Associations between inadequate knee function detected by KOOS and prospective graft failure in an anterior cruciate ligament-reconstructed knee

Knee Surg Sports Traumatol Arthrosc. 2015 Apr;23(4):1135-40. doi: 10.1007/s00167-014-2925-5. Epub 2014 Mar 12.


Purpose: First, to evaluate whether the 2 year post-operative Knee injury and Osteoarthritis Outcome Score (KOOS) in primary anterior cruciate ligament reconstructions (ACLRs) was significantly different between patients that did not go on to have a subsequent revision after the 2 year post-operative control and the ones that did. Second, to test whether the "clinically failure" value of KOOS quality of life (QoL) < 44 was indicative of a clinically relevant difference in the risk of subsequent revision ACLR.

Methods: ACLRs reported to the Norwegian Knee Ligament Registry between June 2004 and December 2009. 5,517 primary ACLRs with at least 2-year follow-up with KOOS QoL before revision surgery.

Results: There were clinically significant differences, adjusted and unadjusted, in both the KOOS Sport and Recreation and QoL subscales in patients with a later revision surgery compared to those that did not have a revision surgery. In adjusted models, the risk of later ACLR revision was 3.7 (95 % CI 2.2-6.0) higher in patients with a 2-year KOOS QoL < 44 compared to patients with a KOOS QoL ≥ 44. For every 10-point reduction in the KOOS QoL, a 33.6 % (95 % CI 21.2-47.5 %) higher risk for later ACLR revision was observed.

Conclusions: This study reveals an association between inadequate knee function, as measured by KOOS, and a prospective ACL-reconstructed graft failure.

Level of evidence: Prognostic study (prospective cohort study), Level II.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Anterior Cruciate Ligament / surgery*
  • Anterior Cruciate Ligament Injuries
  • Anterior Cruciate Ligament Reconstruction / adverse effects*
  • Female
  • Follow-Up Studies
  • Humans
  • Knee Injuries / physiopathology
  • Knee Injuries / surgery*
  • Knee Joint / physiopathology*
  • Knee Joint / surgery
  • Male
  • Medical Futility
  • Prospective Studies
  • Quality of Life
  • Range of Motion, Articular / physiology*