MRI signal intensity of anterior cruciate ligament graft after transtibial versus anteromedial portal technique (TRANSIG): A randomised controlled clinical trial

•Two drilling techniques for ACL reconstruction: transtibial and anteromedial portal.•Signal intensity measures on MRI are independent predictors of graft properties.•No difference in signal intensity was detected between drilling techniques.•Follow-up studies are needed to measure graft intensity differences in the long term. Two primary surgical femoral drilling techniques are used to reconstruct the anterior cruciate ligament (ACL): the transtibial (TT) technique and the anteromedial portal (AMP) technique. Currently there is no consensus on which surgical technique elicits the best clinical and functional outcomes. MRI-derived measures of the signal intensity (SI) of the ACL graft have been described as an independent predictor of graft properties. The purpose of this study was to assess MRI-derived SI measurements of the ACL graft one year after ACL reconstruction, in order to compare graft maturation of both AMP and TT ACL reconstruction techniques. This randomised controlled trial included 33 patients admitted for primary unilateral ACL reconstruction. Primary outcome was MRI Signal intensity ratio (SIR) of the ACL graft one year after ACL reconstruction. Differences in MRI SIR were assessed on two MRI sequencies: sagittal Proton Density Turbo Spin Echo weighted images (PDTSE) and 3D T2 Gradient Echo (T2*) weighted images. Analysis of interobserver and intraobserver variability was conducted for the SIR measurements. No difference in signal intensity of the graft was found between the TT and AMP techniques one year after ACL reconstruction (PDTSE p = 0.665, T2* p = 0.957). Both interobserver and intraobserver variability showed strong agreement (ICC 0.64–0.94). No differences in signal intensity of the graft on MRI were seen between the femoral drilling techniques one year after ACL reconstruction, suggesting similar graft maturation at that time. Follow-up studies are needed to determine whether graft intensity changes in the long term. Therapeutic study with level of evidence I.