MSK Knee Examination - Dr James Thing
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JT Dr James Thing
My name’s James Thing. I’m a Sports and Exercise Medicine Consultant with Connect Physical Health and we’re going to be doing a knee examination today. I would normally start with the patient in a standing position with shorts on so that the entire legs are exposed. From this position you can have a look at their lower limb alignment to see whether they have any obvious knee valgus or varus. We can also have a look at the quadriceps muscle bulk and we can look and see whether there’s any obvious swelling of the knees. We can also go down and have a look and see whether they have any particular flat foot or high arch deformity.
From this position I would then get them to do a single leg squat. So I would ask them to balance on one of their legs and then do a semi squat and I’m looking at the control that they have. I’d then ask them to go onto the other leg and again, a single semi leg squat position. That’s it. And in this position I’m looking particularly at the control, whether they’re particularly wobbly in this position and I’m also looking to see whether the knee deviates into a valgus position.
From having done the single leg squats we would then ask them to do a full double leg squat and we’re looking particularly for pain and to see whether they’re favouring one knee rather than the other, which may be an indication of meniscal injury. From this position I would then ask them to do a duck walk, which is in that fully flexed knee position, walking forwards and this is a very good test for meniscal pathology; if this recreates their pain then the chance of a meniscal injury is quite high.
With the patient in a supine position we can assess to see whether there’s any obvious effusion of the knee joint. We can do this by first of all observing and then we can do the sweep test where we empty the medial compartment and then compress the lateral compartment and we’re looking for a bulge of fluid, again in the medial compartment. The other test is the patella tap, where we press posteriorly on the patella and we’re looking to see whether that taps against the front of the femur and we can do that on both sides.
From here we would then assess for excessive movement of the patella, so we can move the patella medially and laterally looking for pain and excessive movement. Then we can come onto Clarke’s test that looks at patella femoral pain. We place our finger above the patella and ask the patient to push their leg down into the bed. By doing that we’re activating their quads muscles and looking to see whether they get any pain at the top of their patella which will be consistent with patella femoral pain syndrome or patella femoral OA and we would compare both sides at that stage.
I would then go on to look at range of movement. I’d ask them to bend their knee up fully, keeping their foot on the bed. I then mark the position on the bed where their heel gets to and ask them to drop their leg down again and then I’d repeat it on the other side, keeping my position; if you can bend your right knee all the way up—and here you can see that the position is similar on both legs—so that’s full and normal active flexion.
I would then check into extension, looking for slight hyperextension, which is normal and which is present on both sides. I’d then ask the patient to bend their knee up again and you can take them passively into full flexion and full extension. I would then do resisted movement so I’d ask them to bend their knee by pulling the foot in towards their bottom and then pushing out against me into extension. That’s looking at the range of movement.
For this position then I would do a McMurray’s test so I’d ask the patient to bend their knee up fully and I’m going to externally rotate the foot, flex and then extend the knee and same, internally rotate the foot and flex and extend the knee. In this position you’re looking for a painful click which would be consistent with meniscal pathology.
Having done this I can then go on to assess the collateral ligaments. We can assess the medial collateral ligament by asking the patient to just allow me to take the full weight of their leg. Then we can put a valgus force on the knee, looking for pain and laxity at full extension and then in a little bit of flexion, so 30 degrees of flexion. Then we can repeat that; that’s for the medial collateral ligament. We can repeat it for the lateral collateral ligament, again in full extension and then at 30 degrees flexion.
Having done this I’d then ask the patient to bend both knees up to 90 degrees and we can have a look and see whether there’s any obvious drop of the tibia on the femur. We can compare both sides by looking at the front here. I would then ask them to drop their right leg down and I’m going to stabilise their left leg by sitting on their foot. You then want them to fully relax their hamstrings, making sure they’re fully relaxed, put your fingers on the front of the tibia here and pull forward. You’re looking for laxity and a firm end point. I can tell that there is a firm end point here. The most important thing is to compare both sides because different people have different degrees of laxity.
Another test that we can do is the Lachman test, which is where they drop their knee down onto your knee and you stabilise the femur with one hand and pull the tibia forwards with the other. Again you’re looking for laxity there. Okay?
At this stage I’d move on to palpation and I’d start at the tibial tuberosity, moving up the patella tendon, up and palpate around the patella itself, again looking for pain. Then I would palpate along the lateral joint line and the medial joint line, looking for tenderness which would be compatible with a meniscal tear. I’d then move on to palpating the medial collateral ligament, the lateral collateral ligament, the pes anserinus, which lies about five to ten centimetres distal to the medial joint line and then posteriorly into the popliteal fossa, looking for pain, tenderness and swelling.
That completes the examination.
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