Acromio-clavicular joint (ACJ) injuries represent nearly half of all athletic shoulder injuries. Stability of this joint depends on the integrity of the acromio-clavicular and coracoclavicular ligaments. Although the traumatic acromioclavicular joint separation is a well-known topic, there are different classifications, diagnostic procedures, concepts of intervention, and a great variety of implants. In this paper, we present an overview of the recent literature about this issue and the results of a retrospective non-randomized study with 2 different techniques. At the first Orthopedic Department of University of Pisa, a retrospective study was performed starting from January 2007 to February 2011 in our electronic database. We selected patient treated with two different techniques (tight-rope(®) system and hook plate) by the same senior surgeon with experience in shoulder surgery. The mean Costant score was 90 for the tight-rope(®) system group and 75 for the hook plate group. At the final follow-up, most of the patients had returned to their preinjury level of activity. Two patients had a breakage of the fixating system. The above-mentioned techniques provided satisfactory results with no loss of reduction except in two cases. The use of the hook plate is useful in fracture-dislocation of ACJ, but this requires another surgery to remove it. On the contrary, the use of the tight-rope(®) system does not require a new surgery or use of expensive synthetic graft or a graft harvested from a distant donor site.