Jones Fractures May Be More Stable With Metal Plates

Jones fractures typically occur near where the fifth metatarsal connects to the ankle. The small pinky toe is connected to the ankle by the fifth metatarsal bone. Fractures that happen here often are caused because of repetitive stress that happens during any weight bearing activities, making athletes vulnerable to this injury. Current care standards include implanting a screw into the canal of the fifth metatarsal bone in order to draw the fractured ends back together. As much as 30% of fractures repaired with a screw can reoccur.

12 pairs of foot models were divided into 2 groups by the researchers with one foot from each pair being assigned to have the traditional screw repair and the other having the plate repair to test durability of the plate versus screw. After Jones fractures were created and treated with either method, the fifth metatarsal was removed from the foot model.  Each bone underwent load bearing testing until failure occurred by applying force that was increased every 10 cycles until a failure occurred, this process was to recreate stresses placed on the fifth metatarsal that would be seen under normal foot motions of running and walking.

Researchers noted during the testing process that failures occurred where the bone connected with the implant, either the bone pulled away from the plate or the screw pulled out of the bone. It was observed that on average the screw group failed at 37.3 cycles compared to plate group which failed at 63.9 cycles. The screw was able to withstand 21.7 pounds of force on average, while the plate was able to withstand 35.8 pounds of force on average.

Further research is needed and these results are early, but results are promising indicating that repairing Jones fractures with a plate is safe and a more effective technique than the technique that is accepted and currently being used, helping to avoid a second event according to the researchers.