Examination of the knee Flashcards
How to take a proper history of the knee?
1) Onset: insidious, acute or post-trauma
2) Nature: aching (degen.), sharp catching (Mechanical), associated with morning stiffness( Arthritic), With instability(Iig tear)
3) With specific movements, uphill or downhill, felt in the retro patellar area (PatelloFem joint)
4) Site of pain: medial, lateral, retropat.,back (this helps us in ruling out referred pain (which is very common in knee injury, especially from the hip, Some patients can have osteoarthritis of the hip, yet they have knee pain, and when all investigations are done it appears that the hip is the problem. A very classical case is slipped upper femoral epiphysis usually in 11-12 yr old chubby boys whose epiphysis of the femur is not fully developed (which is a weak point) due to some sort of hit will injure it and moving it and limping, complaining of knee pain rather than hip. The second cause of referred pain is lower back)
5) What relieves the pain?
6) Other symptoms :
Swelling post activity ( +instability, or meniscal tear), Locking, true ie: LB, Bucket handle, Clicking or grating ( degen., meniscal)
What is the mechanism of hyperextension injury?
- It is from anterior to posterior, thus the likely injured structures are ACL, PCL, and the capsule
Describe the valgus injury
A force coming laterally where the MCL and the meniscus are injured
How to examine the knee?
- Any knee problem, the patient wont be able to pray
- well exposed-no shirts, pants, etc, gowns
Inspect joint(s)in question:
1) Signs of inflammation, injury (swelling, redness, warmth)
2) Deformity? Compare w/opposite side
3) Observe normal activity–what can’t they do? Specific limitations
4) Palpate joint warmth.
5) Point of max tenderness (imagine what structure under your fingers) Over what structure(s)?
6) Range of motion, active (patient moves it) and passive (you move it).
7) Strength, neuro-vascular assessment.
8) Specific provocative maneuvers
What are the surface landmarks that are found in the knee?
1) Patella
2) Patellar tendon
3) medial joint line and lateral joint line
4) Quadriceps muscle, hamstring muscle group, tibia, anterior tibial tuberosity (site of patellar tendon insertion), distal femur
Describe the use of the mechanical axis of the lower limb
- It is an axis from the central of the femoral head to the center of the ankle
- Basically, it shows where the load is distributed you trace an axis from the head of the femur to the center of the ankle (talus) and the line passes medially to the knee then this is a normal knee and the load is distributed evenly other than that it means that the load is not distributed equally, genu varum when the axis is medial in relation to the knee and genu valgum when it is lateral
What are the causes of genu varum?
1) Rickets “vitamin D deficiency” in young age
2) Osteoarthritis in old age, it is also the cause of geno-uvalgum
What are the things to feel when examining the knee?
1) All joint structures (joint lines, femorotibial, PF joint)
2) Tendons (quads, patellar)
3) Ligaments (MCL, LCL)
4) Effucsion or any swelling
5) Always look for the maximum point of tenderness (guides you to focus on the potential source of complain)
How do you feel osteoarthritis when examining the knee?
When moving the patient’s leg you may feel a grinding sensation (crepitus)
What is ballottetment?
- Assessment for a large effusion
To examine it:
1) Extend the knee
2) Hand on supra-patellar pouch above patella, pushing distally fluid that communicates with joint space.
3) Push down with your hand on the distal femur closing the pouch.
4) Push down on patella w/thumb.
If a large effusion is present, the patella floats & “bounces” back up when pushed down.
How to evaluate a meniscal injury?
- Joint line palpation
1) Slightly flex knee
2) Find joint space along lateral & medial margins, Joint line perpendicular to long axis tibia.
3) Palpate along medial, then lateral margins
4) Pain suggests underlying meniscus damage or OA
Describe the McMurray’s test
- It tests the medial meniscus
1) Put your Left hand w/middle, index, & ring fingers on the medial joint line.
2) Grasp the heel w/right hand, and fully flex the knee
3) Turn the ankle, foot pointed outward (everted), Direct knee, pointed outward.
4) Holding the foot in an everted position, extend & flex the knee.
- If the medial meniscal injury, you will feel a “click” w/hand on the knee w/extension. May also elicit pain
- TO TEST THE LATERAL MENISCUS:
1) Return the knee to a fully flexed position, and turn the foot inwards (inverted)
2) Direct the knee so pointed inward.
Hand on knee, fingers along joint lines
3) Extend and flex the knee
- If there was a lateral meniscal injury, you will feel a “click” w/fingers on the joint line; May also elicit pain.
Describe the Apley grind test
- The patient must be in a prone position
1) Grasp the ankle & foot w/both hands, and flex the knee to ninety degrees
2) Hold the patient leg down w/your leg on the back of the thigh
3) Push down while rotating the ankle.
- It Puts direct pressure on menisci, if injured-pain.
What is the normal anatomy and function of the knee ligaments?
- Four ligaments connect the femur and tibia (ACL, PCL, MCL “medial collateral ligament”, AND LCL “lateral collateral ligament”)
- Injury to the ligaments requires significant force and energy (like the leg being struck from the side while the foot is fixed)
- The symptoms are acute pain, swelling & they often report gearing a sound “pop”
- After acute swelling & pain, the patient may report pain and/or instability (sensation of the knee giving out) and inability to put weight
What is an important thing to do when testing a tear to the LCL or the MCL?
Keep the knee flexed at 20 degrees
