Joints and Ligaments of the Lower Extremity and Back Flashcards
Sacroiliac Joint
General Characteristics
Articulations
Ligaments (List)
Movements
General Characteristics:
Stable synovial joint where weight is transferred between the lower limb and the trunk
Articulations:
The auricular surface of the Ilium articulates with the auricular surface of the sacrum. Ridges above the auricular surfaces of both bones interlock with each other
Ligaments:
- Posterior Sacroiliac
- Anterior Sacroiliac
- Interosseous Sacroiliac
- Sacrotuberous
- Sacrospinous
Movements:
Limited to slight gliding and rotation
Ligaments of the Sacroiliac Joint: Attachments and Function
Posterior Sacroiliac Ligament
Thick Broad Band
Runs from the posterior surface of the sacrum to the Iliac Tuberosity
Reinforces the posterior aspect of the joint
Ligaments of the Sacroiliac Joint: Attachments and Function
Anterior Sacroiliac Ligament
Thin band; thinner than posterior iliac ligament
Runs from the Ventral Surface of the Sacrum to the medial part of the iliac fossa
Reinforces the joint anteriorly
Ligaments of the Sacroiliac Joint: Attachments and Function
Interosseous Sacroiliac Ligament
Between the Ilium and the Sacrum
holds the bones together on the irregular surface above the auricular surface of the Iluim
Ligaments of the Sacroiliac Joint: Attachments and Function
Sacrotuberous Ligament
Large band running from the posterior and lateral surfaces of the sacrum and coccyx to the Ischial tuberosity
Works with the Sacrospinous ligament to:
Creates the greater and lesser sciatic foramen
Prevent upward movement of the inferior end of the sacrum due to the downward force of the body weight coming down through the spinal column
Ligaments of the Sacroiliac Joint: Attachments and Function
Sacrospinous Ligament
Runs from the Anterolateral surface of the sacrum to the ischial spine
Works with the Sacrotuberous ligament to:
Creates the greater and lesser sciatic foramen
Prevent upward movement of the inferior end of the sacrum due to the downward force of the body weight coming down through the spinal column
Pubic Symphysis
General Characteristics
Articulations
Ligaments (List)
Movements
General Characteristics:
Fibrocartilaginous, symphyseal joint
Articulation:
Articulation between adjacent symphysial surfaces of pubis bones
There is a fibrocartilaginous disc between the bones
Ligaments:
- Superior Pubic Ligament
- Inferior Pubic Ligament
Movement:
None
Ligaments of the Pubic Symphysis: Attachments and Function
Superior Pubic Ligament
Superior to the Joint
Extends between the pubic crests
Strengthens the joint superiorly
Ligaments of the Pubic Symphysis: Attachments and Function
Inferior Pubic Ligament
Inferior to the Joint and to the disc
Extends between the pubic rami
Strengthens the joint inferiorly
Hip Joint
General Characteristics Articulation Articular Capsule Ligaments (List) Movements Blood Supply
General Characteristics:
Ball and socket type synovial joint
Mobility is sacrificed for stability
Articulation:
Head of the femur articulates with the acetabulum of the hip bone, which is enlarged by a ring of fibrocartilage called the acetabular labrum
Articular Capsule;
Outer fibrous and inner synovial layers
Outer capsule loosely surrounds the joint to allow for greater mobility.
It runs from the acetabulum and acetabular ligament to the intertrochanteric line of the femur anteriorly and the base of the neck of the femur posteriorly
A portion of the synovial membrane protrudes inward forming a bursa.
Ligaments:
- Ligament of the Head of the Femur
- Transverse Acetabular Ligament
- Iliofemoral Ligament
- Pubofemoral Ligament
- Ischiofemoral Ligament
Movements:
Flexion/Extension, Abduction/Adduction, IR/ER, Circumduction
Blood Supply:
Medial and Lateral Circumflex Femoral Arteries
Artery of the head of the Femur
Ligaments of the Hip Joint: Attachments and Function
Ligament of the Head of the Femur
Runs from the acetabulum into the head of the femur
Not very strong
Carries the artery of the head of the femur to the femur - not really for joint support
Ligaments of the Hip Joint: Attachments and Function
Transverse Acetabular Ligament
Runs across the inferior part of the acetabulum where it is deficient.
