Arthrodesis implant

A resorbable implant for osteosynthesis for stiffening in a central joint (e.g., the proximal interphalangeal joint referred to as PIP) during arthrodesis or for stiffening in an end joint (e.g., the distal interphalangeal joint referred to as DIP) during arthrodesis and for osteosynthesis and stabilization of fractures of small bones of the human skeleton includes two shafts placed against each other. At least one fixing aid is located between the shafts. The fixing aid protrudes beyond a diameter of the shafts. Each shaft may have longitudinal grooves and transverse grooves. The implant is a magnesium-based material which can be resorbed by the human body. The disclosed implant has a relatively high tensile strength, excellent stability, optimal healing properties, and an optimally adapted resorption speed.