Symptoms
Some typical symptoms are indicative for the presence of a meniscus lesion. Pain is of course in the foreground. These can occur or even get worse during rotary motion and also generally under stress.
Often late damage manifests itself in severe pain under stress. The pain can be accompanied by a risk of entrapment and effusion due to irritation. If a pain occurs in the knee joint that runs along the joint space, this is an indication of a meniscus lesion.
Other classic symptoms are swelling, crepitations and restricted mobility. To be more precise, the extension and flexion movements are hardly or no longer possible. Furthermore, a blockage in the knee joint can occur as a result of a torn meniscus.
If the part of the meniscus that is attached or torn off gets stuck in the joint, this event causes severe pain and a blockage of the joint. The presence of a positive function test for the menisci is also considered a symptom. With the help of special function tests, it is possible to diagnose a meniscus lesion relatively reliably.
Due to the large number of tests, a clear differentiation is possible regarding the inner or outer meniscus, localization and type of lesion. A positive test indicates a meniscus lesion, but the exact diagnosis can only be made by combining the various functional tests.The basis is to put the menisci under stress by pressure, shear forces or tension. If this triggers pain, the test is called a positive test; otherwise a test is negative.
For the evaluation of a meniscus lesion, there are countless function tests available, which are explained in the following. The patient lies on his stomach and has one knee bent at 90°. The examiner now fixes the patient’s thigh with one hand or leg.
At the same time, the examiner uses the other hand to rotate the patient’s leg once under pressure and once under tension. If pain occurs during the inner rotation, the outer meniscus is damaged, but if pain occurs during the outer rotation, the inner meniscus is damaged. This test is also called abduction and adduction stress test.
The examiner uses one hand to stabilize the thigh of the patient lying on his back and the other hand to cover the ankle region. To test the inner meniscus, the upper hand grasps the inside of the thigh or knee and the lower hand grasps the outer ankle. Now the examiner bends and stretches the leg while simultaneously adducting it, i.e. placing it under varus stress.
To test the outer meniscus, the hands must grasp the outside of the thigh and the inside of the ankle. Then a valgus stress can be exerted with simultaneous flexion and extension, i.e. an adduction movement. During both examination steps, the compression pressure can trigger pain in the corresponding meniscus and indicate its lesion.
From the supine position, the knee joint should be in a 90° position. The examiner now grasps the foot with one hand and with the other hand palpates the medial (located in the middle of the body) and lateral (located on the side of the body) joint space. He now rotates the leg once outward and inward and then changes from the flexed to the extended position.
If the medial meniscus is damaged, the Bragard test shows pain on the one hand due to the palpation of the medial joint space and on the other hand due to the external rotation. The transition to the extended position under further external rotation usually makes the pain worse. In the case of an external meniscus lesion, the opposite is true: pain at the lateral joint space and during internal rotation.
This test checks whether the patient can extend his knee against the resistance of the examiner without pain. The starting position is for the patient to lie on his back and slightly roll over the affected leg by placing the foot on the lower leg of the healthy side. The examiner grasps the lower leg and at the same time palpates the lateral, i.e. lateral joint space.
Now the patient is asked to stretch the leg while the examiner holds it slightly. Depending on how severe the pain is, the patient may not be able to fully extend the leg. The pain occurs in an outer meniscus lesion at the outer joint space and can partially extend into the posterior joint space.
The patient assumes a low squatting position so that the heels already touch the buttocks and should then move in the duckling walk. If there is a meniscus lesion, or more precisely a lesion of the posterior horn of the menisci, the patient is not able to perform the duck walk because he feels strong pain at maximum flexion and at the time of the extension. The pain may be accompanied by a “cracking or snapping” sound, since this is the moment when the menisci become trapped.
The patient lies on his back and bends his leg in both the knee and hip joints to the maximum. The examiner now grasps the patient’s leg and performs an internal and external rotation in the position he has taken. The examiner continues these two rotations while stretching the patient’s leg to a right-angled knee joint position.
