Does an 8-week exercise intervention impact knee-related symptoms 3-15-years following intra-articular knee injury? a pilot randomized controlled trial

Purpose: Knee injury has been established as a risk factor for developing osteoarthritis It is not known if post-traumatic osteoarthritis can be prevented or delayed following a knee injury It has been established that symptoms (e g , knee-related pain, stiffness, locking etc ) and functional deficits (i e , quadriceps weakness, balance, hopping performance) can persist for years following an intra-articular knee injury We hypothesized that a neuromuscular training program that targets quadriceps strength and frontal plane knee control could improve knee-related symptoms in young adults 3 to 15 years after an injury Furthermore, it is possible that improved function could reduce the risk or delay the onset of osteoarthritis, the illness The purpose of this study was to describe the effect of pilot 8-week physiotherapist-led neuromuscular training intervention on self-reported knee symptoms in individuals with a 3 to 15-year history of a youth sport-related intra- articular knee injury Methods: This is a preliminary analysis of a pilot stepped-wedge randomized controlled trial Participants include a sub-sample of the Alberta Youth Prevention of Early Osteoarthritis (PrE-OA) historical cohort who experienced a time-loss, medical attention youth sport-related intra-articular injury 3-15 years previously The present study is limited to the participants who completed their baseline testing before the in-person testing and exercise intervention were cancelled due to the coronavirus pandemic After providing informed consent and completing a baseline Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, participants were randomly assigned to immediate (intervention) and 8-week delayed (control) groups in permuted blocks of varying size and stratified during randomization by sex To ensure allocation concealment, the trial biostatistician, who was not involved in participant recruitment or the intervention, generated the randomization sequence The allocation was concealed in a computer file only accessible by the biostatistician and a designated research assistant Once the baseline KOOS was completed, the physiotherapist leading the intervention contacted the research assistant who provided the randomization information As a result, the study physiotherapist (AMR) was not blinded to group status The KOOS was repeated at 8-weeks The 8-week intervention consisted of twice weekly 60-minute physiotherapist-led group exercise classes and once weekly 30-minute independent home exercise session Exercise classes were delivered in a multi-purpose room at the University of Calgary using standard exercise equipment (e g , step boards, mats, 5-15 pound dumbbells) Each class consisted of a warm-up, three sets of seven exercises (i e , squats, single-leg squats, lunges, jumping and landing, hip adductor strength, hamstring strength, trunk control), followed by five minutes of exercises addressing additional functional movement patterns (e g lateral movements, deceleration) Each exercise had 4 to 6 levels of progression Decision to progress to the next level was shared between the physiotherapist and the participant Knee-related pain was monitored at the beginning and end of each class and 24 hours following the class The primary outcome was the change in KOOS Symptoms subscale score from baseline to 8-week intervention/delay This subscale is comprised of 7 questions, each scored on 5-point Likert scale, ranging from no problems to extreme problems The scores were totalled and the total was transformed to a 0-100 scale with higher scores indicating better outcome Between-group differences in KOOS symptoms change were assessed with the Mann-Whitney U test (p < 0 05) Results: Nineteen participants were recruited and randomized to immediate (n=10) and delayed (n=9) exercise program delivery One participant dropped out of the immediate delivery and three participants in the delayed delivery group were unable to participate in the follow-up testing due to COVID-19-related restrictions Fifteen participant were included in the analysis Nine participants (6 women, 3 men;age 27 6±3 2 years;height 170 2±9 6 cm;weight 86 5±17 7 kg;body mass index 30 1±7 2) completed the 8-week intervention and 6 participants (3 women, 3 men;age 25 7±2 2 years;height 176 1±8 3 cm;weight 82 2±11 2 kg;body mass index 26 5±2 3) in the delayed group served as controls Scores for the KOOS subscales are presented in Table 1 The median change in symptoms from baseline to 8-week follow-up was -3 6 (range -10 7 to 3 6) in the immediate and -1 8 (range -3 6 to 3 6) in the delayed group There was no statistically significant difference (p=0 22, Z= -1 33) in the change in the symptom score between those completing the intervention and the delayed group over the 8-week period The change in the KOOS Symptom subscale for each participant is presented in Figure 1 Conclusions: There were no differences found between groups when comparing change in knee-related symptoms in individuals 3-15 following an intra-articular knee injury after an 8-week exercise intervention, compared to those waiting for the intervention Some individuals reported more knee-related symptoms after the intervention, even though the exercises were adapted for individual needs and pain was monitored It is important to bear in mind that the change in the KOOS symptoms score in both groups is less than the Minimal Detectable Change that previous studies have reported to be 5 to 8 5 points in populations with knee injury It is possible that the increased focus on the knee during the study leads to decreased scores in knee-related symptoms at follow-up It should also be taken into consideration that it is possible that the 8-week intervention is too short to elicit positive changes in knee-related symptoms In the future, the impact of an exercise intervention on knee-related symptoms will be explored in a larger group to allow for more robust analysis in which potentially confounding factors can be considered (e g , time since injury, sex) [Formula presented] [Formula presented]