Lateral Extra-articular Tenodesis Notably Reduced Residual Knee Instability and Anterior Tibial Translation in Patients With an Anterior Cruciate Ligament Injury Combined With a High-Grade Pivot-Shift Phenomenon.

Abstract

Background: A preoperative high-grade pivot-shift phenomenon (2+ and 3+) is often a predictor of inferior knee rotational stability and excessive anterior tibial translation of the lateral compartment (L-ATT) after an anterior cruciate ligament (ACL) injury. Lateral extra-articular tenodesis (LET) has been reported to reduce failure rates and improve knee stability in patients with an ACL injury. However, the effect of LET on knee rotational stability and L-ATT is still not entirely clear in patients with an ACL injury and a high-grade pivot-shift phenomenon.

Purpose: To explore the effect of LET on knee rotational stability and L-ATT in patients with an ACL injury and a high-grade pivot-shift phenomenon.

Study design: Cohort study; Level of evidence, 3.

Methods: A total of 254 patients who underwent ACL reconstruction (ACLR) between January 2019 and December 2020 were retrospectively reviewed, and 71 patients (43 male and 28 female) with a preoperative high-grade pivot-shift phenomenon were included. Of these, 24 patients who underwent ACLR combined with LET and 47 patients who underwent ACLR alone were categorized as the study and control groups, respectively. Knee stability was evaluated by the KT-1000 arthrometer side-to-side difference and the pivot-shift test, and L-ATT was measured on magnetic resonance imaging. Baseline patient characteristics, preoperative and postoperative knee stability, and preoperative and postoperative L-ATT were compared between the 2 groups. Moreover, the relative risk of a residual pivot-shift phenomenon after ACLR combined with LET versus ACLR alone was calculated.

Results: The mean time from injury to surgery in the study group was significantly longer than that in the control group (29.9 ± 54.7 vs 10.1 ± 23.1 months, respectively; P = .035). Other baseline patient characteristics, preoperative knee stability, and preoperative L-ATT showed no significant differences between the groups. At the final follow-up (26.4 ± 4.7 and 28.1 ± 11.0 months for study and control groups, respectively), knee rotational stability (residual pivot-shift phenomenon: 2/24 vs 16/47, respectively; P = .018) and L-ATT (4.6 ± 2.6 vs 6.3 ± 2.6 mm, respectively; P = .010) were superior in the study group compared with the control group. Furthermore, the relative risk of a residual pivot-shift phenomenon was significantly lower in the study group (0.176 [95% CI, 0.037-0.845]; P = .030).

Conclusion: ACLR combined with LET was an effective treatment strategy for ACL injuries with a high-grade pivot-shift phenomenon, associated with satisfactory clinical outcomes, significantly improved rotational stability, and reduced L-ATT.