Summary

Higher preoperative pivot shift grade and greater posterior tibial slope may be associated with re-injury after combined ACL and ALL reconstruction.

Abstract

Objective

The purpose of this study is to investigate the characteristics of anterior cruciate ligament (ACL) re-injury in athletes who underwent combined ACL and anterolateral ligament (ALL) reconstruction surgery (ACL/ALL reconstruction).

Methods

Of the primary ACL reconstructions performed on patients with Tegner activity score 7 or higher from April 2013 to March 2023, 183 knees underwent ACL/ALL reconstruction using hamstring tendon according to Sonnery-Cottet's technique, of which 8 knees had re-torn ACL graft (4.3%; the re-injured group).
The Lysholm score, the International Knee Documentation Committee (IKDC) subjective evaluation, the side-to-side difference in anterior tibial translation, and the pivot shift grade were investigated in 82 patients who could be followed up for more than 2 years after the surgery.
As for the re-injured group, the timing of re-injury, the return to competition status at the time of re-injury, and the injury mechanism at the time of re-injury were investigated, furthermore, multivariate logistic regression analysis was performed using age, gender, Tegner activity score, preoperative pivot shift grade, posterior tibial slope (PTS), hyperextended knee of more than 5 degrees, meniscus injury, and waiting period for surgery of more than 1 year as independent variables, and re-tear as dependent variable. The statistical significance level was set at p<0.05.

Results

For the 82 knees that were observed for an average of 28.4 months after surgery, the Lysholm score averaged 71.5 points preoperatively and 96.3 points at the last observation, IKDC subjective evaluation scores were 57.8 points and 94.3 points, respectively, the side-to-side difference in anterior tibial translation was 5.7 mm and 0.7 mm, respectively, and the pivot shift grade was 2.3 and 0.02, respectively, all of which were significantly improved.
The mean time of re-injury was 14.6 months postoperatively. 5 knees were re-injured after full return to competition, 2 knees were re-injured shortly after return to practice, and 1 knee was re-injured during rehabilitation. 7 knees had a non-contact injury mechanism except for one knee for which the injury mechanism was unknown.
Multivariate logistic regression analysis showed that the following two variables were statistically significant as risk factors for re-tear;
-Preoperative pivot shift grade: OR 9.16 (95% CI: 1.62-90.32, p=0.025)
-Posterior tibial slope (PTS): OR 1.48 (95%CI: 1.09-2.18, p=0.023)

Conclusions

Although ACL/ALL reconstruction is associated with better clinical outcomes and lower re-injury rate, it is not completely free from re-injury. Particular attention should be paid to patients with higher preoperative pivot shift grade and greater PTS. For cases with these characteristics, it may be necessary to delay the timing of return to competition or adapt more stringent conditions for return to competition.