Technical variables of ACL surgical reconstruction: effect on post-operative static laxity and clinical implication

S. Zaffagnini, C. Signorelli, T. Bonanzinga, T. Roberti Di Sarsina, A. Grassi, A. Budeyri, G. M. Marcheggiani Muccioli, F. Raggi, L. Bragonzoni, N. Lopomo, M. Marcacci

Research output: Contribution to journalArticle

Abstract

Purpose: The hypothesis was that an alteration of different surgical variables of ACL reconstruction would produce significant changes in post-operative static laxity of knee joint. Methods: Joint laxity was acquired by a surgical navigation system for 17 patients just after graft fixation during single-bundle reconstruction with extra-articular lateral tenodesis. The analysed laxity parameters were: internal/external rotation at 30° (IE30) and 90° (IE90) of flexion, varus/valgus rotation at 0° (VV0) and 30° (VV30) of flexion and anterior/posterior displacement at 30° (AP30) and 90° (AP90) of flexion. As surgical variables, the angles between the tibial tunnel and the three planes were defined as well as the lengths of the tunnel and the relationship between native footprints and tunnels. The same analysis was performed for the femoral side. All surgical variables were combined in a multivariate analysis to assess for predictive factors between them and post-operative laxities values. To quantify the performance of each multivariate model, the correlation ratio (η2) and the corresponding P value (*P < 0.050) have been evaluated. Results: Multivariate analysis underlined statistically significant models for the estimation of: AP30 (η2 = 0.987; P = 0.014), IE30 (η2 = 0.995; P = 0.005), IE90 (η2 = 0.568; P = 0.010), VV0 (η2 = 0.932; P = 0.003). The parameters that greatly affected the identified models were the orientation of the tibial tunnel with respect to the three anatomical planes. The estimation of AP30, IE30 and IE90 got lower value as the orientation of the tibial tunnel with respect to transverse plane decreases. Considering the orientation to sagittal (θSAGT) and coronal (θCORT) plane, we found that their reduction provoked a decrease in the estimation of AP30, IE30 and IE90 (except θSAGT that did not appear in the estimation of AP30). The estimation of VV0 got an increase of θSAGT, and θCORT which led to a laxity reduction. Conclusion: The main finding of the present in vivo study was the possibility to determine significant effects on post-operative static laxity level of different surgical variables of ACL reconstruction. In particular, the present study defined the conditions that minimize the different aspects of post-operative laxity at time-zero after surgery.

Original languageEnglish
Pages (from-to)3496-3506
Number of pages11
JournalKnee Surgery, Sports Traumatology, Arthroscopy
Volume24
Issue number11
DOIs
Publication statusPublished - Nov 1 2016

Keywords

  • ACL reconstruction
  • Multivariate analysis
  • Navigation system
  • Post-operative laxity
  • Prediction

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

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    Zaffagnini, S., Signorelli, C., Bonanzinga, T., Roberti Di Sarsina, T., Grassi, A., Budeyri, A., Marcheggiani Muccioli, G. M., Raggi, F., Bragonzoni, L., Lopomo, N., & Marcacci, M. (2016). Technical variables of ACL surgical reconstruction: effect on post-operative static laxity and clinical implication. Knee Surgery, Sports Traumatology, Arthroscopy, 24(11), 3496-3506. https://doi.org/10.1007/s00167-016-4320-x