The influence of the intercondylar notch dimensions on injury of the anterior cruciate ligament: a meta-analysis

The aim of this meta-analysis was to examine the effect of the intercondylar notch dimensions, intercondylar notch width index (NWI) and intercondylar notch width (NW), separately in anterior cruciate ligament (ACL) injury. The PubMed and Wanfang database were searched through until 1 November 2011 to identify studies that met pre-stated inclusion criteria. Reference lists of retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies, the characteristics of the study participants, exposure and outcome assessments and control for potential confounding factors. Either a fixed- or a random-effects model was used to calculate the overall weighted mean difference (WMD). Sixteen studies (n = 4,291) were included (1,222 subjects in ACL-injured group and 3,069 subjects in the control group). Statistically significant differences were observed in the NWI (WMD, -0.02; 95 % confidence interval, -0.04 to -0.01), and in the NW (WMD, -2.15; 95 % confidence interval, -3.09 to -1.21) among the ACL-injured group when compared to the control group. The meta-analysis findings concluded that narrow intercondylar notch dimensions were associated with the risk of ACL injury. A lower NWI or NW stenosis predisposes an individual to ACL injury. Further original studies should include more anatomical risk factors that could be associated with the risk of ACL injury. III.