Elbow + Radioulnar Joint Flashcards
Classify the elbow joint.
Synovial hinge.
What movements are permitted by the elbow joint?
Flexion and Extension.
What are the articular surfaces of the elbow joint?
Humerus (trochlea and capitiulum) with Ulna and Radius respectively.
Which other joint is contained within the same capsule as the elbow joint?
Superior Radioulnar Joint.
What does the trochea articulate with?
Ulna. The capitulum articulates with the radius.
Where are the coronoid and radial fossae?
Anterior humerus, above trochea/capitiulum.
Where is the olecranon fossa?
Posterior humerus.
What do the fossa of the humerus contain?
Fat Pads
Where does the joint capsule of the elbow attach?
Annular ligament (and not radius) to permit supination/pronation. It then attaches around the ulna
Where is the joint capsule of the elbow the weakest?
Anteriorly and posteriorly.
What strengthens the elbow joint capsule anteriorly and posteriorly?
Brachialis and triceps muscles.
What ligaments stabilise the elbow joint?
Collateral ligaments.
Where do the collateral ligaments of the elbow joint attach?
Medial - Medial epicondyle of humerus to ulna.
Lateral - lateral epicondyle of humerus to annular ligament and radial notch of ulna.
Which muscles permit flexion of the elbow?
Brachioradialis, biceps brachii, brachialis, and some forearm flexors.
Which muscles permit extension of the elbow?
triceps brachii and some forearm extensors.
Summaries the structures that provide stability to the elbow joint.
Collateral ligaments, triceps, biceps, brachialis, brachioradialis and flexor/extensor tendons of the forearm.
When is the elbow joint most stable?
At 90*, with arm mid-pronation/supination.
Classify the superior and inferior radioulnar joints.
BOTH SYNOVIAL PIVOT
Where is the interosseous membrane?
Between radius and ulna.
Which muscles permit pronation?
Pronator teres (and pronator quadratus)
Which muscles permit supination?
Supinator and Biceps Brachii (when flexed)
In which age group is annular ligament displacement most common?
1-4 yo. It occurs when the radial head slips under the annular ligament because the annular ligament has not fully developed.
Classify the Knee Joint
Modified synovial hinge joint
What are the articulating surfaces of the knee joint?
Condyles of the femur and tibial plateau
What movements are permitted at the knee joint?
Flexion and extension. A small amount of lateral/medial rotation can occur when the knee is flexed.
What is the shape of the capsule of the knee joint?
Cylindrical passing between femur and tibia. (Deficient anteriorly for the patella)
What is the name for the reflections of the synovial membrane in the knee joint?
PLICAE. These may become trapped in inflammation.
What strengthens the knee capsule?
Anteriorly - tendon of quadriceps.
Laterally - iliotibial tract
Where does the iliotibial tract insert distally?
Lateral tibial condyle.
Name the ligaments that stabilise the knee joint.
Medial + Lateral collateral ligaments, anterior + posterior cruciate ligaments, oblique and arcuate popliteal ligaments.
Where does the medial collateral ligament of the knee attach?
Medial epicondyle of femur to medial aspect of shaft of tibia. it also connects to the medial meniscus.
Where does the lateral collateral ligament of the knee attach?
Lateral epicondyle to the head of fibula. The popliteus muscle separates it from the joint capsule.
Where do the anterior and posterior cruciate ligaments attach?
Anterior - to the anterior part of the tibial plateau.
Posterior - to the posterior part of the tibial plateau.
What are the names of the 2 popliteal ligaments?
Oblique and arcuate popliteal ligaments. Also remember the anterolateral ligament.
What are the menisci made of?
Fibrocartilage
What are the functions of the menisci?
Increase joint congruency, assist in weight-bearing, act as shock absorbers, aid lubrication and facilitate knee-locking.
Which menisci is attached to its corresponding collateral ligament?
Medial. The lateral collateral ligament is separated from the joint capsule by the popliteus muscle.
Describe the tearing of a meniscus.
More common on the medial meniscus due to its attachment to the collateral ligament. Often occurs as a result of rotation. The inner part can become separated from the outerpart (buckethandle rupture). Part of it may move into the middle of the joint an prevent full extension of the knee joint.
With which bone does the patella articulate?
Femur
What structure lies between the tibia and patella?
Infrapatellar fat pad
Name and locate the bursase around the knee joint.
Suprapatellar - between femur + quadriceps
Gastrocnemius - beneath 2 heads of gastrocnemius
Subcutaneous prepatellar + infrapatellar bursae - between patella/patella ligament and overlying tissues
Deep infrapatellar bursa - between patella ligament and tibia
Name the knee bursae
Suprapatellar, deep infrapatellar, gastrocnemius and subcutaneous prepatella/infrapatella bursae.
Which nerves innervate the knee joint?
Femoral, obturator, tibial and common peroneal nerves.
How do the menisci receive their nutrition?
Diffusion from surrounding synovial fluid
What stabilise the knee joint?
Collateral ligaments, cruciate ligaments, iliotibial tract, sartorius, semitendinosus + gracilis + quadriceps femoris.
In what position is the knee said to be in the closed packed position?
Fully extended
What is the benefit of the closed packed position?
the knee is stabilised for weight bearing. Ligaments of the knee are rightened.
How is the closed packed position formed?
anterior medial rotation of the femur around the ACL.
What unlocks the knee from the closed packed position?
Popliteus muscle
How does the popliteus unlock the knee?
Laterally rotates the femur on the tibia.
What type of bone is the patella?
Sesamoid
Where is the patella located?
In the quadriceps femoris tendon over the femur.
Where can hyaline cartilage be found on the patella?
Posteriorly. For articulation at the patellofemoral joint.
