ISAKOS: 2019 Congress in Cancun, Mexico

2019 ISAKOS Biennial Congress Paper #130


Predictors of Poor Outcome Following ACL Reconstruction with or without Lateral Extra-Articular Tenodesis: The Stability Experience

Dianne M. Bryant, PhD, London, ON CANADA
Alan Getgood, MD, FRCS(Tr&Orth), DipSEM, London, ON CANADA
Robert Litchfield, MD, FRCSC, London, ON CANADA
Robert G. McCormack, MD, New Westminster, BC CANADA
S. Mark A. Heard, MD, FRCS, Canmore, AB CANADA
Peter B. MacDonald, MD, FRCS, Dip Sport Med, Winnipeg, MB CANADA
Tim Spalding, FRCS(Orth), Leamington Spa, Warwickshire UNITED KINGDOM
Peter Verdonk, MD, PhD, Zwijnaarde BELGIUM
Devin Clarke Peterson, MD, FRCSC, Dip Sport Med, Ancaster, Ontario CANADA
Davide Bardana, MD, Kingston, ON CANADA
Alex Rezansoff, MD, FRCSC, Calgary, AB CANADA
Stability Study Group, MD, London, ON CANADA

Fowler Kennedy Sport Medicine Clinic, Western University, London, ON, CANADA

FDA Status Not Applicable


We performed a logistic regression to determine variables that influence outcome within patients entered into a randomized clinical trial comparing ACL reconstruction with or without lateral extra-articular tenodesis (LET). The most important predictors of failure were ACLR without LET and younger age at the time of surgery.



The results of our recent multicenter randomized clinical trial investigating anterior cruciate ligament reconstruction (ACLR) with or without lateral extra-articular tenodesis (LET) in patients at high risk of graft failure (Stability Study) suggest that LET reduces the rate of ACL failure at two years post-operative.


The purpose of this study was to investigate what morphological and physical factors predict failure within the trial.


624 patients were randomized with a mean age of 18.9 (range: 14-25), 293 male. A regression analysis was performed to determine what factors would be most predictive of graft failure. Within the model, the primary outcome (combined graft failure + persistent rotatory laxity as measured by an asymmetric pivot shift) was the dependent variable and the following independent variables were investigated: 1) sex, 2) group, 3) age at surgery in years, 4) medial meniscus (no pathology, degenerative, excision, repair), 5) lateral meniscus (no pathology, degenerative, excision, repair), 6) Beighton score, 7) presence of knee hyper-extension, and 8) pivot shift under anesthesia


At two years post-operative, 104/252 (41%) of ACLR alone patients suffered the primary outcome compared to 61/252 (25%) of the ACLR+LET patients. 39 patients had suffered graft rupture, 28/252 (11%) in the ACLR group compared to 11/242 (4.5%) in the ACL+LET group. The most significant predictor of failure was the group allocation i.e ACLR alone or ACLR + LET with ACLR alone having an odds of failure about two times greater than those who got the LET (OR=2.1 95%CI 1.4 to 3.0, p<0.001). After controlling for group, for every year of?age, the odds of failure was?reduced by just over 5%?(OR=0.94, 95%CI 0.93 to 0.96, p<0.001).?Compared to having no medial meniscal pathology, the odds?of failure if there is a partial excision is more than two times greater (OR=2.2, 95%CI 1.2 to 4.3, p=0.01). Sex, pivot shift under anesthesia,?lateral meniscal status, Beighton score, and presence or absence of knee hyper-extension were not significant predictors of failure. When graft failure was used as the dependent variable, group and age remain significant predictors of outcome.


Not performing a LET at the time of ACLR and younger age at the time of surgery are significant predictors of poor outcome when performing a hamstring tendon autograft, single bindle ACLR in patients aged 15-25 years old.