Editorial Commentary: Narrow Knee Intercondylar Notch Width Is a Risk Factor for Anterior Cruciate Ligament Injury, and Hetrogeneous Methods Are a Risk Factor for "Between Study" Error in Meta-analyses.

Abstract

The anatomic dimensions of the intercondylar notch have been associated with and anterior cruciate ligament (ACL) injury; however, these findings have been shown to be highly heterogeneous in a previous systematic review. Early studies used conventional radiographs to image the knee, whereas recent studies have employed magnetic resonance imaging. The different imaging techniques are a potential source of heterogeneity, prompting a systematic review of magnetic resonance imaging studies only. Although a narrower intercondylar notch width and intercondylar index were again associated with ACL injury, statistical heterogeneity remains persistent. Subgroup analysis successfully identified sources of between-study error among studies measuring notch width but was unable to account for differences in studies examining notch width index. These findings have provided greater insight into the relation between the anatomic dimensions of the intercondylar notch and ACL as well as the importance of between-study error in meta-analysis.