Rib Fractures – Causes, Presentation and Treatment

Rib fractures are the most common injury sustained after blunt chest trauma. Rib fractures are more common in elderly and adults [older people are more prone than young adults] than children.

Elderly are more likely to have associated injuries and complications.

Rib fractures can be associated with injury to internal organs. This includes injury to lung parenchyma, hemothorax, pneumothorax etc. In first rib injury underlying vessels and spinal injuries.

Fracture of the lower ribs usually is associated with injury to abdominal organs [spleen, liver, kidney].

When there is an associated pelvic fracture with lower rib fractures, there is a higher incidence of solid organ injury.

Ribs 4 to 9 are the most commonly injured.

Patients with fractured ribs and vital capacity of less than 30% have been found to have a higher rate of pulmonary complications.

Pathophysiology of Rib Fracture

The chest wall protects underlying sensitive structures and is necessary for normal respiration. Rib fractures may compromise ventilation due to

• Pain from rib fractures can cause respiratory splinting, resulting in atelectasis and pneumonia.
• Multiple contiguous rib fractures interfere with normal costovertebral and diaphragmatic muscle excursion [flail chest] leading to ventilatory insufficiency.
• Hemothorax or pneumothorax.

The posterior angle is the structurally weakest area of the rib. Ribs commonly fracture at the posterior angle or point of impact.

In the first rib, the thinnest and weakest portion of the first rib is at the groove for the subclavian artery. The fracture of the first rib is often caused by a violent contraction of the scalene muscles due to sudden forward movement of the head and neck.

First rib fractures have often been associated with serious head injury, cervical spine injury, delayed subclavian vessel thrombosis, aortic aneurysm, tracheobronchial fistula, thoracic outlet syndrome, and Horner syndrome

Causes of Rib Fracture

• Blunt trauma
  • Motor vehicle accidents [most common mechanism]
  • Motorcycle injuries
  • Assault
  • Falls, especially down staircases

• Coughing spells
• Child abuse [non-accidental trauma in children]
• Elderly abuse
• Repetitive minor trauma
  • In athletes
  • Causes stress fractures

Clinical Presentation

The presentation is varied owing to the multiple methods of causation.

Conscious patients with rib fracture frequently complain of pain on inspiration and dyspnea.

Tenderness on palpation, crepitus, and chest wall deformity are common findings.

Paradoxical chest wall excursion with inspiration is seen with flail chest. A flail chest compromises respiratory function and may necessitate intubation and ventilatory support.

Signs of ventilatory insufficiency

• Cyanosis
• Tachypnea
• Retractions and use of accessory muscles
• Anxiety
• Agitation.

In fracture of the lower ribs is look for abdominal tenderness and coastal margin tenderness which may indicate an injury to intra-abdominal organs.

Differential Diagnoses

• Abdominal Trauma, Blunt
• Acute Aortic Dissection
• Clavicle fracture
• Mechanical Back Pain
• Sternal Fracture

Lab Studies

Laboratory studies are generally not useful for evaluation of isolated rib fractures.

Urinalysis in cases of lower rib fractures, as hematuria may indicate associated renal injury.

Arterial blood gas measurements) are used to determine if the lungs have been contused.

Imaging

Chest X-ray

Anteroposterior (AP) and lateral chest films are done for chest injuries.

The x-rays of the chest are not very sensitive [50%] for rib fracture  [sensitivity as low as 50%]

Presence of a sternal fracture or scapular fracture should increase suspicion for rib fractures.

Chest radiographs are useful in the diagnosis of underlying injuries, including hemothorax, pneumothorax, lung contusion, atelectasis, pneumonia etc.

The aortic injury is marked by a widening of the mediastinum.

A skeletal survey should be done in infants suspected of being abused. Presence of multiple rib fractures/other bone fractures in various stages of healing will be seen.

Ultrasonography

Ultrasound is useful in pediatric rib fractures. It tells about the fracture in unossified bone and diagnosis of other rib fractures that may be missed on plain radiographs.

It also detects costal cartilage fractures and costochondral junction fractures better.

CT scan

• More sensitive than plain
• Better fracture delineation
• Useful in stress fractures

Abdominal CT in lower rib injuries should be considered in lower rib fractures with a suspected visceral injury.

Angiography

It can be done in first and second rib fractures as these are often associated with vascular injury.

