Knee Meniscal Injuries are a very common form of injury effecting approximately 61 cases per 100,000 with an approximate prevalence of 12-14% (Fox, AJ et al, 2015).
The definition of a meniscal injury is essentially when the integrity of the structure is compromised and the cartilage begins to tear, break, crack or split.
How Are Meniscal Tears Caused
There can be a range of different types and causes of meniscal tears, but a combination of axial loading and rotational force on the meniscus creates a shear force which can disturb the structure of it (Fox, AJ et al, 2015).
Acute Meniscal Tears
- Caused by trauma and are commonly found in a younger population of people.
- Ages of 21- 30 are most commonly effected
- Age related change and accumulative stress and deterioration over time
- Approximately responsible for 30% of cases
What are Meniscus and what do they do?
- Crescent shaped pads of fibrocartilage between the femoral condyles and tibial plateaus that help with load distribution, knee stabilization during rotation, and lubrication of the knee joint.
Morphology of Meniscal Tears
- Vertical Longitudinal: these tears occur parallel to the long axis of the meniscus between the circumferential collagen fibers. They tend to occur medially in isolated meniscus tears and laterally with ACL tears. May be asymptomatic and able to be repaired with suture fixation.
- Radial: These are vertical tears that occur at the posterior and middle-thirds of the meniscus and track from the inner margin to the periphery. Are usually traumatic with a large proportion occurring at the posterior horn of the meniscus.
- Horizontal: These tears are parallel to the tibial plateau and cause a division of the meniscus into superior and inferior portions. Most commonly, they occur in the posterior aspect of the medial meniscus.
- Oblique/Bucket Handle: This is a vertical or oblique tear with extension of the tear towards the anterior horn of the meniscus. The inner fragment is often displaced toward the intercondylar notch. These tears usually involve the entire meniscus and are the most common type of displaced flap tear.
- Complex Degenerative: This is the most common type of meniscal lesion and typically involves two or more tear configurations and is seen with other degenerative joint changes. These are not amenable to meniscal repair. Suspect displaced and bucket-handle tears when mechanical symptoms (buckling, catching, popping, or locking) are present along with limited range of motion.
- Medial Meniscus: Less mobile, firm attachments to deep medial collateral ligaments. Typically, associated with vertical longitudinal tears.
- Lateral meniscus: typically associated with radial tears.
- Root Tear: This is a tear of the posterior attachment of the medial meniscus. Less common than meniscal body tears and frequently unrecognized. These tears often lead to medial meniscal extrusion, a risk factor for rapid joint degeneration. Treatment of root tears with meniscus repair has been found to be the most effective approach.
Examination of Meniscal Injury
Clinical Examination of meniscus injury
Your Physiotherapist will have a range of orthopaedic tests they can utilise to assess for the likelihood of meniscus damage in your knee. This combined with a thorough subjective and movement analysis are a good indicator of potential damage.
Your Physiotherapist will sometimes send you off for an MRI scan on your knee to confirm or rule out the presence of a meniscal injury or other potential damage to the structure of the knee.
Treatment of a Meniscal Injury
Meniscal tears have a very high success rate of recovery when treated conservatively approximately 75% of patients experience significant improvement between 3-6months (Mordecai SC, et al 2014).
Acute Meniscal Injury Management
Initial management is similar to acute management of most injury , being centred around pain and swelling control, this can be achieved well with some ice, compression, NSAIDs (anti-inflammatory medications) and pain killers.
In some cases depending on the type of tear rapid surgical management may be warranted particularly if the patients knee is locked and they are unable to straighten.
Sub-Acute Management and Conservative Rehabilitation
Sub acute and conservative management of meniscal tears is of the route chosen by most people to avoid any surgical intervention. This form of treatment is about gradually exposing the tissue to load to build resilience back into the knee.
It is accomplished through a variety of means;
- Reduction in pain and swelling
- Ensure full range of motion of the knee has been restored
- Ensure improved gait and walking patterns have been restored
- Graduated strengthening of the surrounding tissue (hamstrings, quads, calves, gluteals).
- Neuromuscular coordination training and optimisation
- Graduated return to sport and sporting demands or work demands through individualised and tailored rehabilitation.
Management of meniscal injury is determined by the type of tear, age of the patient, the level of function and goals that need to be attained. It is important to consult with you Physiotherapist or medical professional to ascertain which options would be most beneficial to you and your situation.
Fox AJ, Wanivenhaus F, Burge AJ, Warren RF, Rodeo SA. The human meniscus: a review of anatomy, function, injury, and advances in treatment. Clin Anat. 2015 Mar;28(2):269-87.
Mordecai SC, Al-Hadithy N, Ware HE, Gupte CM. Treatment of meniscal tears: An evidence based approach. World J Orthop 2014; 5(3): 233-241 Available from: URL: http://www. wjgnet.com/2218-5836/full/v5/i3/233.htm DOI: http://dx.doi. org/10.5312/wjo.v5.i3.233