Patients that maintain their pre-injury level of physical activity 3–5 years after ACL reconstruction are, 18 months after surgery, characterised by higher levels of readiness to return to sport

Purpose To characterise patients who had returned to their pre-injury physical activity (PA) or higher at 18 months and maintained that level of PA 3–5 years after the primary ACL reconstruction and to describe the level, frequency, and type of PA participation during the first 5 years after ACL reconstruction Method Data, from follow-ups at 18 months and 3–5 years after an ACL reconstruction, were extracted from a rehabilitation-specific register. Patients, 15–65 years of age, were included. The data comprised patient-reported outcomes and the results from two questions with respect to the level, frequency, and type of PA. Comparisons were made between patients who had and had not maintained their pre-injury level of PA at the follow-up 3–5 years after an ACL reconstruction. Results A total of 272 patients met the inclusion criteria. The mean follow-up time was 3.8 years (min–max: 2.9–5.1) after the ACL reconstruction. Of patients who had returned to their pre-injury or a higher level of PA at the 18 month follow-up ( n = 114), 68% ( n = 78) maintained that level at the 3- to 5-year follow-up after ACL reconstruction. These patients reported a higher level of psychological readiness to return to sport (98 versus 79; p = 0.013). Moreover, these patients were 6.0 years older ( p = 0.016) and were characterised by male sex (56% versus 44%; p = 0.028) and a lower level of pre-injury PA ( p = 0.013). At the follow-up 3–5 years after the ACL reconstruction, more than 90% met the recommendations for PA. However, the prevalence of physical inactivity had increased and the involvement in organised PA had decreased compared with the 18-month follow-up. Conclusions Two out of three patients who have returned to their previous level of PA at 18 months can be expected to maintain that level, 3–5 years following ACL reconstruction. These patients were mainly characterised by a higher level of psychological readiness, especially in patients who participated in knee-strenuous sport and were younger than 20 years of age. The results of this study suggest that patients become more physically inactive over time, implicating the importance of clinicians helping patients find a suitable PA that may help patients maintain an active lifestyle.