severity of the Injury
The severity of an AC joint separation is determined using a standard medical classification system, ranging from Grade I to Grade VI. Grades I through III are the most common. This grading is based on the extent of ligament damage and the degree of clavicle displacement, which guides the appropriate treatment pathway.
A Grade I injury represents a mild sprain where the AC ligaments are stretched but remain intact, resulting in minimal instability. There is no significant displacement of the clavicle, and the pain is mild.
A Grade II separation involves a partial or complete tear of the AC ligaments, with only a sprain or partial tear of the stronger CC ligaments. This grade shows a slight separation and a noticeable bump, but the clavicle remains partially contained.
A Grade III injury signifies a complete tear of both the AC and the CC ligaments. This results in significant upward displacement of the clavicle and a prominent, visible bump on the shoulder. Higher-grade separations (IV, V, and VI) involve even greater displacement or displacement in other directions and are much less common.
Diagnosis is confirmed through X-rays, which visualize the alignment of the bones. Imaging of both the injured and uninjured shoulders is often performed for comparison. While stress views (where the patient holds a weight during the X-ray) are sometimes used to evaluate instability, this practice is not universally recommended due to patient discomfort.
Treatment Pathways and Rehabilitation
Treatment for an AC joint separation is dictated by the determined grade of the injury. Non-surgical management is the standard approach for the majority of separations, specifically Grades I, II, and most Grade III injuries. This conservative treatment focuses on pain relief and protecting the joint while the ligaments heal.
Initial treatment involves rest, applying ice, and pain management with non-steroidal anti-inflammatory drugs (NSAIDs). A sling is often used for a short period, typically a few days up to four weeks, to immobilize the arm and provide comfort. The goal is to discontinue the sling as soon as the acute pain subsides to prevent shoulder stiffness.
Physical therapy is a key component of recovery, beginning with gentle range-of-motion exercises shortly after the injury. For Grade I and II injuries, a full recovery and return to sports can often be expected within a few weeks once full strength is regained. The rehabilitation program progresses to include strengthening exercises, focusing on the muscles surrounding the shoulder blade for stability.
Surgical intervention is reserved for high-grade separations (Grade IV, V, and VI) or chronic Grade III injuries resulting in persistent instability or pain. These procedures aim to reconstruct or repair the torn ligaments, restoring the correct alignment of the clavicle. Even with surgery, a comprehensive rehabilitation program is necessary, and full functional recovery can take 6 to 12 weeks or longer.