Related Experiment Video
Updated: May 13, 2026

Autologous Microfractured and Purified Adipose Tissue for Arthroscopic Management of Osteochondral Lesions of the Talus
Published on: January 23, 2018
The ALPS classification: Predicting ACL graft failure based on deviation from mean posterior tibial slope-A
Tom Murphy1, Georgia Brady1, Michael Dan2,3,4
1School of Medicine Sydney, University of Notre Dame Australia, Sydney, New South Wales, Australia.
Purpose:
To quantify the association between posterior tibial slope (PTS) and anterior cruciate ligament (ACL) graft failure using meta-analysis. This study introduces the anatomic-lateral-posterior slope (ALPS) classification as a simple, clinically oriented, slope-based risk stratification tool.
Methods:
Embase, MEDLINE, Scopus and Cochrane were searched from inception through 30 August 2024 for studies comparing PTS in ACL graft failure versus control knees. Random-effects models synthesized mean differences (MDs) and adjusted odds ratios (aORs). Studies reporting slope-category data were mapped to ALPS risk bands based on standard deviations from the failure-group mean slope. Subgroup analyses and meta-regression examined imaging modality and measurement technique.
Results:
Twenty-four studies (6335 knees; 1597 failures) were included. Lateral PTS was associated with higher graft-failure risk per 1° increase (aOR = 1.15; 95% confidence interval: 1.06-1.23). Failure incidence rose across ALPS categories (9% green; 16%-23% blue; 41% red and 50% black). Medial PTS differences were smaller and not consistently predictive. Heterogeneity was substantial. Time to re-injury was an independent determinant; other moderators were collinear.
Conclusion:
Increased PTS-particularly lateral slope-is associated with ACL graft failure. The ALPS classification offers a pragmatic way to communicate slope-related risk; however, given non-significant aORs in some analyses and an anomalous signal in one 'low-risk' subgroup, its predictive capability should be viewed as preliminary pending prospective validation.
Level Of Evidence:
Level III.
More Related Videos
09:01Treatment of Ankle Osteoarthritis with Total Ankle Replacement Through a Lateral Transfibular Approach
Published on: January 24, 2018
06:28Anterior Cruciate Ligament Transection and Synovial Fluid Lavage in a Rodent Model to Study Joint Inflammation and Posttraumatic Osteoarthritis
Published on: September 2, 2025