case_images: PMC10695686_01
case_images: Three-dimensional computed tomography images at the time of injury: (a) patient 1; (b) patient 2; (c) patient 3.
case_images: CRIOR2023-5008141.001.jpg
case_images: PMC10695686_01_CRIOR2023-5008141.001.jpg
case_images: fig1
case_images: Patient 1 was a 76-year-old woman with a left distal humerus fracture (AO/OTA classification: 13A2.3), patient 2 was an 82-year-old woman with a left distal humerus fracture (AO/OTA classification: 13A2.3), and patient 3 was a 34-year-old woman with a left distal humerus fracture (AO/OTA classification: 13C3, combined with fractures of the olecranon and radial neck) (Figure 1).
case_images: UNC method in practice (circled area is the medial epicondyle of the humerus). (a) The ulnar nerve (white arrowhead) is kept attached to the triceps brachii muscle, and the muscle is divided longitudinally about 1 cm lateral to the ulnar nerve (white arrow). (b) Distally, the Osborne ligament (black arrow) is first dissected, and the ulnar nerve is identified. Next, the ulnar head of the flexor carpi ulnaris with the ulnar nerve is elevated under the periosteum. (c) After ulnar nerve dissection with the UNC method, the ulnar nerve is approximately semicircumferentially covered by the triceps brachii and flexor carpi ulnaris muscles. The distal dissection should extend to the point where the medial plate can be applied.
case_images: CRIOR2023-5008141.002.jpg
case_images: PMC10695686_01_CRIOR2023-5008141.002.jpg
case_images: fig2
case_images: Next, the triceps brachii was longitudinally dissected approximately 1 cm from the ulnar nerve, with the triceps still attached to the ulnar nerve (Figure 2(a)). Distal to the medial epicondyle, the Osborne ligament was first dissected to identify the ulnar nerve, and the ulnar head of the flexor carpi ulnaris muscle was then raised under the periosteum with the ulnar nerve (Figure 2(b)). With these maneuvers, the ulnar nerve was elevated, proximally wrapped around the triceps brachii muscle, and distally wrapped around the flexor carpi ulnaris muscle (Figure 2(c)).
case_images: Position of the ulnar nerve and medial plate with the elbow flexed at 75 degrees. When the triceps muscles are sutured together after plate fixation, the ulnar nerve (white arrowhead) returns to its anatomical position and does not interfere with the medial plate (white arrow).
case_images: CRIOR2023-5008141.003.jpg
case_images: PMC10695686_01_CRIOR2023-5008141.003.jpg
case_images: fig3
case_images: After bony fixation, the ulnar nerve was returned to its anatomical position by suturing the divided triceps muscle and fascia of the flexor carpi ulnaris (Figure 3).
case_images: X-ray images at the final follow-up: (a) patient 1; (b) patient 2; (c) patient 3.
case_images: CRIOR2023-5008141.004.jpg
case_images: PMC10695686_01_CRIOR2023-5008141.004.jpg
case_images: fig4
case_images: The postoperative follow-up period was 6 to 8 months, and all three patients achieved bony union (Figure 4).