Cartilago manubrii (cartilago cariniformis)
The cariniform cartilage is the keel-shaped cartilaginous extension of the manubrium (the cranial-most part of the sternum). It projects forward between the first pair of ribs and is palpable at the “point of the chest.” It serves as an attachment site for the sternomandibularis and sternohyoideus muscles and helps anchor the cranial thoracic inlet. Because it is cartilaginous, it remains somewhat flexible. With age the sternebrae ossify and fuse, but the cariniform cartilage retains its role as a soft-tissue anchor. It is rarely a primary site of clinical disease, though trauma to the point of the chest can injure it or the surrounding muscles.
Direct trauma or falls can bruise or fracture the manubrium/cariniform region. Sternal fractures are uncommon but diagnosed with ultrasound or radiography. The area is used as a landmark for certain ultrasound examinations of the thorax.
## Overview Sternal fracture is a break of the breastbone from direct ventral trauma such as a fall or collision. It causes ventral chest pain, crepitus, reluctance to lie down, pain when girthed, an
## Overview A pectoral abscess is a collection of pus in the chest muscles between the forelimbs. The classic cause in the western United States is Corynebacterium pseudotuberculosis (pigeon fever),
Swelling, heat, or reluctance to lower the head after a fall or collision into a solid object warrants veterinary examination. Most soft-tissue bruising resolves with rest; persistent pain or difficulty breathing needs imaging.
## Overview Sternal fracture is a break of the breastbone from direct ventral trauma such as a fall or collision. It causes ventral chest pain, crepitus, reluctance to lie down, pain when girthed, and sometimes ventral edema. Multiple sternebrae may be involved. ## Causes Blunt trauma to the ventral chest. ## Diagnosis Palpation and radiographs or ultrasound of the sternum. ## Treatment Rest and pain management. Surgical repair is rarely performed. Most heal with time. ## Recovery and Prognosis Good for uncomplicated fractures. ## Prevention Trauma avoidance. Signs include: ventral chest pain; crepitus on palpation; reluctance to lie down; pain when girthed; ventral edema
## Overview A pectoral abscess is a collection of pus in the chest muscles between the forelimbs. The classic cause in the western United States is Corynebacterium pseudotuberculosis (pigeon fever), producing large, painful swellings. Injection reactions can also cause abscesses. Horses show heat, pain, fever, and stiff forelimb movement. ## Causes Corynebacterium pseudotuberculosis or other bacteria introduced by wounds or injections. ## Diagnosis Clinical appearance, ultrasound, and culture of aspirated pus. ## Treatment Allow the abscess to mature, then lance and drain. Antibiotics are used in some cases. Hot packing helps maturation. ## Recovery and Prognosis Good for external abscesses once drained. ## Prevention Fly control and wound management in endemic areas. Signs include: hot painful swelling in the chest; reluctance to move the forelimbs; possible draining tract; fever; stiff gait
Direct trauma or falls can bruise or fracture the manubrium/cariniform region. Sternal fractures are uncommon but diagnosed with ultrasound or radiography. The area is used as a landmark for certain ultrasound examinations of the thorax.
Swelling, heat, or reluctance to lower the head after a fall or collision into a solid object warrants veterinary examination. Most soft-tissue bruising resolves with rest; persistent pain or difficulty breathing needs imaging.
See the Cariniform Cartilage (Cranial Sternal Projection) on our interactive 3D horse model. Open 3D Model