Tibial slope, remnant preservation, and graft size are the most important factors affecting graft healing after ACL reconstruction

Abstract

Purpose The aim of this study was to determine the anatomic, operative and biological factors that inluenced graft healing after single-bundle anterior cruciate ligament (ACL) reconstruction. Methods One hundred fourteen consecutive patients who underwent anatomic single-bundle ACL reconstruction with quadrupled hamstring tendon autografts between 2016 and 2019 were retrospectively analyzed. Ninety-four patients met the inclusion criteria with minimum follow-up of 12 months. Patients were evaluated with multiple clinical measurements, including International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Lyshom Scores, and Marx activity scale. To evaluate graft healing, the signal-to-noise quotient (SNQ) was measured at intra-articular graft and intratunnel integration were evaluated on magnetic resonance imaging (MRI) at one year after surgery. Potential factors afecting graft healing, including age, sex, body mass index, time from injury to surgery, posterior tibial slope, lateral femoral condyle ratio, notch width index, meniscal injury, remnant preservation, tunnel aperture locations, graft size, graft bending angle, graft/remaining notch volume ratio were evaluated for their association with graft SNQ value by stepwise regression analysis. Results A total of 94 patients were evaluated with mean follow-up 28.5 ± 9 months. Univariate regression analysis showed that posterior tibial slope, notch width index, remnant preserving procedure, high femoral tunnel, anterior tibial tunnel, graft bending angle, and graft/remaining notch volume ratio signiicantly associated with graft SNQ values. Multivariate regression analysis showed that lateral tibial slope, remnant preservation, and graft/remaining notch volume ratio were independent factors correlated with graft SNQ values. Also, the graft SNQ values was weakly correlated with femoral tunnel integration and Marx activity scale at one year. There was no correlation between graft SNQ values and IKDC-SKF and Lysholm scores. There was no correlation between graft SNQ values and International Knee Documentation Committee and Lysholm scores. Conclusions Tibial slope, remnant preservation and graft/remaining notch volume ratio were signiicant independent associated factors of graft SNQ value at one year. The graft SNQ values were also weakly correlated with femoral tunnel integration and the Marx activity scale. These factors should be taken into account for ensuring the ideal graft healing and for the return to sport decision-making. Level of evidence Level IV.

Effects of remnant preservation in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

“…Lower SNQ represents lower graft water content, more ligamentization, and better biomechanical properties ( 34 ). Remnant preservation is an independent associated factors of graft SNQ ( 35 ). Takahashi et al performed a retrospective analysis and showed that SNQ values of ACL grafted tendon at 2 years after surgery in ACLR-R Group were better than those in ACLR-S Group ( 30 ).…”

Effect of Anterolateral Structure Augmentation on Graft Maturity After Anterior Cruciate Ligament Reconstruction: A Clinical and MRI Follow-up of 2 Years

“…Various demographic and radiological parameters have been reported to be predictive factors of SNQ values, while the results were quite different among studies. 2,23,36,47 Li et al 23 found that the SNQ value was positively correlated with age and TAS and negatively correlated with follow–up time and ACL graft–Blumensaat line angle in a stepwise regression analysis of 104 male patients with autograft or allograft ACLR. Okutan et al 36 evaluated 94 patients with hamstring autograft ACLR and concluded that the lateral tibial slope, remnant preservation, and graft–notch volume ratio were independently associated factors of graft SNQ.…”

“…2,23,36,47 Li et al 23 found that the SNQ value was positively correlated with age and TAS and negatively correlated with follow–up time and ACL graft–Blumensaat line angle in a stepwise regression analysis of 104 male patients with autograft or allograft ACLR. Okutan et al 36 evaluated 94 patients with hamstring autograft ACLR and concluded that the lateral tibial slope, remnant preservation, and graft–notch volume ratio were independently associated factors of graft SNQ. However, most previous studies analyzed the overall SNQ value while ignoring the variation along the graft route.…”

“…Age, sex, BMI, hip–knee–ankle angle, medial tibial slope, lateral tibial slope, ACL graft inclination, ACL graft–Blumensaat line angle, graft diameter of the AMB, graft diameter of the PLB, ALSA, partial lateral meniscectomy, amount of remnant ACL, and TAS at 24 months were included in the multivariate model. 2,23,36,47 The intraobserver and interobserver reliabilities were evaluated using the intraclass correlation coefficient (ICC) and classified as good (≥0.75), fair (0.50-0.74), and poor (<0.50). Statistical analyses were performed with the SPSS software (Version 25.0; IBM Corp).…”

Morphological Changes in the Tibial Tunnel After ACL Reconstruction With the Outside-In Technique and Adjustable Suspensory Fixation

“…The most possible reason is related to the mechanical effect of remnant tissue that limits the flow of synovial fluid into the tibial tunnel by covering the tunnel aperture. 20,21,26 Several studies have reported that synovial fluid contains high levels of inflammatory cytokines that inhibit bone formation, and it tends to propagate into the tibial tunnel under the effects of gravity. 11,31 Also, Sun et al 25 showed that the preservation of remnant tissue decreased fluid leakage into the tibial tunnel.…”