Abstract
Objectives:
Outcomes after anterior cruciate ligament reconstruction (ACLR) are not uniformly acceptable and are worse among young female athletes. Developing better rehabilitation and return-to-sport (RTS) training programs and evaluating their outcomes are essential. The purposes of this study were to: 1) Test the effect of strength, agility, plyometric, and secondary prevention (SAPP) exercises with and without perturbation training (SAPP+PERT) on strength, hops, functional outcomes, activity levels, and RTS rates in young female athletes 1 and 2 years after ACLR; and 2) Compare 2-year functional outcomes and activity levels among young female athletes in the ACL-SPORTS trial to homogeneous cohorts who completed criterion-based post-operative rehabilitation alone (MOON) and in combination with extended pre-operative rehabilitation (DE-Oslo). We hypothesized that SAPP+PERT would result in superior outcomes compared to SAPP alone; and female athletes who structured completed post-operative RTS training, compared to those who did not, would have higher functional outcomes.
Methods:
Aim 1 is a randomized control trial (NCT01773317) while aim 2 is a cohort study. For aim 1, we enrolled 39 female athletes, based on power calculations described previously. Athletes were enrolled 3-9 months after primary ACLR when they achieved impairment resolution. Participants were randomized to 10 SAPP or SAPP+PERT sessions (˜2x/week) and tested 1 and 2 years after ACLR on quadriceps strength, 4 hop tests, functional outcome measures, and RTS rates. We used 2x2 mixed-model ANOVA to test aim 1 (α = 0.05). Secondary to no group differences, we collapsed across SAPP and SAPP+PERT for aim 2. We applied inclusion/exclusion criteria and constrained sex (female) and age (13 to < 25 years) to compare these athletes who received post-operative RTS training (ACL-SPORTS) to homogeneous subsets who completed criterion-based post-operative rehabilitation alone (MOON) and combined with extended pre-operative rehabilitation (DE-Oslo) on 2-yr outcomes: the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Marx Activity Rating Scale. We tested aim 2 using 3-way ANOVA and Chi-Square test of proportions to compare the proportion of individuals in each group who met the Patient Acceptable Symptom State (PASS) thresholds.
Results:
There were no significant or clinically meaningful differences between SAPP and SAPP+PERT; groups were collapsed for comparison to the other cohorts. ACL-SPORTS had the highest scores on every outcome (Table 1). A higher proportion of ACL-SPORTS achieved the PASS thresholds for the IKDC, KOOS Activities of Daily Living, and KOOS Sport and Recreation (Fig 1, p ≤ .01).
Conclusion:
Our 1st hypothesis, that the addition of perturbation training would result in superior clinical and functional outcomes, was not supported. Our 2nd hypothesis, that a structured RTS training program would improve outcomes over existing cohorts, was supported. Post-operative RTS training incorporating strengthening, agilities, and plyometrics but not necessarily perturbation training, may improve functional outcomes and activity levels among young female athletes after ACLR. We provide a prototype for RTS training that would be feasible to implement into group or non-clinical environments. Future RCTs should assess the comparative effectiveness of RTS training in various settings.
All 2-year functional outcome measures differed across groups. Values are mean (SD).
| Outcome Variables | MOON | DE-Oslo | ACL-SPORTS | P-Value |
|---|---|---|---|---|
|
|
10.6 (5.1) | 12.5 (2.7) | 13.5 (3.3) | 0.008 |
|
|
83.6 (13.9) | 91.7 (8.6) | 95.9 (6.8) | <0.001 |
|
|
90.4 (10.3) | 94.4 (9.4) | 97.9 (3.9) | <0.001 |
|
|
83.4 (14) | 89.6 (9.4) | 93.5 (6.3) | <0.001 |
|
|
95.7 (7.1) | 98.8 (4.2) | 99.8 (0.5) | 0.002 |
|
|
81.6 (17.1) | 86.0 (15.4) | 94.4 (7.6) | 0.001 |
|
|
76.3 (18.7) | 78.3 (17.6) | 89.1 (13.9) | 0.004 |
Proportion Who Met IKDC PASS Threshold
Proportion Who Met KOOS ADL PASS Threshold
Proportion Who Met KOOS Sport/Rec PASS Threshold