Pain during external rotation is caused by a lesion of the inner meniscus, while pain during internal rotation is caused by damage to the outer meniscus. If there is a “snapping” sound during stretching, the lesion is more likely to be in the middle area of the meniscus. However, if the snap noise occurs in the maximum flexion position, the posterior meniscus is more likely to be damaged.
The examiner clamps the leg of the patient lying on his back under his arm and palpates the joint space with his free hand. He then bends and stretches the patient’s knee.During flexion, it also exerts valgus stress, and during extension, varus stress. Pain can be provoked with this functional test in the event of a longitudinal or flap tear of the meniscus.
The retentiveness test is used to check the rotation ability. The patient is asked to stand on the leg of the sick side and bend it slightly. Then he should lift the other leg slightly and rotate the thigh once outwards and once inwards.
In this way he limits the inner and outer rotation of the lower leg on the sick leg, which can be fixed to the floor by the examiner for assistance. If the external rotation of the thigh causes pain, this indicates external meniscus damage, since the movement of the external rotation on the healthy thigh corresponds to an internal rotation on the lower leg of the diseased supporting leg. Conversely, pain during inner rotation of the thigh is indicative of damage to the inner meniscus.
The pain symptoms are particularly pronounced because the entire body weight is on the knee and thus on the menisci in this test, so that the axial compression or compression pressure is very high. For this test, the patient must assume a cross-legged sitting position on the examination couch. The examiner now presses the knees, which are currently in an externally rotated and flexed position, moderately strongly towards the support.
If the exertion of pressure in the medial joint space is perceived as painful, the patient probably has a meniscus lesion in the rear area. The Steinmann I test aims to trigger pain in rotation. The patient lies on his back and bends the knee about 30°.
The examiner grasps the lower leg with one hand and the heel with the other, from where he performs one internal rotation and then an external rotation. Typically, pain during external rotation indicates damage to the inner meniscus and during internal rotation indicates damage to the outer meniscus. In the second Steinmann test, the patient also lies on his back.
The examiner tries to trigger a pain in the respective meniscus by palpating the medial and lateral joint space. A medial pain speaks for an inner meniscus lesion. It is important that the pain point can move: During flexion, the pain in the affected joint space moves backwards and during extension it moves forwards.
In addition, the examiner rotates the patient’s leg inwards and outwards while simultaneously exerting axial compression (i.e. pressure from below against the knee joint). External rotation pain is indicative of an internal meniscus lesion and internal rotation pain is indicative of an external meniscus lesion. In this test the patient stands barefoot on one leg.
To maintain balance, the examiner holds the patient’s outstretched arms. Now the supporting leg should be bent by 5° and then the upper body should be rotated 3 times outwards and inwards. The procedure is first performed on the healthy leg, then on the diseased leg.
Then the patient should do the same again, but with 20° flexion (flexion) in the knee. Pain that occurs in the joint space during this test indicates a meniscus lesion in the corresponding painful leg. In addition, a joint blockage can be provoked by the Thessaly test.
In the presence of an inner meniscus lesion there is a hypersensitive (hyperesthetic) skin area on the inside of the knee joint. Through mechanical and thermal irritation, the Turner’s sign can be tested positive and be an indication of a meniscus lesion. The reason for hypersensitivity can also be the chronic irritation of the supplying nerve, a branch of the saphenous nerve (R. infrapatellaris nervi sapheni).
The patient sits on a chair. The examiner clamps the affected leg between his own legs approximately at the level of the knee joints and then palpates the medial joint space with both thumbs. In order to be able to perform an internal and external rotation, the examiner must perform a kind of gyroscopic movement; the leg remains clamped between his own legs.
The rotation test triggers pain at the medial joint space in the case of an inner meniscus lesion, while in the case of an outer meniscus lesion the pain occurs on the outside of the knee joint, i.e. at the lateral joint space. The Tschaklin sign is not really a functional test.The Tschaklin sign is considered positive if, on the one hand, an older meniscus lesion causes tissue loss (atrophy) of the large thigh muscle (quadriceps muscle) or if, on the other hand, the vastus medialis muscle is atrophied due to a medial meniscus lesion and another muscle, the sartorius muscle, increases its tone for compensatory reasons.
