Wire mesh as a post-operative physiotherapy assistive device following peripheral nerve graft repair in the rat

Traditional methods of assessing nerve recovery following injury, including histomorphometry and electrophysiology, do not necessarily correlate with return of motor and sensory function. Accordingly, many investigators have used walking track analysis as an assessment of global functional recovery following sciatic, peroneal or tibial nerve injury. However, walking track reliability may be compromised by the development of flexion contractures secondary to neurologic loss. To prevent this, regular manual physiotherapy is recommended which is a time-consuming and often frustrating process for both the animal and investigator. We report the use of a wire mesh as a simple post-operative assistive device to provide constant physiotherapy. Twelve Lewis rats were randomized to one of two experimental groups. Each rat received a 2 cm posterior tibial nerve autograft. Postoperatively, animals in group 1 received manual physiotherapy, consisting of repeated flexion and extension exercises of the ankle, knee and hip every two weeks. Group 2 rats were permitted to climb freely on a 30 x 18 cm piece of wire mesh placed at a 45 degree angle within their cage. Group 2 rats received no manual physiotherapy throughout the course of the study. Serial walking tracks were performed every four weeks until sacrifice at sixteen weeks. There was no development of flexion contractures in the injured hind limbs of either group. There was no morbidity such as blisters associated with the use of the wire mesh. There was no statistical difference in walking track recovery between groups at any time period. However, a trend towards better functional recovery was seen in the group receiving constant physiotherapy via the wire mesh. The use of a wire mesh as a post-operative assistive device is an inexpensive, simple and reliable method to provide continuous physiotherapy to animals following denervation.