Clavicle Bone Fractures

A table summarizing the key points about clavicle fractures, including types, clinical presentations, diagnostic imaging, and management strategies:

Introduction

Clavicle fractures are common injuries, especially among young, active individuals, accounting for approximately 2.6-4% of all fractures in adults. The clavicle, or collarbone, is a long, S-shaped bone that connects the sternum to the scapula, providing support and stability to the shoulder girdle. Clavicle fractures can occur in different segments: the medial end, the midshaft, and the distal end. Each segment presents unique challenges in terms of diagnosis, management, and treatment. This article provides a comprehensive overview of clavicle fractures, covering their anatomy, types, clinical presentations, and the latest management strategies, particularly focusing on the nuances of surgical indications and techniques for orthopedic residents.

Anatomy of the Clavicle

The clavicle is a subcutaneous, S-shaped bone with two main ends:

• Medial End: Articulates with the sternum at the sternoclavicular joint.
• Lateral End: Connects to the scapula at the acromioclavicular joint.

The clavicle serves as a strut to keep the upper limb away from the thorax, allowing for maximum range of motion. Its unique curvature and subcutaneous position make it susceptible to fractures from direct trauma or falls onto an outstretched arm.

Types of Clavicle Fractures

1. Midshaft Clavicle Fractures: The most common type, accounting for about 75-80% of all clavicle fractures. These fractures usually occur due to direct trauma to the shoulder or a fall onto an outstretched hand. They can be further classified based on displacement and comminution:
   • Non-Displaced Fractures: Minimal or no gap between bone fragments.
   • Displaced Fractures: Bone fragments are separated, often with a shortening of the clavicle.
   • Comminuted Fractures: The bone is broken into multiple pieces.
2. Distal Clavicle Fractures: These account for 10-25% of clavicle fractures and often result from direct trauma to the shoulder. The classification of these fractures is crucial due to the involvement of coracoclavicular (CC) ligaments:
   • Type I: Fracture occurs lateral to the CC ligaments with minimal displacement.
   • Type IIA/IIB: Fractures involving the ligaments with significant displacement.
   • Type III-VI: Fractures involving intra-articular extensions or significant displacement.
3. Medial Clavicle Fractures: Rare, representing less than 5% of clavicle fractures. These fractures are often associated with high-energy trauma and can involve the sternoclavicular joint:
   • Anterior Displacement: The medial fragment is displaced anteriorly.
   • Posterior Displacement: The medial fragment is displaced posteriorly, posing a risk of injury to mediastinal structures.

Clinical Presentation

Clavicle fractures typically present with pain, swelling, and a visible deformity over the fracture site. Specific signs and symptoms vary depending on the fracture location:

• Midshaft Fractures: Swelling, tenderness, and deformity over the midshaft of the clavicle. The patient may exhibit guarding or reluctance to move the affected arm.
• Distal Fractures: Pain and swelling near the acromioclavicular joint. There may be a noticeable bump or tenderness over the lateral clavicle.
• Medial Fractures: Pain and swelling over the sternoclavicular joint. Posterior displacement can cause dyspnea, dysphagia, or vascular compromise due to compression of mediastinal structures.

Diagnostic Imaging

• Radiographs: Standard imaging includes anteroposterior (AP) and cephalic tilt views of the clavicle. For distal fractures, a Zanca view (15° cephalic tilt) can help assess displacement and ligamentous injuries.
• CT Scans: Indicated for complex fractures or when there is suspicion of mediastinal involvement in medial fractures. CT scans provide detailed imaging of fracture patterns and can differentiate between sternoclavicular dislocations and medial clavicle physeal fractures.
• MRI: Useful in assessing soft tissue injuries, particularly in complex lateral clavicle fractures where ligamentous integrity is a concern.

Management Strategies

Nonoperative Management

Nonoperative treatment is the standard for most non-displaced or minimally displaced clavicle fractures. It involves:

• Sling Immobilization: The affected arm is immobilized in a sling or figure-of-eight brace to allow for healing while maintaining the shoulder's normal anatomical alignment. This method is most effective for midshaft and non-displaced distal clavicle fractures.
• Rehabilitation: Gentle range of motion exercises are typically initiated at 2-4 weeks post-injury, with strengthening exercises commencing at 6-10 weeks once healing is confirmed radiographically.