Bone Scan

• For diagnosis of stress fracture [see below]

MRI

MRI is able to provide a better spectrum of soft tissues injuries associated. It is also useful in the stress fracture.

Management of Rib Fractures

The approach to rib fracture would depend on the condition of the patient, associated injuries.

In an emergency setting, evaluation and stabilization of the trauma patient are priorities

Pain control is fundamental to the management of rib fractures to decrease chest wall splinting and alveolar collapse in order to clear pulmonary secretions.

Isolated rib fractures, without associated injuries, may be managed on an outpatient basis with oral analgesics, with NSAIDs or opioids or both.

Rib belts or binders control pain but are not recommended as they have been linked to hypoventilation, atelectasis, and pneumonia.

Patients with greater injuries [and risk of complications]need admission.

Consider admission and observation in the following situations

• Isolated rib fractures but patient not able to cough and clear secretions adequately
• Underlying lung disease or decreased pulmonary reserve.
• Older persons with isolated rib fractures >65 years
  • hypoventilation, hypercapnia, atelectasis, and pneumonia
• Initial systolic blood pressure < 90 mm Hg
• Hemothorax
• Pneumothorax
• 3 or more unilateral rib fractures
• Pulmonary contusion.

If required nerve blocks like a paravertebral block and an intercostal nerve block may be used for pain control. The incentive spirometer is used for prevention of splinting.

Admission also gives an opportunity to find occult visceral injuries.

All patients who had just been observed and have isolated rib fractures who are able to cough and clear secretions adequately can be discharged after 24 hours.

Other patients need to be managed as guided by the presence of other injuries and their progress.

Open reduction and internal fixation may be considered in flail chest, chest wall deformity and in >3rib fractures with severe symptoms.

The surgery used is open reduction and internal fixation. Surgical treatment lowers mortality, shortens the duration of mechanical ventilation and the need for tracheostomy.

Complications

Complications of rib fracture may include the following:

• Respiratory failure
• Hypoventilation
• Hypercapnia
• Hypoxia
• Atelectasis
• Pneumonia
• Damage to underlying visceral organs
  • Pneumothorax
  • Hemothorax
  • Aortic injury
  • Pulmonary contusion
  • Intra-abdominal organ injury

Stress Fractures of Ribs in Athletes

Stress fractures of ribs are not that common and occur in athletes.

First rib is the most common site where stress fractures occur anterolaterally. Stress fracture of the first rib is noted in baseball pitchers, basketball, weightlifters and ballet dancers.

Stress fractures are in middle ribs (4-9th)  occur laterally and anterolaterally and increased incidence is noted in competitive rowers. Posteromedial stress fractures are noted in novice golfers

Risk factors

• Extreme overuse
• Repetitive use
• Repetitive coughing paroxysms
• Females
  • amenorrhea
  • osteopenia / osteoporosis

Pathophysiology of Stress Fracture

• Repetitive contraction of attached muscle places stresses on the rib. More so during training, because muscles strengthen more rapidly than bone
• Muscle fatigue during prolonged activity places a bone at risk for fracture by lessening the ability of a muscle to absorb and dissipate opposing forces
• Anatomic sites of weakness make the bone prone. For example, first rib stress fracture occurs at the groove for the subclavian artery. The fracture is caused by superiorly directed forces from the scalene muscles and inferiorly directed forces from the serratus anterior and intercostal muscles

Clinical Presentation

The athlete would complaint of an insidious onset of pain worsened with coughing, deep inspiration, and overhead activities. Acute presentations are known where the patient might have heard the snap [complete fracture of fatigued bone] while performing the activity.

On examination, there would be focal tenderness directly over the affected rib. In chronic injuries, a palpable callus may develop

Imaging

X-rays are negative for a fracture in as many as 60% of patients with rib fracture of any etiology

The bone scan should be done when clinical suspicion remains in spite of negative x-ray. It would show increased activity.

CT scan shows clear delineation of the fracture pattern

MRI is done when x-rays are negative and clinical suspicion remains. It is used more commonly than bone scans in athletes. MRI shows marrow edema signifying stress response; the fracture line may or may not be seen.

Treatment

It is mostly nonoperative consisting of rest, analgesia, stopping of inciting activity and correction of training errors or faulty mechanics

Majority of rib fractures heal uneventfully

References

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