Anatomy 2: Joints of the Lower Limb

Question 1

Understand the components of the hip joint - especially the joint capsule and ligaments. Understand the movements of the hip joint.

Answer 1

1. Iliofemoral ligament - prevents hip extension (often considered strongest ligament in body)
2. Pubofemoral ligament - prevents hip abduction.
3. Ischiofemoral ligament - weakest of the 3 ligaments; resists internal rotation.
4. CLINICAL COMMENT:
   i. Fracture = typically presents appearing shorter and EXTERNALLY ROTATED.
   ii. Dislocation = typically posterior, appears shorter and INTERNALLY ROTATED, with difficulty abducting.

Question 2

Understand the blood and nerve supply of the hip joint.

Answer 2

i. Medial circumflex femoral artery - MOST IMPORTANT BLOOD SUPPLY OF HIP JOINT
ii. Nerve supply (follows Hilton’s Law - nerves supply muscles across a joint also provide sensory info.)
- -i.Anterior - femoral nerve (hip flexors)
- -ii.Superiorly - superior gluteal (hip adductors)
- -iii.Inferoposterior - obturator and sciatic (lateral rotators)

Question 3

Understand the components of the knee joint. Describe the joint capsule of the knee joint, and the extra-articular and intra-articular ligaments of the knee joint. Understand the movements of the knee joint.

Answer 3

a. Extra-articular
i. MCL
ii. LCL
iii. Medial patellofemoral ligament, medial patella retinaculum, lateral patella retinaculum.
iv. Oblique popliteal ligament, arcuate popliteal ligament

b. Intra-articular
i. ACL
ii. PCL

Question 4

Describe the blood supply and nerve supply of the knee joint.

Answer 4

Genicular anastomosis

i. Descending branch from lateral femoral circumflex
ii. Genicular branch of femoral artery
iii. Superior medial and lateral and inferior medial lateral genicular arteries from anterior tibial artery

Nerve supply
i.Femoral, tibial, common fibular

Question 5

Describe the components of the ankle joint. Understand medial and lateral ligaments of the ankle joint. Relate joint anatomy to the clinical implications during dorsiflexion.

Answer 5

i.Larger anterior surface makes joint more stable during dorsiflexion and weaker during plantar flexion.

ii. Medial collateral ligament (DELTOID)
- 1.Anterior tibiotalar
- 2.Posterior tibiotalar
- 3.Tibionavicular
- 4.Tibiocalcaneal

iii. Lateral collateral (relatively weak)
- 1.Anterior talofibulat (ATF - ALWAYS TEARS FIRST)
- 2.Posterior talofibular
- 3.Calcaneofibular (second to be injured)

Question 6

Identify the foot joint(s) where the majority of eversion and inversion take place.

Answer 6

Most inversion and eversion occurs at TALOCALCANEALNAVICULAR JOINT (2 parts cannot function independently)

Question 7

Describe the joint(s) separating hindfoot from midfoot and midfoot from forefoot.

Answer 7

Transverse tarsal joint - 2 joins separate hindfoot from midfoot.

i. Calcaneocuboid and talonavicular joint.
ii. Some inversion/eversion occurs here.

Question 8

Describe the ligaments of the foot.

Answer 8

Medial and lateral collateral ligaments unite metatarsophalangeal and interphalangeal joints.

Question 9

Understand the components of the arches of the foot.

Answer 9

a. Longitudinal arch
- i.Medial longitudinal - MOST IMPORTANT ARCH. Includes 1st 3 metatarsals, 3 cuneiforms, navicular, talus and calcaneus.
- -1.SPRING LIGAMENT (PLANTAR CALCANEONAVICULAR)
- -2.Tibialis a/p tendons
- ii.Lateral longitudinal - 4th and 5th metatarsals, cuboid and calcaneus
- -1.LONG AND SHORT PLANTAR LIGAMENTS
- -2.PLANTAR APONEUROSIS
- -3.Fibularis longus and brevis tendons

b. Transverse arch
i. Between longitudinal arches; between base of metatarsals, cuneiforms and cuboid.

c. Components supporting arch
i. Bony articulation
ii. Ligaments
iii. Tendons