AC Joint Injuries
AC joint injuries refer to damage to the acromioclavicular joint, which is the small joint at the top of the shoulder where the collarbone meets the shoulder blade. This joint helps connect the arm to the body and allows smooth shoulder movement. Injuries occur when the ligaments that stabilize this joint are stretched, partially torn, or completely torn.
These injuries are often called shoulder separations. They range from mild sprains to severe dislocations, depending on the extent of ligament damage. At Orthopedic Associates of Northern California, evaluation focuses on identifying the severity of the injury and creating a treatment plan tailored to the patient’s activity level and goals.
What are the symptoms of an AC joint injury?
Symptoms can vary depending on the grade of the injury, making proper evaluation important for appropriate care. Common symptoms of AC joint injuries include:
- Pain at the top of the shoulder, especially after a fall or direct impact
- Pain that worsens when lifting the arm across the body or raising it overhead
- In mild cases, pain may be present only during certain movements, while in severe cases, pain can be constant and significant
- Difficulty with daily activities such as dressing, lifting objects, or sleeping on the injured side may become difficult
- Swelling, bruising, and tenderness over the joint
- In more severe injuries, a raised or deformed joint
- In some cases, a reduced range of motion and weakness in the affected shoulder.
What are the causes of AC joint injuries?
AC joint injuries are most commonly caused by a direct blow to the shoulder or a fall onto the tip of the shoulder. This is common in sports such as football, hockey, cycling, and skiing. Accidents such as motor vehicle collisions or workplace falls can also lead to these injuries.
In all these cases, the force drives the shoulder blade downward while the collarbone stays in place, stressing or tearing the stabilizing ligaments.
Repetitive overhead activity may contribute to irritation in some cases, although acute trauma is the primary cause. The severity depends on the force of impact and the position of the arm at the time of injury. Younger, active individuals are more likely to experience these injuries due to participation in contact or high risk sports.
What are the risks for an AC joint injury?
Certain factors can increase the likelihood of AC joint injuries including:
- Participation in contact sports or high impact activities raises the risk due to frequent falls and collisions
- Lack of protective equipment or poor technique during sports can also contribute
- Individuals with a history of previous shoulder injuries may be more susceptible to reinjury because the joint may be less stable
- Aging can increase risk slightly as ligaments become less flexible, although these injuries are more common in younger, active people
- Occupational risks include jobs that require repetitive lifting, overhead work, or manual labor
- Environmental hazards such as slippery surfaces or uneven terrain can also increase the chance of falls leading to injury
How is an AC joint injury diagnosed?
AC joint injuries are diagnosed through a combination of physical examination and imaging tests. Accurate diagnosis is important to distinguish AC joint injuries from other shoulder conditions such as rotator cuff tears or fractures.
Your Orthopedic specialist will discuss with you how the injury occurred and assess symptoms. During the exam, the shoulder is checked for tenderness, swelling, deformity, and range of motion. Specific movements may be used to identify pain patterns and instability.
X-rays are commonly used to determine whether the collarbone is displaced and to classify the severity of the separation. In some cases, additional imaging such as MRI or ultrasound may be used to evaluate soft tissue damage and ligament injuries.
Following diagnosis, your clinician at Orthopedic Associates of Northern California will review the severity of the injury and discuss treatment options based on the patient’s lifestyle and functional needs.
When you or a loved one suffers an acute injury to your shoulder it is important to seek professional evaluation. Contact Orthopedic Associates of Northern California to schedule a consultation and discover compassionate and thorough care. Don’t wait. Early and accurate diagnosis helps guide appropriate care and may reduce the risk of long term pain or instability.
