|Classification and external resources|
The fifth metatarsal.
A Jones fracture is a fracture of the diaphysis of the fifth metatarsal of the foot. The fifth metatarsal is at the base of the small toe. The proximal end, where the Jones fracture occurs, is in the midportion of the foot. Patients who sustain a Jones fracture have pain over this area, swelling, and difficulty walking. The fracture was first described by British orthopedic surgeon Sir Robert Jones (who sustained this injury himself while dancing) in the Annals of Surgery in 1902.
A patient with a Jones fracture may not realize that it is a fracture, and could mistake it for a sprain.
The diagnosis is made with general diagnostic x-rays. These need to be taken from anteroposterior, oblique, and lateral views. They should be made with the foot in full flexion.
If a Jones fracture is not significantly displaced, it can be treated with a cast, splint or walking boot for four to eight weeks. Patients should not place weight on the foot until instructed by their doctor. Three-fourths of fractures treated like this should heal.
In the case of acute fracture in an athlete, a dynamic compression plate can be placed on the tension side of the fracture, K-Wire with monofilament wire in a figure 8 fashion due to the nature of a transverse fracture. Internal fixation with cortical or cancellous screw would require an oblique fracture that could be addressed through "The rule of 2's" in regards to Internal fixation with screws.
This injury must be differentiated from the physiologic developmental apophysis commonly and normally occurring at this site in adolescents. Differentiation is possible by characteristics such as absence of sclerosis of the fractured edges (in acute cases) and orientation of the lucent line: transverse (at 90 degrees) to the metatarsal axis for the fracture (due to avulsion pull by the peroneus brevis muscle inserting at the proximal tip) - and parallel to the metatarsal axis in the case of the apophysis.
If a Jones fracture fails to unite (malunion or non union), which is a common problem with these fractures, it can become a chronic condition. If this is the case, podiatrists will likely recommend that the patient spend more time in a cast, up to twenty weeks.
For several reasons, a Jones fracture often does not heal. The diaphyseal bone, where the fracture occurs, is an area of poor blood supply. In medical terms, it is a watershed area between two blood supplies. This makes healing difficult. In addition, there are various tendons, including the peroneus brevis and fibularis tertius, and two small muscles attached to the bone. These may pull the fracture apart and prevent healing.
Other proximal fifth metatarsal fractures
Other proximal fifth metatarsal fractures exist, although they are not as severe as a Jones fracture. If the fracture enters the intermetatarsal joint, it is a Jones fracture. If, however, it enters the tarsometatarsal joint, then it is an avulsion fracture caused by pull from the peroneus brevis. An avulsion fracture is sometimes called a Pseudo-Jones fracture or a Dancer's fracture.
- Jones, Robert (Jun 1902). "I. Fracture of the Base of the Fifth Metatarsal Bone by Indirect Violence.". Ann Surg 35 (6): 697–700. PMC 1425723. PMID 17861128.
- Jones fracture - wheelessonline.com