Summary

The long-term failure rate of LARS-ACL reconstruction was 3.8% at mean 8 years postoperative with inaccurate bone tunnel position as the main reason for surgical failure

Abstract

Purpose

To investigate the long-term failure rate of ACL reconstruction using Ligament Advanced Reinforcement System (LARS).

Method

A multicenter retrospective study was launched by the China Artificial Ligament Study Group (CALSG), which consisted of 19 orthopedic / sports medicine centers in China. The subjects accepted ACL reconstruction using the LARS during 2004 and 2010. The surgical failure included recurrent instability (positive pivot test and/or Lachman test and/or level test, KT-1000>5mm), graft rupture (arthroscopic confirmed) and limited range of motion (ROM deficiency: > 15°flexion, > 5°extension). The failure impact of daily life activity and sports function was reviewed. In addition, the time between surgery and failure, bone tunnel position, and rupture of graft were investigated for the reason of surgical failure. Moreover, activity level of failure cases were evaluated by the Tegner Activity Score (TAS) respectively at pre-injury, pre-surgery, between surgery and failure, and after failure. Postoperative complications were also recorded in this study, which included screws loosening, synovitis, infection as well as stiffness.

Outcome:
A total of 1217 cases accepted ACL reconstruction, and 207 of them were excluded according to selection criteria. For 1010 included cases, 809 were available with the follow-up rate of 80.1%. The mean follow-up time was 96 months. Surgical failure occurred in 31 cases (3.8%). Among them, recurrent instability was observed in 20 cases (64.5%), graft rupture in 5 cases (16.1%), limited range of motion in 4 cases (12.9%), combination of recurrent laxity and limited ROM in 2 cases (6.5%). Inaccurate bone tunnel position was regarded as a main reason for surgical failure. Failure occurred in 18 cases without clear re-injury history. The mean time between surgery and failure was 24.8 months. The TAS was 6.2 pre-injury, 2.3 pre-surgery, 4.9 between surgery and failure, 2.8 after failure. Complications were observed in 28 cases (3.5%). Synovitis occurred in 6 cases (0.7%), stiffness in 2 cases (0.3%), and infection in 3 cases (0.4%), and screw related symptoms occurred in 17 cases (2.1%).

Conclusion

The long-term failure rate of LARS-ACL reconstruction was 3.8% at mean 8 years postoperative. Inaccurate bone tunnel position was a main reason for surgical failure. Complications rate was 3.5% with the screw related symptoms concerning.