To the Editor:

Thank you for your comments regarding our manuscript. We found three additonal reports of isolated plantar dislocation of the intermediate cuneiform after publication of our manuscript ( 1,2,. Therefore, our case report is in fact the fifth example of this injury that has been reported.

Regarding the mechanism of this rare injury, we agree with the mechanisms you (1) and Dysek (2) proposed that it is caused by blunt trauma to the dorsum of the foot.

However,our anatomic dissection showed that isolated plantar dislocation of the intermediate cuneiform did not occur only with blunt trauma to the dorsum of the foot. This wedge shaped bone could not displace in a plantar direction without opening the plantar window. Our message was that when the force was applied to the dorsum of the foot, the transverse and longitudinal arches were depressed, thereby widening the plantar window around the intermediate cuneiform sufficiently to allow extrusion of that bone plantarward. We think our speculation gave support your theory.

1.Hubbell JD, Goldhagen P, O'Connor D, Denton JR. Isolated Plantar Fracture-Dislocation of the Middle Cuneiform. American Journal of Orthopedics.1998;3:234-6

2.Dysek M, Izolovane' vykloubeni. II. Kostiklinove. Acta Chir Orthop Traumatol Chec. 1975; 42:390-92

3. Khatri M, Briggs PJ. Isolated plantar dislocation of the intermediate cuneiform. A case report and review of the literature. The Foot 2001; 11: 215-217.

To the Editor:

The injury complex described in this case report is truly a rare occurrence and one that we described in a case report in The American Journal of Orthopedics in 1988(1). Our literature review at that time also discovered that this had previously been described in the Czechoslovakian literature by Dysek in 1975(2).

In both our case report and that of Dysek, the mechanism of injury was due to blunt trauma to the dorsum of the foot. The case reported by Nishi was similar to ours in that the middle cuneiform fracture in figure 2 is an avulsion fracture representing a disruption of the bony attachment of the dorsal naviculcuneiform ligament to the middle cuneiform.

John D. Hubbell, M.D.

References:

1.Hubbell JD, Goldhagen P, O’Connor D, Denton JR. Isolated Plantar Fracture-Dislocation of the Middle Cuneiform. American Journal of Orthopedics.1998;3:234-6

2.Dysek M, Izolovane’ vykloubeni. II. Kostiklinove. Acta Chir Orthop Traumatol Chec. 1975; 42:390-92