Association Between Magnetic Resonance Imaging–Measured Intercondylar Notch Dimensions and Anterior Cruciate Ligament Injury: A Meta-analysis

Abstract

To explore the association between the magnetic resonance imaging (MRI)-measured intercondylar notch dimensions, including the intercondylar notch width (NW) and intercondylar notch width index (NWI), and the risk of anterior cruciate ligament (ACL) injury by performing a meta-analysis of studies that relied on the multiplanar imaging and soft-tissue visualization strengths of MRI. The MEDLINE, Embase, and SportDiscus databases were searched from inception to March 2017. Observational studies reporting on the associations of the NWI and NW with ACL injury were retrieved. A random-effects model was used to calculate the overall weighted mean difference (WMD) between the ACL injury group and control group. A total of 20 studies were included in this meta-analysis. The combined data showed that subjects with ACL injury, as compared with the control group, had a significantly decreased NW (pooled WMD,-1.53 [95% confidence interval,-1.81 to-1.25]; P < .00001) and NWI (pooled WMD,-0.02 [95% confidence interval,-0.03 to-0.01]; P < .00001). Similar findings were observed in subgroup analyses in terms of different injury mechanisms. No significant difference in NWI was found in the axial view. A significantly decreased NW and NWI were found in other plane views. The sensitivity analyses after the exclusion of studies enrolling only athletes or skeletally immature subjects reached similar outcomes. The Begg rank correlation test showed no publication bias. With the accumulation of evidence, this meta-analysis concluded that the NW and/or NWI measured by MRI was significantly lower in ACL-injured patients than in control subjects. For persons with a narrow intercondylar notch, preventive measures can be prepared for the prevention of ACL injuries. Level III, meta-analysis of Level II and III studies.