Is hourglass syndrome common?

Hourglass syndrome, also known as Morgagni syndrome or anterior thoracic wall syndrome, refers to a rare disorder characterized by chest and rib cage abnormalities. People with hourglass syndrome have a sunken or concave chest wall (pectus excavatum) and protruding ribs flaring outward near the ribs (pectus carinatum). This gives the chest a distinctive hourglass shape.

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What causes hourglass syndrome?

The exact cause of hourglass syndrome is unknown, but it likely arises during development in the womb. The chest bones and cartilage don’t form properly, leading to abnormalities in the shape of the ribs and breastbone (sternum). Genetic factors may play a role, as the condition sometimes runs in families. Connective tissue disorders are also associated with an increased risk.

What are the symptoms of hourglass syndrome?

The hallmark symptom is the abnormal hourglass shape of the chest and ribs. Other signs and symptoms may include:

Sunken or caved-in chest (pectus excavatum)
Protruding ribs that flare out (pectus carinatum)
Narrowing of the chest at the mid-to-lower sternum

Shortness of breath
Chest pain
Fatigue

Rapid heart rate
Respiratory infections
Heart palpitations

The deformity can range from mild to severe. Many people have no other symptoms apart from the abnormal chest shape. But moderate to severe cases can press on internal organs, restrict lung capacity, and interfere with heart function.

Who is at risk for hourglass syndrome?

Hourglass syndrome is very rare, estimated to affect 1 in 1000 people. The disorder can affect both men and women. Key risk factors include:

Family history – Cases often run in families, suggesting a genetic component.

Connective tissue disorders – People with Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome have increased risk.
Scoliosis – Children with scoliosis or other spinal curvature abnormalities are more likely to develop hourglass syndrome.
Being underweight – Low body weight and poor nutrition may contribute to bone/cartilage formation abnormalities.

How is hourglass syndrome diagnosed?

Hourglass syndrome is typically diagnosed through a medical history and physical exam. The doctor will check for the characteristic chest deformity and rib flare. Diagnostic tests may include:

Chest X-ray – Provides images of the sternum, ribs, spine, and lungs.
CT scan – Gives a 3D view of the chest bones and tissues.

Pulmonary function tests – Assess breathing capacity and lung function.
Echocardiogram – Checks structure and function of the heart.
Genetic testing – Screens for connective tissue disorders.

What are the complications of hourglass syndrome?

Potential complications of hourglass syndrome include:

Reduced lung capacity – The caved-in chest restricts room for lung expansion.
Respiratory infections – Impaired lung function increases infection risk.

Heart problems – Compression and displacement of the heart can lead to mitral valve prolapse, arrhythmias, palpitations.
Psychological effects – Some people experience body image issues, social anxiety, depression.
Scoliosis – Spinal curvature develops in around 30% of cases.

Pregnancy complications – The deformity may interfere with growth of the uterus.

How is hourglass syndrome treated?

Treatment options for hourglass syndrome include:

Observation – Mild cases may just be monitored over time.

Breathing exercises – Can help maximize lung expansion.
Posture training – Improves chest configuration and appearance.
Chest bracing – External braces can reshape the thorax in growing children.

Surgery – Ravitch procedure remodels the sternum and ribs. Less invasive Nuss procedure implants a bar internally.

Surgery is usually reserved for severe cases causing heart/lung complications. It’s typically performed in adolescence when the chest bones are more pliable.

What is the prognosis for people with hourglass syndrome?

The outlook for hourglass syndrome depends on severity. Mild cases often cause no issues and require no treatment. Moderate cases can usually be managed with breathing exercises and bracing. People with severe deformities that compress the heart and lungs generally have the highest risks of complications. However, symptoms and function often improve significantly after corrective surgery.

How common is hourglass syndrome?

Hourglass syndrome is considered very rare, though the exact prevalence is unknown. Estimates range from 1 in 1000 to 1 in 10,000 people. Some key points about the incidence include:

More common in males – Approximately 75% of cases are in males.
Often diagnosed in childhood – Symptoms typically appear between 5-10 years old.

