AC Joint Injuries Surgical Treatment

Surgery is recommended for patients who have:

• Type IV injuries: The collarbone displaced backward through the trapezius, which does not reduce and does not heal in position.
• Type V injuries: Marked vertical displacement with the deltotrapezial fascia stripped off, where the soft tissue envelope that would otherwise support healing is disrupted.
• Type VI injuries: The rare pattern with the collarbone displaced beneath the coracoid.
• Type III injuries that have failed nonoperative treatment: Persistent pain or functional limitation at three to six months despite a well-executed scapular program.
• Type III injuries with horizontal instability: Noticeable forward and backward shifting of the collarbone, which predicts a poorer nonoperative result.
• Selected type III injuries in high-demand patients: Overhead athletes and heavy laborers, individualized after a candid discussion of the evidence.
• Chronic symptomatic separations: Patients years out from the original injury with ongoing pain, fatigue, or scapular dysfunction.

A visible bump alone, in a patient with full function and no pain, is not an indication for surgery. Dr. Rynecki Baker says this plainly, because the deformity is what most often prompts patients to ask about an operation.

Within roughly the first three to six weeks, the torn coracoclavicular ligaments are still capable of healing. An operation in that window restores the collarbone to its correct position and holds it there with a fixation construct while the patient’s own ligaments heal, and no graft is required. This is a smaller operation with a more reliable result.

Beyond that window, the ligaments have scarred and shortened, and holding the joint reduced with fixation alone is no longer enough. Chronic injuries require reconstruction of the ligaments with a graft, which is a larger procedure. This is the reason a type V mistaken for a type III has real consequences, and why Dr. Rynecki Baker obtains comparison and axillary views at the first visit rather than after a failed trial of a sling.

Arthroscopic-Assisted Coracoclavicular Fixation

The most common approach for acute high-grade injuries. Through small incisions, a suture button construct is passed from the underside of the coracoid up through the collarbone, holding the reduction while the ligaments heal. The arthroscopic approach allows accurate placement on the coracoid under direct vision and permits assessment of the joint for associated injuries, which are present in a meaningful proportion of these patients. It avoids a second operation to remove hardware.

Anatomic Coracoclavicular Ligament Reconstruction

The standard for chronic injuries and for revision cases. A graft, typically a donor tendon, is passed around the collarbone and around the coracoid to reproduce the conoid and trapezoid ligaments at their anatomic positions. It is often combined with a suture button construct, which protects the graft.

Reconstruction with AC Capsular Augmentation

Because horizontal instability is increasingly recognized as a cause of persistent symptoms after otherwise successful vertical stabilization, the AC joint capsule itself may be repaired or augmented at the same time. Patients with prominent forward and backward shifting of the collarbone are specifically assessed for this, since addressing vertical displacement alone can leave them symptomatic.

Hook Plate Fixation

A plate that sits on the collarbone with a hook passing beneath the acromion, holding the reduction rigidly. It provides strong fixation, allowing the ligaments to approximate, and is useful in selected cases, particularly with associated distal clavicle fracture, but it requires a second operation to remove the plate once healing has occurred, and it can irritate the underside of the acromion while in place.

Distal Clavicle Excision as an Adjunct

When a chronic separation has produced arthritis of the joint itself, or when pain is localized to the joint rather than to the instability, a small amount of the end of the collarbone may be removed alongside the reconstruction. This is done selectively and conservatively, since removing bone from a joint being stabilized can work against the reconstruction if it is overdone.

Recovery after AC joint stabilization is deliberately protective, because the weight of the arm pulls directly on the reconstruction.

• Sling use: A sling is worn for approximately six weeks, supporting the arm so its weight does not load the construct.
• Motion: Passive motion begins early within a protected range, with elevation typically limited below shoulder height for the first six weeks and cross-body reaching avoided.
• Progression of motion: Active motion and full elevation from around six weeks, with full range generally restored by three months.
• Strengthening: Scapular and rotator cuff strengthening begin at around six to eight weeks, progressing through the third and fourth months.
• Lifting and pressing: Deferred until around three months, reintroduced gradually with attention to grip width and range.
• Return to sport: Non-contact activity generally at three to four months; contact and collision sport at approximately six months, once healing is confirmed and strength has been restored.