lower leg and ankle arthrology

Question 1

what are the functions of the interosseous membrane?

Answer 1

-forms a strong bond between the tibia and fibula- stabilises the leg and ankle joints
- facilitates movements of the fibula during ankle movement
-reduces torsional stress on the fibula
-separates muscles of anterior and posterior compartments of the leg
- provides a large surface area for muscle attachment

Question 2

what joint type is the superior tibiofibular joint?

Answer 2

synovial plane joint

Question 3

what joint type is the inferior tibiofibular joint?

Answer 3

syndesmosis (fibrous joint)

Question 4

does any active movement occur at the tibiofibular joints?

Answer 4

no, only passive movements as a result of movement at the talocrural joint

Question 5

what is the full classification of the talocrural joint?

Answer 5

compound, synovial joint, uni-axial, hinge

Question 6

what bones articulate to form the talocrural joint?

Answer 6

body of talus, tibia and fibula

Question 7

describe the articular surface of the superior aspect of the talus

Answer 7

-convex in AP direction
-slightly concave transversely
-surface is broader anteriorly

Question 8

what ligament is vital for posterior stability of the ankle joint?

Answer 8

transverse tibiofibular ligament

Question 9

name the static stabilisers of the ankle joint

Answer 9

• fibrous capsule of joint
  -transverse tibiofibular ligament
  -anterior and posterior ligaments
• lateral collateral ligament
• medial collateral(deltoid) ligament
• inferior tibiofibular joint ligaments
• interosseous membrane

Question 10

describe the lateral collateral ligament of the ankle

Answer 10

strong ligament comprising of 3 bands, reinforces joint capsule laterally

Question 11

what are the 3 bands of the lateral collateral ligament

Answer 11

• anterior talofibular lig
  -calcaneofibular lig
• posterior talofibular lig

Question 12

what are the attachments of the anterior talofibular ligament

Answer 12

runs between anterior border of lateral malleolus and talar neck

Question 13

what are the attachments of the posterior talofibular ligament

Answer 13

runs horizontally from malleolar fossa to lateral posterior tubercle of talus

Question 14

what are the attachments of the calcaneofibular ligament

Answer 14

passes from tip of lateral malleolus to the lateral calcaneal surface behind the peroneal tubercle and blends with the joint capsule

Question 15

describe the deltoid ligament

Answer 15

-medial collateral ligament
-very strong
-consists of 4 bands of fibres

Question 16

what are the 2 deeper bands of the deltoid ligament?

Answer 16

anterior and posterior tibiotalar ligaments

Question 17

where do the deeper bands of the deltoid ligaments attach?

Answer 17

attach to medial side of neck and body of talus, blending with the joint capsule

Question 18

what are the superficial bands of the deltoid ligament?

Answer 18

tibionavicular and tibiocalcaneal ligaments

Question 19

where do the superior bands of the deltoid ligament attach?

Answer 19

have a continous attachment from the navicular tuberosity to the sustentaculum tali, including the spring ligament

Question 20

what is the role of the collateral ligaments?

Answer 20

-maintaining stability at the ankle joint
- allowing movements at the ankle joint

Question 21

what movements occur at the talocrural joint during dorsiflexion?

Answer 21

-wide part of trochlear surface of talus rocks backwards into posterior tibiofibular mortise joint, pushing tibia and fibula apart
-talus becomes wedged between malleoli

Question 22

what movements occur at the tibiofibular joints during dorsiflexon?

Answer 22

• fibula displaced laterally
• increased tension in interosseous membrane and the ligaments
• superior gliding of fibula
• passive movements

Question 23

what is the normal range of movement for dorsiflexion?

Answer 23

20-30 degrees

Question 24

what are the limiting factors of dorsiflexion?

Answer 24

• Lateral collateral ligament
  -Deltoid ligament
• posterior part of joint capsule
• extent of articular surface

Question 25

what is the close packed position of the talocrural joint?

Answer 25

dorsiflexion- there is maximum contact between the talus and the mortise joint