Patients return to sports and to work after successful treatment of septic arthritis following anterior cruciate ligament reconstruction
Authors: Themessl Alexander , Mayr Felix , Hatter Kate , Rupp Marco-Christopher , Pogorzelski Jonas , Imhoff Andreas B. , Buchmann Stefan 
Published: December 2021

Abstract
Purpose
To determine specific return to sports (RTS) and return to work (RTW) rates of patients with septic arthritis following anterior cruciate ligament reconstruction (ACLR), and to assess for factors associated with a diminished postoperative return to physical activity after successful eradication of the infection.

Methods
In this study, patients who were treated for postoperative septic arthritis of the knee following anterior cruciate ligament reconstruction between 2006 and 2018 were evaluated at a minimum follow-up (FU) of 2 years. Patients’ outcomes were retrospectively analyzed using standardized patient-reported outcome scores including the Lysholm score and the subjective IKDC score, as well as return to sports and return to work questionnaires to assess for the types, number, and frequency of sports performed pre- and postoperatively and to evaluate for potential occupational changes due to septic arthritis following ACLR. To assess for the signifiance of the graft at follow-up, outcomes were compared between patients with a functioning graft at FU and those without, as well as between patients with initial graft retention and those with graft removal and consecutive revision ACLR.

Results
Out of 44 patients eligible for inclusion, 38 (86%) patients at a mean age of 36.2 ± 10.3 years were enrolled in this study. At a mean follow-up of 60.3 ± 39.9 months, the Lysholm score and the subjective IKDC score reached 80.0 ± 15.1 and 78.2 ± 16.6 points, respectively. The presence of a graft at FU yielded statistically superior results only on the IKDC score (p = 0.014). There were no statistically significant differences on the Lysholm score (n.s.) or on the IKDC score (n.s.) between patients with initial graft retention and those with initial removal who had undergone revision ACLR. All of the included 38 patients were able to return to sports at a median time of 8 (6–16) months after their last surgical intervention. Among patients who performed pivoting sports prior to their injury, 23 (62.2%) returned to at least one pivoting sport postoperatively. Overall, ten patients (26.3%) returned to all their previous sports at their previous frequency. The presence of a graft at FU resulted in a significantly higher RTS rate (p = 0.010). Comparing patients with initial graft retention and those with graft removal and consecutive revision ACLR, there was no statistically significant difference concerning the RTS rate (n.s.). Thirty-one patients (83.8%) were able to return to their previous work.

Conclusion
Successful eradication of septic arthritis following anterior cruciate ligament reconstruction allows for a postoperative return to sports and a return to work particularly among patients with ACL-sufficient knees. However, the patients’ expectations should be managed carefully, as overall return rates at the pre-injury frequency are relatively low.

Level of evidence
IV.