Sternoclavicular (SC Joint)

The sternoclavicular (SC) joint is a small but crucial structure in the upper body. It is a type of shoulder joint. Despite its size, it plays a vital role in connecting the shoulder girdle to the rest of the skeleton, providing support and mobility for a wide range of upper body movements. While injuries to this joint are relatively rare, they can be complex and challenging to treat. This blog will delve into the anatomy of the sternoclavicular joint, common injuries, treatment options, and the importance of proper rehabilitation.

Anatomy and Function of the Sternoclavicular Joint

The SC joint connects the clavicle (collarbone) to the sternum (breastbone) at the base of the neck. This joint is the only direct bony attachment between the upper limb and the axial skeleton, providing essential support and mobility for arm and shoulder movements.

1. Structure of the SC Joint

The Sternoclavicular joint is classified as a synovial saddle joint. It has an articular disc (fibrocartilage pad) between the clavicle and the sternum, which helps to enhance joint congruity, absorb shock, and enhance stability. The joint`s anatomy is designed to offer a broad range of motion in multiple planes, permitting the arm to move upward, backward, and rotate.

Key components of the SC joint encompass:

• Articular Disc: The fibrocartilage disc acts as a cushion, absorbing impact and assisting smooth movement.
• Joint Capsule: The SC joint capsule surrounds the joint and stabilizes it while allowing movement.
• Ligaments: Several ligaments aid the SC joint, including the costoclavicular, interclavicular, and sternoclavicular ligaments. These ligaments provide stability and prevent excessive movement.

2. Function and Movement

The SC joint allows 3 primary movements:

• Elevation and Depression: Upward and downward movements, vital for raising and lowering the shoulder.
• Protraction and Retraction: Forward and backward movements of the shoulder girdle, crucial for reaching and pushing.
• Rotation: Slight rotational movement of the clavicle occurs during arm elevation, allowing for smooth and coordinated shoulder movements.

Together, these movements make the SC joint essential for a wide range of shoulder and upper limb actions, permitting functional tasks like lifting, reaching, and pushing.

Common Injuries to the Sternoclavicular Joint

While injuries to the SC joint are less common than other shoulder injuries, they can be serious and are often associated with high-impact trauma, including in contact sports or car accidents.

1. Sternoclavicular Joint Sprains

SC joint sprains are the most common injuries to this joint. They are usually due to a direct blow or fall onto the shoulder. SC joint sprains are classified into three grades based on the severity of ligament damage:

• Grade I: Mild sprain with partial ligament damage but no joint instability.
• Grade II: Moderate sprain with more significant ligament harm and some joint instability.
• Grade III: Severe sprain involving complete ligament rupture, often resulting in joint dislocation.

Symptoms of an SC joint sprain include pain, swelling, and limited movement at the joint. A visible deformity may occur in more severe cases.

2. Sternoclavicular Joint Dislocation

Dislocations of the SC joint are rare but serious injuries that can be life-threatening if the dislocation is posterior. This is due to the risk of compressing or damaging nearby vital structures, including blood vessels, the trachea, and the esophagus.

SC joint dislocations can be either:

• Anterior Dislocations: The clavicle displaces forward, typically as a result of direct trauma or a fall on the shoulder. Anterior dislocations are more common and typically less risky than posterior ones.
• Posterior Dislocations: The clavicle displaces backward toward the chest, posing risks to nearby organs and blood vessels. Posterior dislocations require immediate medical attention.

Dislocations are usually accompanied by severe ache, swelling, and a visible deformity at the joint. In cases of posterior dislocation, additional signs like difficulty breathing, swallowing, or abnormal pulse may indicate compression of surrounding structures.

3. Degenerative Changes and Arthritis

Over time, the SC joint can develop degenerative changes or arthritis, particularly in older adults or individuals who carry out repetitive overhead activities. Symptoms of SC joint arthritis include pain, tenderness, and stiffness, mainly during movements that involve lifting the arm or reaching.

