Objective     To evaluate the therapeutic effect on reconstruction of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) simultaneously by using allogeneic patellar tendon under arthroscopy.       Methods     From May 2003 to November 2005

10 cases of ruptured ACL and PCL were fixated with compressed screws and reconstructed under arthroscopy with allogeneic patellar tendon in one stage. The clinical results were evaluated according to IKDC

Lysholm

and Tegner clinical rating scales.       Results     All patients were followed up for 12-30 months (average 18 months ). At the end of follow-up

there was no knee extension limitation and the knee flexion was between 120 and 135

with an average of 128.38. The Lysholm score of the 10 cases was (66.5±5.6) before operation

and (89.8±3.4) at the end of follow-up. Statistically

the difference between the two Lysholm scores was significant (P0.01). The average Tegner activity score decreased in patients from (6.9±1.7) (range from 4 to 9) before injury to (5.5±1.6) (range from 2 to 9) at follow-up. At termination of follow-up

IKDC score was graded as A in four cases (40.0%)

B in five cases (50.0%)

and C in one case (10.0%). Of the 10 patients

8 patients returned to the pretraumatic sports level and 2 were under the level.       Conclusion     Arthroscopically assisted combined reconstruction of ACL and PCL with allogeneic patellar tendon has the advantages of minimal trauma in surgery and reliable satisfactory outcome.