The meniscus is made up of two wedge-shaped fibro-cartilage discs, namely the medial (inside of the knee) and lateral (outside of the knee) meniscus and are semi-lunar in shape.
These discs are especially important to assist with load transfer in (weight on) the knee joint and also provide other benefits:
- harmony or congruence between the joints;
- maintain joint proprioception (the sense that lets us perceive the location, movement, and action of parts of the body);
- provide lubrication; and
- resist joint sheering forces (sudden change in direction).
What are meniscal tears?
Meniscus injuries such as meniscal tears are one of the most frequent types of acute knee damage one may experience. There are several tear types which will influence the stability and nature of management post injury.
These include a longitudinal, degenerative, flap tear; radial; bucket handle and horizontal tears (See image below).
How can a meniscus injury occur?
- The most common mechanism of injury is a twisting of the knee joint with the foot anchored to the ground. This is most common in sports such as football, basketball, and rugby.
- Twisting movement of the knee which can occur due to a decelerating speed.
- The medial meniscus is more commonly prone to injury compared to the lateral meniscus as it is less mobile.
Symptoms of meniscus injuries
Patients may experience different degrees of pain with an acute meniscus injury and this varies depending on the various symptoms noted below.
- A “tearing” (ripping) sensation at the time of injury;
- Swelling around the knee joint 24-48hrs after the injury for small meniscus tears;
- Pain with descending and ascending stairs;
- Pain with sit-to-stand movements;
- Intermittent locking of the knee joint in more severe meniscus tears such as flap tears or bucket handle tears due to impingement of the joint surfaces;
- Pain along the joint line either medially (towards the inside/centre) or laterally (on the outside) depending on how the injury occurred;
- Degenerative tears occurring in the elderly may exhibit swelling in the knee joint with resultant minor tearing;
- Pain when squatting;
- Decreased ability to flex the knee and have a full range of movement may occur with a torn flap of the meniscus or swelling.
Treatment options for Meniscus Injuries
First of all, a diagnosis will be done:
- Pain assessment by palpation (a method of feeling with the fingers or hands during a physical examination) over the knee joint line where the meniscus lies.
- Specialised tests can then be done by your physiotherapist: a positive McMurray test, Appley Grind test and Thessaly test.
- MRI imaging, which is the gold standard, is also used to diagnose the type and severity of the meniscal tear.
Treatment can be conservative or surgical in nature.
Arthroscopies (a surgical method) are done to observe the nature of the injury within the knee (see illustration). There are various types of surgical interventions, with the main aim being to preserve as much of the meniscus as possible.
- Meniscectomies: removal of the damaged part of the meniscus.
- Meniscal repair: a more favourable method which allows for preservation of the meniscus as far as possible to allow better long-term outcomes.
- Meniscal allografts: artificial scaffolding used especially when there is significant meniscal damage.
Considerations
- The outer 1/3 of the meniscus generally has a good blood supply with a positive prognosis for healing, so knee injuries in this location will probably be managed conservatively.
- The inner 2/3 of the meniscus has a poor blood supply and therefore has a less positive forecast for healing. These lesions (damaged tissue) are often managed surgically.
- The severity of the tear, the location and the restrictions experienced by the patient (such as joint locking and being able to put weight on the leg), will be taken into account when guiding the decision for surgical or conservative treatment.
Conservative physiotherapy interventions and post-operative care
If the management is conservative, the physiotherapist will manage the acute injury by doing all or some of these treatments:
(a) reduce the swelling;
(b) improve the knee’s range of movement;
(c) increase the strength of the quadriceps and hamstrings;
(d) improve hip internal and external rotator function;
(e) aim at achieving joint proprioception that allows the patient to carry out sport-specific and functional activities without difficulty. The process will be to increase training loads carefully without causing a repeat in the knee symptoms.
If the treatment is surgical, the patient will have physiotherapy done for pre-habilitation to strengthen the surrounding muscles before the operation. This will assist the patient with a faster recovery post-operatively.
The two approaches (surgical and conservative) aim to:
- Reduce the pain and swelling through gentle range of motion, manual therapy and electrotherapy treatments.
- Give exercises in a pain-free range to maintain the strength of the quadriceps, hamstrings, gluteal/hip abductor/hip extensor muscles.
- Protect against further joint damage through the use of assistive devices such as crutches, knee braces and strapping.
- Improve weight-bearing on the affected leg.
- Regain full range of motion in the knee joint.
- Progress the strengthening exercises mentioned above on a consistent basis.
- Progress balance and proprioceptive exercises.
- Return to functional and sport-specific activities.
After a meniscus repair with no other associated injuries and sufficient rehabilitation, an athlete may be ready to return to play within 4 weeks. If you return to sports before the knee is properly rehabilitated, you are at risk of recurrent joint swelling and chronic knee pain. It is, therefore, important to complete your physiotherapy rehabilitation programme and be cleared by a medical professional before you return to sport.
This article was updated by Lamberti Physiotherapy Sandton branch. If you suspect you may have a meniscus injury, please complete this website form to make an appointment for an assessment.
References:
- Brukner, P., Khan, K. M., Bahr, R., Blair, S., Cook, J. L., Crossley, K., McConnell, J., McCrory, P. R., & Noakes, T. (2012). Brukner & Khan’s Clinical Sports Medicine. (Fourth Edition ed.) McGraw-Hill Education.
- Physiopedia contributors, ‘Meniscal Lesions’, Physiopedia, , 06 February 2024, 09:04 UTC, [accessed 14 March 2024].