Indications for Nonoperative Management:

• Non-displaced or minimally displaced fractures.
• Fractures without neurovascular compromise.
• Stable fracture patterns in low-demand patients.

Operative Management

Surgical intervention is recommended for specific clavicle fractures to ensure proper alignment, prevent nonunion, and restore optimal shoulder function.

Indications for Surgery:

• Absolute Indications:
  • Open fractures.
  • Fractures with neurovascular compromise.
  • Floating shoulder (concurrent clavicle and scapular fractures).
  • Severe comminution with significant displacement or shortening (>2 cm).
• Relative Indications:
  • Displaced midshaft fractures in young, active individuals.
  • Distal fractures with CC ligament disruption (Neer Type IIB, V).
  • Medial fractures with posterior displacement causing mediastinal compression.

Surgical Techniques:

1. Plate Osteosynthesis: The preferred method for midshaft and distal clavicle fractures, involving the application of a contoured plate to the clavicle for stabilization. This technique considers the bone's anatomy, including its curvature and diameter, and avoids disruption of periosteal vascularization and acromioclavicular ligament integrity.
   • Superior Plating: Provides strong fixation but poses a risk to the supraclavicular nerves and subclavian vessels.
   • Anterior Plating: Used when superior plating is contraindicated; however, it may have lower biomechanical strength.
2. Intramedullary Fixation: Involves the insertion of a rod or pin into the clavicle's medullary canal. This technique is less invasive and preserves soft tissue, but it may have higher complication rates due to hardware migration and difficulty in controlling rotational stability.
   • Indications: Suitable for simple, non-comminuted fracture patterns.
3. Coracoclavicular Ligament Reconstruction: Often performed in conjunction with open reduction and internal fixation for distal clavicle fractures. This procedure stabilizes the clavicle by reconstructing or reinforcing the CC ligaments, using either autograft, allograft, or synthetic materials.
4. Open Reduction and Internal Fixation (ORIF): For medial clavicle fractures, especially those with posterior displacement. Surgical reduction is performed under anesthesia with careful manipulation to avoid damaging mediastinal structures. ORIF can involve sutures, plates, or screws depending on the fracture pattern and patient anatomy.
5. Hook Plate Fixation: Employed for distal clavicle fractures, particularly when there is insufficient bone stock for conventional plate fixation. A hook plate is placed under the acromion to stabilize the clavicle. This method requires subsequent removal after healing due to the potential for shoulder impingement.

Postoperative Care and Rehabilitation:

• Early Rehabilitation: Begins with sling immobilization for 7-10 days, followed by active motion exercises once pain subsides and radiographic union is evident.
• Late Rehabilitation: Strengthening exercises start around 6 weeks, with a return to full activity, including sports, by 3 months if the healing process is uncomplicated.
• Complications: Potential complications include hardware irritation, infection, nonunion, neurovascular injury, and adhesive capsulitis. Regular follow-up and rehabilitation are essential to minimize these risks.

Special Considerations for Pediatric Patients

Medial and Distal Clavicle Physeal Fractures:

• Medial Physeal Fractures: Often present as pseudodislocations of the sternoclavicular joint. Nonoperative management is usually sufficient due to the high remodeling capacity of the pediatric clavicle. Surgery is reserved for cases with posterior displacement affecting mediastinal structures.
• Distal Physeal Fractures: Typically treated nonoperatively with sling immobilization, given the intact periosteum and strong potential for bone remodeling. Surgery is indicated in cases of open fractures or significant soft tissue compromise.

Growth Considerations:

• Clavicle fractures in children and adolescents require careful consideration of growth plates and future bone development. The clavicle's medial and lateral physes are the last to close in the body, necessitating a conservative approach unless absolutely necessary.

Conclusion

Management of clavicle fractures has advanced significantly over the past decade, with a growing emphasis on personalized treatment approaches based on the patient's activity level, fracture characteristics, and anatomical considerations. The choice of surgical technique—whether plate osteosynthesis, intramedullary fixation, or ligament reconstruction—must be carefully tailored to the fracture type and patient-specific factors. Continued research, particularly large-scale randomized studies, is needed to refine these techniques and optimize outcomes for patients with clavicle fractures. For orthopedic residents, a comprehensive understanding of the clavicle's anatomy, fracture classifications, and management options is essential for effective treatment planning and improved patient care.