CLAVICLE PSEUDOARTHROSIS

QUESTIONS AND ANSWERS

Understanding the Pathophysiology of Congenital Pseudoarthrosis of the Clavicle

Congenital pseudoarthrosis of the clavicle is a condition that arises from a disruption during the early stages of bone development. The clavicle, being the first bone to form via membranous ossification, connects the sternum to the acromion and plays a pivotal role in ensuring shoulder functionality.

Key Factors in Pathophysiology:

• Ossification Disruption: Normally, the clavicle develops through the fusion of two primary ossification centers. However, in congenital pseudoarthrosis, these centers fail to unite properly.
• Formation of a Fibrous Bridge: Instead of a solid bone, a fibrous bridge forms between the separated segments of the clavicle. This bridge links to the periosteum, the membrane covering the bone, and a synovial membrane arises, adding to the complexity of the condition.
• Vascular Implications: Predominantly affecting the right side, the absence of situs inversus implies that the underlying vascular structures, particularly where the subclavian artery crosses the first rib, may influence the development of pseudoarthrosis.

Significantly, congenital pseudoarthrosis of the clavicle has never been linked to malignant changes, indicating its benign nature despite the structural abnormalities. This understanding underscores the importance of considering both environmental and anatomical factors in its development.

Understanding the Epidemiology of Congenital Pseudoarthrosis of the Clavicle

Congenital pseudoarthrosis of the clavicle is a remarkably rare condition, with only about 200 documented cases in the English-speaking medical literature. Despite its rarity, the specifics of its prevalence and incidence remain unclear.

Key Characteristics:

• Side of Occurrence: The condition predominantly affects the right side of the clavicle. Instances involving the left side are less common and usually linked to more complex conditions like dextrocardia (a heart position abnormality) and situs inversus (where organ positions are mirrored).
• Bilateral Occurrences: Although extremely rare, bilateral occurrences can happen and are often associated with certain genetic syndromes.

Understanding these patterns can guide clinicians in anticipating and diagnosing this condition, especially in the presence of its associated anomalies.

Understanding the Etiology of Congenital Pseudoarthrosis of the Clavicle

Congenital pseudoarthrosis of the clavicle is known for its mysterious origins, as the exact cause remains unidentified. Despite initial theories, there is no proven connection between this condition and neurofibromatosis. One hypothesis suggests that irregularities during the development of the aortic arch could be a contributing factor. This might help explain why the condition frequently manifests on the right side of the body.

The condition arises due to the incomplete merging of the clavicle’s two primary ossification centers. Interestingly, when the left side is affected, it often coincides with anatomical variations like dextrocardia or situs inversus. Additionally, there is a noted 15% occurrence rate of associated cervical ribs among patients. However, naturally occurring recovery from this condition is exceedingly rare, making it a unique challenge in pediatric orthopedics.

Symptoms of Clavicle Pseudoarthrosis

The symptoms of clavicle pseudoarthrosis can vary depending on the severity of the condition. Some people may have no symptoms at all, yet others may experience significant pain and disability. Common symptoms of clavicle pseudoarthrosis include:

• Pain: Pain around the site of the fracture is a common symptom of clavicle pseudoarthrosis. The pain may be constant or intermittent and may be worse with movement.
• Swelling: Swelling around the site of the fracture may occur due to inflammation or fluid accumulation.
• Instability: Pseudoarthrosis can cause instability in the shoulder, making it difficult to move the arm or lift objects.
• Limited range of motion: Pseudoarthrosis can limit the range of motion in the affected shoulder, making it difficult to perform certain activities.
• Visible deformity: In some cases, the clavicle may protrude through the skin, causing an open wound or visible deformity.
• Muscle weakness: Pseudoarthrosis can cause muscle weakness and atrophy in the affected arm.
• Numbness or tingling: Pseudoarthrosis can compress nerves in the area, leading to numbness or tingling in the arm or hand.

It is important to note that not all clavicle fractures will result in pseudoarthrosis.  In addition, not all cases of pseudoarthrosis will have noticeable symptoms. If you have any concerns about a clavicle fracture or pseudoarthrosis, it is important to consult with a healthcare provider.

Clinical Presentation of Congenital Pseudoarthrosis of the Clavicle

When analyzing the clinical signs of congenital pseudoarthrosis of the clavicle, one may notice specific indicators. A key feature is the appearance of an unusual, painless protrusion over the right clavicle. This noticeable mass is often what leads concerned parents to seek medical advice.

Additional observation typically reveals:

• Absence of Pain: Despite the visible bulge, children usually do not experience discomfort, which can be reassuring to caregivers.
• Limited Mobility Issues: The condition rarely restricts shoulder movement, allowing more or less normal activity levels despite the anomaly.
• Visual Asymmetry: The affected clavicle may look uneven compared to the other side, drawing further attention to the area.

These clinical signs guide healthcare professionals in diagnosing the condition, leading to appropriate care paths.

