|Fractures of the Base of the Fifth Metatarsal|
|Fractures of the base of the foot's fifth metatarsal bone are common fractures seen both in recreational and competitive athletes. This type of fracture is generally referred to as a Jones Fracture, named after Sir Robert Jones, who first described this fracture pattern in 1902.
The metatarsal bones are a group of 5 bones in the foot that contribute to the foot's normal arched shape. The fifth metatarsal is located on the little toe side (or lateral side) of the foot, and connects the small toe's proximal phalanx to the cuboid bone near the ankle joint. Strong ligaments attach the base of the fifth metatarsal to the cuboid bone and the fourth metatarsal bone. Because of these strong ligament attachments, Sir Robert Jones concluded that it was easier for an individual to break or fracture the fifth metatarsal, than to dislocate it.
|The fracture seen in this x-ray of the fifth metatarsal is typical of the transverse fracture pattern seen in Zone II fractures, as described below.|
|ZONES OF FIFTH METATARSAL FRACTURES
There are three patterns of Jones fractures, according to the actual location of the fracture on the bone. Fractures in Zone I are typically avulsion type fractures, wherein a small fragment of bone is broken off the proximal end of the bone. Zone II fractures involve an area of the bone a little more distal (or toward the toes), and most typically appear as horizontal or transverse fractures. Zone III fractures usually occur in the shaft of the metatarsal bone.
This drawing depicts the three most common locations, or zones, of these fractures of the proximal metatarsal bone.
|Fractures to the fifth metatarsal base are thought to occur in different ways. The acute type of fracture, meaning a sudden, severe fracture, or one with a rapid onset, happens all at once from one single, forceful incident. Such a fracture might occur when excessive forces are applied to the lateral slide (small toe side), or lateral ball of the foot.
A chronic fracture represents those fractures that occur due to bone stress or bone fatigue. These stresses on the metatarsal bone occur over time from repetitive forces to the lateral foot area. These types of fractures do not happen all at once from one single injury, but may be a result of weeks or even months of traumatic stress. X-rays of these fractures usually show evidence of a pre-existing stress reaction in this area.
|SOME FRACTURES REQUIRE SURGERY
Some of the more minor fractures that are stable, and not displaced, may be successfully treated with bracing or casting. At times, however, these fractures may require surgery to fix (or reduce) the fracture. This surgery may include the placing of an intramedullary screw (much like a long wood screw) into the bones shaft. This procedure stabilizes the fractured bone, and holds it securely in place while healing occurs. This internal fixation technique frequently enhances bone healing, and allows for an earlier return to athletic activities.
|Intramedullary screw like those pictured on the left are placed into the shaft of the metatarsal to fix (or reduce) the fracture.|
|The final x-ray shows complete bone healing with new bone formation at the site of the original fracture.|