Open Navicular Dislocation With Midfoot Dissociation in a 45-Year-Old Man

The American Journal of Orthopedics. 2017 May;46(3):E186-E189

June 20, 2017|The American Journal of Orthopedics

Dean N. Papaliodis, MD;Timothy T. Roberts, MD;Maria Vanushkina, MD;Shankar Das, MD;Jordan Lisella, MD;John DiPreta, MD

Traumatic dislocation of an intact tarsal navicular is an uncommon injury. In this article, we report a case of open medial navicular dislocation in a 45-year-old man. The injury was managed with open reduction and stabilization with Kirschner wires within the acute period. Ten months after injury, the patient developed avascular necrosis of the navicular and exhibited progressive collapse of the medial midfoot. He underwent naviculocuneiform arthrodesis 1 year after the index surgery. Two years after fusion, he was pain-free and ambulating independently. Successful treatment of midfoot fractures and dislocations requires an intimate understanding of anatomy, biomechanics, and both short- and long-term sequelae of injury.

Take-Home Points

Stability of the foot is dependent on both the medial and lateral longitudinal columns; injuries to a single column alone are extremely rare.
Midfoot fractures that are recognized and treated early have generally favorable outcomes compared to those identified in a delayed fashion.
The most frequent complication of navicular dislocation is AVN, which is said to occur in as many as 25% of cases.
Many specialists agree that navicular dislocations are best treated with open reduction.
Ultimately, the goals of surgical intervention are to minimize pain and to establish stability of the plantigrade foot.

Traumatic dislocation of the tarsal navicular (especially without a navicular body fracture) is uncommon.¹ The regional anatomy and ligamentous architecture confer stability to the midfoot.^2-6 Navicular dislocation is part of a complex disruption involving structures in the adjacent column.⁶

Navicular dislocation has been associated with several bony and soft-tissue injury patterns, including comminuted intra-articular fracture of the calcaneus and associated calcaneocuboid joint subluxation; fracture and subluxation of the calcaneocuboid joint; fracture-dislocation of the calcaneocuboid joint with fractures of the third and fourth metatarsals; and a combination of fractures of the intermediate cuneiform, the second through fourth metatarsals, and the cuboid.^4–11In this article, we report a case of open complete navicular dislocation with talar head fracture and associated subtalar and calcaneocuboid subluxations in a 45-year-old man. The injury was managed with open reduction and stabilization with Kirschner wires (K-wires), which later required naviculocuneiform and intercuneiform fusion for posttraumatic avascular necrosis (AVN). The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 45-year-old man sustained blunt trauma to the right foot in a high-speed head-on collision. He was hemodynamically stable with isolated complaints of pain in the foot. Physical examination revealed a grossly open 10-cm wound extending from the heel pad medially to the dorsal surface of the navicular. The navicular was clearly visible through the wound.

Plain radiographs of the foot showed complete medial dislocation of the navicular with complete disruption of all 3 naviculocuneiform joints (Figures 1A-1C).

The subtalar and calcaneocuboid joints were subluxed but remained ligamentously stable on subsequent examination. There was marked subcutaneous soft-tissue swelling surrounding the injury.

On day of presentation, the patient was taken to the operating room for irrigation, débridement, reduction of the joints, and primary closure of the right foot wound. Minimal contamination was noted. Attempted gentle reduction maneuvers included distraction, adduction, and pronation of the forefoot with concomitant lateral pressure on the navicular.

Initial reduction attempts were unsuccessful because of interposition of the flexor hallucis longus and peroneus longus tendons. Retraction of these plantar structures with the mentioned maneuvers resulted in a palpable and visible naviculocuneiform reduction. Intraoperative radiographs showed adequate reduction of the naviculocuneiform, with restoration of the normal subtalar and calcaneocuboid alignments. The naviculocuneiform joints remained grossly unstable, however, and would have readily dislocated in the absence of manual pressure.

Therefore, two 0.062-inch K-wires were passed from the medial cuneiform across the talonavicular joint. Intraoperative radiographs (Figures 2A, 2B) and a postoperative radiograph (Figure 3) showed adequate alignment of the naviculocuneiform articulations.

An especially prominent medial navicular was noted on postreduction films. Initially, this suggested inadequate reduction of the naviculocuneiform joints, but, on close radiographic examination of each naviculocuneiform joint and imaging of the contralateral foot, we determined that the prominence represented a type III accessory navicular, also known as a cornuate navicular. Contralateral imaging showed an identical and asymptomatic medial prominence.

After surgery, the patient was made non-weight-bearing in a splint, received intravenous antibiotics for 48 hours, and was discharged shortly thereafter. Radiographs at 3 and 6 weeks after injury showed maintenance of the reduction. K-wires were removed at 6 weeks. The patient was advanced to partial weight-bearing at 6 weeks and to full weight-bearing at 3 months.

Over succeeding months, the patient developed pain accompanied by significant midfoot deformity and was found to have navicular collapse consistent with AVN and posttraumatic arthritis (Figures 4A, 4B).

Ten months after the initial procedure, instrumented fusion of the naviculocuneiform and intercuneiform complex was performed, along with chondral decortication, navicular decompression, and iliac crest grafting. The patient was made non-weight-bearing in a cast for 6 weeks and was then slowly, progressively advanced.

Twenty-four months after fusion, the patient was fully ambulatory with no significant discomfort or disability.

The most recent radiographs showed adequate alignment and bony fusion (Figures 5A, 5B).

References

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