case_images: PMC8055420_01
case_images: Radiographs of a left humeral shaft fracture. A fracture can be seen with the third and fourth fragments in the mid shaft. The AO-OTA classification of this fracture is 12-C3.
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case_images: PMC8055420_01_CRIOR2021-5548729.001.jpg
case_images: fig1
case_images: A 24-year-old man injured his upper limb during snowboarding and was diagnosed with a left humeral shaft fracture, which was categorized as 12-C3 based on the AO-OTA classification (Figure 1).
case_images: Radiographs just after the first surgery using IMN. The surgery was performed using a curved nail 8 days after the injury.
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case_images: PMC8055420_01_CRIOR2021-5548729.002.jpg
case_images: fig2
case_images: Osteosynthesis with IMN (diameter 7 mm) was performed at another hospital (Figure 2).
case_images: Radiographs at the first visit to our hospital. Nonunion was observed with callus formation on the medial side.
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case_images: fig3
case_images: On radiography, callus formation was observed (Figure 3), and bone scintigraphy showed high uptake at the nonunion site (Figure 4).
case_images: Bone scintigraphy showing intense accumulation at the nonunion site of the left humerus. The black circles indicate the nonunion site.
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case_images: fig4
case_images: On radiography, callus formation was observed (Figure 3), and bone scintigraphy showed high uptake at the nonunion site (Figure 4).
case_images: Radiographs just after the nonunion surgery was performed at our hospital. The gap between bone fragments seemed to be reduced by compression ((a) before nonunion surgery and (b) after the nonunion surgery). The compression screw appeared to be curved.
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case_images: fig5
case_images: Therefore, we performed exchange nailing and used the MultiLoc  Humeral Long Nail (DePuy Synthes, West Chester, USA), which is a thicker nail (diameter 8.5 mm) that uses more locking screws, including 5 proximal screws with 3 screw-in-screws and 3 distal screws (Figure 5).
case_images: Radiographs comparing the gap before and after the nonunion surgery. (a) The gap before the surgery and (b) the gap after the surgery. It can be noted that the gap was reduced by compression.
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case_images: fig6
case_images: The gap between the bone fragments was reduced (Figure 6).
case_images: Radiographs at 7 months after the surgery. Bony union was obtained. At 15 months after the second surgery, we performed surgery to remove all implants including the screws and the nail.
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case_images: fig7
case_images: Seven months after the operation, we confirmed bony union on radiography (Figure 7), and the patient had good functional recovery.
case_images: The compression screw removed after bone union was bent because of the compression force.
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case_images: fig8
case_images: When we removed the implants, we confirmed that the screw was bent (Figure 8).
case_images: Range of motion of the left shoulder and elbow joints was not limited at the final follow-up 2 years and 4 months postoperatively.
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case_images: fig9
case_images: At the final follow-up 2 years and 4 months after the nonunion surgery, the patient had full range of motion in the left shoulder and elbow joints (Figure 9) and did not experience any pain.