%0 Journal Article %A Stephanie Filbay %A Frank Roemer %A Stefan Lohmander %A Aleksandra Turkiewicz %A Ewa M Roos %A Richard Frobell %A Martin Englund %T 32 Spontaneous healing of the ruptured anterior cruciate ligament: observations from the KANON trial %D 2022 %R 10.1136/bmjsem-2022-sportskongres.8 %J BMJ Open Sport & Exercise Medicine %P A3-A3 %V 8 %N Suppl 1 %X Introduction It is often assumed that an acutely ruptured ACL cannot heal. We evaluated ACL healing using MRI within 5 years of ACL rupture; described 2- and 5-year outcomes stratified by healing status and treatment; and investigated the relationship between ACL healing, sport/recreational function and quality of life (QOL) at 2- and 5-years following ACL injury.Materials and Methods Secondary analysis of KANON Trial data following randomisation to rehabilitation and optional delayed ACL reconstruction (ACLR), or early-ACLR. Outcomes included Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, activity level, mechanical stability, and osteoarthritis. Mixed linear regression estimated the relationship between healing status, KOOS-Sports/Rec and KOOS-QOL, adjusted for age, sex, smoking and unmeasured person-specific time-invariant confounding.Results Following management with rehabilitation-alone at 5-years (n=26), 56% had a healed-ACL at 2-years and 58% at 5-years. One in twenty-three (4%) had a healed ACL before undergoing delayed-ACLR. People with a healed-ACL reported high KOOS scores at 2-years and 63–93% met the patient acceptable symptomatic state criteria, compared to 31–61% in the non-healed or reconstructed groups. Two-year KOOS Sport/Rec and QOL scores were worse in the non-healed (mean difference (95% CI) -21.9(-38.8, -5.0); -26.9(-41.7, -12.1)), delayed-ACLR (-25.0 (-39.8, -10.1); -19.4(-32.3, -6.4)) and early-ACLR (-18.0(-31.5, -4.5); -13.9(-25.6, -2.1)) groups compared to the healed-ACL group, or findings excluded the possibility of better findings in the reconstructed groups.Conclusion There was a high rate of ACL healing in patients managed with rehabilitation alone and these individuals reported better patient-reported outcomes compared to the non-healed and reconstructed groups. %U https://bmjopensem.bmj.com/content/bmjosem/8/Suppl_1/A3.2.full.pdf