SHEATHS II

Question 1

name this sheath of the anterior crural compartment

• extends from just proximal to the transverse crural ligament to midway between the bands of the cruciate crural ligament
• passes within the transverse crural ligament and the upper band of the
  cruciate crural ligament; begins and ends most proximal

Answer 1

Tibialis Anterior Synovial Sheath

Question 2

name this sheath of the anterior crural compartment

• extends from just proximal to the upper band of the cruciate crural
  ligament (near the level of the malleoli) to the base of the first metatarsal - begins and ends more distally than the synovial sheath of the tibialis
  anterior tendon
• passes within the cruciate crural ligament

Answer 2

Extensor Hallucis Longus Synovial Sheath

Question 3

name this sheath of the anterior crural compartment

• the 4 slips of the extensor digitorum longus tendon and the tendon of
  peroneus tertius muscles are enclosed within the same synovial sheath; begins more narrowly and expands distally; short when compared to the
  other two synovial sheaths of the extensor compartment
• extends from just proximal to the upper band of the inferior extensor retinaculum (the level of the malleoli) to the level of the base of the
  fifth metatarsal
• passes within the cruciate crural ligament

Answer 3

Extensor Digitorum Longus and Fibularis Tertius / Peroneus Tertius
Synovial Sheath

Question 4

name this sheath of the lateral crural compartment

• extends from a level just superior to the lateral malleolus to the level of the cuboid; passes deep to both the superior and inferior fibular / peroneal retinacula
• the inferior fibular retinaculum has fibers that attach to the fibular tubercle and splits the synovial sheath as the tendons pass around the fibular tubercle

Answer 4

Fibular / Peroneal Synovial Sheath

Question 5

name this sheath of the lateral crural compartment

• extends plantarly across the foot
• may be a continuation of the combined fibular synovial sheath or a separate sheath

*subtype of the fibular/peroneal synovial sheath

Answer 5

Fibularis Longus Synovial Sheath

Question 6

name this sheath of the posterior crural compartment

i. Proximal Sheath
- surrounds the flexor digitorum longus tendon as it courses posterior to
the ankle joint and into the plantar foot
- begins posterior to the medial malleolus and ends proximal to the knot
of Henry
- passes within the laciniate ligament

ii. Distal Sheaths
- a second sheath is present and surrounds each of the four tendons as
they pass along the plantar aspects of the lesser digits from the
metatarsophalangeal joints to the middle phalanges

Answer 6

Flexor Digitorum Longus Synovial Sheaths

Question 7

name this sheath of the posterior crural compartment

i. Proximal Sheath
- surrounds the flexor hallucis longus tendon as it courses posterior to
the medial malleolus and inferior to the sustentaculum tali
- begins at the distal end of the tibia and ends at the knot of Henry
- begins and ends most distally
- passes within the flexor retinaculum

ii. Distal Sheath - surrounds the flexor hallucis longus tendon as it passes along the plantar aspect of the hallux from the metatarsal head to the central proximal phalanx

Answer 7

Flexor Hallucis Longus Synovial Sheaths

Question 8

name this sheath of the posterior crural compartment

• surrounds the tibialis posterior tendon as it courses posterior to the ankle joint
• begins at the proximal posterior medial malleolus and ends after passing
  through the porta pedis
• begins and ends most proximally
• passes within the laciniate ligament

Answer 8

Tibialis Posterior Synovial Sheath