AAOS Introduces First Clinical Practice Guideline for Management of Acute Isolated Meniscal Pathology

In June, the AAOS Board of Directors approved the first Clinical Practice Guideline (CPG) for the Management of Acute Isolated Meniscal Pathology. The CPG introduces guidelines for diagnosing and managing patients with acute isolated meniscal injury, establishing the foundation for future evidence-based research to inform subsequent iterations of the CPG.

“Meniscus tears are notoriously difficult to study due to the variability in meniscus pathology,” said Matthew Best, MD, co-chair of the guideline development group. “Despite the limited amount of evidence for treatment of acute meniscal injuries, the importance of understanding this pathology substantiated an introductory CPG to help drive future research and improved patient outcomes.”

Acute meniscal pathology predominantly affects younger, active individuals, particularly those engaged in year-round sports or those focused on early sports specialization. These injuries can not only have physical and emotional impacts on patients but also pose a higher risk of progressive joint degeneration and osteoarthritis.

The CPG concentrates exclusively on acute isolated meniscus pathology and excludes evidence related to patients with concurrent ligament issues such as anterior cruciate ligament tears or patients suspected to have chronic or degenerative meniscal tears. It was developed in collaboration with representatives from the American Orthopaedic Society for Sports Medicine, Pediatric Orthopaedic Society of North America, American Academy of Physical Medicine and Rehabilitation, National Athletic Trainers’ Association, American Physical Therapy Association, and American Medical Society for Sports Medicine.

The CPG includes three recommendations—one strong and two moderate—focused on diagnosis and the importance of preserving the meniscus for joint health and reducing the risk of osteoarthritis. “These recommendations should not surprise the orthopaedic community, given they are already well accepted,” said Robert Brophy, MD, FAAOS, co-chair of the guideline development group. “Instead, these are necessary fundamental first steps so we can think about how our recommendations for patients with this injury should evolve based on emerging treatment techniques and evidence.”

The strong recommendation favors MRI as the preferred imaging modality to diagnose acute meniscal tears because of its high accuracy. When MRI is not available or is contraindicated, CT arthrography or ultrasound can be used.

The moderate recommendations advise that a physical examination, including joint line tenderness, the McMurray test, and the Thessaly test, can effectively diagnose acute meniscal tears and may yield more accurate results when combined. Separately, when indicated in the treatment of acute meniscal tear, surgery should preserve as much functional meniscal tissue as possible to mitigate patient risk for osteoarthritis, underscoring the importance of trying to preserve the meniscus to delay or prevent the advancement of joint degeneration.

Seven options were formulated due to little, conflicting, or no evidence on the topic—three limited-strength options and four consensus options. Dr. Best acknowledged the challenges of having low to moderate levels of evidence on treatment. “These options are designed to help surgeons and their patients make informed decisions regarding the use of surgery, the type of surgery, and modalities to optimize outcomes such as physical therapy or biologics,” he said.

Based on limited-strength evidence, the workgroup advises that patients with an acute meniscal tear who have failed conservative nonoperative treatment, such as physical therapy, may have better outcomes from surgical intervention within 6 months of injury. “If a patient initially opts out of surgery but doesn’t improve, it is probably in their best interest to undergo surgery sooner, rather than later, to preserve meniscus and optimize outcomes for patients,” Dr. Brophy explained.

Two other limited-strength options state that meniscus repair can improve patient outcomes compared to partial meniscectomy in acute isolated meniscal tears with healing potential. Although the goal is to preserve as much healthy meniscus tissue as possible, this decision depends on factors such as the pattern, location, and quality of the tear, necessitating case-by-case judgment. Additionally, biological enhancements, specifically bone-marrow venting or platelet-rich plasma, can be considered to improve outcomes in patients undergoing surgical repair of acute isolated meniscal tears.

It is the consensus of the workgroup that patients with a displaced or displacing acute meniscal tear, particularly those with restricted knee range of motion, can benefit from acute surgical intervention. The workgroup also advises that patients with a symptomatic acute meniscal tear who could benefit from repair should be considered for early surgical intervention, as it could optimize the likelihood of success. “If there are significant mechanical issues where the knee locks or loses motion, or the patient is young and healthy, orthopaedic surgeons might consider operating sooner rather than later to optimize the clinical outcome,” Dr. Brophy advised.

Based on the workgroup’s clinical opinion, physical therapy/rehabilitation may be beneficial for patients who present with an acute non-displaced isolated meniscal tear not amenable to repair when implemented as a nonoperative treatment option, as well as postoperatively for patients recovering from meniscal surgery. “There is no doubt physical therapy is a helpful part of the treatment algorithm for people with acute meniscal tears,” Dr. Brophy continued. “While there are reasons to promptly conduct surgery after an acute meniscus tear, physical therapy can be a helpful component of recovery after surgery or utilized if patients are trying to avoid or delay surgery.”

The workgroup also issued a consensus statement regarding the method of surgery and agreed that when repairing acute isolated meniscal tears, surgeons may favor the inside-out technique to reduce the risk of repair failure in certain tear patterns or all-inside techniques to reduce the risk of other complications. “While an inside-out technique is generally less expensive, it tends to be a longer surgery, while the all-inside approach mitigates potential complications from the incisions,” Dr. Best said. “Although the all-inside method has not consistently demonstrated the same efficacy as the inside-out technique, emerging evidence suggests the effectiveness is comparable. Ultimately, the choice requires careful consideration of the overall clinical context by patients and surgeons.”

Although the CPG outlines a path forward, there is still much to be done and learned. “The CPG does not provide absolute directives, and that is particularly important because of the heterogeneity in terms of the pathology and the evolving nature of the evidence,” Dr. Brophy said. “This CPG is the first beacon, illuminating the path forward to building more robust guidelines in the future.”

Click here to view an infographic about the Clinical Practice Guideline for the Management of Acute Isolated Meniscal Pathology.

Jennifer Lefkowitz is a freelance writer for AAOS Now.