Summary

A 2 years follow-up after an acute ACL-injury, regarding new injuries in patientes treated with or without ACL-reconstruction

Abstract

Background

ACL injury is common among young athletes, but the optimal treatment choice is unknown. There are some previous studies showing an increased risk for new injuries when the ACL-injury is not treated with ACL reconstruction, but many of these studies suffer of selection bias and the evidence is low. The aim with the present study is to describe the frequency of new injuries within two years after an ACL-injury, in a cohort of patients with acute ACL-injury treated with either ACL reconstruction (ACLR) and rehabilitation or with rehabilitation alone.

Methods

Data from a national multicenter cohort ACL study (the NACOX-study) were analyzed (1). Patients with an acute ACL injury were included within 6 weeks from the injury and treated according to usual care at recruiting centers, usually with a rehabilitation period before a decision for ACLR. The treatment decision making process for these patients has been published (2,3). Data about ACLR and new serious knee injuries was collected through continuously and regularly digital questionnaires (initially weekly), follow-up evaluations and by medical journal reviews. Serious injury was defined as graft rupture or an injury leading to a specific treatment (e.g. arthrocentesis) or surgery.

Results

275 patients (52% females) with a mean age of 25.2 (SD 7.0) were included. The majority were active in sports prior to injury (median Tegner activity level 7 (IQR 4-9), 70% were active in contact and/or pivoting sports) and 259 (94%) had the goal to return to sport. At 2 years after injury, 169 (61%) had undergone ACLR in a mean of 6.8 (SD 6.7) months after injury. 55 (33%) had ACLR within 3 months from injury, 58 (34%) between 3 and 6 month, 44 (26%) between 6 and 12 months and 12 (7%) between 12 and 24 months. 30 (11%) patients sustained new injuries within 2 years. 4 (4%) in the group treated with non-ACLR had a new injury, 7 (4%) in the ACLR group got the injury before, and 19 (11%) got injured after the ACLR. 12 patients in the ACLR-group sustained a graft rupture.

Discussion

The 11 injuries that occurred before the ACLR could have been avoided if the patients had undergone an early ACLR. On the other hand, 19 injuries occurred after the ACLR, including 12 graft ruptures. Only 4 patients who were treated without ACLR (rehabilitation alone) sustained a new serious injury within 2 years from index injury.

Conclusion

One in 9 patients sustained a new knee injury within 2 years from index ACL injury. The association between new injuries and ACL treatment is complex and more analyses is needed. Further analyses of this is “real life” study following patients who were treated according to clinical praxis and had ACLR at different time points after the index injury, and future studies, may help clinicians in the decision for the best treatment of patients with ACL-injury.

References
1. Kvist J, Gauffin H, Tigerstrand Grevnerts H, et al. Natural corollaries and recovery after acute ACL injury: the NACOX cohort study protocol. BMJ Open 2018;8(6):e020543. doi: 10.1136/bmjopen-2017-020543 [published Online First: 2018/06/29]
2. Grevnerts HT, Sonesson S, Gauffin H, et al. Decision Making for Treatment After ACL Injury From an Orthopaedic Surgeon and Patient Perspective: Results From the NACOX Study. Orthopaedic Journal of Sports Medicine 2021;9(4):23259671211005090. doi: 10.1177/23259671211005090
3. Grevnerts HT, Krevers B, Kvist J. Treatment decision-making process after an anterior cruciate ligament injury: patients’, orthopaedic surgeons’ and physiotherapists’ perspectives. BMC Musculoskeletal Disorders 2022;23(1):782. doi: 10.1186/s12891-022-05745-4