This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.
1. Trial at a Glance
MIRACL is a randomized, parallel, single-masked clinical trial evaluating motor imagery training after anterior cruciate ligament reconstruction.
| Feature | MIRACL |
|---|---|
| NCT ID | NCT05168033 |
| Title | Motor Imagery After Reconstruction of the Anterior Cruciate Ligament |
| Lead sponsor | University Ghent |
| Phase | NA |
| Status | UNKNOWN |
| Allocation | RANDOMIZED |
| Design model | PARALLEL |
| Masking | SINGLE |
| Primary purpose | TREATMENT |
2. Clinical Question
Population
Patients with anterior cruciate ligament rupture undergoing reconstruction.
Intervention
Motor imagery training.
Comparator
Classic rehabilitation.
Primary question
Does motor imagery training influence recovery-related outcomes after ACL reconstruction compared with classic rehabilitation?
3. Trial Design
Enrollment
70 participants
Randomization
Two arms
Treatment
Motor imagery or rehabilitation
Assessment
Functional and questionnaire outcomes
Follow-up
Up to 15 months
Motor imagery training (other).
Classic rehabilitation (other).
4. Endpoints
| Endpoint | Time frame | Description |
|---|---|---|
| KOOS Questionnaire | From preoperative screening (1 week before surgery) until return to sport screening (28 weeks postoperative) | Patient opinion about knee and associated problems; higher score indicates less dysfunction. |
| ACL-RSI Questionnaire | From preoperative screening (1 week before surgery) until return to sport screening (28 weeks postoperative) | Measures emotions, confidence, and risk assessment when returning to sport; lower score indicates more concerns. |
| VAS Questionnaire | From preoperative screening (1 week before surgery) until return to sport screening (28 weeks postoperative) | Subjective pain measure from 0-100; higher score indicates more pain. |
| Knee confidence | From preoperative screening (1 week before surgery) until end of follow up (15 months postoperative) | Confidence in operated knee expressed relative to nonoperated side. |
| Limb circumference | From preoperative screening until 4 weeks postoperative | Knee effusion measured at two thigh locations. |
| Knee flexion and extension range of motion | From preoperative screening until 4 weeks postoperative | Measured using a goniometer. |
| Quadriceps muscle strength | From preoperative screening until return to sport screening (28 weeks postoperative) | Measured using a handheld dynamometer. |
| Balance | From 8 weeks postoperative until return to sport screening (28 weeks postoperative) | Measured using Y-balance test - lower quadrant. |
| Hop tests | From 16 weeks postoperative until return to sport screening (28 weeks postoperative) | Single leg hop, vertical jump, and side hop compared using Limb Symmetry Index. |
| Change in movement quality | From 8, 12 and 24 weeks postoperative until return to sport screening (28 weeks postoperative) | Movement quality assessed using 2D video camera setup. |
5. Planned Analysis
The registry does not report posted statistical analyses or trial results on ClinicalTrials.gov. The planned outcomes are primarily repeated clinical measurements and questionnaire-based assessments collected over postoperative follow-up periods.
Questionnaire outcomes such as KOOS and ACL-RSI are commonly analyzed using comparisons of score changes over time between randomized groups. Continuous functional measurements such as range of motion, strength, balance, and movement assessments are typically evaluated using appropriate comparisons of postoperative measurements or trajectories over time.
Because no formal statistical analyses were posted to ClinicalTrials.gov, the registry does not provide the statistical model specifications, estimation methods, confidence intervals, or hypothesis-testing framework used for these endpoints.
6. Statistical Methodology
Randomization
Randomization is the foundation of the treatment comparison. By assigning participants to intervention groups, randomized trials aim to balance measured and unmeasured characteristics between groups on average.
Longitudinal outcome analysis
MIRACL evaluates outcomes at multiple postoperative time points. Statistical approaches for longitudinal data account for the correlation between repeated measurements from the same participant.
Continuous outcomes
Scores, measurements, and functional tests are quantitative outcomes. Analysis generally focuses on differences between groups, changes over time, or both.
7. Statistical Methods Explained
Why are questionnaire scores analyzed statistically?
Measures such as KOOS and ACL-RSI convert patient-reported experiences into numerical scales. Statistical analysis evaluates whether observed differences between randomized groups are compatible with chance variation.
Why does follow-up timing matter?
Recovery after ACL reconstruction changes over time. Measurements collected before surgery and after surgery provide information about recovery trajectories rather than a single snapshot.
Why are repeated measurements different from independent measurements?
Multiple observations from one patient are related because they come from the same individual. Statistical methods must account for this within-person correlation.
Why is randomization important?
Randomization supports unbiased comparisons between intervention groups by creating treatment groups defined before outcomes occur.
Why are functional tests included alongside questionnaires?
Patient-reported outcomes describe perceived recovery, while strength, balance, movement quality, and hop tests provide objective functional assessments.
8. Limitations
- No posted statistical analyses: ClinicalTrials.gov does not report formal statistical analysis results for MIRACL.
- Multiple endpoints: The trial evaluates multiple clinical and functional outcomes, which requires careful interpretation of statistical comparisons.
- Longitudinal measurements: Outcomes collected over different postoperative periods require methods appropriate for repeated observations.
- Registry information: Detailed statistical analysis plans, missing-data approaches, and multiplicity procedures are not reported in the registry record.
9. Why This Trial Matters Statistically
| Concept | How it appears in MIRACL |
|---|---|
| Randomization | Randomized parallel two-arm treatment comparison. |
| Repeated measures | Outcomes collected across postoperative follow-up periods. |
| Patient-reported outcomes | KOOS, ACL-RSI, VAS, and knee confidence questionnaires. |
| Functional testing | Strength, balance, hop tests, and movement quality assessments. |
| Clinical measurement | Objective recovery-related assessments after surgery. |