A Disruption in the Midfoot

Author: Michael Lee, DO

Peer-Reviewer: Brandon Godfrey, MD

Editor: Alex Tomesch, MD

A 26 year old female presents with left midfoot pain after tripping and falling down the stairs while intoxicated. Radiograph of her foot is below.

Figure 1- Lateral Radiograph of Left Foot (Author's Own Image)

What is your diagnosis?
What findings may be present on physical exam?
What imaging can help make the diagnosis?
What is your management in the ED?

-- see below for answers--

What is your diagnosis?

Navicular dislocation with an associated comminuted navicular fracture.

Pearl: Fracture-dislocation of the navicular is a relatively rare injury with an estimated incidence of 0.26% of all fractures. It is most commonly the result of high-energy trauma. [1]

What findings may be present on a physical exam?

Physical exam findings may include edema over the dorsomedial aspect of the foot, tenderness to palpation of the "N spot" which is the proximal dorsal region of the navicular bone, and pain with active inversion or passive eversion of the foot. [2]

3. What imaging should be obtained in the ED?

Anteroposterior, lateral, and oblique radiographs of the foot should initially be obtained with the patient weight bearing if possible. Computed tomography should also be considered as it will provide more details in terms of the fracture, relation to other midfoot bones, and any other bony injuries that may be difficult to appreciate on radiographs. [3]

4. What is your management in the ED?

For isolated navicular fractures, closed reduction can be attempted, and the lower extremity can be placed in a short-leg cast. However, successful closed reduction is often difficult to achieve due to the swelling, and surgical management is often required. [3]

Pearl: Isolated navicular dislocations are extremely rare with fewer than 20 reported cases since 1924. [1] The goal in these cases should be early stable reduction as it decreases the risk of vascular compromise. [2]

In cases of navicular fracture-dislocation, there does not appear to be a consensus on management as it is an uncommon injury; however, some type of surgical intervention will likely be required to maximize functional outcome. [1]

Because of the complexity and rarity of this injury, it would be prudent to consult orthopedic surgery for further guidance.

REFERENCES

1. Jimenez I, Rodriguez-Alvarez JP, Navarro-Navarro R. Dorsal Fracture-Dislocation of the Tarsal NavicularCase Report and Review of a Rare Injury. J Am Podiatr Med Assoc. 2017;107(3):226-230. doi:10.7547/15-103

2. Ansari MAQ. Isolated complete dislocation of the tarsal navicular without fracture: A rare injury. Ci Ji Yi Xue Za Zhi. 2016;28(3):128-131. doi:10.1016/j.tcmj.2014.11.003

3. Ramadorai MUE, Beuchel MW, Sangeorzan BJ. Fractures and dislocations of the tarsal navicular. J Am Acad Orthop Surg. 2016;24(6):379-389. doi:10.5435/JAAOS-D-14-00442