Rare in adults – Most adult cases are mild and identified incidentally.
True incidence likely higher – Many mild cases likely go undiagnosed.

While overall incidence is low, hourglass syndrome appears substantially more common in certain groups. An estimated 8% of people with Marfan syndrome have some degree of hourglass deformity. The prevalence also rises to around 30% in scoliosis patients.

Can hourglass syndrome be prevented?

There are no definitive ways to prevent hourglass syndrome, since the cause is unclear. However, the following measures may help lower risk in susceptible children:

Achieve optimal prenatal nutrition – Ensures proper bone/cartilage development.
Monitor growth milestones – Catch any chest abnormalities early.

Treat spinal curvature – Bracing scoliosis may help prevent progression to hourglass syndrome.
Practice good posture – Reduces risk of developing misshapen ribs.
Maintain healthy weight – Helps bones/joints develop normally.

Early intervention with braces or surgery may also prevent worsening of the deformity in diagnosed cases.

What is the role of gender in hourglass syndrome?

Hourglass syndrome is significantly more common in males. About 75% of cases occur in males versus 25% in females. Some factors behind this gender difference may include:

Genetic predisposition – More common gene mutations in boys.

Hormones – Estrogen may help protect bone/cartilage formation in girls.
Growth patterns – Boys tend to have growth spurts that could disrupt bone development.

However, females are also clearly at risk. When the condition does develop in girls, the symptoms and treatment approach are typically similar to males. The deformity may have a greater psychological impact on body image in females though.

Can hourglass syndrome affect pregnancy or delivery?

Severe hourglass syndrome has the potential to complicate pregnancy and delivery. However, mild to moderate cases generally do not cause issues. Concerns with pregnancy may include:

Small uterus – The sunken sternum sometimes limits room for the uterus to expand.
Reduced lung capacity – Can exacerbate pregnancy shortness of breath.

Heart dysfunction – Preexisting cardiac effects may worsen.
Vaginal delivery issues – The narrow pelvis may require a Caesarean section.

These effects are mainly risks with severe deformities compressing internal organs. Women with mild hourglass changes usually tolerate pregnancy well. But the chest shape may become more pronounced after pregnancy as ligaments stretch.

Does hourglass syndrome increase mortality risk?

Overall, hourglass syndrome alone does not substantially impact mortality risk. The lifespan for people with uncomplicated cases is normal. However, severe cases can indirectly increase the risk of early death if cardiac or respiratory function is impaired. The main potentially life-threatening complications are:

Severe cardiac dysfunction – Can lead to heart failure, arrhythmias, sudden death.
Major lung restriction – Raises the risk of respiratory failure.

Operative complications – Surgeries like the Ravitch procedure have an associated mortality risk.

With appropriate monitoring and treatment of these complications, the prognosis can be very good. Mild hourglass syndrome has no effect on life expectancy.

How is hourglass syndrome monitored over time?

Ongoing monitoring of hourglass syndrome involves periodic exams to check for progression and complications. Recommendations include:

Clinical exams every 6-12 months – Evaluate heart, lungs, spine.
Chest x-rays every 1-3 years – Assess bone changes.
Lung function tests annually – Check respiratory status.

ECG as needed – Monitor heart rhythm.
Consider CT scans – Help visualize bone/tissue structures.
Assess mental health – Screen for anxiety, depression.

Patients who’ve had surgery need close follow-up to check for recurrence. More frequent monitoring is required if complications develop.

What is the connection between hourglass syndrome and scoliosis?

There is a strong link between hourglass syndrome and scoliosis – abnormal sideways curvature of the spine. Around 30% of people with hourglass syndrome also have scoliosis. Theories about the relationship include:

Shared genetic factors – Gene mutations affect bone/cartilage formation.

Mechanical factors – Rib deformity may lead to uneven forces on the spine.
Common origins – Both arise during bone development in the womb/childhood.
Low vitamin D – Associated with both scoliosis and bone abnormalities.

The two disorders likely share common causal pathways. Scoliosis could potentially lead to hourglass changes over time due to altered spine and ribcage mechanics. Screening scoliosis patients for chest wall abnormalities is recommended.

What surgical procedures are available for hourglass syndrome?

If nonsurgical options are ineffective, the following surgical procedures may be used to correct hourglass deformities:

Ravitch procedure – Incisions allow removal of cartilage and reconstruction of the sternum and ribs.

Nuss procedure – A curved bar is inserted behind the sternum through small lateral incisions to reshape the chest.
Sternal turnover procedure – The sternum is partially cut, rotated and reattached in the correct alignment.
Costal cartilage resection – Portions of ribs may be removed to loosen the chest.

The Ravitch procedure is the traditional open surgery technique. The Nuss procedure is now preferred for most patients as it is less invasive. Both have risks like infection, bleeding, and recurrence of the deformity.

Surgical Procedure Outcomes

Procedure	Benefits	Risks
Ravitch	Direct access to bones Low recurrence rate	Invasive open surgery Long recovery time
Nuss	Minimally invasive Short hospital stay	Hardware complications Higher recurrence risk

What postoperative care is needed after surgery for hourglass syndrome?

The postoperative recovery process typically involves:

Hospital stay 3-7 days – Longer after open surgery.

Incision care – Keeping dressings clean and dry.
Pain management – Medications as needed, often intravenous at first.
Breathing exercises – To prevent lung complications.

Gradual return to activity – No heavy lifting for 6-8 weeks.
Bar stabilization after Nuss – Bar remains in place 3-4 years.
Follow-up exams – To check results and monitor for complications.

Full recovery can take up to 2-3 months for open procedures and slightly less for Nuss. Support groups and counseling help with psychosocial effects.

What is the role of physical therapy in hourglass syndrome?

Physical therapy can play an important role both before and after surgery for hourglass syndrome. Goals of PT include:

Stretching exercises – Increase flexibility of the chest and back.

Posture training – Teach proper body mechanics.
Strengthening – Build up chest, shoulder, and back muscles.
Breathing techniques – Maximize lung expansion capabilities.

Activity progression – Gradually increase exertion levels post-surgery.
Pain management – Use modalities like heat/ice, massage, TENS.

PT helps maintain range of motion and function. It may also prevent loss of correction after surgery. PT is typically recommended for at least 2-3 months post-operatively.

What special accommodations are needed at school for students with hourglass syndrome?

Children with hourglass syndrome may need certain accommodations at school, especially after surgery. Common recommendations include:

Extra time between classes – To avoid rushing while recovering.
Restricted physical education – No contact sports or strenuous exercise.

Weight limits on backpacks – To avoid loads pulling on the chest.
Allowance of brace – If wearing an external support.
Alternative changing areas – For privacy when changing clothes.

Special seating – Chairs with backs and arm desks to allow proper posture.
Elevator access – To avoid frequent stairs while fatigued.

Accommodations should be tailored to the individual case. Most special provisions are temporary until the student has healed from surgery.

What is the impact of undiagnosed hourglass syndrome into adulthood?

Undiagnosed hourglass syndrome often causes few ongoing issues if it remains mild into adulthood. Many adults are unaware they have the condition if it was undetected in childhood. Possible effects include:

Cosmetic concerns – Some have continued body image issues.
Mild symptoms – Shortness of breath, fatigue, chest pain with exertion.

Social anxieties – Embarrassment about appearance.
Progression risk – Deformity could worsen over decades.
Surgical complications – Operating at older ages has higher risks.

Severe undiagnosed cases are less common but could potentially affect heart/lung function. Milder forms generally don’t reduce lifespan or cause medical problems if left untreated.

Conclusion

In summary, hourglass syndrome is a rare chest wall deformity leading to an abnormal hourglass configuration. Exact prevalence is uncertain but estimated around 1 in 1000 people, with males more often affected. Mild cases may cause only cosmetic concerns, while severe cases can impair breathing and cardiac function. Diagnosis is by physical exam and imaging like chest X-rays and CT scans. Nonsurgical treatments involve breathing exercises and bracing, while surgery can reconstruct the ribcage. Scoliosis is closely associated with the syndrome. With appropriate monitoring and therapy, most people with hourglass syndrome can live normal lives.