Lower Limb Joints Flashcards
Classify all the joints of the lower limb
All are synovial except inferior tibiofibular joint
Classify hip joint accord to type, articular surface and stability
Type-Synovial ball & socket
Acetabulum and head of femur
Most stable joint because:
1. Shape of articular surfaces(deep acetabulum and small head, labrum increases concavity to prevent dislocation)
2. strong ligaments
3. Surrounding muscles
4. Atmospheric pressure
3 Accessory ligaments of the hip joint and their function
1.Iliofmeroal- preventing hyperextension
2. Pubofemoral- prevents hyper abduction
3. Ischiofemoral- prevents excessive medial rotation
Classify knee joint( include type, articular surfaces etc)
Synovial condylar, biaxial
Femoral and tibial condyles and patella
modified hinge( allows some med and lat rotation)
Describe the stabilty of the knee joint
relatively weak due to incongruency of articular surfaces
static= bones and ligaments, dynamic= muscles and tendons
**Ligaments:
1.capsular- fibrous capsule and is lined by synovial membrane{forms suprapatellar bursa)
2.ligamentum patellae- connects a
Functions of the knee menisci
1.Adapt femoral condyles to tibial condyles
2. Absorb shocks
3. Lubricate the articular surfaces
-Medial meniscus is more liable to injury because it is fixed( it is attached to the capsule and to medial collateral ligament)
Ligaments of the knee joint and function
- Medial(tibial) collateral - extends from medial epicondyle of femur to medial condyle of tibia
- Lateral(fibular) collateral - from lateral epicondyle of femur to styloid process of fibula
They prevent side to side displacement of the tibia
- Capsular ligament- deficient anteriorly
- Ligamentum patellae- tendon of insertion of quadriceps femoris
Inside:
1. Anterior cruciate ligament (ACL)- prevents hyperextension and displacement of tibia anteriorly
2. Posterior cruciate ligament (PCL)- prevents hyperflexion and posterior displacement of tibia
Factors maintaining knee joint stability
static= bones and ligaments, dynamic= muscles and tendons
Muscular factors:
-Strength and action of the surrounding muscles
-medial and lateral vastal retinacula
-ITB stabilizes slightly flexed knee
Ligamentous factors:
-Oblique polpiteal and collateral ligaments maintain side to side stability and stability in flexion
-Cruciate ligaments maintain anteroposterior stability
Bony factors:
-Intercondylar eminence of the tibia projects into intercondylar notch of femur preventing side to side displacement.
What are the relations of the knee joint?
Anteriorly:
-prepatellar bursa, patellar ligament, patella, patellar nerve plexus.
Anteromedially:
-Medial patellar(vastal) retinaculum
Anterolaterally:
-lateral patellar retinaculum and ITB
Posteriorly:
-Popliteal vessels, tibial nerve and oblique popliteal ligament
Posterolaterally:
-Tendon of biceps femoris, common peroneal nerve, lateral head of gastrocnemius and plantaris.
Posteromedially:
-Sartorius, gracilis,semitendinosus( pes anserinus), semimembranosus, medial head of gastrocnemius and popliteus
Describe the bursae around the knee joint.
Anterior bursae:
(a) subcutaneous prepatellar bursa(housemaid’s bursa)- in front of patella
(b) subcutaenous infrapatellar bursa- between skin and tibial tuberosity
(c) Deep infrapatellar bursa- between ligamentum patellae and upper part of tibia
(d) Suprapatellar bursa- upward extension of synovial membrane. Lies between lower part of femur and lower part of quadriceps femoris.
2. Lateral bursae:
(a) Bursa between fibular collateral ligament and biceps tendon.
(b) Bursa between lateral condyle of tibia and popliteus tendon-communicates with joint cavity
(c)Bursa between popliteus tendon and fibular collateral ligament
3. Medial bursae:
(a) Bursa between tendon of semimembranosus and medial collateral ligament
(b) Anserine- separates tendons of S.G.S from each other and from tibial collateral ligament
(c) Bursa between tendon of semimbranosus and medial condyle of tibia- may communicate with knee joint.
4. Posterior bursae:
(a) bursa between lateral head of gastrocnemius and capsule of joint.
(b) bursa between medial head of gastrocnemius and capsule of joint- brodie’s bursa
Describe the movements that occur at the knee joint.
- Flexion(hamstrings) and extension(quadriceps femoris)- differs from normal hinge movements; transverse axis is not fixed and there is conjunct rotation of the knee. Occur above menisci.
