PSYCHOLOGICAL READINESS FOLLOWING ANTERIOR CRUCIATE LIGAMENT INJURY AND REINJURY IN ADOLESCENTS AND YOUNG ADULTS: A RETROSPECTIVE COHORT STUDY IN SPORTS PHYSICAL THERAPY CLINICS

This retrospective cohort study of 332 adolescents and young adults found that psychological readiness to return to sport following ACL reconstruction significantly improves over time and is generally higher in males than females, but is not significantly affected by whether the injury was a primary event or a reinjury.

The Gist

Imagine your knee is like the suspension system on a high-performance race car. When that suspension breaks (an Anterior Cruciate Ligament or ACL tear), the car can't race anymore. You have to take it to the shop for a rebuild (surgery) and then spend months in the garage learning how to drive it again (rehabilitation).

But here's the twist: It's not just about fixing the metal parts; it's about fixing the driver's mind.

This study is like a report card for the "drivers" (young athletes aged 15–25) to see how confident they feel getting back on the track after their crash. The researchers used a special "Confidence Meter" called the ACL-RSI (which stands for Return to Sport after Injury). This meter measures three things:

1. Emotions: Are you feeling scared or excited?
2. Confidence: Do you trust your knee to handle the turns?
3. Risk: Do you feel like you're going to crash again?

The Big Questions

The researchers wanted to know:

• Does the confidence meter go up as time passes?
• Do boys and girls feel differently about getting back in the race?
• Does it matter if you broke your knee for the first time or if you broke it again (either the same leg or the other one)?

What They Found (The Race Results)

1. Time Heals the Mind (Mostly)
Just like a car that gets smoother the more you drive it, the athletes' confidence scores went up the longer they were in rehab. The more time passed after surgery, the more they felt ready to race.

2. The Gender Gap
There was a clear difference between male and female drivers. Males consistently had higher confidence scores than females.

• Analogy: Imagine two drivers. Driver A (Male) thinks, "I've got this, I'm ready to go!" Driver B (Female) thinks, "I'm ready, but I'm a little worried about hitting a pothole." The study found this worry was more common among the female drivers, regardless of whether it was their first crash or a second one.

3. The "Second Crash" Surprise
The researchers had a hunch that athletes who broke their knee again would be much more scared than those who broke it for the first time. They thought, "If you crashed once, you'd be terrified to crash twice!"

• The Reality: They were wrong. The confidence scores for people who broke their knee again were not significantly lower than those who broke it for the first time.
• Why? Maybe by the time they get to the "Return to Sport" test, everyone has worked through their fears. Or maybe, after a second crash, some athletes just decide, "You know what? I'm not racing at that level anymore," which changes how they answer the questions.

4. The "Same Leg" vs. "Other Leg" Difference
Here is the most interesting part. While breaking it again didn't make people less confident overall, where it broke did matter.

• Contralateral (The Other Leg): If you broke your left knee, fixed it, and then broke your right knee, your confidence was actually higher.
• Ipsilateral (The Same Leg): If you broke your left knee, fixed it, and then broke your left knee again (the graft failed), your confidence was lower.
• Analogy: Breaking the other leg feels like a new, unrelated problem. But breaking the same leg again feels like the repair shop did a bad job, or that your car has a fundamental flaw. It shakes your trust in the fix itself.

The Takeaway for the Garage

The main lesson here is that psychological readiness is a moving target. It changes based on:

• Who you are: (Men tended to feel more confident than women).
• How long you've been rehabbing: (Confidence grows with time).
• Which leg broke: (Breaking the same leg twice hurts confidence more than breaking the other leg).

The Bottom Line:
Doctors and physical therapists shouldn't just look at the knee to see if an athlete is ready to play. They need to check the "driver's mind" too. If a young athlete (especially a female) is still feeling scared or unsure, they might need extra mental coaching before they get back on the field, regardless of whether this is their first injury or their second.

The study suggests that while time heals, the type of injury and the person's mindset play a huge role in whether they feel ready to hit the gas pedal again.

Technical Summary

1. Problem Statement

While psychological readiness is a critical determinant for Return to Sport (RTS) following ACL reconstruction (ACLR), there is limited understanding of how this readiness evolves over time across different patient subgroups. Specifically, gaps exist in the literature regarding:

• Injury History: Whether patients with ACL reinjuries (contralateral native ACL or ipsilateral graft) exhibit different psychological trajectories compared to those with primary ACL injuries.
• Biological Sex: How males and females differ in psychological readiness, given prior evidence suggesting females often report lower scores.
• Longitudinal Trajectory: Many studies assess readiness only at the point of RTS clearance rather than tracking the trajectory over time post-surgery.
• Age Demographics: Previous studies often focus on older populations, whereas the 15–25 age group represents the highest risk demographic for ACL injuries and RTS.

