Factors Associated with High-Grade Lachman, Pivot-Shift, and Anterior Drawer at the Time of ACL Reconstruction

Purpose— To determine which patient and injury factors are associated with the detection of high-grade laxity at examination under anesthesia prior to anterior cruciate ligament (ACL) reconstruction. Methods— 2318 patients who underwent primary ACL reconstruction without associated ligament injuries were identified. Demographic data and information regarding meniscal tears were collected. Patients with high-grade Lachman (>10mm difference from contralateral), pivot-shift (IKDC grade 3), or anterior drawer (>10mm difference from contralateral) were identified by physical examination under anesthesia prior to ACL reconstruction. Logistic regression modeling was used to evaluate whether chronicity of the ACL injury, patient age, sex, body mass index, generalized ligamentous laxity, and presence of meniscal tears were associated with increased odds of high-grade laxity, controlling for examining surgeon. Results— Patients with chronic tears (>6 months from injury) had greater than twice the odds of having a high-grade Lachman, pivot-shift, and anterior drawer (all p<0.001) relative to patients with acute tears (<3 months from injury). Generalized ligamentous laxity (OR=2.33, p<0.001) and the presence of medial (OR=1.63, p<0.001) or lateral (OR=1.41, p=0.013) meniscus tears were associated with increased odds of a high-grade Lachman. Age less than 20 years (OR=1.34, p=0.023), female sex (OR=1.49, p=0.001), generalized ligamentous laxity (OR=3.46, p<0001), and the presence of a medial (OR=1.53, p <0.001) or lateral (OR=1.27, p=0.041) meniscus tear were associated with increased odds of a high-grade pivot-shift. Generalized ligamentous laxity (OR=2.27, p<0.001) and the presence of a medial (OR=1.73, p=0.001) or lateral (OR=1.50, p = 0.010) meniscus tear were associated with increased odds of a high-grade anterior drawer. Conclusion— Chronic ACL tears, generalized ligamentous laxity, and meniscus tears are associated with increased odds of high-grade laxity with all three tests. Female patients and age under 20 is associated with increased odds of a high-grade pivot33 shift. detected with these physical examination tests. Previous work has demonstrated an increased incidence of a positive Lachman, anterior drawer, and pivot-shift in the setting of more chronic ACL injuries. (6–10) Previous studies have demonstrated a higher prevalence of lateral meniscus tears in patients with a high49 grade pivot-shift (11, 12) and in those with a positive anterior drawer test. (13) The influence of patient demographic factors on the findings of these pre-operative physical examination tests has not been explored in detail, although females have been noted to have increased anterior laxity in some series following ACL reconstruction. (14) All previous studies on the subject have involved relatively small patient numbers, limiting the number of potential factors that could be evaluated. The purpose of this study is to determine which patient and injury factors are associated with the detection of high-grade laxity at examination under anesthesia prior to ACL reconstruction. We hypothesized that younger age, female sex, lower body mass index (BMI), generalized ligamentous laxity, concomitant meniscus injuries, and increased time from ACL injury to reconstruction are associated with high-grade laxity prior to ACL reconstruction.