Ribs and Thorax Fractures

Published on 16/04/2015 by admin

Filed under Surgery

Last modified 22/04/2025

Print this page

rate 1 star rate 2 star rate 3 star rate 4 star rate 5 star
Your rating: none, Average: 0 (0 votes)

This article have been viewed 1654 times

6 Ribs and Thorax Fractures

Anatomy of the Ribs and Thorax

image

Thoracic Skeleton

Ribs

• Mature rib: largely cancellous bone, light, easily fractured
• Cortical bone can fracture into sharp spicules, damaging pleura, lungs, and neurovasculature.
• Parts and landmarks: head, neck, tubercle, angle, shaft/body, notch, costal cartilage
• Ribs are overlaid and protected superiorly by pectoral girdle bones and muscles: pectoralis major and minor, subclavius, serratus anterior, scapula, rhomboids, and trapezius.
• Intercostal muscles span the intervals between successive ribs, from T1-T12: external, internal, and innermost layers.
• Intercostal neurovascular bundles lie between internal and innermost intercostal muscles.

image Superior (large) lie along the lower borders of ribs, within costal notches.
image Inferior (small, variable) lie just above the lower rib of each intercostal space.

• Proximal articulations are synovial.

image Costovertebral joints: articular facets of heads of ribs with hemifacets on bodies of successive vertebrae
image Costotransverse joints: between articular tubercles of ribs and transverse processes of related vertebrae

• First sternocostal (distal rib) joint: fibrous
• Sternocostal joints T2-T7: synovial
• Costochondral joints: costal cartilages of T8-T10 (false ribs) attach to T7 cartilage
• T11 and T12 floating ribs with no distal joints
• Free movement of most rib joints needed for unrestricted ventilation in normal thorax

Sternum

• Formed from sternebrae (multiple ossification centers) during development: gaps can persist
• Manubrium: articulations with clavicles, jugular (suprasternal) notch
• Body: lateral articular recesses for synovial, sternocostal joints
• Xiphoid process: may be bifid, notched, perforated
• Manubriosternal joint: symphysis (secondary cartilaginous), between manubrium and body (sternal angle of Louis); site of rib 2 articulations
• Xiphisternal joint: synchondrosis (primary cartilaginous) between body and xiphoid process
image

Thoracic Wall: Intercostal Nerves and Vessels

Neurovascular Supply

• Intercostal neurovascular bundles usually run in the intercostal space in top-down order: vein, artery, nerve (VAN).

Intercostal Nerves

• Anterior primary rami of spinal nerves
• Run with vessels in intercostal spaces below numbered ribs, between internal and innermost intercostal muscles
• Divide proximally into superior and inferior trunks, running in costal angle and above next rib, respectively
• Provide innervation for the layers of intercostal muscles as well as parietal pleura, deep tissue and cutaneous sensation in overlapping strips corresponding with spinal segment dermatomes

Arterial Supply

• Intercostal arteries have anatomical connections with

image Thoracic aorta

image Posterior, bilateral, segmental posterior intercostal arteries, T1-T11 levels
image Subcostal arteries, T12

image Aortic arch → subclavian → internal thoracic (mammary) arteries

image Anterior intercostal arteries, T1-T6 levels
image Intercostal branches of musculophrenic arteries below T6

Venous Drainage

• Intercostal veins parallel intercostal arteries.
• Anterior drainage into internal thoracic (mammary) veins → subclavian veins → brachiocephalic veins → superior vena cava
• Posterior drainage into azygos, hemiazygos, accessory hemiazygos, right and left superior intercostal veins (upper few segments)
• Azygos system drains into superior vena cava and connects with ascending lumbar veins, which connect with inferior vena cava; bypass pathway in caval obstruction

Clinical Correlates

Fractures in Thoracic Injuries

• Rib fracture types: oblique, transverse, overriding, costochondral separation, compound by penetration, multiple
• Complications

image Trauma to costal pleura, visceral pleura, lung, intercostal vessels
image Pneumothorax
image Hemothorax
image Spleen rupture (left posterior inferior)
image Subcutaneous emphysema

• Rib fractures may be accompanied by sternal fractures.
• Subclavian arteries and veins pass above T1 ribs anterolaterally (trauma risk).
• Flail chest (life threatening)

image Detached area of chest wall produced by fractures of 2 or more adjacent ribs in 2 places each
image Paradoxical motion: affected segment moving inward on inspiration instead of expanding with undamaged thorax
image About 50% mortality rate with flail chest, respiratory failure frequently due to associated pulmonary contusion

• Children’s ribs

image Extremely pliable, may be fractured by relatively low force
image Underlying lung may be contused with few external signs of trauma.

image

Thoracic Cage Injuries and Anesthesia

Intercostal Nerve Block

• To relieve pain of rib fracture
• Anesthetic infiltration sites

image Preferred site dorsal, at angle of rib
image Posterior axillary line
image Anterior axillary line
image Fracture site
image Parasternal site

• Aspirate before injecting to prevent pneumothorax.

Related posts:

Skull and Face Fractures Appendix Diseases Vertebral Fractures Uterus and Adnexal Diseases Biliary Diseases Pelvic Fractures