Lateral meniscus repair contributes to controlling pivot shift in patients undergoing anterior cruciate ligament reconstruction with steeper lateral posterior tibial slope.
case_series · Level IV
Where this comes from
- Record sourced from PubMed, PMID 41988225.
- Also identified by DOI 10.1002/jeo2.70717 and PMC identifier 13078125.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The lateral meniscus (LM) controls anterolateral rotatory instability (ALRI) and is considered a secondary restraint. However, how the anterior cruciate ligament (ACL) and LM contribute to ALRI control remains unclear. This study investigated the degree to which ACL and LM contribute to ALRI control and examined factors contributing to ALRI during anterior cruciate ligament reconstruction (ACLR). Twenty-six patients in ACL and LM-injured knees were enroled. Tibial acceleration in pivot shift was measured using a triaxial accelerometer by adjusting ACL graft tension before and after LM repair. ACL graft tension required for below-healthy-side pivot shift acceleration (minimum required tension [MRT]) was measured before and after LM repair. Patient factors for a larger contribution of LM to ALRI were determined by univariate linear regression analysis between changes in pivot shift acceleration before and after LM repair, and explanatory variables included patient and morphological factors. Furthermore, multiple regression analysis was conducted to identify independent factors significantly associated with the change. LM repair reduced the pivot shift acceleration in most cases, even following ACLR fixed at 10 N for each bundle (20 N in total) and pivot shift acceleration decreased significantly from 4.3 ± 1.2 to 2.9 ± 0.9 m/s<sup>2</sup> by LM repair (<i>p</i> < 0.001). The MRT was 10 N without LM repair in 13 patients (50%). LM repair reduced MRT to 10 N in 11 of the remaining 13 patients. Only the lateral posterior tibial slope (PTS) significantly correlated with changes in pivot shift acceleration (<i>r</i> = 0.60, <i>p</i> = 0.001). In the multiple regression analysis as well, lateral PTS was the only factor identified as a significant predictor. LM repair decreased pivot shift acceleration and MRT, indicating the importance of LM repair in force-sharing with the ACL. LM contributes significantly to ALRI in patients with a larger lateral PTS. During ACLR, the LM should be repaired as much as possible. Level III, diagnostic study.