Objective To study the operative techniques and clinical effect of arthroscopic reconstruction for posterior cruciate ligament (PCL) with ligament advanced reinforcement system (LARS)Y-shape double bundles artificial ligament.Methods From June 2006 to August 2010,14 patients (10 males and 4 females,at age range of 19-58 years,mean 38 years) with PCL ruptures were treated with LARS under arthroscopic observation.The injury causes included sports contusion in nine patients,traffic accidents in three and falling from height in two.Five patients were with left knee injury and three with right knee injury.The course of injury was 10-30 days (average 15.7 days).MRI indicated complete PCL ruptures in 14 patients and complete anterior cruciate ligament (ACL) ruptures in two.The combined injuries included medial meniscus injury in five patients,lateral meniscus injury in three and posterior acetabular wall fracture in one.The preoperative Lysholn score was (40 ± 7.9 ) points ( range,20-55 points).According to the international knee documentation committee (IKDC) grading,three patients were rated as grade C and 11 as grade D preoperatively.The operation was performed under arthroscopic observation.The ending point and tunnel of PCL of the femur and tibia were drilled with the help of a locator.ResultsAll the patients obtained primary healing,with no complications such as infection,spontaneous rupture or laxity of graft postoperatively.The regular follow-up for all cases ranged from6-60 months ( average 20.5 months).The postoperative Lysholn score was ( 88 ± 3.6 ) points ( 84-93 points),with statistical difference in comparison with the preoperative score (P ＜ 0.05 ) The IKDCgrading was A in 10 patients and B in four 12 months postoperatively. ConclusionsArthroscopic reconstruction with LARS artificial ligaments can effectively recover the stability of the knees,avoid the complications brought by autologous tendon and prevent the allograft rejection complications induced by allogenic tendon graft.The treatment is characterized by simple procedures,minor wound and fast recovery.

AIM: To study the phosphatidylinositol metabolism of vascular endothelial cells exposed to projectile's pressure wave METHODS: The cultured endothelial cells were exposed to bullet's pressure wave as experimental model. The intracellular inositol-1,4,5-triphosphate(IP_3), intracellular free calcium ([Ca 2+ ]i), protein kinase C(PKC) and lactate dehydrogenase (LDH) activities in cultural medium were assayed after the cultured cells exposed to bullet's pressure wave. After blocking phosphatidylinositol metabolism with neomycin, the above biochemical parameters of cells exposed to bullet's pressure wave were also measured. RESULTS: Bullet's pressure wave induced increase in the intracellular IP_3, [Ca 2+ ]i, and PKC activity obviously. The change of LDH activity paralleled with above biochemical changes. Blocking phosphatidylinositol metabolism partially inhibited these changes. CONCLUSION: Bullet's pressure wave may activate phosphatidylinositol metabolism, which may trigger the injury to the endothelial cells and lead to leakage of plasmatic LDH.