The newly approved clinical practice guideline (CPG) on the “Management of Anterior Cruciate Ligament (ACL) Injuries” is remarkable both for the total number of recommendations (20) and the percentage of those recommendations backed by evidence characterized either as Strong or Moderate (Table 1).
“Due to the amount of higher-quality research, there is a lot of good information for physicians and patients about best practices for ACL injury,” said Kevin G. Shea, MD, of St. Luke’s in Boise, Idaho, who chaired the ACL CPG work group. “Patient-centered care is important, and the guidelines play an important role in this.”
“This CPG reflects the distillation of more than 12,000 articles on the ACL,” stated James L. Carey, MD, MPH, of the University of Pennsylvania, who served as vice-chair of the ACL CPG work group. “Ultimately, after full text review and quality analysis, about 150 articles informed these 20 recommendations.”
The CPG includes the following Strong recommendations:
- The practitioner should obtain a relevant history and perform a musculoskeletal exam of the lower extremities, because these are effective diagnostic tools for ACL injury.
- MRI can provide confirmation of ACL injury and assist in identifying concomitant knee pathology such as other ligament, meniscal, or articular cartilage injury.
- In patients undergoing intra-articular ACL reconstruction, the practitioner should use either single-bundle or double-bundle technique, because the measured outcomes are similar.
- In patients undergoing intra-articular ACL reconstruction using autograft tissue, the practitioner should use bone-patellar tendon-bone or hamstring-tendon grafts, because the measured outcomes are similar.
- In patients undergoing ACL reconstructions, the practitioner should use either autograft or appropriately processed allograft tissue, because the measured outcomes are similar, although these results may not be generalizable to all allografts or all patients, such as young patients or highly active patients.
A sequential process
“The recommendations in this CPG were sequentially ordered to help guide the clinician from the initial evaluation (history and physical examination) to the review of imaging studies to the decision on whether to proceed with surgery to the performance of certain surgical techniques to the postoperative rehabilitation and return-to-play criteria,” Dr. Carey said.
Among the recommendations in the new CPG is one that favors reconstructive surgery within about 5 months of injury, in appropriately selected patients. “Moderate-strength evidence suggests that operating within this time frame serves to protect articular cartilage and the meniscus,” Dr. Shea said. “Research demonstrated that in active patients, if you wait too long to reconstruct the ACL, the risk of damage to other structures is higher.”
For reconstructive procedures to repair a sprained or torn ACL, the CPG supports the use of either autograft or appropriately processed allograft tissue.
Dr. Carey elaborated on the allograft question, saying, “Younger or highly active patients may not do as well with allograft tissue, as indicated by recent research that found a higher failure rate among patients younger than age 25 who underwent allograft surgery.”
For some patients, a nonsurgical approach may be appropriate, according to the guidelines.
“Some patients who are not involved in sporting activities that require rapid changes of direction or those with lower demand work activities may not place as much demand on their knees,” said John Polousky, MD, of Rocky Mountain Hospital for Children in Denver, one of the CPG work group members. “So a rehab program, followed by a good conditioning program, may offer adequate knee function in selected patients. After several months, if the patient has recovered from the acute injury, has had appropriate rehabilitation, and is still doing poorly, he or she may benefit from reconstructive surgery. But in carefully selected patients, nonsurgical treatment may be appropriate.”
In addition, the ACL CPG includes the following:
- Finds no strong evidence supporting the use of knee braces to prevent ACL injury before or after surgery
- Indicates that postoperative therapy with accelerated and nonaccelerated programs demonstrates similar outcome
The recommendation for neuromuscular training, which carries a Moderate strength rating, may have special significance for girls and women, Dr. Shea said. Females are at higher risk for ACL injury compared with males.
“Young female athletes who participate in activities that involve pivoting and shifting, such as soccer and basketball, have among the highest risks for sustaining an ACL injury,” he said. “Research continues to explore what is different about female athletes and their increased risk of knee injury. Is it anatomy, strength, endurance, hormones, neuromuscular landing patterns, or a combination of these?
“Neuromuscular training programs have focused on addressing differences in the way females jump, land, and change direction compared to men,” he continued. “Evidence suggests that training may be able to reduce injuries. However, a large number of patients must be treated to prevent a single ACL injury. According to the analysis, 109 patients must be treated to prevent one ACL injury. In the perfect world you would treat five or fewer patients to prevent one ACL tear. The guideline shows that more research would be beneficial.”
For return to sport, the guideline states that evidence is Limited and does not support a specific time from surgery/injury or yield a specific functional goal prior to return to participation. Dr. Shea noted that conclusive guidance on this issue would be welcomed by physicians and their patients.
“We’d all love to be able to conclude that this patient is ready to go back to this sport at 4 months, 6 months, 10 months, or whenever,” he said. “We need a lot more research to demonstrate the safest and most efficient rehab protocol so that patients can go back to sports and work with lowest risk of repeat injury.”
In current practice, Dr. Shea said, “Orthopaedists probably err on the side of caution—having the person go back later rather than too early. I tell patients I’d rather delay a month or two than send them back on the field or to work too early. There is a healing time; the ACL reconstruction tissue has to be integrated and reattach itself to the bone. The neuromuscular system also needs to heal and recover adequate balance, strength, and coordination.
“The exact time frame for recovery is ill-defined,” he continued, “but probably takes no less than 6 months for most patients, and perhaps even 8 to 12 months in others. The research in this field is challenging, but ongoing prospective cohort studies from the American Orthopaedic Society for Sports Medicine (AOSSM) and other groups may help answer these questions.”
Although keeping a patient out of participation for too long may not have a physical down side, Dr. Shea said, there can be a psychosocial cost. “Many young people and their families derive great pleasure from participating in sports and being part of a team,” he said. “These things are hard to measure, but I can tell you these things matter to athletes. From a patient-centered perspective, these questions have real value.”
Another area in need of further research is that of injury to the other knee. “Some studies show that individuals who have torn one ACL are at fairly high risk of tearing the contralateral ACL. This is a very important research area,” Dr. Shea said.
On the ACL guideline as a whole, Dr. Shea commented: “This is information physicians can provide to patients and help them make appropriate decisions. Much of this information makes patients better consumers. As orthopaedists, we should encourage patients to pursue, embrace, and own their problem. We want to be consultants to them and help them make the best decision possible. Patient-centered care is important, and the guidelines play an important role in this.”
The CPG on the “Management of ACL Injuries” is endorsed by the National Academy of Sports Medicine, AOSSM, and the National Athletic Trainers Association.
The complete guideline, including the evidence report, list of work group members, and peer review, can be accessed at www.aaos.org/guidelines
Terry Stanton is a senior science writer for AAOS Now. He can be reached at firstname.lastname@example.org