Association between time from anterior cruciate ligament injury to reconstruction and morphological changes of the intercondylar notch using MRI and arthroscopy.

Background: Few studies have measured the dimensions of intercondylar notch under direct arthroscopic visualization. The purpose of our study was to analyse the association between time from anterior cruciate ligament (ACL) injury to reconstruction and the morphological changes of intercondylar notch using magnetic resonance imaging (MRI) and arthroscopy.

Methods: Data was collected for patients who received knee arthroscopic surgery during 2014-2015. According to the time from ACL injury to reconstruction, these patients were divided into five groupsACL non-injured group (NI), acute rupture group (AR, <3 months), chronic rupture group 1 (CR1, 3-12 months), 2 (CR2, 1-5 years) and 3 (CR3, >5 years). MRI measurements of femoral condylar width (FCW) and intercondylar width (ICW) were undertaken before surgery. The widths at the base, middle and top of the intercondylar notch (ICWb, ICWm, ICWt, respectively) and the intercondylar notch height (ICH) were measured during arthroscopy. Intercondylar notch width index (NWI) and notch shape index (NSI) were then calculated and analysed among groups.

Results: A total of 272 patients were allocated to groups NI (n = 89), AR (n = 84), CR1 (n = 51), CR2 (n = 30) or CR3 (n = 18). Statistical analysis showed significant differences in ICW, ICWb, ICH, NWI and NSI between groups NI and AR. Among the groups with ACL-injury, ICWb and ICWt and NWI in group CR3 were statistically smaller than the other three groups (P = 0.004, 0.016, and 0.005, respectively).

Conclusions: The width of intercondylar notch had a negative correlation with time from ACL injury to reconstruction. Significant secondary notch stenosis was observed over 5 years after ACL rupture.