Meniscus tears are a common reason to seek orthopaedic evaluation, representing 14% of all isolated knee injuries and can also occur in combination with ligament and/or bony injuries. Meniscus tears can occur in a variety of locations and types, but a meniscus root tear is defined as a radial tear within 1cm of the meniscus root attachment or a bony/soft tissue avulsion.
The prevalence of identifying a meniscus root tear during knee arthroscopy has been reported between 7-9%. Lateral meniscus root tears are more likely to be found in younger patients who sustained a concurrent anterior cruciate ligament (ACL) tear or multiligamentous knee injury (MLKI). In contrast, medial meniscus root tears are more often degenerative in nature, found in middle aged patients, and can be the result of a less significant traumatic injury. Risk factors for posterior meniscus root tears are increased body mass index (BMI), age, female sex, malalignment, and increased Kellgren-Lawrence grade.7
Non-operative management consists of activity modification, maintenance of ideal body weight, over the counter non-steroidal anti-inflammatory medications, physical therapy, and intra-articular corticosteroid or platelet rich plasma injections.8 Operative treatment ranges from simple arthroscopic lavage and debridement to anatomic meniscus root repair via transtibial or all-inside techniques.9
Meniscus root tears have a limited healing potential and can present a complex treatment scenario. A number of factors must be considered when making treatment decisions, such as cartilage status, mechanical alignment, concomitant ligament injury, as well as individual patient characteristics such as age, activity level, and smoking status.
As the natural history of meniscus root tears is poor, with up to 28% of patients undergoing a total knee replacement at a mean of 3.2 years after diagnosis, most appropriate surgical candidates are offered surgery who do not have substantial arthritic changes of that compartment.
Furthermore, the superiority of root repair over partial meniscectomy continues to be supported in the literature. Chung et al. compared the 5-year outcomes of 37 root repair patients to 20 patients with a partial meniscectomy and showed superior knee function scores in the root repair group as well as a 35% conversion to total knee replacement (TKA) in the partial meniscectomy group (versus 0% in the root repair group).
The clinical outcomes of meniscus root repair have shown positive and durable outcomes. LaPrade et al. published favorable short-term outcomes of 45 patients with a 6.7% revision rate. Chung et al. published mid-term results with a 5 to 10-year follow-up study of 91 patients showing significant improvement in patient reported outcome scores and an overall Kaplan-Meier probability of survival after repair of 99% at 5 years, 95% at 7 years, and 92% at 8 years.
The current literature supports the superiority of meniscus root repair over meniscectomy or conservative treatment for operative candidates, but long-term outcomes are yet to be reported in the literature.
Following meniscus root repair, strict adherence to a rehabilitation protocol is critical to promote full recovery. The presented rehabilitation protocol is informed by the existing literature and incorporates current rehabilitation principles, the science of meniscus healing, and adaptations based on an individual’s readiness to progress through subsequent phases.
