The case
A self-proclaimed dance team superstar presents after injuring her foot at a regional competition. She tried to finish the routine after landing awkwardly. But was having difficulty bearing weight. She applied ice overnight and despite ibuprofen is still in pain, and presents to the ED the next day.On her exam the neruovascular exam is normal, and she has pain along the proximal edge of the 5th metatarsal. You get an X-Ray.
The foot X-Ray taken of the foot of the patient with the foot problem
The Diagnosis
She has a fracture at the base of the 5th metatarsal (Jones fracture). These injuries are the result of an acute process and are seen at the point where the metaphysis meets the diaphysis within 1.5 cm of the metatarsal tuberosity extending towards or into the intermetatarsal joint. I like to think of these injuries as the scaphoid fracture of the foot, as this location of the metatarsal in particular has relatively poor blood supply. As you’d expect, some diagrams help here.
5th metatarsal fractures from foothyperbook.com/
This injury often occurs in athletes during a sudden change in direction with the heel off the ground. Most have pain along the lateral edge of the foot, with difficulty weight-bearing. They should be differentiated from a stress fracture by their abrupt onset of pain. Distinguishing between the two can be difficult. See the following XRays for example.
Management
The XRays of stress fractures and acute fractures can look similar, but the management differs significantly. Neurovascular compromise is, as always, a cause for immediate referral. Otherwise, injuries that are displaced >2mm will probably require internal fixation and should be see semi-urgently by an orthopedist. The rate of nonunion in displaced fractures managed conservatively may be up to 50%. This high rate could relate to the difficulty in adherence to a regimen of several weeks of non-weight bearing and casting. I did come across a randomized trial comparing surgery vs no surgery in which the authors compared 18 patients with casting alone, to 19 who received a bone screw. The risk of treatment failure and delay in return to sports were significantly greater in those managed with casting alone.
