Introduction and Background
The meniscus, once considered a functionless remnant of leg muscle, has been recognized in recent decades as a vital structure of the knee joint. Scientific investigations have highlighted its anatomical, biomechanical, and functional importance. The incidence of meniscal injuries is increasing, partly due to the growing participation of youth in sports activities. Magnetic resonance imaging (MRI) remains the preferred imaging modality, and surgical management is the primary treatment for meniscal tears. Arthroscopic partial meniscectomy (APM) is currently the most commonly performed orthopedic procedure worldwide. However, recent studies have demonstrated that outcomes after APM are no better than those after a sham/placebo surgery. Meniscal repair is now considered a viable and effective alternative. It aims to achieve meniscal healing while avoiding the adverse effects of partial meniscectomy. Meniscal repairs have gained popularity over the past three decades and have proven to be a more efficient alternative. Attempting meniscal repair is increasingly recommended for all repairable tears, particularly in young and physically active patients. Partial meniscal implants have also shown excellent long-term outcomes, but their efficacy in acute settings requires further research. Promising research has been conducted on various meniscal regeneration techniques, and regenerative medicine appears to be the way forward. This review critically discusses the current understanding of the meniscus, its role in the biomechanics of the knee joint, and the current methods used to diagnose and manage meniscal tears.
Role of the Meniscus
The meniscus, despite its limited blood supply, plays a crucial role in the biomechanical function of the knee. It enhances the congruence of the articulating surfaces, absorbs shock, transmits loads during activities, provides knee joint stability, limits extreme knee joint angles, and contributes to proprioception. These factors have led to an increased interest in meniscal injuries in recent years.
Meniscal tears can cause various symptoms, including pain along the joint line, swelling, clicking, catching, locking, and a sensation of the knee “giving away.” They are more commonly observed in men than in women, with approximately 80% of all meniscal tears reported in men. Some patients experience pain that wakes them up from sleep, possibly due to the tender medial aspect of the knee colliding with the other knee during rolling movements. Meniscal injuries often occur in conjunction with damage to other structures, such as the anterior cruciate ligament (ACL), posterior cruciate ligament, or bones.
Orthopedic surgeons must effectively correlate clinical information, radiological images, and their clinical expertise to devise an individualized management plan for meniscal tears. Clinical history and examination alone may not always lead to a definitive diagnosis, necessitating radiographic and arthroscopic evaluations for confirmation. Although clinical tests such as McMurray’s, Apley’s, and Thessaly’s tests have long been recommended, their accuracy and reliability are poor. Plain radiographs are not recommended for routine evaluation of meniscus tears but may be useful in select conditions. MRI remains the gold standard imaging modality, with high sensitivity and specificity for diagnosing meniscus tears. Meniscal tears are typically diagnosed on MRI as a linear signal intensity that extends from the meniscal substance to a free edge.
With a better understanding of the meniscus’s vital functions and the potential early onset of osteoarthritis in its absence, orthopedic surgeons have shifted their management goal from resection to preservation, repair, and reconstruction of the meniscus. Treatment choices depend on factors such as age, comorbidities, symptoms, and the type and location of the tear.
Conservative management is typically considered for patients with degenerative meniscal tears, where the tear is not amenable to repair. This approach may include pain management, physical therapy, and lifestyle modifications to reduce stress on the knee joint.
For acute meniscal tears, surgical intervention may be necessary. The main surgical options are arthroscopic partial meniscectomy (APM) and meniscal repair. APM involves removing the torn or damaged portion of the meniscus, while meniscal repair aims to suture and heal the torn meniscal tissue.
Arthroscopic partial meniscectomy has been the standard surgical treatment for many years and can provide relief from symptoms. However, studies have shown that the long-term outcomes of APM are not superior to conservative treatment in many cases, raising concerns about the potential for accelerated joint degeneration.
In recent years, there has been a shift towards meniscal repair whenever possible. Meniscal repair techniques aim to restore the integrity and function of the meniscus by suturing the torn edges together. This approach is most effective for tears located in the vascularized outer region of the meniscus, where sufficient blood supply exists to support healing. Meniscal repairs have shown promising results, especially in younger patients, with a higher likelihood of preserving the meniscus and preventing further joint damage.
In cases where the meniscus is extensively damaged or irreparable, meniscal transplantation or meniscal allograft transplantation may be considered. These procedures involve replacing the damaged meniscus with a donor meniscus to restore its function. However, these techniques are typically reserved for specific cases and require careful patient selection.
Recent advancements in regenerative medicine have also sparked interest in meniscal regeneration techniques. These approaches aim to promote the natural healing and regeneration of the meniscus using tissue engineering strategies, such as the use of scaffolds, growth factors, and stem cells. While still in the experimental stage, these techniques hold promise for the future of meniscal repair and regeneration.
In conclusion, the understanding and management of meniscal injuries have evolved significantly, emphasizing the preservation, repair, and regeneration of this vital structure within the knee joint. While traditional surgical approaches like arthroscopic partial meniscectomy have been widely practiced, recent evidence highlights the effectiveness of meniscal repair techniques, particularly for suitable cases and younger patients. Exciting advancements in regenerative medicine offer even more promise for meniscal regeneration in the future. However, optimizing postoperative outcomes requires comprehensive data analysis. This is where Fitknees, an AI-driven device, comes into play. Fitknees enables precise measurement and analysis of postoperative data, providing valuable insights for monitoring recovery progress, tracking outcomes, and fine-tuning treatment plans. By leveraging Fitknees‘ cutting-edge technology, healthcare professionals can ensure optimal patient care and improve long-term joint health..