Diagnosis of Sternoclavicular Joint Injuries

Proper diagnosis of SC joint injuries involves a aggregate of clinical examination and imaging studies. During a clinical exam, a healthcare provider will assess for tenderness, deformity, and variety of movement.

Imaging Techniques:

• X-rays are often the first imaging method used to assess bone alignment, however they’ll not always provide clear images of the SC joint.
• CT Scans are considered the gold standard for evaluating SC joint dislocations, as they provide detailed images of both bone and surrounding structures, making it easier to assess posterior dislocations.
• MRI can provide information on soft tissue injuries, including ligament and cartilage damage, as well as signs of arthritis.

In cases of suspected posterior dislocation, prompt imaging is essential to determine the chance of injury to nearby organs and vessels.

Treatment Options for SC Joint Injuries

Treatment for SC joint accidents relies upon on the kind and severity of the harm. Most mild injuries can be managed conservatively, while severe injuries, particularly posterior dislocations, may require surgical intervention.

1. Non-Surgical Treatment

For most mild to moderate SC joint sprains and anterior dislocations, conservative treatment includes:

• Rest and Immobilization: Patients are often advised to use a sling or brace to help the arm and limit movement.
• Ice and Anti-Inflammatory Medications: Applying ice and taking NSAIDs can help to lessen swelling and pain.
• Physical Therapy: Once the pain has subsided, physical therapy is essential to repair strength, stability, and range of motion in the shoulder and upper body. Exercises focus on gradually increasing mobility, strengthening surrounding muscles, and preventing stiffness.

2. Surgical Treatment

Surgery is considered in cases of severe SC joint dislocation, specially for posterior dislocations or in cases wherein conservative treatment fails. Surgical options consist of:

• Closed Reduction: An attempt to manually realign the joint with out making an incision. This approach can be successful in some anterior dislocations.
• Open Reduction and Fixation: In cases of posterior dislocation or if closed reduction fails, an open reduction process can be necessary. This surgical operation realigns the joint and stabilizes it with screws, pins, or sutures.

Surgical intervention requires careful consideration due to the proximity of vital structures. Following surgery, a period of immobilization and a structured rehabilitation program are essential.

Rehabilitation and Recovery

Recovery from an SC joint injury depends on the severity of the injury and the treatment approach. Physical therapy is a cornerstone of the rehabilitation process, which typically progresses through several stages:

1. Initial Phase: Gentle, pain-free exercises to restore range of motion and prevent stiffness. This phase includes pendulum exercises and other passive movements.
2. Strengthening Phase: Once the range of motion is restored, strengthening exercises are introduced to improve stability around the SC joint and shoulder girdle. Resistance exercises targeting the rotator cuff, deltoids, and scapular muscles help enhance stability.
3. Advanced Functional Exercises: As strength and stability improve, patients can begin functional exercises that simulate daily activities, preparing them for a safe return to normal activities.

A gradual and progressive rehabilitation program is essential to prevent reinjury and ensure a full recovery.

Preventing Sternoclavicular Joint Injuries

While some SC joint injuries are caused by trauma and may not be preventable, there are steps that can reduce the risk, especially for individuals in contact sports or occupations requiring repetitive shoulder movements.

1. Strengthening Exercises: Building strength in the shoulder girdle, chest, and back muscles can provide added support to the SC joint.
2. Flexibility and Mobility Training: Maintaining flexibility in the shoulders and chest can reduce stress on the SC joint, making it less prone to injury.
3. Proper Technique: Using proper techniques in sports and lifting activities reduces the likelihood of SC joint injury.

Conclusion

The sternoclavicular joint, although small, plays a vital role in shoulder and upper limb function. Injuries to this joint, while uncommon, can significantly impact mobility and quality of life. A better understanding of the SC joint’s anatomy, types of injuries, and treatment options can help patients and healthcare providers approach these injuries with confidence and care. Whether through conservative management or surgical intervention, proper rehabilitation is key to a successful recovery and the prevention of future injuries.