|The fifth metatarsal.|
A Jones fracture is a fracture of the fifth metatarsal of the foot. The fifth metatarsal is at the base of the small toe, and 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 middle/outside area of their foot, swelling, and difficulty walking.
It may not be an obvious fracture to the patient, and could be mistaken for a sprain.
The diagnosis is made with general, diagnostic x-rays consisting of three views: AP or anteroposterior view, oblique view, and lateral view. These should be made with the foot in full flexion.
Treatment of an acute Jones fracture that is not significantly displaced consists of a cast or walking boot for 4-8 weeks. Patients should not place weight on the foot until instructed by their doctor. Three-fourths of those treated conservatively should heal.
In the case of acute fracture in an athlete, a single screw with or without bone graft can be placed into the 5th metatarsal through the proximal end. Per doctor preference and the size of the metatarsal anything from a 4.5mm to 6.5mm, cannulated or solid screw can be used. The length of the screw also varies depending on where the fracture is and again how long the metatarsal is. Even after the screw is inserted some nonunions may still occur in which case a bone graft is done, the graft usually coming from the hip, or the distal tibia.
Jones fractures can become chronic conditions if the fracture fails to unite. If this is the case, orthopedic surgery will likely be recommended to secure the fracture in place with a screw. The more common conservative treatment is to spend more time in a cast, up to 20 weeks.
A Jones fracture often does not heal for several reasons. This location is an area of poor blood supply. In medical terms it is a watershed area between two blood supplies. In addition there are various tendons attaching in the area pulling the fracture apart causing motion at the site of healing.
Other proximal 5th metatarsal fractures
Other proximal 5th metatarsal fractures exist. If the fracture enters the intermetatarsal joint it is a Jones fracture. If the fracture enters the tarsometarsal joint then it is an avulsion fracture caused by pull from the peroneus brevis.
Dancer's fracture is a fracture caused by a tendon pulling off a small portion of bone. There are two small muscles on the end of this bone, one of the main causes of the bone piece not rejoining; non-union or delayed union is common. Other treatments commonly encouraged are increased intake of vitamin C and calcium.