Introduction:
Extensive scientific research in recent decades has classified the meniscus as a crucial component of the knee joint with morphological, biomechanical, and functional value. Despite being first characterized as a functionless remnant of a leg muscle, this has changed now. Meniscal injuries are becoming more common, partly due to increased sports involvement, recent advancements, and the widespread availability of diagnostic equipment like MRI (magnetic resonance imaging). The probability of meniscal tears is approximated at 60 per 100,000 people, but the real frequency is much higher. In reality, meniscal injury is one of the most prevalent sports injuries in daily practice. Therefore, early detection and treatment have become more significant in orthopedic research.
How Does Meniscus Work?
The meniscus has insufficient blood supply and is a comparatively avascular structure. However, it is an essential component of the biomechanical operation of the knee. The meniscus improves the congruence of the knee joint's articulating surfaces. In addition to this, the meniscus is crucial for walking and other tasks that require weight transmission and shock absorption. Additionally, it helps the knee joint by stabilizing it, preventing severe knee flexion and extension, and enhancing proprioception. These factors together may account for the recent rise in interest in meniscal injuries.
What Are the Signs and Symptoms of Meniscus Tears?
Meniscal tears can result in various symptoms, including localized pain in the joint line, clicking, swelling, catching, and locking, as well as the well-known "giving away" of the knee. As much as 80% of all meniscal tears have been documented in men, making them more common in men than women. Numerous patients have also mentioned being awakened from sleep by the pain they experienced. It can be described by the painful medial aspect of one knee slamming against the other knee when the person suffering turns over in his sleep. Meniscal injuries frequently occur associated with bone or ligament injuries, such as the anterior cruciate ligament (ACL) or posterior cruciate ligament.
What Are the Diagnostic Options Available?
Although specialized clinical procedures like McMurray's, Apley's, and Thessaly's tests have long been advised to identify a tear, their accuracy and dependability still need improvement. Plain radiographs should only be used in certain circumstances, such as chondrocalcinosis, and are not advised for routine examination of meniscus tears. MRI is still the preferred imaging technique, with sensitivity and specificity for identifying meniscus injuries are 93% and 88%, respectively. Meniscal tears on an MRI are often identified by a linear signal intensity extending from meniscal material to a free edge. It is not advised to perform arthroscopy just for diagnostic purposes.
What Are the Recovery Options Available for Meniscus Tears?
Orthopedic surgeons have changed their therapy objective from resection to preservation, repair, and reconstruction of the meniscus due to recent literature highlighting the essential roles of the meniscus and the potential for early-onset osteoarthritis without the presence of the meniscus. However, several factors, including age, comorbidities, symptoms, and the nature and position of the tear, continue to influence the course of treatment.
It is recommended to use a conservative approach for meniscus tears found in the red zone or surrounding 30% of the medial meniscus and 25% of the lateral meniscus, which are high vascularity zones of the meniscus. Since these tears are regarded as stable, there is a higher chance of success if their diameter is less than 5 mm.
The primary method of treatment for all other varieties of meniscal tears is surgery. Open meniscectomy was the go-to surgical procedure for meniscal injuries until 1960. The first arthroscopic repair was carried out by Ikeuchi in 1969, and since then, many arthroscopic procedures have developed.
Total meniscectomy is an ineffective therapeutic alternative because it can directly cause increased contact stress, a quicker onset of osteoarthritis, and possibly symptomatic varus abnormalities in the older age range. The most common orthopedic surgery worldwide is an arthroscopic partial meniscectomy (APM).
Recent research has, however, unequivocally demonstrated that the results of an APM are not superior to those of a sham or placebo operation. Numerous researchers have referred to the surgery as "useless," and new clinical guidelines are increasingly cautioning against having it done.
In recent years, meniscal repair has gained popularity as a feasible and efficient substitute. Meniscal repair strives to accomplish meniscal healing while avoiding the adverse outcomes of partial and total meniscectomy. Meniscal repairs have had generally positive short-term results, with a failure rate of less than 10% at two-year evaluations.
However, the long-term outcomes have not been encouraging, with failure rates of up to 30% recorded at five-year follow-ups. The failure rates during long-term follow-ups have remained fairly steady, ranging from 23% to 30%, irrespective of the development of numerous procedures, including the inside-out technique, outside-in approach, meniscal fixators, and all-inside technique.
Meniscal allografting is one of the available alternative treatments. Despite being a difficult treatment, 10-year follow-up survival was an encouraging of about 89.2 percent. The FDA recently approved less difficult, minimally invasive techniques, including meniscal scaffolds. The purpose of scaffolds, which are readily available off the shelf, is to allow tissue to simulate physiological replacement by growing on the scaffold. Partial meniscal replacements, which aim to restore the distribution of load across the knee joint and hence offer chondroprotective properties, are another potential alternative.
Conclusion:
Meniscal tears are a frequent orthopedic disease that can be difficult to repair. An MRI nearly always confirms meniscal injury diagnosis in addition to a thorough history taking and clinical examination. To create an efficient management strategy, it is crucial to have a complete grasp of the distinct anatomical structure, vascularity, and zonal classification of tears.
Partial meniscectomy is the most common treatment for meniscal injuries, even though conservative therapy has a place and may be necessary for individuals with modest rips or severe osteoarthritis. Although its effectiveness is debatable, its quick learning curve and tolerable short-term results have discouraged many orthopedic surgeons from switching to more efficient treatments.
