Flail Segment

This article is currently under review and may not be up to date. Please come back soon to see the finished work! (22/09/2019)


A flail segment is a portion of the rib cage that breaks due to trauma and becomes unattached from the chest wall. (Pettiford, Luketich & Landreneau, 2007). It can occur when 3 or more ribs are broken in at least two places, although not everyone with type of injury will develop a flail chest. However, if these injuries cause a segment of the chest to move independently, Generation of negative intrapleural pressure indicates a true paradoxical flail segment (May, Hillermann & Patil, 2015). This condition is of clinical significance in elderly patients or patients who have chronic lung disease.  

Muscles of Respiration

Refer to the Physiopedia page below for clinically relevant anatomy and how the muscles involved in breathing mechanics operate

Muscles of Respiration


“A break in the structural continuity of the bone” that can be caused by trauma, stress and pathological factors." (Apley, Solomon, Warwick, Nayagam & Apley, 2005)


  • Complete
  • Incomplete
  • Physeal

Classification according to the nature of the fracture:

  • Spiral
  • Transverse
  • Comminuted
  • Compression

Associated conditions:

Pulmonary complications 48-72 hours after admission (Battle, Hutchings, James, & Evans, 2013):

  • Haemothorax
  • Pneumothorax
  • Atelectasis
  • Pneumonia
  • Pleural effusion
  • Subcutaneous emphysema
  • ARDS (Acute Respiratory Distress Syndrome)
  • Pulmonary emboli
  • Aspiration
  • Lobar collapse

Risk factors for developing associated conditions (Battle, Hutchings, James, & Evans, 2013):

  • >65 years old
  • >3 rib fractures
  • Hx. of chronic lung conditions or CVD
  • Pre-injury anti-coagulant use
  • <90% SpO2

Clinical Presentation

The patient may complain of severe chest wall pain and may have tachypnea. On close observation there may be paradoxical chest wall movement. On inspiration the flail segment will move inwards whilst the rest of the chest expands and on expiration the flail segment will move outwards whilst the rest of the chest contracts.

If the patient is mechanically ventilated or on Bilevel Positive Airway Pressure (BiPAP) it may be difficult to diagnose and may only become obvious after extubation.

Diagnostic Procedures

Radiologists use Chest X-Rays to look for the following:

“Three or more adjacent ribs are fractured in two or more places. Clinically this can be a segment of only one or two ribs can act as a flail segment” (Stanislavsky, 2018).

Outcome Measures

Modified BORG Scale

VAS Scale for Pain

Physiotherapy Management / Interventions

Chest physiotherapy management consists of the following:

1. Ventilatory Management - supplemental oxygen therapy, continuous positive airway pressure or intubation if necessary (May, Hillermann & Patil, 2016)

  • CPAP - for negative intrapleural pressure and paradoxical movement,  increases TV (May, Hillermann & Patil, 2015)
  • Open/closed suction if patient intubated (Berney, Haines & Denehy, 2012)

2. Pain Management and Education (May, Hillermann & Patil, 2016)

  • Education on fracture healing

3. Early mobilization if possible (May, Hillermann & Patil, 2016)

  • Transfers to sitting out of bed
  • Mobilization 2-3x daily and SOOB 3-4x/day

4. Chest and airway clearance techniques (if inadequate) (May, Hillermann & Patil, 2016)

  • ACT: nebulizer with ACBT and education
  • Bubble PEP or Flutter

5. Deep breathing exercises and supported coughing technique (May, Hillermann & Patil, 2016)

  • Supported Cough: Wrap around technique or rolled up towel
  • DBE/TEE’s with SMIs (2-4 secs hold)

6. Positioning (Berney, Haines & Denehy, 2012)

  • Positioning in side lying and high sitting

Medical Management

Medications: (May, Hillermann & Patil, 2016)

  1. Simple Analgesics
  2. Opioids
  3. Patient Controlled Analgesia
  4. Operative fixation and Regional Anaesthetic


Conservative (May, Hillermann & Patil, 2016)

  • Regional anaesthesia
  • Serratus anterior block
  • Paravertebral block
  • Thoracic epidural

Internal fixation (May, Hillermann & Patil, 2015)

  • Decreases stay in ICU and MV duration (Leinicke et al., 2013)
  • Similar to thoracotomy but incision but spares Latissimus Dorsi
  • Anterior # - plates and locking screws
  • Posterior # - intramedullary splints




https://www.wcpt.org/wcpt2017/FS-01 </div>


  1. Battle C, Hutchings H, Evans PA. Blunt chest wall trauma: A review. Trauma. 2013;15(2):156-75.

2. Berney S, Haines K, Denehy L. Physiotherapy in Critical Care in Australia. Cardiopulmonary Physical Therapy. 2012;23(1):19-25.

3. Jena R, Agrawal A, Sandeep Y, Shrikhande N. Understanding of flail chest injuries and concepts in management. International Journal of Studentsí Research. 2016;6(1):3-5.

4. Leinicke AJ, Elmore DL, Freeman AB, Colditz AG. Operative Management of Rib Fractures in the Setting of Flail Chest: A Systematic Review and Meta-Analysis. Annals of Surgery. 2013;258(6):914-21.

5. May L, Hillermann C, Patil S. Rib fracture management. BJA Education. 2016;16(1):26-32.

6. Pettiford BL, Luketich JD, Landreneau RJ. The Management of Flail Chest. Thoracic Surgery Clinics. 2007;17(1):25-33.

7. Solomon L. Apley's concise system of orthopaedics and fractures. 3rd ed.. ed. Warwick D, Nayagam S, Apley AG, editors. London : New York: London : Hodder Arnold New York : Distributed in the United States by Oxford University Press; 2005.

8. Stanislavsky A. Radiology Reference Article. Flail chest. https://radiopaedia.org/articles/flail-chest (accessed 15 June 2018).