The study hypothesized that patients with ACL reinjuries would demonstrate lower ACL-Return to Sport after Injury (ACL-RSI) scores than primary injury patients, and that females would score lower than males across all injury statuses.

2. Methodology

• Study Design: Retrospective cohort study.
• Setting: Sports physical therapy clinics within a large health system (Sanford Health).
• Participants:
  • Total: 332 patients aged 15–25 years.
  • Groups:
    1. Primary ACL Injury ($n=251$).
    2. Contralateral ACL Reinjury ($n=42$).
    3. Ipsilateral ACL Graft Reinjury ($n=53$).
  • Inclusion Criteria: Patients undergoing ACLR with at least one ACL-RSI observation.
  • Exclusion Criteria: Age <15 or >25, allograft usage, or autograft harvest from the non-injured leg.
• Outcome Measure: The ACL-RSI (Anterior Cruciate Ligament – Return to Sport after Injury) scale.
  • A 12-item unidimensional scale measuring emotions, confidence in performance, and risk appraisal.
  • Scores range from 0% to 100% (higher scores indicate greater readiness).
  • Data was collected at various intervals post-ACLR (typically 3–9 months).
• Statistical Analysis:
  • Model: Linear mixed-effects model.
  • Variables:
    • Dependent: Logit-transformed ACL-RSI scores.
    • Independent: Time post-ACLR (continuous), Biological Sex (categorical), Injury Status (categorical: Primary, Contralateral, Ipsilateral).
  • Covariates/Structure: Random effects for patient ID to account for repeated measures; continuous autoregressive correlation structure for time; variance functions to address heteroscedasticity.
  • Software: R (v. 4.2.2).

3. Key Results

• Time Effect: ACL-RSI scores significantly increased over time post-ACLR ($p < .001$).
• Sex Effect: Males reported significantly higher ACL-RSI scores than females ($p < .001$) across all injury statuses.
• Injury Status (Primary vs. Reinjury):
  • There was no significant difference in ACL-RSI scores between patients with primary ACL injuries and those with ACL reinjuries (contralateral or ipsilateral combined).
  • This finding contradicted the initial hypothesis that reinjury patients would have lower scores.
• Injury Status (Contralateral vs. Ipsilateral):
  • Patients with contralateral reinjuries demonstrated significantly higher scores than those with ipsilateral graft reinjuries ($p = .006$).
• Interaction Effects:
  • A significant interaction was found between biological sex and injury status ($p = .009$).
  • Post-hoc analysis confirmed that females consistently scored lower than males, regardless of injury type.
  • Specifically, females with ipsilateral graft reinjury had significantly lower scores than males with primary injuries ($p = .006$) and males with contralateral reinjuries ($p < .001$).

4. Key Contributions

• Differentiation of Reinjury Types: The study distinguishes between contralateral and ipsilateral reinjuries, revealing that the location of the reinjury (same leg vs. opposite leg) impacts psychological readiness differently, with ipsilateral graft failure being more psychologically detrimental than contralateral injury.
• Longitudinal Insight: By analyzing the trajectory over time rather than a single RTS time point, the study suggests that psychological readiness may converge between primary and reinjury groups as rehabilitation progresses, masking early differences.
• Age-Specific Data: Provides robust data specifically for the high-risk 15–25 age demographic, filling a gap left by studies focusing on older adults.
• Refutation of "Reinjury Penalty": Challenges the assumption that a history of ACL reinjury automatically results in lower psychological readiness compared to a primary injury, suggesting that the type of reinjury matters more than the mere fact of reinjury.

5. Significance and Clinical Implications

• Individualized Monitoring: Clinicians should not assume all reinjury patients have poor psychological readiness. However, special attention is required for females and those with ipsilateral graft failures, as these groups are at higher risk for maladaptive psychological responses.
• Rehabilitation Strategy: The finding that scores improve over time supports the need for longitudinal psychological monitoring throughout the rehabilitation process, rather than a single assessment at the end.
• Risk Stratification: Since low ACL-RSI scores are linked to reinjury risk, identifying the specific subgroups (females, ipsilateral reinjury) who struggle most allows for targeted psychological interventions (e.g., cognitive-behavioral therapy, confidence-building drills) before RTS clearance.
• Limitations & Future Directions: The study notes limitations such as irregular data spacing and the lack of control for concurrent pathologies (e.g., meniscal repairs). Future research should investigate the "desire to return" as a confounding variable, as a second injury might alter a patient's motivation to return to sport entirely, potentially skewing readiness scores.

Conclusion: Psychological readiness following ACLR is dynamic and heavily influenced by biological sex and the specific nature of the reinjury (ipsilateral vs. contralateral), but not necessarily by the history of reinjury itself when compared to primary injuries in young athletes.