ObjectiveTo explore the surgical treatment for neglected posterolateral rotatory dislocation of knee joint and evaluate the effect. MethodsSixteen patients with neglected knee posterolateral rotatory dislocation treated between January 2006 and December 2010 underwent surgical treatment. Arthroscopic lysis was first performed followed by open reduction, and then ligament reconstruction or repair was carried out in order to restore its stability. Some stiff knee joint patients underwent Patients with joint stiffness were fixed with external fixator across knee for six weeks. All the patients received preoperative and postoperative imaging examination and functional scoring. ResultsTibiofemoral and patellofemoral congruence in all the 16 patients was fully restored. Joint stability was recovered with different degrees. Two patients underwent anterior cruciate ligament reconstruction and 1 underwent posterior cruciate ligament revision during the later stage, and their joint functional status at the end of follow-up was satisfying. ConclusionThe treatment for neglected knee posterolateral rotatory dislocation by combined arthroscopy with open surgery is relatively satisfying, which is a new therapeutic approach for this type of injury.