Joints of the Lower Extremity - A Partial Study Guide

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Types of Joints

The Knee Joint in General

• articular capsule - fibrous membrane
  • intracapsular - popliteus, cruciate ligaments
• synovium - generally, but not always, confined by the articular capsule
  • secretes synovial fluid - reduces friction
  • intrasynovial - fluid only in non-pathological state
• articular cartilage - hyaline cartilage
  • not covered by synovial membrane
• articular meniscus

Hip Joint - a synovial ball and socket joint

• bones - femur, greater trochanter, lessser trochanter, acetabulum and bony contributions
• artery of the ligament of the head of the femur - foveal fossa of femoral head
• cartilage on head of femur and in acetabular fossa
• articular capsule -
• synovial membrane
• acetabular labrum - crosses transverse acetabular ligament
• capsular specializations
  1. iliofemoral ligament - y shaped, resists extension
  2. pubofemoral liglament - resists abduction and extension
  3. ischiofemoral ligament - resists extension
• "screw home mechanism" - the wringing of a wash cloth
  • most stable on extension as in quiet standing, line of gravity is posterior to horizontal axis and, thus, drives extension
• movements at the hip
  • flexion - iliopsoas, tfl, rectus femoris, sartorius, pectineus
  • extension - hamstrings, not short head bf,
    • limits - iliofemoral, pubofemoral,
  • abduction - gluteus medius and minimus, reverse origin/insertion
    • limits - pubofemoral ligament
  • adduction - adductor longus, brevis, magnus (anterior part)
    • limits - opposite limb, ligament of the head of the femur (ligamentum capitus)
  • lateral rotator - the five short rotators of the gluteal region, obturator externus,
    • much more powerful than medial rotation
  • medial rotation - gluteus medius, minimus and tensor fascia lata

Knee Joint

• lateral view
  • quadraceps tendon and patella ligament
  • synovium interrupted by posterior surface of patella, cartilage of the femur, and cartilage of the tibia
  • anterior cruciate ligament - limits anterior diplacement of tibia
    • intracapsular and extrasynovial
  • posterior cruciate ligament - limits posterior movement of tibia
  • suprapatellar bursa
  • infrapatellar bursa
• coronal view
  • tibial collateral ligament
  • fibular collateral ligament
  • articular cartilage
  • synovium
  • lateral meniscus - NOT attached to the fibular collateral ligament
  • medial meniscus - connected to tibial collateral ligament
• superior surface of tibia
  • the menisci are fibrocartilagenous
  • c shaped medial meniscus - less mobile that the lateral meniscus
  • o shaped lateral meniscus - separated from fibular collateral meniscus by the tendon of origin of the popliteus
  • transverse genicular ligament
  • tibial tuberosity
  • intercondylar region - attachment of anterior and posterior cruciate ligament
• saggital view of intercondylar region
  • cruciate ligaments - "cross"
  • anterior cruciate ligament ACL
  • posterior cruciate ligament PCL
• posteriorr view of knee joint
  • tibial and fibular collateral ligaments
  • origin of plantaris
  • oblique popliteal ligament - expansion of semimembranosus
  • arcuate ligament
  • popliteus muscle - unlocks the knee joint
  • * summary table of movements
  • extension - quadraceps femoris, TFL?
  • flexion - hamstrings, pes anserinus, short head biceps
  • lateral rotation
  • medial rotation
  • quadraceps reflex
• subcutaneous bursa
  • prepatellar bursa - housemaids
  • intrapetella bursa - clergyman's knee

Ankle joint - stable on extension

• medial view
  • deltoid ligament and thee parts
    1. lig
    2. lig
    3. lig
• lateral view
  • inversion injuries are common
  • posterior talofibular ligament
  • calcaneofibular ligament
  • anterior talofibular ligament
• inferior view
  • long plantar ligament
    • calcaneus to base of lateral 3 metatarsals
  • short plantar ligament
    • calcaneus to the cuboid
  • spring ligament - plantar calcaneonavicular ligament
  • osseofibrous tunnel for peroneus longus tendon
  • tibialis anterior
  • tibialis posterior
  • flexor hallucis longus
• Movements of the talocrual joint, transverse joint, subtalar joint
  • extension - most stable, tibials ant, ext. dig,, ext hallucis longus, peroneus tertius
  • flexion - triceps surae, tibialis posterior, flexor digitorum longus, flexor hallucis longus, peroneus longus and brevis
  • inversion
  • eversion

