A spinal cord device comprises a body formed of a biocompatible, biodegradable matrix. The body includes proximal, cranial and distal, caudal surfaces for connection to two ends of an injured spinal cord after removal of an injured section and has through channels with openings in the cranial and caudal surfaces for connection of descending motor pathways and ascending sensory pathways. The device has a transversal diameter (Dt), an anteroposterior diameter (Da) and a length (L), wherein Dt is from 9 to 13 mm and the ratio anteroposterior diameter/transverse diameter (RAPT) is from 0.5 to 1.0 and wherein the position and dimension of the channels, RAPT value, and cranial surface area and/or caudal surface area of the device are adopted to the shape, level, dimension of white and gray matter, and size of the injured spinal cord for optimal connection between spinal cord tracts. Kits and methods employ such devices.