The acromioclavicular (AC) joint is located at the top of the shoulder, connecting the collarbone (clavicle) to the acromion of the shoulder blade. This connection is stabilized by the acromioclavicular and coracoclavicular ligaments. An AC joint sprain, often called a shoulder separation, occurs when these ligaments are stretched or torn, usually resulting from a direct blow to the shoulder or a fall onto an outstretched hand. Healing time depends highly on the extent of the ligament damage, which is assessed through a standardized grading system.
Grading AC Joint Injuries
AC joint injury severity is classified using the six-grade Rockwood classification, though grades I, II, and III are the most common. Grade I is the mildest form, involving only a stretch or partial tear of the acromioclavicular ligament without bone displacement. This injury presents with localized pain and tenderness.
A Grade II injury involves a complete tear of the acromioclavicular ligament and a partial tear of the coracoclavicular ligaments. This allows for some upward movement of the collarbone, creating a small, visible bump on the shoulder. Grade III is a complete separation where both the acromioclavicular and coracoclavicular ligaments are completely torn. This results in significant displacement of the collarbone, sitting higher than the acromion.
Non-Surgical Recovery Timelines
Most AC joint injuries (Grades I, II, and many Grade III cases) are managed without surgery, allowing ligaments to heal naturally. Non-surgical recovery is divided into three phases, with timelines varying based on the initial injury grade.
The acute phase focuses on pain management and protection, lasting between one and two weeks. For a Grade I sprain, this initial phase constitutes the entire recovery, with a return to light activity possible within one to three weeks. Treatment involves rest, ice application, and a brief period of immobilization in a sling.
The subacute phase focuses on restoring passive and active range of motion. For a Grade II injury, initial immobilization may last up to three weeks, with a full return to function taking four to six weeks. Conservatively treated Grade III injuries require a longer period of protection, needing a sling for three to four weeks before beginning range-of-motion exercises.
The final stage is the strengthening phase, extending from six to twelve weeks post-injury, depending on severity. Full recovery and return to sport for Grade II and Grade III separations requires six to twelve weeks. This phase focuses on exercises that stabilize the shoulder blade and strengthen surrounding musculature to regain full, pain-free function and ensure stability before resuming heavy lifting or contact activities.
Surgical Treatment and Extended Healing
Surgery is reserved for the most severe injuries (Grade IV, V, and VI separations) and for certain Grade III cases that do not respond to conservative treatment or occur in high-demand athletes. These higher-grade injuries involve extreme displacement of the collarbone and require surgical stabilization to restore proper joint alignment.
Recovery following AC joint surgery is longer and more structured than non-surgical management. The initial post-operative period requires strict immobilization, often in a sling, for four to six weeks to protect the repaired ligaments and allow for tissue healing. During this time, the patient is restricted to passive or minimal active range-of-motion exercises.
Structured physical therapy dominates the subsequent months, beginning with regaining motion and progressing to intense strengthening. The full post-operative recovery timeline to achieve near-maximal function spans four to six months. A complete return to heavy overhead work, contact sports, or activities that place significant stress on the shoulder may require six to twelve months, depending on individual progress and procedure complexity.
Variables Affecting Recovery Speed
While the injury grade provides the primary framework for recovery, several individual factors influence healing speed. Age is a significant determinant, as younger patients experience a faster healing rate due to increased cellular activity and tissue regeneration capacity.
Adherence to the prescribed physical therapy protocol is a major variable, as consistent execution of exercises is necessary to restore strength and range of motion efficiently. Skipping therapy sessions or attempting to progress too quickly can lead to setbacks, chronic pain, or instability.
A person’s overall health status plays a role, with factors such as nutrition and smoking cessation supporting better tissue repair. The specific demands of a patient’s daily life or sport also dictate the practical recovery duration. An individual with a sedentary job may feel fully recovered sooner than an overhead athlete, such as a baseball pitcher or construction worker, who must achieve a high level of strength and stability.