Plantar incision with severe muscle injury can be a cause of long-lasting postsurgical pain in the skin

Although chronic local inflammation in deeper tissues after skin wound healing might produce chronification of acute postsurgical pain, its mechanisms have not been fully elucidated. We hypothesized that muscle injury and severe would prolong pain by central nervous system mechanisms. After approval the Animal Care Committee, experiments were performed Male Sprague-Dawley rats weighing 250–300 g. Plantar incision plantar combined with cryoinjury flexor digitorum brevis made group group, respectively. Pain-related behaviors assessed, inflammatory cells isolated from injured analyzed flow cytometry. Spinal microglial activation was assessed Iba-1 staining. Mechanical hyperalgesia day 5 to 8 spontaneous pain-related behavior 3 7 significantly greater than (P < 0.05), whereas there no significant difference between two groups thermal hyperalgesia. In number on 4 larger spinal expression levels days higher those 0.05). Surgical deep accompanying induced prolonged persistence but a mechanism involving at level cord.