case_images: PMC11420005_01
case_images: (A) AP view of the fracture before percutaneous fixation with K-wires. (B) Lateral view. The images show a humeral supracondylar linear fracture, which could have been treated conservatively, but the patient received K-wire fixation at another hospital. (C) Left distal humerus supracondylar fracture, status post closed reduction and internal fixation with cross k-wires fixation. (D) Marked claw deformity of the 4th and 5th fingers. (E) Intrinsic muscle atrophy with weakness in thumb and finger adduction (positive Froment sign and Wartenberg sign).
case_images: fped-12-1398624-g001.jpg
case_images: PMC11420005_01_fped-12-1398624-g001.jpg
case_images: F1
case_images: Upon initial evaluation at other hospital, the x-ray revealed left distal humerus supracondylar linear fracture (Figures 1A,B), which could be treated nonoperatively with long arm cast. However, on the same day, he underwent closed reduction and cross k-wires fixation (Figure 1C). During the physical examination at our OPD, the patient exhibited numbness in both the dorsal and volar regions of the hypothenar area, marked claw deformity of the 4th and 5th fingers (Figure 1D), intrinsic muscle atrophy with weakness in thumb and finger adduction (positive Froment sign and Wartenberg sign) (Figure 1E), and diminished power in 4th and 5th finger flexion.
case_images: (A,B, elbow). (A) Scars of previous k-wires fixation. (B) No notable adhesions, evident ruptures, or neuroma formations were found along the ulnar nerve pathway. However, slight scarring within nerve fascicles suspected to be caused by K-wire penetration was observed. (Above green patch) (C-E, Forearm). (C) AIN and the PQ muscle were exposed. (D) AIN was traced to the AIN- PQ muscle junction first, and further dissected distally by releasing the PQ muscle. (E) The motor component of the ulnar nerve, located between sensory component and the dorsal cutaneous branch of ulnar nerve, was further dissected. (F) AIN was transferred to the dorsal surface of ulnar nerve motor component. (White arrow). AIN, Anterior interosseous nerve; PQ, pronator quadratus; UN, ulnar nerve; DCB, dorsal cutaneous branch.
case_images: fped-12-1398624-g002.jpg
case_images: PMC11420005_01_fped-12-1398624-g002.jpg
case_images: F2
case_images: A penetrative scar was observed on the medial side of the elbow, located between the medial epicondyle and olecranon (Figure 2A). However, slight scarring within nerve fascicles suspected to be caused by K-wire penetration was observed (Figure 2B). AIN and the PQ muscle, which were located beneath these structures (Figure 2C). After confirming that the PQ muscle response was robust following electric stimulation of the AIN, the AIN was traced to the AIN-PQ muscle junction. It was then further dissected distally by releasing the PQ muscle, thereby gaining additional nerve length (Figure 2D). Under the microscope, the motor component of the ulnar nerve, located between sensory component and the dorsal cutaneous branch of ulnar nerve, was further dissected and prepared to serve as the recipient nerve (Figure 2E). Epineurial and perineurial windows measuring 2 mm were created and then the anterior interosseous nerve (AIN) was transferred to the dorsal surface of the ulnar nerve motor component (Figure 2F).
case_images: (A) After a six-month OPD follow-up, the 4th/5th finger claw deformity returned to normal. (B) No atrophy of intrinsic muscle or weakness in thumb and finger adduction.
case_images: fped-12-1398624-g003.jpg
case_images: PMC11420005_01_fped-12-1398624-g003.jpg
case_images: F3
case_images: After a six-month OPD follow-up, the 4th/5th finger claw deformity returned to normal (Figure 3A) without intrinsic muscle atrophy (Figure 3B).