A few practice-reinforcing recommendations stand out
Anterior cruciate ligament (ACL) tears are high-profile injuries. Every week, they are highlighted on sports TV, radio, and social media. Here in Houston, Texans rookie quarterback Deshaun Watson’s strong campaign for NFL rookie of the year was abruptly halted by an ACL tear.

If we look at the sport the rest of the world calls football, the United States women have a stellar record in World Cup competition. However, U.S. teams feature many players who have torn their ACL one or more times—Alex Morgan, Megan Rapinoe, Ali Krieger, and Brandi Chastain, to name a few.

ACL tears are common injuries. Although they may not make the evening news, the vast majority of ACL tears occur outside the ranks of elite athletes.

Estimates vary but suggest several hundred thousand tears occur annually in the United States, largely among agility athletes and, in particular, adolescent and young adult females participating in soccer and/or basketball.

In 2017, the AAOS Committee on Evidence-Based Quality and Value published a series of impactful statements for the management of ACL injuries. These statements were derived from the Management of Anterior Cruciate Ligament (ACL) Injuries Clinical Practice Guidelines (CPG) and are augmented by two appropriate use criteria (AUC) as well as two clinician checklists.

Of the 20 AAOS CPG recommendations, the following five statements stand out as offering the most impact on patient care. In theory, these statements should be less practice-altering and more practice-reinforcing.

ACL reconstruction should be performed in young (18 – 35 years old) active adult patients with an ACL tear.

This may seem obvious to most orthopaedic surgeons, but it is important to counsel patients regarding the evidence supporting the recommendation to have surgery. Patients returning after “prehab” free of pain and effusion may misinterprete the improvement as meaning that their knee was okay. In some cases, these pateints ask if surgery is truly necessary. Other patients found out the hard way that their knees were still unstable. This deceptive feeling that the knee is healed during simple activities, when it is in fact still unstable, is particularly important in light of the second statement—timing matters.

ACL reconstruction, when indicated, should be performed within the first five months of injury to protect the articular cartilage and menisci.

A thorough discussion about surgery should also cover the risks of nonsurgical treatment. The literature supports surgery within the first five months, but what we need to communicate to patients is that when an unstable ACL-deficient knee gives out, other structures of the knee are at risk. Many of us have operated on patients who delayed ACL surgery in whom significant meniscal and chondral damage was found during arthroscopy.

Bone-patellar tendon-bone or hamstring-tendon autografts should be used in patients undergoing intra-articular ACL reconstruction, as measured outcomes are similar.

Once the decision for surgery is made and scheduled, evidence supports use of patellar tendon or hamstring autografts.

A comprehensive discussion of graft choice is beyond the scope of this article. Large multicenter trials, notably the Multicenter Orthopaedic Outcomes Network and Multicenter ACL Revision Study group studies, have reported increased rerupture risk with allografts compared to autografts in primary and revision cases. Use of quadriceps tendon autografts will likely be queried when these guidelines are updated. For evidence-based surgical ACL practice, autograft is best.

Functional knee bracing after isolated ACL reconstruction should not be routinely used, as there is no demonstrated efficacy.

What about functional knee braces postoperatively? What evidence supports this approach?

Many patients expect to use a functional brace based on what they have seen from friends, family, teammates, or athletes on TV. The challenging nature of this topic may rank bracing as recommendation with the lowest adherence.

I recommend that patients focus on appropriate rehabilitation, with specific criteria for activity progression. I explain that there is no evidence that functional braces help prevent a recurrent ACL tear. Many patients find this liberating. I admit to bracing particularly apprehensive patients, as well as some revision and multiligament repairs. Counselling patients about the evidence on bracing decreases their interest in functional bracing.

Neuromuscular training programs could be used as they can reduce ACL injuries; however, the number of athletes treated to prevent one ACL injury is very high.

Neuromuscular training is related to rehabilitation and a key component of agility work in preparation for return to sport, as expressed by this CPG impactful statement.

A patient who has torn his or her ACL is at increased risk of both ipsilateral and contralateral future ACL injuries, so extrapolating from available evidence, it is reasonable to prescribe neuromuscular training as part of return-to-play progressions.

This recommendation is important for clinicians to recognize, as many patients will ask after a minor sports-related knee injury what they can do to prevent future major injuries. In addition, team physicians should be aware of these programs and discuss implementation with athletic trainers, strength and conditioning coaches, and athletes.

For more information on AAOS CPGs, AUCs, checklists, and impactful statements, visit www.orthoguidelines.org, or download the free OrthoGuidelines App available for both iOS and Android.

Theodore B. Shybut, MD, is an orthopaedic sports medicine specialist at Baylor College of Medicine, Houston, Texas, and a member of the AAOS Committee on Evidence-Based Quality and Value, member of the AOSSM Public Relations Committee, and team physician for Texas Southern University and Houston SaberCats Rugby. He can be reached at shybut@bcm.edu.