- Medial and lateral rotation- usually occur with flexion and extension (conjunct rotations) but may occur independently if the knee is flexed (adjunct rotations). Occur below menisci
Describe locking and unlocking mechanism.
1.Locking:(screw home mechanism)
When the foot is on the ground, medial rotation of femur on tibia during terminal phase of extension.Brought about by quadriceps femoris. When the knee is locked it becomes rigid and all the ligaments are taut.
** 2.Unlocking:**
When the foot is on the ground, Lateral rotation of femur on tibia during initial phase of flexion. Brought about by popliteus.Tight ligaments are untwisted therefore movement can occur. Unlocked knee can further be flexed.
during locomotion, locking and unlocking occurs simultaneously.
locking of the knee is essential for bearing load durin erect posture.
Name the chief muscles producing movement at the knee joint.
Flexion- semimembranosus, semitendinosus, biceps femoris ; popliteus(initiates flexion), sartorius, gracilis, gasrocnemius, plantaris
Extension- Quadriceps femoris ; TFL
Medial rotation- semitendinosus, semimembranosus, popliteus ; sartorius, gracilis
Lateral rotation- biceps femoris ; glut. max, TFL
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Unhappy triad
- Tibial collateral
2.medial meniscus - Anterior cruciate ligament
Describe the blood supply of the knee joint.
Arterial anastomosis around the knee:
1. 5 genicular branches of popliteal artery.
2. descending genicular branch of femoral artery
3. descending branch of lateral circumflex femoral artery
4. two recurrent branches of anterior tibial artery.
5. circumflex fibular branch of posterior tibial artery
Describe the nerve supply of the knee joint.
- femoral nerve through its branches to vasti (especially vastus medialis)
- tibial and common peroneal through their genicular branches
- obturator nerve through its posterior division
rich nerve supply
clinical correlation of knee joint
1.Injuries to cruciate ligaments- ACL is more prone to injury
2.Injury to menisci- medial meniscus is more prone to injury because it is more fixed.
3.Osteoarthritis
Classify the tibiofibular joints and state their innervation
1.Superior-synovial plane ; nerve to popliteus and recurrent genicular
2.Middle- fibrous ; nerve to popliteus
3.Inferior- fibrous syndesmosis ; deep peroneal, tibial and saphenous nerves.
Classify ankle joint (talocrural)
include type, variety and articulating surfaces
Synovial hinge joint
articular surfaces:
-Proximally- lower end of tibia including medial malleolus, lateral malleolus and inferior transverse tibiofibular ligament(form deep tibiofibular socket/mortise)
-Distally- trochlear surface of body of talus
discuss the stability of the ankle joint mentioning factors maintaining it.
trochlear surface of talus is wider superiorly thus more stable during dorsiflexion
Factors:
1. close interlocking of articular surfaces
2. strong medial and lateral collateral ligaments
3. deepening of tibiofibular socket posteriorly by the inferior transverse tibiofibular ligament.
4. tendons( 4 in front, 5 behind) crossing the ankle joint
5. other ligaments
Name the relations of the ankle joint.
Anteriorly: from medial to lateral
1.Tibialis anterior
2.extensor Hallucis longus
3.Anterior tibial Artery
4. Anterior tibial Nerve(deep peroneal)
5. extensor Digitorum longus
6. Peroneus tertius
The Himalayas Are Not Dry Plateaus
Posteromedially: medial to lateral
1. Tibials anterior
2. flexor Digitorum longus
3. posterior tibial Artery
4. posterior tibial Nerve
5. flexor Hallucis longus
- The Doctors Are Not Here*
What is the neurovascular supply of the ankle joint?
Arterial: anastomosis around the ankle; by malleolar branches of anterior tibial, posterior tibial and peroneal arteries
Innervation: branches of deep peroneal and tibial nerves (segmental is L4,5,S1,2 spinal nerves)
Describe the Movements of the ankle joint and muscles responsible.
- Dorsiflexion- tibialis anterior ; EDL, EHL and PT (maximum congruence of articular surfaces and tension of ligaments)
- Plantar flexion- gastrocnemius and soleous ; plantaris, TP, FHL, FDL
When the foot is in plantar flexion, ankle joint permits some degree of side to side gliding, rotation,adduction and abduction
Describe the clinical anatomy of the ankle joint.
- Pott’s fracture- occurs during forced evertion. (a) Oblique fracture of lateral malleolus due to internal rotation of tibia.
(b) transverse fracture of medial malleolus due to pull by strong deltoid ligament.
(c) fracture of posterior margin of lower end of tibia because its carried forward.
Identify and classify the joints of the foot.
1.talo-calcaneo-navicular-Synovial ball & socket
