The association of tibial slope and anterior cruciate ligament rupture in skeletally immature patients

Arthroscopy. 2015 Jan;31(1):77-82. doi: 10.1016/j.arthro.2014.07.019. Epub 2014 Sep 16.


Purpose: The purpose of our study was to investigate the relation between posterior tibial slope and anterior cruciate ligament (ACL) rupture in patients with open physes.

Methods: A retrospective case-control study was performed comparing skeletally immature patients with an ACL rupture with an age-matched control group. Posterior tibial slope was measured on plain lateral radiographs in both groups by blinded readers, at 2 separate time intervals, using a previously examined and accepted technique.

Results: Thirty-two patients were included in the study group (mean age, 13 years; age range, 9 to 17 years) and compared with 32 patients in the control group (mean age, 13 years; age range, 9 to 16 years). The mean posterior tibial slope in the ACL-injured population was 10.0° ± 3° versus 8.5° ± 3° in the control group (P = .0128). Statistical significance was seen in comparisons of slope measurements between the ACL-injured and control groups for 2 of the 3 readers (readers 1 and 3) at both time points (P = .0348 and P = .0051 for reader 1 and P = .0009 and P = .0059 for reader 3). Intrarater reliability proved superior with values correlating with moderate to good reliability, whereas inter-rater reliability values corresponded with fair to moderate reliability. The average posterior tibial slope was 9.5° (range, 3° to 14°) for female patients and 9.8° (range, 2° to 16°) for male patients.

Conclusions: On the basis of the results of this study, the data support the notion that a moderate association may exist between an increased posterior tibial slope and ACL injury in pediatric patients with open physes.

Level of evidence: Level III, case-control study.

MeSH terms

  • Adolescent
  • Anterior Cruciate Ligament Injuries*
  • Case-Control Studies
  • Child
  • Female
  • Humans
  • Knee Joint / anatomy & histology
  • Knee Joint / diagnostic imaging
  • Male
  • Observer Variation
  • Radiography
  • Reproducibility of Results
  • Retrospective Studies
  • Rupture / etiology
  • Tibia / anatomy & histology*
  • Tibia / diagnostic imaging