42 LO SCALPELLO (2010) 24:42-50 DOI 10.1007/s11639-010-0058-2 Classificazione e trattamento dell’instabilità scafo-lunata post-traumatica B. Battiston, D. Ciclamini, B. Panero, M. Boffano U.O.C. Traumatologia muscolo-scheletrica - U.O.D. Microchirurgia Ospedale C.T.O. - Torino ABSTRACT – SCAPHOLUNATE POST-TRAUMATIC INSTABILITY : CLASSIFICATION AND TREATMENT Scapholunate instability is the most common form of dissociative carpal instability and it represents the first stage of perilunate dislocations. From a biomechanical point of view the injury of the scapholunate ligament is the first step towards an abnormal carpal kinematics with a progressive joint degeneration. Clinical history and physical examination are very important for the diagnosis but imaging techniques, such as plain radiographs and arthro-MR, play a fundamental role. In early and mild stages only arthroscopy allows a correct diagnosis. An early diagnosis and treatment correspond usually to a better functional result but, unfortunately, a delay often occurs. Four stages of scapholunate lesions, increasing in severity, can be recognized: predynamic instability, dynamic instability, static instability and scapholunate advanced collapse (SLAC). According to the parameters established by Garcia-Elias (the integrity of dorsal scapholunate ligament, the healing potential of the ligament after surgery, the alignment of the scaphoid, the reducibility of the carpal malalignment, the presence of a cartilage damage), scapholunate dissociations can be grouped in 6 different classes of severity and prognosis and an algorithm of treatment is proposed. The surgery ranges from conservative treatments, such as K-wire fixation, ligament suture, capsulodesis, tendon reconstruction with different techniques, to demolitive procedures as proximal row carpectomy or bone fusion that can be either partial or total. The aim of this article is to review the different surgical treatments than can be performed in the evolution of scapholunate instability and to underline the importance of an adequate and early management. Aggiornamenti Introduzione L’instabilità scafo-lunata (SL) rappresenta la forma più comune di instabilità carpale disso- ciativa. Il termine può descrivere un ampio spettro di quadri clinici che partono da una le- sione parziale del legamento SL a quadri più gravi (lussazioni perilunari) con implicazioni sempre più importanti fino a portare come esi- to finale a un collasso carpale. Il problema le- gamentoso può essere isolato o associarsi ad altre lesioni come le fratture dello scafoide e del radio distale. Patomeccanica Il legamento interosseo SL, elemento di stabi- lità fra scafoide e semilunare, è formato da 3 componenti con diverse proprietà meccaniche: una spessa regione dorsale formata da corte fi-