The average age of participants at follow-up was 59 years (range, 47-74 years); 30% were female. 58% of all patients had been treated non-surgically initially, and 38% remained non-surgically treated at the longterm follow-up. At baseline, 58% had a meniscus injury.
Compared with an age- and sex-matched Swedish population, patients with ACL injuries had a lower KOOS for pain, sport/recreational activities, and quality of life. For example, KOOS for knee pain was around 65-70 for those with prior ACL injuries, compared with 80-90 for those without ACL injuries, where 100 indicates the best outcome or least pain and zero the worst.
KOOS was not affected by whether or not patients had initial ACL surgery or surgery at any point in their follow up. It also did not appear to matter if patients had a meniscal injury at baseline or not.
Quadriceps and hamstring strength at the 3-7 year postinjury assessment did not affect the longterm KOOS, but the ability to hop on one leg did: Those who were not able to hop on one leg for more than 90% of the time on the unaffected limb at the 3-7 years follow-up had worse pain, symptoms, function, and quality of life at the longterm follow-up point.