Fig 1.
Surgical view and imaging of macrodactyly.
(A) Enlargement in the digital nerve in type II macrodactyly (black arrows). (B, C) Adipose overgrowth and bone hypertrophy can be assessed by X-ray and magnetic resonance imaging; however, these techniques cannot accurately display nerve enlargement and functional damage.
Fig 2.
Median nerve damage and compensatory communication branch from ulnar nerve (BA type) in macrodactyly, which was investigated by electromyogram.
(A to D) Median nerve damage. In a typical patient without a communication branch from the ulnar nerve to the median nerve, the median nerve was stimulated and showed a prolonged latency and decreased amplitude of electrophysiological signals in the digital nerve of the second finger (A) before surgery and (B) during surgery. Simultaneously, when the median nerve was stimulated, no electrophysiological signals were recorded in the digital nerve of the second finger (C), which suggested no compensatory communication branch from ulnar nerve to median nerve. When the ulnar nerve was stimulated, a normal electrophysiological signal was recorded in the digital nerve of the fifth finger (D). (E to H) Berrettini anastomosis (BA) type. In a typical patient with a communication branch from the ulnar nerve to the median nerve, when the median nerve was stimulated a prolonged latency and decreased amplitude of electrophysiological signals were recorded in the digital nerve of the second fingers before surgery (E) and during surgery (F). Simultaneously, when the ulnar nerve was stimulated, a significant electrophysiological signal was recorded in the digital nerve of the second finger (G), which suggested a compensatory communication branch from the ulnar nerve to the median nerve. We stimulated the ulnar nerve and recorded a normal electrophysiological signal in the digital nerve of the fifth fingers (H).
Fig 3.
Hematoxylin and eosin (HE) stained paraffin sections and toluidine blue–stained resin sections of the macrodactylous enlarged nerve and the normal digital nerve tissue.
(A) HE-stained paraffin sections of the normal digital nerve tissue (scale bars, 50 μm). (B) HE-stained paraffin sections of macrodactylous nerve showed an overgrowth of the nerve bundle, which were separated by thickened epineurium and perineurium (B, red arrows) (scale bars, 50 μm). (C) Toluidine blue–stained resin sections of the normal digital nerve tissue (scale bars, 100 μm). (D) Toluidine blue–stained resin sections of macrodactylous nerves were extensively infiltrated with adipocytes (D, black arrows) and displayed a hyperplasia in interfascicular epineurium (D, red arrows) (scale bars, 100 μm). (E) Intensive distribution of myelinated nerve was found in the normal digital nerve tissue (E, red arrows) (scale bars, 50 μm). (F) A clear decrease in the myelination of the macrodactylous nerve was apparent (F, red arrows). The lipid droplets invaded the interfascicular epineurium and the perineurium (black arrow), but not the endoneurium of the nerve bundle (scale bars, 50 μm).
Fig 4.
Ultrastructure and immunofluorescent staining of the macrodactylous enlarged nerve (MEN) and normal digital nerve (NDN) tissue.
(A) NDN tissue. Myelinated fibers were intensively distributed (scale bars, 5.0 nm). (B) MEN tissue showed a significant decrease in the number of myelinated nerve fibers compared with those in NDN tissue (scale bars, 5.0 nm) and collagen density of the nerve fibers was distinctly increased (B, white arrows) (C) The diameter of the myelinated fiber was apparently reduced in the new regenerative nerve structures (C, yellow arrows), which was found in Berrettini anastomosis (BA) (scale bars, 5.0 nm). (D to F) Compared with NDN tissue, myelin sheath damage was found in both MEN and BA tissues (E, white arrows), while the density of the neurofilament (NF) showed no significant change in the myelinated fiber (D, E, F, yellow arrows) (scale bars, 500 nm). (G to I) The density of the NF of unmyelinated fiber decreased (G, H, I, yellow arrows). (J) Compared with NDN tissue, the number of myelinated and unmyelinated fibers decreased in MEN tissue, while new regenerative nerve structures (BA) increased to nearly normal level (**P < .01). (K to N) Immunofluorescent staining showed dense distribution of NF (red) in NDN tissue (K, L), while the density of NF expression decreased, the fluorescence intensity significantly decreased in some areas (M, N, yellow arrows), which showed an aberrant distribution of NF in the macrodactylous nerve tissue (scale bars, 100 μm).
Fig 5.
Diagnostic and treated procedures of the enlarged nerve for patients in with type Ⅱ macrodactyly.