Smoking and secondary ACL rupture are detrimental to knee health post ACL injury-a Bayesian analysis

Micah Nicholls; Thorvaldur Ingvarsson; Stephanie Filbay; Stefan Lohmander; Kristin Briem

doi:10.1186/s40634-023-00638-4

Smoking and secondary ACL rupture are detrimental to knee health post ACL injury-a Bayesian analysis

J Exp Orthop. 2023 Aug 9;10(1):79. doi: 10.1186/s40634-023-00638-4.

Authors

Micah Nicholls¹, Thorvaldur Ingvarsson², Stephanie Filbay³, Stefan Lohmander⁴, Kristin Briem⁵

Affiliations

¹ Faculty of Medicine, Research Centre for Movement Sciences, The University of Iceland, Sæmundargata 2, Reykjavík, 102, Iceland. mkn1@hi.is.
² Department of Orthopaedic Surgery, University of Akureyri, Akureyri, Iceland.
³ Department of Physiotherapy, Faculty of Medicine Dentistry and Health Sciences, The University of Melbourne, Melbourne, Australia.
⁴ Department of Clinical Sciences Lund, Orthopaedics, Lunds Universitet, Lund, Sweden.
⁵ Faculty of Medicine, Research Centre for Movement Sciences, The University of Iceland, Sæmundargata 2, Reykjavík, 102, Iceland.

Abstract

Purpose: To identify potential prognostic factors for patient-reported outcomes in an Icelandic cohort of ACL injured subjects.

Methods: All knee MRI reports written in Iceland between the years 2001 to 2011 were read to identify individuals with a possible ACL injury. These individuals were contacted and asked to complete an online questionnaire regarding their injury and current knee related health. The questionnaire collected information on years since surgery, injury circumstance, brace use, physiotherapy, ACL surgery, second ACL injury and current smoking status. In addition, the baseline status of their meniscii were assessed from the original MRI report and medical records were used to identify any subsequent, non-ACL surgery. The patient-reported Knee Osteoarthritis and Injury Outcome Score (KOOS) was used assess current knee related health. A Bayesian proportional odds model was used to assess the effect of all potential prognostic factors above as well as age and sex on KOOS outcomes.

Results: A total of 408 subjects completed the questionnaire indicating that they did rupture their ACL. The following variables were associated with worse outcomes across all KOOS subscales: having a subsequent arthroscopy, reinjury to your ACL, and smoking. Having physiotherapy for 9 months was associated with worse KOOS pain scores than having 6 months of physiotherapy. Conversely KOOS pain score tended to be higher if you injured your knee during sports.

Conclusion: Reinjuring your ACL, smoking and having subsequent (non-ACLR) surgery predict your knee related health following an ACL injury. Strategies should be implemented to reduce the risk of secondary ACL injury, and patients should be strongly advised not to smoke.

Keywords: ACL reconstruction; Bayesian; Knee injury; National cohort; Nonoperative management; Patient-reported outcomes.