Jones fracture

A person with a Jones fracture may not realize that a fracture has occurred. Diagnosis includes the palpation of an intact fibularis brevis tendon, and demonstration of local tenderness distal to the tuberosity of the fifth metatarsal, and localized over the shaft of the proximal metatarsal. Diagnostic X-rays include anteroposterior, oblique, and lateral views and should be made with the foot in full flexion. Differential diagnosis :- Proximal diaphysis, typically stress fracture.- Metaphysis: Jones fracture-Tuberosity: Pseudo-Jones fracture (avulsion fracture).- Os vesalianum, an accessory bone. Other proximal fifth metatarsal fractures exist, although they are not as problematic 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 likely an avulsion fracture caused by pull from the fibularis brevis tendon. An avulsion fracture at the base of the fifth metatarsal is sometimes called a "dancer's fracture" or a "pseudo Jones fracture", and usually responds readily to non-operative treatment. The X-ray appearance of the developmental "apophysis" in this area may have some resemblance of a fracture, but is not a fracture; it is the secondary ossification center of the metatarsal bone. It is a normal finding that occurs at this site in adolescents. If an injury to that area has occurred, the physician is often able to interpret certain radiographic clues to make the differentiation. An avulsion fracture at this location is typically extra-articular and oriented transversally as compared to the longitudinal orientation of an unfused apophysis. ==Treatment==

Casting Initial treatment is typically in a cast, without any weight being placed on it, for at least six weeks. For persons who are not athletes, surgery might not be recommended unless healing does not occur after a trial of cast treatment. ==Prognosis==

For several reasons, a Jones fracture may not unite. The diaphyseal bone (zone II), where the fracture occurs, is an area of potentially poor blood supply, existing in a watershed area between two blood supplies. This may compromise healing. In addition, there are various tendons, including the fibularis brevis and fibularis tertius, and two small muscles attached to the bone. These may pull the fracture apart and prevent healing. Zones I and III have been associated with relatively guaranteed union and this union has taken place with only limited restriction of activity combined with early immobilization. On the other hand, zone II has been associated with either delayed or non-union and, consequently, it has been generally agreed that fractures in this area should be considered for some form of internal immobilization, such as internal screw fixation. These zones can be identified anatomically and on x-ray adding to the clinical usefulness of this classification. Surgical intervention is not, by itself, a guarantee of cure and has its own complication rate. Other reviews of the literature have concluded that conservative, non-operative, treatment is an acceptable option for the non-athlete. Image:Gray288.png|Anatomy of the fifth metatarsal. Image:Jones fracture, healing zones according to Polzer.jpg|3 zone description Image:Jones fracture, healing zones according to Polzer 2.jpg|2 zone description == References ==