Non-anatomical double-bundle anterior cruciate ligament reconstruction combined with modified lateral extra-articular tenodesis in high-grade pivot shift anterior cruciate ligament injury：A retrospective study

Abstract Background: Both the non-anatomical double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) and lateral extra-articular tenodesis (LET) show superior performance in controlling the rotational stability of the knee. However there are few studies published to investigate the curative effect of non-anatomical DB ACLR combined with LET in high-grade pivot shift anterior cruciate ligament ruptures. This study aims to evaluate the short-term clinical and imaging results of the treatment program and summarize the advantages of the surgical technique. Method: All the 33 patients we reviewed in this study have accepted the non-anatomical DB ACLR with LET surgery from January 2018 to January 2022 in our Department of Orthopedics. Primary demographic data collected include gender (23 males and 10 females), age (16-37 years, average 23.5 years), BMI (21.8-31.2 kg/m 2 , average 25.7 kg/m 2 ), follow-up period (12-18 months, average 15.2 months) and injury mechanism (25 sports Injuries and 8 traffic accidents). The assessment of clinical outcomes included pre- and post-operative physical examination, knee functional scores and imaging data. Result: All patients in this study were followed up with an average 16.8-month (range 12-26 months) follow-up period. 23 patients had a grade 3 pivot shift and 10 had a grade 2 pivot shift. Immediate postoperative pivot shift tests were all negative, and only one case had a grade 1 pivot shift at the final follow-up. All the cases preoperatively had a positive Lachman test and turned negative at the final follow-up. The average ROM improved from 63.2°± 17.9° to 132.8°±3.6 °at the last follow-up (p<0.001); The VAS score decreased from 5.6±1.8 to 0.9±0.7 (p<0.001); the average KT-1000 healthy-side to affected-side difference decreased from 9.3±1.6 mm to 2.2 ± 0.5 mm. The comparison of all the knee functional scores ( IKDC, Tegner scores and Lysholom ) at pre-operative and last follow-up showed a significant difference (p<0.001). None of the cases had operation-related complications except one with slight prepatellar pain. Conclusion: Non-anatomical double-bundle anterior cruciate ligament reconstruction combined with modified lateral extra-articular tenodesis is a reliable and recommended treatment for anterior cruciate ligament rupture with high-grade pivot shift, showing a striking improvement in knee rotational Stability and function in the short-term follow-up.