title: The Lateral Meniscus as a Guide to Anatomical Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction.
abstract: OBJECTIVE
  The aim of the study is to show, on an MRI scan, that the posterior border of the anterior horn of the lateral meniscus (AHLM) could guide tibial tunnel position in the sagittal plane and provide anatomical graft position.
  
  
  METHODS
  One hundred MRI scans were analysed with normal cruciate ligaments and no evidence of meniscal injury. We measured the distance between the posterior border of the AHLM and the midpoint of the ACL by superimposing sagittal images.
  
  
  RESULTS
  The mean distance between the posterior border of the AHLM and the ACL midpoint was -0.1mm (i.e. 0.1mm posterior to the ACL midpoint). The range was 5mm to -4.6mm. The median value was 0.0mm. 95% confidence interval was from -0.5 to 0.3mm. A normal, parametric distribution was observed and Intra- and inter-observer variability showed significant correlation (p<0.05) using Pearsons Correlation test (intra-observer) and Interclass correlation (inter-observer).
  
  
  CONCLUSIONS
  Using the posterior border of the AHLM is a reproducible and anatomical marker for the midpoint of the ACL footprint in the majority of cases. It can be used intra-operatively as a guide for tibial tunnel insertion and graft placement allowing anatomical reconstruction. There will inevitably be some anatomical variation. Pre-operative MRI assessment of the relationship between AHLM and ACL footprint is advised to improve surgical planning.
  
  
  METHODS
  Level 4.
authors.affiliation: Exeter Knee Reconstruction Unit, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Kassam
authors.affiliation: Exeter Knee Reconstruction Unit, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.
authors.forename: L
authors.initials: L
authors.lastname: Tillotson
authors.affiliation: Exeter Knee Reconstruction Unit, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Schranz
authors.affiliation: Exeter Knee Reconstruction Unit, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.
authors.forename: V I
authors.initials: VI
authors.lastname: Mandalia
keywords: Anatomical; cruciate; ligament; meniscus; reconstruction; tibial; tunnel.