Diagnosing Clavicle Pseudoarthrosis

Diagnosis of clavicle pseudoarthrosis typically involves a combination of medical history, physical examination, and imaging tests. Here are some of the ways a doctor may diagnose clavicle pseudoarthrosis:

• Medical history: The doctor will ask about your child’s symptoms and any previous injuries.  In addition, the doctor will gather medical conditions that may be contributing to your child’s current symptoms.
• Physical examination: The doctor will examine the affected area, looking for signs of swelling, instability, deformity, or other abnormalities.
• Imaging Studies for Congenital Pseudoarthrosis of the Clavicle

In evaluating congenital pseudoarthrosis of the clavicle, utilizing imaging studies is crucial for accurate diagnosis and planning treatment. Here’s a comprehensive look at the imaging studies typically used:

X-Ray

• Initial Assessment: X-rays are often the first step in imaging. They provide a straightforward view of the clavicle’s anatomy and can reveal the presence of pseudoarthrosis.
• Visualizing Characteristics: X-rays help identify anomalies in bone continuity and any abnormal curvature or thinning.

Ultrasound

• Soft Tissue Evaluation: Ultrasound is valuable for assessing adjacent soft tissues. It can help in evaluating surrounding structures that might be involved.
• Non-Invasive and Safe: Given its safety profile, ultrasound can be particularly useful in pediatric cases without the risk of ionizing radiation.

Computed Tomography (CT) Scan

• Detailed Bone Assessment: CT scans offer cross-sectional images, providing a detailed view of the bone structure. This helps in assessing the extent of pseudoarthrosis.
• 3D Reconstruction: Allows for three-dimensional evaluation, aiding surgical planning by visualizing the defect from multiple angles.

Magnetic Resonance Imaging (MRI)

• Bone and Soft Tissue Contrast: MRI provides excellent contrast between bone and soft tissue, which helps in better understanding any associated conditions.
• Assessing Vascularity: It can be useful in assessing the vascularity of the pseudoarthrotic site, which is crucial for determining the best management approach.

Conclusion

Each of these imaging modalities plays a unique role in the comprehensive assessment of congenital pseudoarthrosis of the clavicle. The choice often depends on the specific clinical situation and the information needed to guide effective treatment strategies.

Once a diagnosis of clavicle pseudoarthrosis is made, the doctor will work with you to develop an appropriate treatment plan. Treatment may involve surgery to remove any non-union tissue and to stabilize the bone.  the surgeon will use plates, screws, or wires to stabilize the bones. Rehabilitation and physical therapy may also be necessary to help regain strength and mobility in the affected area.

Potential Complications

When addressing the treatment of congenital pseudoarthrosis of the clavicle, several complications can arise. Below, we delve into potential issues patients might encounter post-treatment.

1. Pain and Discomfort
   While surgery aims to rectify issues such as shoulder girdle hypermobility and visible deformities, patients may experience persistent pain if only resection is performed without additional measures.
2. Surgical Risks
   Like any surgical procedure, there’s a risk of typical complications including infection, bleeding, or adverse reactions to anesthesia.
3. Failed Bone Healing
   If bone grafting is part of the treatment, there’s a possibility that the graft may not integrate properly, leading to incomplete healing or relapse of the condition.
4. Impaired Mobility
   Even after successful treatment, some patients might face continued restrictions in shoulder or arm movement, affecting daily activities.

Understanding these potential complications is crucial for patients and healthcare providers to make informed decisions about the treatment plan, while also considering alternative or adjunct therapies to mitigate these risks.

Approach Considerations for Treating Congenital Pseudoarthrosis of the Clavicle

For those dealing with congenital pseudoarthrosis of the clavicle, medical therapies can be approached in a few ways. In some cases, the condition may simply be observed without immediate intervention, especially if symptoms are mild and manageable.
However, surgical treatment is commonly advised to address specific issues such as shoulder girdle hypermobility and the presence of an unsightly mass. Such surgery usually involves an open reduction process, where the abnormal connection is surgically corrected. This may include resecting the affected area, realigning the bone, and applying osteosynthesis techniques to stabilize it.
Additionally, bone grafting is often employed to aid in proper healing and structural support. This comprehensive surgical approach aims not only to alleviate pain but also to restore functionality and aesthetics. Without the full procedure, some patients may experience ongoing discomfort, making a thorough surgical plan crucial for long-term relief and recovery.

When it comes to addressing congenital pseudoarthrosis of the clavicle, treatment strategies vary based on the severity and symptoms of the condition. Let’s explore these considerations:

1. Observation: In cases where the pseudoarthrosis presents minimally, mere observation might be sufficient. This approach is applicable if the condition doesn’t significantly impact movement or cause discomfort.
2. Surgical Intervention: Typically recommended for more pronounced cases, surgical treatment aims to correct issues like shoulder girdle hypermobility and noticeable mass formation. The procedure often involves:
   • Open Reduction: This technique aligns the bone fragments correctly.
   • Resection: Removal of the pseudoarthrosis can alleviate symptoms but might cause pain if performed alone.
   • Bone Grafting: This method supports the healing process by providing necessary bone tissue to encourage fusion and structural stability.

