+Degree of Fracture.+ A fracture which only involves a portion of the thickness of the bones, so that its continuity has not been entirely lost or a fragment has not been completely detached, is called an _incomplete fracture_. A fracture which involves the entire thickness of the bone, so that it is divided into two or more distinct fragments, is called a _complete fracture_. +INCOMPLETE FRACTURES+ Among the varieties of incomplete fracture are: greenstick; fissured; depressed. +Greenstick Fractures+ (really a bending rather than a break of the bone) are mostly seen under the age of fifteen, and the bones of the leg are rarely affected. +Fissured Fractures+ are those in which there is a split or crack in the bones; they are very rare in the bones of the lower extremity. +Depressed Fractures+ are fractures in which one or more segments of broken bone are depressed; they are most common in fractures of the skull. +COMPLETE FRACTURES+ +Complete Fractures+ are divided according to the line and the seat of the breech of bone continuity. DIRECTIONS OF THE LINES OF FRACTURES +Transverse+, when the line of fracture does not deviate more than ten to fifteen degrees from that of the transverse axis. This variety is rare in the shaft of the long bones. It is usually found at the lower end of the radius or of the femur, and in the short bones. +Longitudinal+, when the break is parallel to the long diameter of the bone; very few cases of this variety are seen. +Oblique+, when the direction of the line of fracture may form any angle with the transverse axis of the bone up to a right angle. When it approaches the latter, it belongs to the group of longitudinal fractures. In the oblique variety, the line of fracture may be single or multiple. This and the spiral form are most frequent in the shafts of the long bones. +Spiral+, when the break line is spiral. This variety of fracture was formerly considered to be very rare. The more systematic use of the X-ray as part of the routine of diagnosis has shown that spiral fractures are quite frequent in the shafts of the tibia and fibula. They are usually the result of a rotating or twisting force. CLASSIFICATION OF FRACTURES +Comminuted+, when there is extensive splintering of the bone adjoining the fracture or one of the fragments. +Impacted+, when the fragments are driven into each other. This variety usually occurs in the neck of the femur. +Compression, or Crushing Fractures+, when the broken bones are compressed or crushed; this variety usually occurs in the tarsal bones. The spongy portion and cortical layer are both crushed. In some cases there is a perfect pulpification of these bones. This condition occurs after falls from a height upon the sole of the foot. LOCATION OF FRACTURE +In the Diaphysis of a Bone.+ Breaks in the diaphysis of a bone are spoken of as fractures of the _shaft_, and to be still more exact, it is stated whether of the upper, middle, or lower third.