10 0 monofilament epineurial microstitch

To investigate the skilled functional outcome, limb muscle reinnervation model was designed (Figures 1(a) and 1(b)). Briefly, all rats were anesthetized with isoflurane (1.5–2%) and a mixture of 30% N₂O and 70% O₂. With the longitudinal incision at the right proximal upper limb, the musculocutaneous nerve (MCN) and the radial nerve were exposed before their innervation of the biceps muscle and the triceps muscle, respectively. For the nerve injury group, both nerves were transected and tightly ligated to prevent the nerve stump regeneration. For the nerve repair group, both nerves were exposed in the same fashion. Then, the stumps of both nerves were immediately anastomosed through a 10-0 monofilament epineurial microstitch (Ethicon, USA) following the nerve transection. For the control group, sham operations were performed, where MCN and radial nerve were exposed as in the injury group, but received no further manipulations.

The paw intrinsic muscle reinnervation model was established to investigate its impact on the skilled functional outcome after PNI (Figures 1(a) and 1(c)). Under anesthesia, a longitudinal incision was placed at the right distal forearm of the rat. The medial and ulnar nerves were explored at the wrist level. Both of the nerves were transected and ligated in the nerve injury group, or transected and then repaired through a 10-0 monofilament epineurial microstitch (Ethicon, USA) in the repair group. In contrast, the nerves were only exposed without any further procedure in the control (sham) group.