Each treatment plan is tailored to the individual’s specific needs, ensuring that both functional and aesthetic outcomes are considered.

Treating Clavicle Pseudoarthrosis

The treatment of clavicle pseudoarthrosis typically involves surgery that removes the non-union issue.  The surgeon will fix damaged tissue and stabilize the bone with plates, screws, or wires. The specific surgical technique used will depend on the location and severity of the pseudoarthrosis.  The surgeon will take into consideration other individual factors such as age and overall health.

Here are some of the surgical options for treating clavicle pseudoarthrosis:

• Bone grafting: This involves taking a piece of bone from another part of the body, such as the hip or leg, and using it to fill in the gap between the non-healing bone ends. The bone graft helps to stimulate new bone growth and promote healing.
• Internal fixation: This involves the use of plates, screws, or wires to stabilize the bone and hold it in the correct position. This allows the bone to heal properly and helps to prevent future instability.
• External fixation: This involves the use of an external device, such as a brace or cast, to hold the bone in place and promote healing. This may be used in conjunction with other surgical techniques or on its own.
• Revision surgery: In some cases, revision surgery may be necessary if the initial surgery did not result in complete healing or if there are complications such as infection or nerve damage.

In addition to surgery, rehabilitation, and physical therapy may also be necessary to help regain strength and mobility in the affected area. The length of rehabilitation and recovery time will vary depending on the severity of the pseudoarthrosis and the specific surgical techniques used.

Surgical Therapies for Congenital Pseudoarthrosis of the Clavicle

When addressing congenital pseudoarthrosis of the clavicle, several surgical options are available to correct the condition and its associated symptoms.

1. Observation vs. Surgical Intervention: Initially, mild cases might only require monitoring. However, for more pronounced symptoms or functional issues, surgical options become necessary.
2. Correcting Shoulder Girdle Hyperactivity: Surgery is generally recommended when there is excessive mobility in the shoulder girdle or when the appearance of the mass is a concern.
3. Open Reduction and Bone Grafting: This procedure involves surgically realigning the clavicle and securing it using bone grafts. It’s effective in treating both mobility issues and cosmetic concerns.
4. Resection Combined with Osteosynthesis: This method involves removing the problematic area of the bone (resection) and using surgical hardware like plates or screws to stabilize the clavicle (osteosynthesis).
5. Avoiding Pain with Combinations: Resection alone may lead to pain; hence, pairing it with bone grafting enhances outcomes, reducing discomfort and improving overall function.

These surgical therapies are tailored to alleviate hypermobility issues while addressing the physical deformity associated with congenital pseudoarthrosis of the clavicle.

Recovering from Clavicle Pseudoarthrosis

The recovery time for clavicle pseudoarthrosis can vary depending on the severity of the condition.  This also includes the type of surgery performed and individual factors such as age and overall health. In general, recovery from surgery for clavicle pseudoarthrosis can take several months. During the first few weeks after surgery, your child may need to wear a sling or brace.  The sling or brace will protect the affected area and allow the bone to heal. Your child may also need to avoid certain activities, such as heavy lifting or overhead movements, to prevent further injury and promote healing.

Finally, after a few weeks, your child may begin physical therapy to help improve the range of motion, strength, and flexibility in the affected area. The length of physical therapy will vary depending on the severity of the pseudoarthrosis and the individual’s progress in rehabilitation. Overall, it can take several months to fully recover from clavicle pseudoarthrosis. Your doctor will provide specific instructions and guidelines for postoperative care and rehabilitation to help optimize your child’s recovery and ensure the best possible outcome.

Prognosis for Congenital Pseudoarthrosis of the Clavicle

Individuals diagnosed with congenital pseudoarthrosis of the clavicle typically experience a very favorable prognosis. With timely and appropriate treatment, patients generally see rapid improvement. Recovery is marked by minimal complications, and most individuals regain full normal function of the affected area.

In the majority of cases, surgical intervention aligns the bone correctly, allowing for proper healing. Following the procedure, patients often undergo physical therapy to restore strength and mobility. The success rate for these interventions is high, ensuring that most people can return to their usual activities without ongoing issues.

Patients and their families can be optimistic about both short-term recovery and long-term outcomes, given the effectiveness of current medical approaches.

Medical City Children’s Orthopedics and Spine Specialists

We invite new patients at our Medical City Children’s Orthopedics and Spine Specialists practice.  We have offices in  Arlington, Dallas, Flower Mound, Frisco, and McKinney, TX and treat children who have broken clavicles or collar bones.

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Footnote:

JAMA: Congenital Pseudarthrosis of the Clavicle