"Both prevention and treatment of anterior cruciate ligament (ACL) injuries can be confusing given the diversity of injured patients—from skeletally immature youth to older adults, low- and high-risk athletes playing a variety of sports, and patients with and without arthritis," acknowledged Robert H. Quinn, MD, Appropriate Use Criteria (AUC) Section Leader on the AAOS Committee on Evidence-Based Quality and Value.

In light of that diversity, the AAOS is making available a new suite of online resources to guide orthopaedic surgeons in the management of these injuries as well as in counseling patients about prevention strategies. At its October meeting, the AAOS Board of Directors approved two AUCs for ACL treatment and prevention programs, along with rehabilitation and function checklists to help guide return to sport and achievement of normal function.

The new Appropriate Use Criteria for the Treatment of Anterior Cruciate Ligament Injuries represent a practical application, with an algorithm-style treatment guide, of the Clinical Practice Guideline (CPG) for management of ACL injury that the Academy issued last year. Treatment paths are based on various patient characteristics, including age, activity level, presence of advanced arthritis, and the status of the ACL tear.

The AUC injury prevention programs (Appropriate Use Criteria for ACL Injury Prevention Programs) are geared to prophylactic treatment of athletes at both the competitive and recreational level who do not have a history of ACL reconstruction or deficiency.

In both AUC, each recommendation is ranked by level of appropriateness, indicated by a numerical value, with 1–3 being "rarely appropriate" (red icon); 4–6 signifying "may be appropriate" (yellow icon); and 7–9 as "appropriate" (green icon).

"What these guidelines do is delineate, in a very easy-to-maneuver way, what the most appropriate treatments are in each category," said Dr. Quinn. "The physician can plug in the patient's specific circumstances, and the AUC highlight where the evidence matches the recommendations."

Two checklists—"Return to Play" and "Postoperative Rehabilitation"—accompany the AUC. "These are evidence-based lists, constructed in a way that realistically sets expectations for what needs to be accomplished," said Dr. Quinn. The Postoperative Rehabilitation checklist outlines the postoperative protocol, from early range of motion, weight bearing, and closed and open chain quad and hamstring therapy, to optional rehabilitative bracing and neuromuscular stimulation.

The Return to Play checklist counsels that patients should feel confident that they can return to their sports and be advised to participate in an ongoing ACL-prevention/movement-retraining program before resuming athletic activities. It notes that patients should be evaluated to verify that the graft and surgical site have fully healed and that range of motion, balance, knee stability, strength and functional skills, have been restored.

From CPG to AUC

The two AUC, Dr. Quinn explained, "take the recommendations of the CPG and make it easier for practitioners—or patients—to see what is most appropriate for a specific scenario. The CPG showed that ACL reconstruction with autograft or allograft is very successful. We have good evidence to suggest that both prevention and treatment are effective. The AUC help alleviate some of the controversy about when some of the good options are most applicable."

The AUC app opens to a set of assumptions and disclaimers applicable to the treatment scenario. In the case of the AUC for ACL injury, the list is rather extensive, and covers both the patient and the physician. The AUC on ACL injury prevention have a shorter list of assumptions and specify which conditions the guidelines do not cover (tibial eminence fracture, collateral ligament injuries, re-tears of prior reconstructions, and partial ACL injuries).

Prevention programs
The prevention app includes a five-category indication profile (sex, pubertal status/maturity, level of activity, sport risk, and athlete risk). Thus the profile of a male pubertal competitive low-risk athlete in a high-risk sport will elicit a different treatment recommendation than a male prepubertal athlete who is competitive in a low-risk sport.
The AUC lists the following components of a supervised prevention program:

• Appropriate instruction and supervision
• Dynamic warm-up
• Strength training (core, hip and thigh)
• Technique training (jumping, cutting)
• Plyometrics
• Balance and proprioceptive training
• Feedback cueing
• High-frequency utilization

"Injury prevention programs are very successful," said Dr. Quinn. "These AUC help alleviate some of the controversy about when these good options are most applicable."

Patient applications
The AUC for the treatment of ACL injury also guide the surgeon to the most appropriate course of action based on the patient's indication profile. Consider, for example, the patient who is younger than 25 years, has a closed or closing physes, participates in a cutting/pivoting sport, has no arthritic changes and no reparable meniscal tear, and for whom optimal nonsurgical measures have been unsuccessful. According to the AUC, the recommended treatment is ACL reconstruction with autograft—with an appropriateness level of 8. Reconstruction with allograft is also appropriate, with a slightly lower appropriateness level.
This patient may derive some benefit from a functional brace and no reconstruction (appropriateness level of 4). However, a self-directed exercise program without reconstruction, a supervised rehabilitation program without reconstruction, and activity modification without reconstruction would rarely be appropriate.
A table in the full AUC document indicates the appropriateness level of treatment options for each possible patient scenario.
Allo or auto?
Certain clinical scenarios address the allograft versus autograft debate. The AUC guideline takes its cue on this issue from the 2014 CPG.

"Clearly autograft reconstruction is the more universally recommended choice," Dr. Quinn explained. "It was harder to find evidence to say that allograft is good all of the time. As someone who does a lot of work with allografts in oncology, I would say that autograft is preferred but, in many situations, an appropriately procured and prepared allograft is a reasonable alternative. That means it is taken from a healthy young host. Sometimes allografts are irradiated for sterility; if the radiation dose is high enough, it can weaken the graft."

For the patient, he continued, "A good explanation would be that allograft is more useful in revision situations in which an autograft was previously used. The AUC and CPG don't really touch on that, but it is an important piece of information.

"The other consideration for using allograft is that a second surgery is not necessary to harvest the graft, and none of the patient's normal tissue is sacrificed for the graft," he continued. "The bone–patellar tendon–bone autograft in particular, has some downsides: taking that strip of patellar tendon can cause some problems with the kneecap. To a lesser degree, this is a consideration with the hamstring tendons."

Return to play
The AUC also address the risk of injury to the contralateral knee after an ACL tear and strategies for its prevention. "We do note that prophylactic bracing doesn't seem to work; that is in the CPG," Dr. Quinn said. "There is evidence that what is done to one knee influences what happens to the other knee, particularly with continued participation in high-level, high-risk sports. But injury prevention would work.

"Take a young female competitive athlete who suddenly injures her left knee and undergoes an ACL reconstruction," he continued. "When she returns to play, she is a high-risk athlete, so we would want to recommend an injury prevention program for the normal knee. There is a lot of science behind the mechanism of ACL rupture, and it seems to differ in males and females in several ways. Prevention programs seem to help females more than males."

The issue of return to play can involve a number of dynamics, and the checklist on that aspect of ACL management can clarify some of the considerations. "Many competing factors, such as scholarships, come into play," said Dr. Quinn. "The return-to-play checklist provides a very nice evidence-based list of what should be going on before the patient goes back to play."

The checklist can be given to patients, giving them goals to accomplish. "If you compare the postop–rehabilitation checklist to the return-to-play checklist, you'll find that items are highly recommended when there is a high level of evidence. If levels of evidence are lower, the item may be optional."

Characterizing the new AUC and checklists, Dr. Quinn commented: "These are not a great departure from last year's CPG. But CPGs provide broad brushstrokes while these resources break things down into categories. The AUC consider all the different circumstances so that you can plug in exactly where the evidence meets the expert recommendation."

Terry Stanton is a senior science writer for AAOS Now. He can be reached at tstanton@aaos.org