Knee Flashcards
Describe the knee joint and explain the two joints that make up the knee.
The knee is a hinge joint with one degree of freedom (flexion/extension). The two joints are the tibia-femoral and the patello-femoral. The menisci are the most important structures.
List the four major ligaments of the knee and their function.
Anterior Cruciate Ligament (ACL)-vital stabilizer-knee extension, anterior translation of tibia, medial rotation of tibia, cutting/pivoting/changing direction
Posterior Cruciate Ligament (PCL)-knee flexion, posterior translation of tibia
Medial Collateral Ligament (MCL) or Tibial collateral ligament-knee flexion, medial translation of the tibia
Lateral Collateral Ligament (LCL) Fibula Collateral–knee flexion, lateral translation of the tibia
Describe the common mechanism of injury for the ACL rupture
While the foot is planted and the knee is in more extension than flexion, a rotate force is applied where the upper leg is displaced backwards or sidewards by impact.
Describe the menisci and their importance to knee function
Menisci (medial and lateral) a flat fibrocartilage band which covers the articular surface of the tibia, stabilizes and supports the outer aspect of the knee joint and provides joint congruency (a tight fit). The outer edge is vascular and the inner part is not. Medial bears more weight and is usually damaged more.
Describe mechanism of injury for the menisci tear.
Occurs when the femoral condyles scrap across. Initial tear usually occurs int he superficial layer, lead to arthritis, osteophyte formation, quad atrophy, and development of PFS.
Describe the retro-patella surface and the articular cartilage covering it.
It is the hyalin cartilage on the bottom side of the patella. It is thicker superiorly and gets thinner as it goes down. Depending on the degrees of knee flexion is how much contact occurs where. 90 is at the top, 45 is middle, 20 is lowest, and 130 is on the edge (odd facet) where very little cartilage is.
List the MET criteria for ACL reconstruction (8)
ACL:
- no open wounds
- full knee ROM
- Good patella mobility (rise and fall w/quad)
- full weight bearing
- de-rotation brace if ordered
- medical clearance
- minimal swelling/pain
- 12 weeks post op
Explain the differences in the quadriceps and patella tendon ruptures.
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Describe the odd facet of the patella.
The odd facet is the medial edge of the patella, where there is very little cartilage, and is the contact area for 135 degrees of knee flexion.
Explain the importance of the muscular imbalance between the vastus lateralis and
vastus medialis with PFS.
If they are imbalanced, the lateralis will pull the patella laterally. This is why medialis strengthening is so important with this client.
Describe how to measure Q-angle and the normal values for men and women.
Measure the angle between the patella and the inferior iliac crest and a straight line to the floor.
Women-15-18
Men-10-12
List the MET criteria (3) and MET management (3) for PFS.
- Minimal swelling (they will have pain)
- Medical clearance
- Full ROM
- Recuit vastus medialis
- Stretch IT band
- Strengthen quads
Describe the MET management for the total knee replacement (4).
- Maintain or improve ROM
- Strengthen the quads w/ ROM
- Recruitment of the vastus medialis
- Improve overall leg strength
List the indications for the use of the anterior drawer and Lachman’s tests.
These tests are used to assess the integrity of the ACL. The anterior drawer test can be affected by hamstring guarding, where the Lachman’s does not.
Describe the procedure for measuring quadriceps bulk.
Measure the mid-point of the patella and then in 1 inch increments superiorly up to 3 inches.