Questions for the Joints of the Lower Extremity

True/False - August 15, 2011

1. The ankle is more stable in extension than in flexion.
2. The acetabular fossa receives contributions from the pubis, ischium, and illium.
3. The hip joint is considered to the the most movable joint of the body.
4. The fovea of the head of the femur is not covered by hyaline cartilage.
5. The artery of the ligament of the head of the femur (ligamentum capitus) is, in children, an end artery.
6. The articular cartilage of the acetabular fossa is covered by a synovial membrane (synovium).
7. The transverse acetabular ligament is a cartilaginous extension of the acetabular articular cartilage.
8. The articular capsule of the hip joint attaches to the intertrochanteric crest.
9. The inferior stem of the "Y ligament of Bigalow" (iiofemoral ligament) extends to the lesser trochanter.
10. The pubofemoral ligament interdigitates with the iliofemoral ligament in the area of the intertrochanteric line.
11. The ischiofemoral ligament has anterior attachments at the intertrochanteric line.
12. The ligamentus specializations of the hip articular capsule are relaxed during quiet standing.
13. The line of gravity falls anterior to the hip joint during quiet standing.
14. The oblique popliteal contributes to the posterior joint capsule of the knee.
15. The synovium of the knee joint covers the deep surface of the patela.
16. The suprapatellar bursa communicates with the intrapatellar bursa and with the synovial joint cavity.
17. The medial collateral ligament attaches, in part, at the neck of the fibula
18. The cruciate ligaments are intracapsular and extrasynovial and the tendon of orgin of the popliteus muscle is both intrasynovial and intracapsular.
19. The lateral meniscus is typically torn when the lateral collateral ligament of the knee ruptures.
20. The anterior cruciate ligament is attached to the anterior region of the intercondylar space.
21. The anterior and posterior ligaments are so named for their relative attachments to the tibia.
22. The crossing of the cruciate ligaments tighten as the femur medially rotates on the tibial plateau.
23. The popliteus tendon intervenes between the medial meniscus and the medial collateral ligament.
24. The tibiocalcaneal ligament of the medial ankle joint is continuous at its calcaneal attachments with the spring ligament.
25. The long plantar ligament form the inferior boundary of a osseofibrous tunnel that transmits the tendon of the peroneus longus to the medial side of the foot.
26. The tendon of flexor hallucis longus is applied to the groove of the cuboid bone.

True/False - August 16, 2010

1. Articular cartilage is typically covered by a synovial membrane.
2. Joint ligaments can, at once, be inside the joint capsule but outside the joint synovial cavity.
3. Included in the intrasynovial space is synovial fluid.
4. The "screw home" mechanism is a carpentry referent applied to the final turn that firmly seats a screw and, thus, stabilizes the joint.
5. The line of force of gravity, anterior to the knee joint, contributes to the "screw home" stability of the knee in extension while standing.
6. The popliteus muscle "unscrews" the extended knee of the planted lower limb by medially rotating the femur.
7. The ligamentum capitis together with the artery to the head of the femur, enters the acetabular fossa, by way of the acetabular notch.
8. The trochanteric fossa receives attachment of the ligamentum capitis.
9. The hip joint is most stable in flexion.
10. The acetabular labrum is interrupted by the acetabular notch.
11. Intervening between the intertrochanteric line and the iliopsoas tendon is the iliofemoral ligament.
12. The iliopsoas tendon crosses the anterior surface of the pubofemoral ligament.
13. Maximum tension of the ischiofemoral, iliofemoral, and pubofemoral ligaments occurs during flexion of the hip joint.
14. That part of the adductor magnus that extends the hip inserts on the adductor tubercle.
15. The posterior part of adductor magnus extends the hip and is innervated by the obturator nerve.
16. The semimembranosus, semitendinosus, biceps femoris, posterior adductor magnus, and the superior all arise from the ischial tuberosity.
17. The oblique popliteal ligament is a thickening of the inner surface of the patellar tendon.
18. The suprapatellar bursa is continuous with the synovial cavity of the knee joint.
19. The prepatellar bursa does not typically communicate with synovial joint cavity.
20. The lateral meniscus, but not the medial meniscus, is attached to the tibial collateral ligament of the knee.
21. The tendon of origin of the popliteus muscle is attached to the fibular collateral ligament.
22. The posterior joint capsule provides a surgical approach to the cruciate ligaments that does not disrupt the synovial joint cavity.1
23. The anterior cruciate ligament resists anterior displacement of the tibia.
24. The posterior cruciate ligament resists posterior displacement of the tibia.
25. Forced abduction of the leg may rupture the medial collateral ligament and, thus, tear the medial meniscus.
26. A blow to the lateral side of the knee joint (football clip) generates a forced abduction of the leg and a forced adduction of the thigh.
27. The deltoid ligament, at the level of the flexor retinaculum, is deep the the plantar vessels and nerves.
28. The long plantar ligament extends distally beyond the groove of the cuboid bone.
29. The short plantar ligament "stops short" of the groove of the cuboid bone.
30. The tendon of the peroneus longus muscle crosses the superior surface of the long plantar ligament.
31. The tendon of flexor hallucis longus crosses the inferior surface of the spring ligament (plantar calcaneonavicular ligament).
32. Inversion injuries of the ankle may disrupt the lateral ligaments of the ankle.

