15. Joints of the Lower Extremity Flashcards
What happens in Pott’s Dislocation Fracture?
An eversion sprain causes the deltoid ligament to avulse the medial malleolus, and the resulting snap causes the talus to strike the fibula, breaking it through the shaft.
What ligament starts on the head of the fibula, crosses over the popliteus, and attaches to another ligament in the middle of the popliteal space?
Arcuate popliteal ligament
Which tendon does the lateral collateral ligament run through?
The tendon of the biceps femoris
What does McMurray’s Test check for, and how is it performed?
Test for the Meniscus. Pt lies supine, Knee is flexed at 90 degrees. Apply internal rotation (to load pressure on the Lateral Meniscus) or external rotation (to load pressure on the Medial Meniscus) and extend the Lower Extremity out straight. Check for pain.
How can you know which nerves innervate joints, generally speaking?
If a muscle crosses a joint, the nerve that innervates that muscle also innervates that joint.
What is the function of the transverse acetabular ligament?
Serves as a gateway for vessels
Connects the inferior aspect of the acetabulum
What is the function of the anterior cruciate ligament?
Limits rolling of the Femoral Condyles on the Tibial Plateau during flexion (forces sliding rather than rolling posteriorly), and prevents hyperextension of the knee.
What is the weakest intrinsic ligament of the hip?
What is that ligament’s function?
The ischifemoral ligament
Preventing posterior dislocation
What is the general cause for dense pes planus?
Deformity or fracture of the bones of the foot
What important ligament passes weight from the talus to the rest of the foot?
The calcaneonavicular (spring) ligament
Which collateral ligament of the knee connects to its meniscus?
The medial collateral ligament of the knee
Give the correct setup and execution for:
Labral Distraction
Pt supine. Flex the patient’s knee to 90 degrees as above, but then lift on the leg to take weight off of the acetabulum. Check for relief of pain
What can cause all the members of the Unhappy Triad of O’Donoghue to tear together?
Lateral impact
What is the function of the posterior cruciate ligament?
Prevents the Tibia from going anterior when the knee is flexed
What is the function of the zona orbicularis?
Support for the relatively weak femoral neck
What gives rise to the oblique popliteal ligament?
The tendon of the semimembranosus muscle
Which of the two collateral ligaments of the knee is most likely to tear?
The medial collateral ligament
Give the correct setup and execution for:
Quads active test
Pt supine, knee bent. Physician pushes on the Tibia (as in Posterior Drawer), and instructs the patient to flex their quadriceps femoris. If the Tibia pushes outwards, it shows that the quads were initially relaxed, are able to be activated, and that there is a laxity in the posterior cruciate ligament.
What are the four structures involved in the Deltoid ligament of the medial ankle?
Anterior tibiotalar ligament
Tibionavicular ligament
Tibiocalcaneal ligment
Posterior tibiotalar ligament