Abstract: An openable retractor for use in an operation wound/surgical incision in the region of a patient's spine. The retractor includes two mutually-hinged halves (2, 4), each of which comprises an upper hinge part (6, 6') which, on the side thereof remote from the hinge, merges with a downwardly-extending shaft (8) at a radial distance from the hinge axis or its extension, a wound widening and restraining part (10) which projects laterally from the lower part of the shaft in a direction away from the hinge axis and which is intended for engagement with muscle tissue on one side of the operation wound, and a latching device (68) which is intended to be applied in the region of the hinge formed by the hinge parts (6, 6') of respective retractor halves and which functions to lock the retractor halves in an outwardly angled active position (functional position).