Definition and Short Answer

1. What intervenes between the lateral collateral ligament and the lateral meniscus?
2. Are the menisci of the knee joint intrasynovial? Or, instead do they face into the synovial cavity?
3. The artery of the ligament of the head of the femur is a branch of what artery?
4. Crossing the anterior surface of the iliofemoral ligament and the pubofemoral ligament is the tendon of ________?
5. What is the relative stability of the hip joint while seated in a car? While standing?
6. Is the patella within the quadraceps tendon, or instead, is the patella between the quadraceps tendon and the patella ligament?
7. What was the surgical approach to the cruciate ligaments before arthroscopic surgery? Why avoid invasion of the synovial cavity?
8. Why is it handy to discuss limitations of movement by the cruciate ligaments in terms of the tibia?
9. What are the bony and fibrous components that make up the osseofibrous tunnel for the peroneus longus tendon.
10. As the inferior lateral genicular artery proceeds anterior having crossed the posterior surface of the popliteus muscle, it crosses the medial (deep) surface of the (blank) ligament and the lateral surface of the (blank) meniscus and the medial surface (deep) of the blank tract.
11. The center of gravity, when standing, is (blank) to the hip joint, (blank) to the knee joint, and (blank) to the ankle joint. Minimal muscle activity is required at the hip largely due to support provided by the (blank) ligament. Minimal muscle activity is required at the knee because of the "screw home" mechanism that brings the joint into a "close packed" position due to a (blank) rotation of the (blank) condyles on the (blank) plateau. Considerable muscle activity is required across the ankle joint and is provided by the (blank) muscles.
12. The lateral plantar arthery crosses the sole of the foot starting medial to lateral: 1) (blank) to abductor hallucis, (blank) to flexor hallucis brevis, and (blank) to quadratus plantae.

Essay

1. What are the relationships of the sustentaculum tali to the spring ligament, deltoid ligament, medial/lateral plantar nerves and arteries, flexor hallucis longus, medial longitudinal arch, and whatever else is adjacent?
2. What nerve distributions contribute to flexion of the knee? Mention key muscles for each distribution. What is the action of these muscles at the hip?
3. Discuss the anatomy of Trandelenberg's gate. Include possible causes for this particularly nerve injury. Consider origins and insertions and the mechanics of compensation (explain the appearance of the gait).
4. Discuss the "screw home" mechanism of the hip joint. When is the hip joint maximally stable? How does this relate to the line of gravity at the hip?
5. What is the significance of the infrapatellar synovial fold in understanding that a structure (anterior cruciate ligament) can be both intracapsular and extrasynovial?
6. Discuss the muscles and nerves that contribute to movement at the hip.
7. Discuss the relations of the fibular collateral ligament of the knee.
8. The tibial portion of the sciatic nerve is lesioned within the middle third of the thigh. Can you still flex the knee using muscles of the posterior compartment on the thigh? The tibial portion of the sciatic nerve is lesioned in the gluteal region. Can you still flex the knee using muscles of the posterior compartment? The tibial and peroneal portions of the sciatic nerve are lesioned in the distal third of the thigh. Can you still flex the knee using muscles of the posterior compartment of thigh? The tibial portion of the sciatic nerve is lesioned in the gluteal region and the peroneal portion is lesioned in the lower third of the thigh. Can you still flex at the knee using muscles of the posterior compartment of the thigh? The tibial and peroneal portions of the sciatic nerve are lesioned in the gluteal region. Can the knee still be flexed by any muscle regardless of compartment?
9. What are the functions of the popliteus muscle?

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