A fracture is a break in the continuity of a bone. The severity of fractures ranges from a partial filiform fissure to a complete rupture of the bone in multiple pieces. Most commonly, fractures are the result of high-energy forces, but in the case of a bone weakened by a disease, the bone can break after minimal trauma, or a break can even occur spontaneously.
Different types of fractures can occur depending on the origin, energy, and direction of the forces applied to the bone and the quality of the bone. It is important to know the etiology and types of forces that can be applied to bones in order to reverse these forces when reducing fractures and understanding the extent of soft tissue disruptions. Several classifications, depending on the bone or joint involved, exist. These will be discussed in their specific sections.
The different etiologies of fracture (Figure 42–1) are as follows:
Traumatic fracture: Fracture caused by an external high-energy force on a healthy bone.
Pathologic fracture: Fracture caused by a minimal energy (even everyday activities) on a bone weakened by disease. The most common causes of disease that weaken bones are congenital (osteogenesis imperfecta), infectious (osteomyelitis), metabolic (osteomalacia, hyperparathyroidism, osteopenia, osteoporosis), neoplastic (bone cyst, enchondroma), malignant (osteosarcoma, metastasis), and rheumatic (Paget disease).
Periprosthetic fracture: Fracture caused by the application of forces on a point of mechanical weakness in the bone, created by the implantation of a prosthesis.
Images of (A) traumatic and (B) pathologic fractures. (B, Reproduced with permission from Skinner HB, McMahon PJ: Current Diagnosis & Treatment in Orthopedics, 5th ed. New York, NY: McGraw-Hill Education; 2014.)
The different fracture patterns (Figure 42–2) are as follows:
Transverse: Fractures induced by a direct impact. The fracture line is at a right angle to the bone’s long axis. These fractures are often accompanied by local tissue disruption.
Oblique and spiral: Fractures induced by torsional forces applied distally from the fracture site. The fracture line is diagonal to the bone’s long axis. Soft tissue disruptions can be observed in areas other than the fracture site.
Greenstick: Incomplete fracture of the bone, involving only one cortex. The bones of children are more predisposed to this kind of fracture, since they are composed of greater conjunctival tissue and less mineral bone than adult bones.
Compression and wedge: Fractures induced by a direct compression of the cancellous bone that collapses the trabeculae. This type ...