Fractures of the clavicle in the middle third usually undergo closed treatment by external fixation, because they heal spontaneously in most cases. However, a correct reposition and fixation by external manner is sometimes impossible, and consolidation in malposition with functional and esthetic disturbance occurs. External fixation can be painful and inconvenient to the patient, and congestion and paresthesia of the upper limbs may occur. Therefore the indication for internal fixation has been extended on fractures in persisting severe malposition despite external fixation and painful congestion and paresthesia of the arms. A method of internal fixation by a Rush pin has been used. The fracture is exposed by a minimal incision, and both fragments are bored open axially and exactly reposed. The Rusph pin is inserted from the medial side through a second small incision. The corticalis layer on both sides of the bend of the clavicle is also to be penetrated by the pin. Postoperatively no external fixation is necessary, and the patient is told to move the shoulder as soon as possible. The pin is removed after three to six months on outpatient basis under local anesthesia. 43 cases of clavicle fractures and three cases of painful non-union after closed treatment, operated in this way, have been analyzed. In two cases of the fractures (4.6%) non-union occurred. Both healed after refixation by a plate. 34 of 41 fractures healed without radiologically visible callus. 64% of the registered patients have been handicapped in their daily activities only for two weeks or even less.(ABSTRACT TRUNCATED AT 250 WORDS)