Does posterior tibial slope influence knee functionality in the anterior cruciate ligament-deficient and anterior cruciate ligament-reconstructed knee?

Arthroscopy. 2010 Nov;26(11):1496-502. doi: 10.1016/j.arthro.2010.02.024.

Abstract

Purpose: The purpose of this study was to investigate the relation between knee functionality and posterior tibial slope in anterior cruciate ligament (ACL)-deficient and ACL-reconstructed patients.

Methods: Patients with isolated ACL injuries on the surgical waiting list and patients who underwent ACL reconstruction with bone-patellar tendon-bone grafts between 18 and 24 months after surgery were recruited from the orthopaedic sports injury clinic. The study included 44 ACL-deficient patients (range 16-49) with a mean age of 26.4 years and 24 ACL-reconstructed patients with a mean age of 27.2 years (range, 25 to 49 years). Posterior tibial slope was measured on a digitalized lateral radiograph by use of the posterior tibial cortex as a reference. The Cincinnati scoring system was used to assess knee functionality.

Results: The posterior tibial slope averaged 6.10° ± 3.57° (range, 0° to 17°) in the ACL-deficient group and 7.20° ± 4.49° (range, 0° to 17°) in the ACL-reconstructed group. An anterior tibial slope was not measured in any of the participants. The mean Cincinnati score was 62.0 ± 14.5 (range, 36 to 84) in the ACL-deficient patients and 89.3 ± 9.5 (range, 61 to 100) in the ACL-reconstructed patients. There was a moderate but nonsignificant correlation (r = 0.47) between knee functionality and slope in the ACL-deficient patients. When we divided posterior tibial slope into intervals of 0° to 4° (mean score, 58.4), 5° to 9° (mean score, 59.6), and greater than 10° (mean score, 75.4), a strong significant correlation (r = 0.91, P = .01) was observed between knee functionality and slope. There was a weak but nonsignificant correlation (r = 0.24) between knee functionality and slope in the ACL-reconstructed patients. When we divided posterior tibial slope into intervals of 0° to 4° (mean score, 78.2), 5° to 9° (mean score, 86.1), and greater than 10° (mean score, 89.4), a strong and significant correlation (r = 0.96, P = .0001) was observed between knee functionality and slope.

Conclusions: The results of this study suggest that ACL-deficient and ACL-reconstructed patients with higher posterior tibial slope have more functional knees.

Level of evidence: Level IV, therapeutic case series.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Anterior Cruciate Ligament / surgery*
  • Anterior Cruciate Ligament Injuries
  • Arthroscopy / adverse effects
  • Arthroscopy / methods*
  • Bone Malalignment / diagnostic imaging*
  • Bone Malalignment / physiopathology
  • Bone-Patellar Tendon-Bone Grafting / adverse effects
  • Bone-Patellar Tendon-Bone Grafting / methods
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Joint Instability / physiopathology
  • Joint Instability / prevention & control*
  • Knee Injuries / diagnostic imaging
  • Knee Injuries / surgery
  • Male
  • Middle Aged
  • Radiography
  • Range of Motion, Articular / physiology
  • Reconstructive Surgical Procedures / adverse effects
  • Reconstructive Surgical Procedures / methods*
  • Recovery of Function
  • Risk Assessment
  • Tibia*
  • Treatment Outcome
  • Young Adult