Patient-reported outcome 32 to 37 years following surgically treated or non-surgically treated acute anterior cruciate ligament injury

Abstract

Purpose: As many as one in four individuals develop knee osteoarthritis within ten years of anterior cruciate ligament (ACL) injury. However, the prevalence of knee impairment and the impact of the ACL-injured knee on quality of life (QOL), more than 30 years after ACL injury is unclear. Additionally, the impact of meniscus injury, surgical or non-surgical ACL treatment, and knee function at mid-term follow-up on patient-report outcomes (PROs) beyond 30 years of injury is uncertain. This study aimed to: i. Evaluate PROs 32-37 years following acute ACL injury ii. Assess whether ACL treatment, baseline meniscus injury and knee function at mid-term follow-up were related to differences in PROs at 32-37 year follow-up. Methods: From 1980-1985, 293 patients who ruptured their ACL <14 days previously were allocated to early surgical (augmented or nonaugmented repair) or non-surgical ACL treatment based on an odd or even birth year. ACL surgery was performed at Linkoping Hospital (Sweden) within 24 (mean 5+/-4) days of injury. Concomitant injuries were diagnosed arthroscopically within 21 days of injury. At mid-term follow-up (mean 4+/-1 (range 3-7) years after ACL injury) quadriceps strength limb symmetry index (LSI), hamstrings strength LSI and oneleg- hop for distance LSI were assessed. At long-term follow-up, all patients aged 16-40 years at the time of injury were invited to complete the Knee Injury and Osteoarthritis Outcome Score (KOOS), ACL-QOL and EQ-5D. Mann-Whitney U tests compared outcomes between sub-groups (ACL surgically treated vs. non-surgically treated within 24 days of injury; ACL surgically treated vs. non-surgically treated at 32-37 year follow-up; baseline meniscus injury vs. no baseline meniscus injury; mid-term quadriceps strength LSI >=89% vs. =90%; and mid-term one-leg-hop LSI >=89% vs. >=90%). To detect clinically meaningful differences in the KOOS (>9-points), we required n = 32 in each sub-group. Results: 225 patients were eligible for 32-37 year follow-up. To date, 177 patients (79%) have completed questionnaires (age 59+/-6, range 47-74 years; 28% female). 101 patients (57%) had initial non-surgical ACL treatment and 65 patients (37%) had not had ACL surgery at longterm follow-up. 10 people (6%) had received a knee replacement (n = 7 ipsilateral; n = 1 contralateral; n = 2 bilateral). PROs for all participants at 32-37 year follow-up were: (median(IQR)) KOOS-Symptoms, 71(54, 89); KOOS-Pain, 86(64, 97); KOOS-Sport/Rec, 53(25, 75); KOOS-QOL, 56(39, 69); ACL-QOL 70(48, 88); EQ-5D, .80(.73, 1.0). KOOS scores were impaired in female and male participants compared with a Swedish population-based sample (Fig. 1). There were no differences (p>0.26) in PROs between patients initially treated with ACL surgery vs. no surgery (Fig. 2), no differences in PROs between patients who had and had not received ACL surgery at longterm follow-up (p>0.34), and in those with (59%) and without baseline meniscus injury (p >= 0.12). A LSI >=89% for quadriceps (29%) or hamstring strength (17%) at midterm follow-up was not associated with long-term PROs (p>0.10). Patients with a one-leg-hop LSI