Introduction:
The common treatment for hallux interphalangeal joint dislocation is closed reduction, but some cannot be reduced by interposition of the sesamoid or the plantar plate in the interphalangeal joint, and such cases need open reduction.
Presentation of case:
In case 1, the patient was a 17-year-old boy who was injured when a motorcycle fell on his right hallux. X-ray revealed Miki type 2 IP joint dislocation. Because closed reduction failed, open reduction via the dorsal approach to the hallux IP joint was performed. In case 2, the patient was a 17-year-old boy who was hit by a car whilst walking. X-ray revealed Miki type 2 dorsal dislocation of the hallux IP joint. After closed reduction, X-ray and CT revealed that the IP joint dislocation changed from Miki type 2 to type 1. Open reduction was performed through the dorsal approach.
Discussion:
Fifteen cases of Miki type 2 changed to type 1 after closed reduction, and type 1 dislocation is often overlooked, leading to some chronic cases. X-rays should be performed after repositioning, specifically in lateral and oblique views.
Conclusion:
We experienced two cases of irreducible dislocation of the hallux IP joint. One of our cases was reclassified from Miki type 2 to type 1, but we did not overlook the failed closed reduction, as we performed CT. Hence, we recommend additional lateral-view X-rays and/or CT imaging.