An inner amputation of the upper extremity is understood to be a rupture of the arm's vascular nerve bundle as well as the shoulder's and scapular's stabilizing muscles and fibrous joints without damage to the dermal soft tissue sheath. This injury is a rare and grave incident which mostly occurs within the scope of a high-energy trauma and in cases of polytraumatized patients in combination with additional life-threatening injuries. In the literature this is referred to by the terms scapulothoracic dissociation (SD) and closed forequarter amputation--the entity of SD was first described by Oreck et al. in 1984. Traction of the upper extremity leads to the rupture of the m. pectoralis major, m. pectoralis minor, the musculi rhomboidei, the m. levator scapulae, the m. latissimus dorsi as well as the m. trapezius. Furthermore the traction causes acromioclavicular or sternoclavicular bursting of the joints or a displaced clavicle fracture. Among the more than 50 cases depicted until now, 94% of the patients exhibit a neurological (plexus) and 80% a vascular lesion, thus corresponding to a genuine inner amputation. The prognosis for this injury is consistently poor: 10% of the patients die, in 52% an nonfunctional extremity remains, and in 21% a untimely amputation has to be performed. The observed complication of cerebral hypoperfusion caused by increasing pressure in the neck compartment, which ultimately leads to the death of the patient, has, as far as we know, not yet been specified and emphasizes the gravity and the magnitude as well as the necessity of rapid diagnosis and appropriate therapy of this infrequent injury.