ACL Return to Sport Testing: It's Time to Step up Our Game

Unverzagt C, Andreyo E, Tompkins J. ACL return to sport testing: It’s time to step up our game. The International Journal of Sports Physical Therapy. 2021;16(4). doi:10.26603/001c.25463

Link to Original Article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8329322/

Key Points

1. The decision on when an athlete is ready to return to sport following anterior cruciate ligament (ACL) reconstruction is complex and should consider biological healing, joint stability, functional performance, and psychological readiness.

2. Current practice patterns for ACL return to sport (RTS) testing often rely on time as the sole determinant of an athlete's readiness, with little emphasis on performance-based criteria.

3. Pooled data from studies has shown that only 65% of individuals return to their preinjury level of sports participation following ACL reconstruction, and approximately 23-29% of athletes under 25 years of age will incur a second ACL injury.

4. There is a need to reevaluate the current state of ACL management and RTS testing, as the fixation on using time as a determinant for RTS may lead to athletes returning to sport before they have achieved a safe level of knee function, increasing the risk of reinjury.

5. The authors propose a more robust model for RTS testing that incorporates temporal and criterion-based factors, intrinsic and extrinsic data, and individualized needs analysis tailored for specific sports and athletes.

6. The authors advocate for a careful interpretation of test data, raising the bar for passing RTS criteria, acknowledging intrinsic risk factors, and using a screening tool to ensure athletes are safe to undergo RTS testing. They also recommend monitoring workload throughout the RTS transition.

Reviewing Current Practice Patterns

The section "Reviewing Current Practice Patterns" highlights the prevalence of anterior cruciate ligament (ACL) injuries, with up to 200,000 cases reported annually in the United States. It discusses the common practice of pursuing ACL reconstruction (ACLR) to enable athletes to return to their previous level of sport. However, it raises concerns about the actual likelihood of successful return to sport, as only 65% of individuals and 55% of competitive athletes were found to return to preinjury levels following ACLR. Moreover, athletes under 25 years of age face a high risk of incurring a second ACL injury, with approximately 23-29% experiencing such an injury. The paper questions the acceptability of current ACL management practices and suggests that the fixation on using time as a determinant for return to sport (RTS) is deeply ingrained in the physical therapy profession.

There is a growing concern of high reinjury rate and low rates of return to sports in ACL injuries. The latest evidence reports 85% of 209 ACLR studies used timed as a criterion for RTS and almost 50% of the study used it as the only criterion. Since 1990’s, providers and patients have pushed the “speed limits” of rehab, and patients suffer with greater consequences if they speed through rehabilitation programs.

Furthermore, the paper presents evidence that the current standard of six to nine months for clearing an athlete for play may not be sufficient, as many individuals do not achieve symmetrical knee function and performance at this stage. It notes the potential limitations of using a limb symmetry index (LSI) for RTS testing, proposing a higher standard care than achieving 100% symmetry for strength and hop testing. The authors note symmetry does not correlate with movement quality or achievement of pre-injury status. The author questions whether LSI is the best practice for RTS as patients who undergo ACLR show deficits for both limbs when compared to healthy athletes. The paper also emphasizes the importance of patient-reported criteria, especially psychological readiness, in RTS decisions, as lower psychological readiness correlates with a higher risk of second ACL injury and decreased likelihood of returning to sport.

In conclusion, the section discusses the disparity between current practice patterns and recommendations for ACL injury management, highlighting the need for a more comprehensive and robust model for RTS testing that incorporates both temporal and criterion-based factors, as well as intrinsic and extrinsic data.

Let’s Get Back To The Basics

The section "Let’s Get Back To The Basics" emphasizes the importance of considering the specific athletic demands of individual athletes when commencing rehabilitation. It highlights the complexity of athletic demands, providing the example of a high school soccer player, and emphasizes the need for tailored criteria to minimize the potential for re-injury during Return to Sport (RTS) testing. The paper offers a practical testing battery for RTS testing, focusing on both extrinsic and intrinsic risk factors.

Table 1

Extrinsic Criterion Used to Assess Return to Sport Readiness

It acknowledges the influence of non-modifiable intrinsic risk factors, such as gender and anatomic factors, on ACL injury, and suggests that these factors should influence an athlete's timeline for sports participation. The section provides a practical scenario comparing two athletes who pass RTS testing but have different intrinsic risk factors, emphasizing the unique management required for each athlete. Overall, the section calls for a more comprehensive consideration of individual athlete needs and risk factors in RTS decision making, going beyond the traditional focus on modifiable risk factors.

Specific Testing Consideration

The authors propose the use of a return to sport (RTS) testing battery as a screening tool to ensure the safety of athletes undergoing RTS testing after an ACL tear. The "Ticket to Entry" tests, including hip, knee, and ankle range of motion (ROM), Functional Movement Screen, Y-Balance Test, Single Leg Squat Test, Tuck Jump Assessment, Landing Error Scoring System, isokinetic testing, hop testing, Hop & Stop Test, lateral agility screen, Flanker Test, and Reactive Agility Test, are suggested for assessing neuromuscular and biomechanical factors. The authors emphasize the importance of using a subscription-based injury prediction algorithm to interpret certain test scores, and they recommend elevating the standard for the Tuck Jump Assessment. Additionally, they suggest sending athletes to specific RTS testing centers with the necessary equipment and expertise, and they recommend having a practitioner complete the testing who was not directly involved in the patient's care to avoid implicit bias. The paper also briefly mentions the importance of the acute:chronic workload ratios in monitoring an athlete's training load as they transition back to sports participation. Finally, the authors highlight the importance of achieving and maintaining optimal loading during an athlete's return to sport.

Table 2

Extrinsic Cut-Off Values Used to Assess Return to Sport Readiness

Table 3

Intrinsic Risk Factors Associated with ACL Re-Injury

An Uphill Battle

In this section, the authors acknowledge that using temporal and criterion-based assessment, taking into account intrinsic and extrinsic risk factors to determine return to sport (RTS), contradicts current practice. They anticipate that many clinicians and patients will view their RTS guidelines unfavorably due to the requirement for additional equipment, testing, and time. Furthermore, it is important to note that the proposed RTS criteria lack validation. The authors suggest various alternative perspectives for physical therapists, such as emphasizing the long-term health and wellness of athletes instead of solely focusing on their return to the field, adopting a holistic approach to evaluate athletes for RTS rather than relying on a one-dimensional checklist, and providing athletes with more transparency regarding reinjury and retear rates, rather than assuring complete healing and success within a 6 to 9-month waiting period.