Post-traumatic stiffness of the elbow joint is a frequent result of immobilisation leading to severe disability in the use of the upper extremity. Recognition of the tendency to stiffness leads to the assumption that the strong self-healing forces of the capsule and ligament apparatus converts the initial instability of the joint after ligament disrupture, into a high-grade undirected stability following immobilisation. Directed stability as it is produced by the natural ligament apparatus of the joint on the other hand produces a guided movement of the joint in one direction. These theoretical considerations lead to the idea that the self-healing forces of the ligament apparatus under continuous guided movement of the joint will result in a stable and movable joint to allow healing of the compromised soft tissue envelope and moreover to maintain free soft tissue access without compromising the stability. For this a unilateral fixator with motion capacity was developed. The joint bridging application approaches the humerus and ulna from the lateral side. The proximal pin group is inserted into the proximal region of the humerus respecting the radial nerve. The distal pin group is implanted from the dorsal side into the middle third of the ulna. The fixator has a hinge joint. The design of the fixator clamps, bars and the hinge joint allows simple alignment with the rotational axis of the elbow. Pro- and supination of the forearm is unhindered. Flexion and extension can be permitted according to the soft tissue situation.