This consensus statement examines the critical role of posterior tibial slope (PTS) as a modifiable anatomical factor in failed anterior cruciate ligament (ACL) reconstructions. It presents expert-based guidelines on when and how to assess and correct increased PTS during revision ACL surgery — helping surgeons improve graft survival and knee stability.
Scope & methodology: international Delphi among ACL revision experts
An international panel of 46 experienced orthopaedic knee surgeons participated in a formal Delphi consensus process to develop statements guiding the role of PTS correction in revision ACL surgery. The consensus covers indication thresholds, measurement techniques, adjunctive procedures (such as slope-reducing osteotomy), and decision-making in complex revision scenarios.
Key findings & consensus statements
- Elevated PTS is recognised as a risk factor for failure after ACL reconstruction, especially in revision settings.
- The panel established assessment standards, recommending full-length and sagittal imaging, measurement reliability checks, and awareness of coronal/sagittal alignment interplay.
- The experts agreed that slope-reducing osteotomy may be indicated in revision ACL surgery when PTS exceeds defined thresholds (often ≥12°–15°) and is accompanied by graft failure, instability, or other modifiable risk factors.
- The consensus emphasised that slope correction should be integrated into the revision plan when there are multiple failure-risk factors (e.g., tunnel malposition, meniscal deficiency, collateral laxity) and that it may be executed alone or in combination with other alignment procedures.
Clinical implications & application
Surgeons performing ACL revision should:
- Routinely evaluate PTS and correlate it with failure mechanisms rather than focusing exclusively on tunnel issues.
- Recognise situations where slope-reducing osteotomy adds value — particularly in younger, active patients with multiple risk factors for graft failure.
- Use the consensus statements as a framework rather than rigid rules — applying them in conjunction with each patient’s unique anatomy, prior surgery, activity level and goals.
Take-home messages
- PTS is a modifiable anatomical risk factor in ACL reconstruction failures and should be assessed in all revisions.
- The consensus provides structured guidance: measurement, thresholds for intervention, technical considerations and combined procedure planning.
- Incorporating PTS correction (when indicated) may improve stability outcomes and reduce graft re-rupture in complex revision ACL cases.
