Joints + ligaments of patella, tibia, fibula

What are the tibiofibular joints

• Proximal tibiofibular joint

• Distal tibiofibular syndesmosis

• Interosseous membrane (joins shafts of tibia and fibula)

What is the fibre direction of the ligaments and membrane of tibiofibular joints

Oblique fibre direction;

Fibres extend inferolaterally from tibia toward fibula

What do the ligaments and membrane of tibiofibular joints do

Allow upward movement of fibula during dorsiflexion when wide end of trochlea of the talus is wedged between the malleoli. Resist downward pull due to 8 muscle origins

What does the proximal tibiofibular joint articulate with

Head of fibula and fibular articular facet on lateral condyle of tibia

What type of joint is the tibiofibular joint

Plane type synovial joint

What ligaments run through proximal tibiofibular joint

Anterior and posterior ligaments of the fibular head

What movement does the proximal tibiofibular joint do

Slight movement during dorsiflexion of foot due to wedging of trochlea of talus between the malleoli

What is the blood supply of the proximal tibiofibular joint

Inferior lateral genicular and anterior tibial recurrent arteries

What is the innervation of the proximal tibiofibular joint

Common fibular nerve and nerve to popliteus

What is the articulation of the distal tibiofibular syndesmosis

Distal medial surface of fibula and fibular notch of tibia

What ligaments run through the distal tibiofibular syndesmosis

• Interosseous tibiofibular ligament (continuation of interosseous membrane)

• Anterior tibiofibular ligament

• Posterior tibiofibular ligament (inferior transverse tibiofibular ligament)

How is the distal tibiofibular syndesmosis an ankle joint stabiliser

• Keeps lateral malleolus firmly against lateral surface of talus

• Inferior transverse ligament forms posterior wall of the malleolar mortise for the trochlea of the talus

What movements does the distal tibiofibular syndesmosis produce

Slight upward movement during dorsiflexion

Blood supply of distal tibiofibular syndesmosis

Perforating branch of fibular artery, and medial malleolar branches of anterior and posterior tibial arteries

What is the innervation of the distal tibiofibular syndesmosis

Deep fibular, tibial, and saphenous nerves

What is the largest and most complex joint in the body

Knee joint

What type of joint is the knee joint and what movements does it produce

Hinge type synovial joint

• Flexion, extension, gliding, rolling, rotation

What are the 3 joints in the single cavity of the knee

• Lateral tibiofemoral joint

• Medial tibiofemoral joint

• Intermediate patellofemoral joint

What does the lateral tibiofemoral joint contain

• Lateral condyle of femur

• Lateral meniscus

• Lateral condyle of tibia

What does the medial tibiofemoral joint contain

• Medial condyle of femur

• Medial meniscus

• Medial condyle of tibia

What does the intermediate patellofemoral joint contain

• Patella

• Patellar surface of femur

Why is the knee joint mechanically weak

Due to incongruence of its articular surfaces - like 2 balls sitting on a tabletop

What is the tibiofemoral joint like

Medial and lateral condyles of femur articulate with medial and lateral condyles of tibia. Non articular area between condyles - it is the weight bearing joint of the knee

What is the articulation of the patellofemoral joint like

Facets of the patella articulate with the patellar groove on anterior surface of femur

What does the patellofemoral joint allow

The pull of the tendon of quadriceps femurs (the main extensor) to be directed anteriorly over knee without tendon wear and increased leverage

What are the borders of the joint capsule of knee joint

• Superiorly: proximal to articular margins of femoral condyles

• Posteriorly: enclosed condyles and intercondylar fossa

• Opening posterior to the lateral tibial condyle for popliteus tendon

• Inferiorly: margin of tibial plateau

External and internal layers of joint capsule of knee joint

External - fibrous layer

Internal - synovial membrane. Excludes cruciate ligaments and the infra patellar fat pad from articular cavity

What are the 5 extracapsular (intrinsic) ligaments of the knee joint

• Patellar ligament

• Fibular (lateral) collateral ligament (FCL/LCL)

• Tibial (medial) collateral ligament (TCL/MCL)

• Oblique popliteal ligament

• Arcuate popliteal ligament

Where does patellar ligament run

Distal part of quadriceps femoris tendon - from patella to tibial tuberosity

Where does the FCL/LCL run

From lateral epicondyle of femur to lateral surface of fibular head

Where does the TCL/MCL run

Medial epicondyle of femur to medial condyle and superior medial surface of tibia - attached to medial meniscus

What does the oblique popliteal ligament do

Reinforces capsule posteriorly

What does the arcuate popliteal ligament do + where does it run

Strengthens joint capsule posterolaterally. Posterior aspect of fibular head to posterior surface of knee joint

What are the intra-articular ligaments of the knee joint

Cruciate ligaments

What is the course of the cruciate ligaments

Criss-cross within joint capsule, but outside synovial cavity

Medial vs lateral rotation of tibia on femur (regarding cruciate ligaments)

Medial: limited to 10 degrees as ligaments wind around each other

Lateral: unwind, permitting 40 degrees lateral rotation of tibia when knee flexed

What does oblique orientation mean

One ligament or part thereof is always in tension

Attachments of anterior cruciate ligament (ACL)

• Anterior intercondylar area of tibia

• Posterior part of medial side of lateral condyle of femur

What does ACL do

Limits rolling of femoral condyles on tibial plateau during flexion (converts rolling to spin)

What does the ACL prevent

• Posterior displacement of femur on tibia

• Hyperextension of knee

Attachments of posterior cruciate ligament (PCL)

• Posterior intercondylar area of tibia

• Anterior part of lateral side of medial condyle of femur

What does PCL do

Limits rolling of femoral condyles on tibial plateau during extension (converts rolling to spin)

What does PCL prevent

• Anterior displacement of femur on tibia

• Hyperflexion of knee

Which two menisci do we have in knee joint

Medial and lateral

What are the menisci

Crescent shaped fibrocartilage with wedge cross section on articular surface of tibia

What are the menisci anchored and attached to

intercondylar area of tibia and attached to joint capsule

What is the medial meniscus fixed to

Tibia collateral ligament

What do the menisci do

Deepen surface to provide passive joint stabilisation + shock absorption

Which meniscus is smaller?

Lateral - and doesn’t have any extra attachments

How many bursae are around the knee

At least 12

Where is the suprapatellar bursa

Between quadriceps and femur

Where is the subcutaneous prepatellar bursa

Between apex of patella and skin

Where is the infrapatellar bursa

Deep and superficial (subcutaneous):

• Deep between tibia and patellar ligament

• Superficial between patellar ligament and skin

Where is the semimembranosus bursa

Between semimembranosus and gastrocnemius muscles

What is an arthrogram

X-ray of joint with contrast medium or other intervention

How to tell bursitis on an arthrogram

Bursa is inflated with carbon dioxide

How many vessels form what around the knee

10 vessels form peri-articular genicular anastomoses around knee

What do the middle genicular branches of popliteal artery do

Penetrate fibrous layer and supply cruciate ligaments, synovial membrane, and peripheral margins of menisci

What do nerves supplying the muscles crossing the knee joint also supply

The joint

What are the nerves supplying knee and what aspects

• Femoral - anterior aspects

• Tibial - posterior aspects

• Common fibular - lateral aspects

• Saphenous (cutaneous) - medial aspect