case_images: PMC6260377_01
case_images: (a, b) After the failed closed reduction, the alignment was good, but the patient cannot move the joint voluntarily. (c, d) X-rays showing the sesamoid bone interposed in the IP joint.
case_images: gr1.jpg
case_images: PMC6260377_01_gr1.jpg
case_images: fig0005
case_images: During the first medical examination, his hallux IP joint was fixed in hyperextension, restricting its movement (Fig. 1a, b). X-rays revealed that the sesamoid bone was interposed in the hallux IP joint, which was greatly expanded (Fig. 1c, d).
case_images: (a) Using the dorsal approach, the sesamoid bone can be seen interposed in the interphalangeal (IP) joint. (b) The sesamoid bone was pushed out with an elevator and reduced whilst pulling the distal phalanx. (c, d) After open repositioning, the unstable hallux IP joint underwent fixation using a 1.2-mm Kirshner wire. (e, f) During the last medical examination, no redislocation or osteoarthritis of the IP joint was noted.
case_images: gr2.jpg
case_images: PMC6260377_01_gr2.jpg
case_images: fig0010
case_images: We cut the lateral margin of the extensor hallucis longus tendon and confirmed that the sesamoid bone was interposed within the hallux IP joint (Fig. 2a). We fixed the IP joint with a 12-mm Kirshner wire (K-wire) (Fig. 2c, d). IP joint was a little limited (injured toe: 0  extension, 10  flexion; opposite toe: 0  extension, 45  flexion) (Fig. 2e, f). In case 2, the patient was a 17-year-old boy who was hit by a car whilst walking, which led to hallux IP joint hyperextension.
case_images: (a). X-rays during the first medical examination showing the posterior dislocation of the hallux interphalangeal (IP) joint. (b) After closed reduction, there was no macroscopic clear abnormality, but the joint cannot be moved. (c) The IP joint expanded a little, and a sesamoid spicule was noted in the IP joint. (d) Computed tomography showing the sesamoid spicule in the IP joint.
case_images: gr3.jpg
case_images: PMC6260377_01_gr3.jpg
case_images: fig0015
case_images: X-ray revealed dorsal dislocation of the hallux IP joint (Fig. 3a). His hallux had good alignment (Fig. 3b) but cannot be moved. X-ray revealed that the IP joint space was enlarged and a bony segment was interposed within the joint (Fig. 3c). Two days after the injury, we performed computed tomography (CT), which revealed that a sesamoid fragment was entrapped in the hallux IP joint (Fig. 3d).
case_images: (a) Using the dorsal approach, a plantar plate was interposed in the hallux interphalangeal (IP) joint. (b) The plantar plate was pushed on the plantar side by an elevator and repositioned whilst the distal phalanx was being pulled. (c) Although IP joint had no apparent instability, it underwent fixation using a 1.2-mm Kirshner wire. (d) During the last medical examination, no expansion or osteoarthritis of the IP joint was noted.
case_images: gr4.jpg
case_images: PMC6260377_01_gr4.jpg
case_images: fig0020
case_images: We cut the medial margin of the extensor hallucis longus tendon and confirmed the volar plate entrapped in the hallux IP joint (Fig. 4a). We pushed out the entrapped volar plate and sesamoid segment using an elevator to the plantar side and reduced the dislocation (Fig. 4b). We fixed the IP joint with K-wire (Fig. 4c). Three months after surgery, the hallux IP joint had full range of motion (injured toe: 0  extension, 25  flexion; opposite toe: 10  extension, 15  flexion), and the patient can walk well without pain (Fig. 4d).