case_images: PMC10879349_01
case_images: Flow chart of the study.
case_images: fneur-15-1351407-g001.jpg
case_images: PMC10879349_01_fneur-15-1351407-g001.jpg
case_images: fig1
case_images: We report a case of a 11-year-old child who approached the Centre for Rehabilitative Medicine "Sport and Anatomy" of the University of Pisa for UN palsy due to acute nerve transection at his left hand, following a domestic accident (Figure 1).
case_images: Clinical presentation of the ulnar nerve injury. (A) Representative picture demonstrating the surgical incision in close proximity to the Guyon's canal; (B) Flattening of the palmar arch of the hand due to a reduction of MCP joint flexion; (C) The occurrence of a positive Froment's sign is evident as a bending of the distal tip of the thumb when attempting to pinch a piece of paper between the thumb and the index finger.
case_images: fneur-15-1351407-g002.jpg
case_images: PMC10879349_01_fneur-15-1351407-g002.jpg
case_images: fig2
case_images: The nerve lesion, secondary to a clear-cut injury (i.e., knife wound) to the wrist, occurred upstream of Guyon's canal (Figure 2A), and resulted in important motor and sensory disabilities, due to the involvement of both sensory and motor branches. The patient came to our observation approximately 1 month after surgery. Upon initial examination, the patient presented a classic claw hand deformity, a hypotrophy of interossei and lumbrical muscles, progressive retraction, joint stiffness, and flattening of the transverse metacarpal arch (Figure 2B). The patient's primary complaint was intense pain, along with stiffness and hand musculature weakness. Again, a hyperextension (10 -15 ) MCP joint of the thumb was evident (Jeanne's sign) along with the hyperflexion of the IP joint (Froment's sign) (Figure 2C).
case_images: Examples of the two splints for ulnar nerve injury. Pictures of the two static splints designed to prevent hand clawing (A) and MCP joints hyperextension (B), respectively.
case_images: fneur-15-1351407-g003.jpg
case_images: PMC10879349_01_fneur-15-1351407-g003.jpg
case_images: fig3
case_images: Finally, two custom-made splint orthoses of thermo-modeling materials were provided (Figure 3). In detail, the first splint was positioned at MCP joints of 4th and 5th fingers to keep them at 70  in a flexed position thus preventing their clawing (Figure 3A). The second one was designed for all MCP joints and positioned at 45  to prevent hyperextension while allowing active flexion and supporting the transverse arch of the hand (Figure 3B).