LEG+ANKLE ARTHROLOGY Flashcards
What is the Tibia and fibula connected by
- Superior and inferior tibiofibular joints
2. Interosseous membrane
Movement tibiafibula joint
No active movement between them
slight passive movement ( involves superior,inferior, gliding, rotation) consequence of movement occurring at talocrual (ankle) joint
interosseous membrane
can be called a Fibrous joint in itself
Tight band of fibrous tissue
Runs between the interosseous borders of tibia and fibula, fibres pass inferolaterllay.
Doesn’t reach superior tibiofibular joint but is continuous with the interosseous ligament of the inferior tibiofibular joint
A superior opening transmits the anterior tibial vessles and an inferior opening in the peroneal artery. It separates and gives attachment to muscles of the anterior and posterior compartments of the leg
Functions interosseous membrane
- Strong bond between tibia and fibula- stabilises leg and talocrural joints
- Facilitates movements of the fibula during ankle movements
- Reduces torsional stress on the tibia, fibula acts as a strut-lies parallel to tibia bone reduces tibial fractures
- Separates the muscles of the anterior and posterior compartments of the leg
- Provides a large surface area for muscle attachment (it’s a large flat sheet)
- Stabilises the ankle and leg
Superior tibiofibular joint
Synovial plane joint multi-axial
Joint between anterior superior and medial oval facet on head of the fibula and this articulates with a similar facet on the posterolateral aspect of the inferior surface of the lateral tibial condyle.
Has a fibrous capsule which surrounds articular margins
The joint is supported by 2 ligaments:
- Anterior ligament of the head of fibula –
short, thick, fibrous bands pass obliquely upwards and medially between the anterior aspects of the fibular head and the anterior lateral tibial condyle - Posterior ligament of the head of fibula – single fibrous band passing upwards and medially between the posterior aspects of the fibular head and the lateral tibial condyle
Inferior tibiofibula joint
This is a fibrous joint (syndesmosis) articulation between a rough triangular convex surface on the medial aspect of the lower end of the fibula and fibular notch on the lateral side of the tibia.
Important function: strong union between tibia and fibula provides integrity for the malleolus mortis of the ankle joint.
The joint is supported by 4 ligaments:
- Interosseous ligament – short, fibrous bands passing inferolaterally unites both bones
- Anterior & posterior tibiofibular ligaments – more superficial pass from the borders of the fibular notch to the anterior and posterior surfaces of the lateral malleolus distally and laterally
- Transverse tibiofibular ligament – lies deep to the posterior tibiofibular ligament and attaches to the length of the postero-inferior tibial surface and the upper part of the malleolar fossa
**projects below the bones deepens socket-
They provide stability by deepening the mortice for the trochlear surface of the talus
Talocrural joint
Type: synovial compound hinge uni-axial joint = forms mortis joint
The tibia and fibula are bound together by strong tibiofibular ligaments. Together, they form a bracket shaped socket, covered in hyaline cartilage. This socket is known as a mortise.
(Between distal ends of tibia and superior trochlear surface of talus) (fits within a box)
Talus articulating surface
Body of the talus forms the entire distal surface of the talocrural joint
Trochlear surface of talus: superior aspect of talus convex in A – P direction slightly concave transversely surface and is broader anteriorly than posteriorly. Bounded by medial abd lateral lips
medially articulating with the tibia- medial surface= comma shaped facet tail points backwards is vertical but anterior surface inclines medially-articulates with lateral aspect of medial malleolus of tibia
Latterly articulating with fibula- (larger articular surface) triangular shaped facet runs obliquely anterolaterally which is concave superoinferiorly and anteroposteriorly
Articulating surface tibia
Articular surface on the distal tibia is continuous with the lateral surface of the medial malleolus
Trochlear surface is concave anteroposteriorly
wider latterly and slightly convex transversely
Posterior aspect of the surface projects father distally down the anterior aspect
Articulating surface fibula
Triangular articular surface on the medial side of the lateral malleolus with inferior convex apex
Lateral collateral ligament
Three parts: reinforces joint laterally, trianglar ligament
- Anterior talofibular ligament - flat band of fibres runs between anterior border tip off lateral malleolus and goes anteromedially to neck of talus (injures most)
- Posterior talofibular ligament- strong thick band runs horizontally from malleolar fossa to lateral posterior tubercle of talus blending with joint capsule
- Calcaneofibular talofibular ligament- narrow fibrous cord separate from capsule passes from the posterior tip of the lateral malleolus to the lateral calcaneal surface behind the peroneal tubercle and blends with joint capsule
Not as strong as medial ligament
Medial ligament of ankle
Deltoid
Strong triangular ligament
Attachment: apex attaches to anterior and posterior borders of the tip of the medial malleolus
Divided into deep x1 and superficial x3 fibres
Deep:
1.anterior tibiotalar ligament runs obliquely anteriorly inferiorly attached to the medial side of the neck and body of talus blending with the joint capsule
Superficial:
- tibionavicular- runs anteriorly and inferiorly attaching to navicular tuberosity
- posterior tibiotalar ligament- thick band of fibres inferiorly and laterally stretching across to attatch to the medial side of the talus and medial tubercle of of posterior process of talus
- tibiocalcaneal ligament- inferiorlly attaches from tip of medial malleolus to the entire length of the sustencaculum tali of calcaneous (shelf on calcaneous) and spring ligament= reinforces it
* On tibiocalcaneal ligaments have a continuous attachment from the navicular tuberosity to the sustentaculum tali including the spring ligament
Joint capsule
Fibrous joint capsule completely surrounds the joint acts above the tibia and fibula articulating margin and below talus. Anteriorly attatches to neck of talus.
Thin and weak anteriorly and posterior to allow dorsiflexion and plantar flexion. Posteriorly attaches to tibiofibular ligaments
Strengthened medially and laterally
synovial membrane
lines the capsule and extends superiorly between tibia and fibula as far as the interosseous ligament of the inferior tibiofibular joint
Static stabilisers of ankle joint
Mortise joint
Fibrous capsule of joint
Transverse tibiofibular ligament depending socket posteriorly
Anterior and posterior ligaments (Interacaspular thickenings)
Lateral collateral ligament
Medial collateral (deltoid) ligament
Inferior tibiofibular joint ligament
Interosseous membrane
