The not-so-common navicular stress fracture is a serious type of overuse injury involving a boat-shaped bone of ankle present at the top of the foot arch. Commonly seen in athletes, gymnasts and people involved in sporting-type dynamics, the fracture is difficult to diagnose, which is why the incidence reports vary.
Navicular stress fracture is an injury marked by an incomplete crack in one of the mid-foot bones. Like all the other stress fractures, this overuse injury is a result of excessive and repetitive compressive forces that act on it during the weight bearing process. These forces initially cause a bone stress reaction and continuous damage eventually leads to fracture.
Navicular bone is specifically prone to fractures because immense mechanical exerts pressure on it during weight-bearing and a poor blood supply limits its healing ability. While repetitive stress is a common reason, there are other factors that make one more susceptible to this overuse injury:
Navicular stress fractures are difficult to diagnose and apart from imaging studies, physical examination findings are also taken into consideration. On physical examination, there is tenderness and pain when standing on toes or hopping is attempted. If X-ray doesn't show a fracture, a bone scan, CT or MRI can be used to confirm the diagnosis. These studies also show if the fracture is complete or incomplete.
Managing Navicular stress fractures serves to be a great challenge for surgeons partly due to the extensive force that the bone absorbs during movement and partly due to the poor blood supply. Whether the fracture will require surgical intervention or not depends on the severity of injury.
Stress reactions where the bone's outer part has not been damaged can be very well managed non-surgically.
In case of failure to heal or bone separation, surgical treatment is sought for proper bone realignment. This involves holding bone in place either with the help of pins and screws or a metal plate, followed by casting or splinting.
The immobilization period is followed by a rehabilitation phase during which strengthening and ankle mobility exercises are done to restore ankle strength and mobility before the foot is fit for functioning.
The ultimate key to reduce the chances of navicular stress fractures is prevention. Preventive steps that can be taken include: