In the present study, we found that baseline characteristics of patients with low apprehension at 6 months after ACL injury differed from those with high apprehension.
Overall, patients with an ACL-RSI score ≥ 60/100 (low apprehension) at 6 months after injury were younger and had less often post-operative knee pain and knee joint effusion than those with an ACL-RSI score < 60/100. Our results were consistent with those of Webster and colleagues, who found a positive effect of younger age and post-operative International Knee Documentation Committee score on the psychological readiness to return to sport [9]. In our study, we observed that nearly half (49%) of the participants were "competitive" athletes, compared to 40% in the study by Sadeqi et al. In addition, 66% practiced a pivot or contact pivot sport compared to 84% in this same study. Finally, concerning the types of surgical procedures, hamstring grafts (ST-G, T4D) represented 81% of the procedures in our study versus 88% in Sadeqi et al.
In our study, 21/37 (57%) patients received preoperative rehabilitation. We found that 2/3 (67%) professional sportsmen and women had preoperative rehabilitation, 10/18 (55%) “competition” sportsmen and women, but only 4/16 (25%) “leisure” sportsmen and sportswomen. Several reasons may explain our observation: surgeons and physicians may have had different prescription habits, preoperative rehabilitation protocols could have differed depending on the profile of the referred patient, and surgeons and physicians could have selected patients to preoperative rehabilitation based on their level of sport.
In multivariate analysis, preoperative rehabilitation was associated with ACL-RSI score at 6 months after injury. In the present study, preoperative rehabilitation was not standardized. Rehabilitation programs usually include muscle strengthening (quadriceps/hamstring) and proprioception exercises [10]. These practices stem from the fact that the strength of the quadriceps/hamstring pair in preoperative care is associated with better knee function at 6 months after surgery [11]. There are no recommendations on the optimal duration, intensity, frequency and mode of delivery of preoperative rehabilitation sessions before ACL surgery. A study of non-superiority did not show any benefits in continuing rehabilitation beyond 10 weeks [12].
Our study has limitations. Firstly, one of the main limitations was the use of different surgical techniques with also different surgeons and the practice of very different sports. Secondly, prescription habits of preoperative rehabilitation could have differed between surgeons and one cannot exclude that an operator effect may have influenced the ACL-RSI score at 6 months. Thirdly, outpatient physiotherapy between 6 weeks and 6 months post-operatively was also left at the discretion of the physiotherapist and was not standardized. Lastly, that some participants, contrary to others, could have received home-based exercises and/or suitable physical activity in addition to the supervised sessions, could also have influenced the ACL-RSI score at 6 months. However, the retrospective and exploratory design of our study did not allow us to comprehensively collect these data and to include them in the analyses. Our small sample size did not allow us to perform robust multivariate modelling. Finally, information about performance-related variable such as isokinetic quadriceps strength, history of previous contralateral injury, Tegner score, involved surgeons, and adherence to rehabilitation were not collected, and effect sizes were not calculated, but could have added relevant information to our dataset.