Ligaments of the Hip Joint: Attachments and Function
Iliofemoral Ligament
Runs from the AIIS to the intertrochanteric line of the femur (superior/anterior aspect of the joint
Shaped like an Inverted Y
Runs a spiral course so that when it gets taught (with extension), it screws the head of the femur into the acetabulum
Limits Hyperextension
Provides major static restraint against gravitational force in quiet standing
Ligaments of the Hip Joint: Attachments and Function
Pubofemoral Ligament
Runs from the Pubis to the fibrous capsule of the hip joint
Blends with the Iliofemoral Ligament - also has a spiral course and contributes to screwing the head of the femur into the acetabulum as the hip goes into extension and the ligaments get taught
Reinforces the capsule inferiorly and anteriorly
Limits hyper abduction
Ligaments of the Hip Joint: Attachments and Function
Ischiofemoral Ligament
Winds around the joint from anterior to posterior, running from the ischial part of the acetabular rim to the neck of the femur posteriorly.
Blends with the joint capsule and runs a spiral course, allowing it to help screw the head of the femur into the acetabulum with extension. This prevents hyperextension at the hip.
Reinforces the posterior aspect of the joint
Knee Joint: General Characteristics
Synovial joint
Modified Hinge
Incongruent shape of articular surfaces leads it to be mechanically weak
Stability of the knee is due largely to surrounding muscles, soft tissue, tendons, and ligaments
The joint has the most congruency with the knee is in extension
Knee Joint: Articulations
The knee is primarily the articulation of the tibia and the femur and is called the tibiofemoral joint.
It can be subdivided into:
Lateral Tibiofemoral - lateral femoral condyle articulates with lateral tibial condyle
Medial Tibiofemoral - medial femoral condyle articulates with medial tibial condyle
The Patella also articulates with the patellar surface of the femur at the patellofemoral joint
The fibula IS NOT involved in the articulation at the knee and is not weight bearing
Knee Joint: Articular Capsule
The fibrous external layer:
Thin, incomplete sleeve.
It attaches to the medial meniscus but not to the lateral meniscus
It has an opening posteriorly for the tendon of popliteus to pass through and attach to the tibia
The Inner synovial membrane:
Lines the fibrous capsule and lines all of the surfaces not covered by the outer fibrous layer
Attaches to the superior and inferior outer margins of the menisci
Centrally, it becomes separated from the fibrous layer
From the posterior aspect of the joint, the synovial layer reflects inwardly making a loop around the cruciate ligaments so that they are excluded from the joint capsule
The cruciate ligaments are not enclosed in the synovial layer
It forms 2 Bursae (pouches) that provide low friction surfaces for tendons:
- Suprapatellar bursa - located superiorly between the distal end of the femur and the quadriceps femoris tendon; continuous with the synovial membrane; muscle slips from vastus intermedius (articular muscle of the knee) attach to it and pull it out of the way so that it doesn’t get impinged when the knee is extended.
- Subpopliteal recess - located posterolaterally; lies betweel the lateral meniscus and the popliteus tendon.
Knee Joint: Structures Reinforcing the Joint Capsule
Anteriorly: Patella Patella Ligament Quadriceps Tendon Medial and Lateral Retinacula (extensions of the insertions of vastus lateralis and medialis)
Posteriorly:
- Arcuate ligament - inserts on the joint capsule and covers the popliteus wehre it runs between the FCL and the knee joint
- Oblique Popliteal ligament - extension of semimembranosus tendon
Medial:
TCL
Pes Anserine Tendons
Lateral:
FCL
Iliotibial Tract
Knee Joint: Ligaments
Patella Ligament
Extracapsular
Thick fibrous band that extends from the base of the patella to the tibial tuberosity
Blends with the Medial and Lateral patellar retinacula
Continuation of the central portion of the quadriceps tendon
Knee Joint: Ligaments
Arcuate Ligament
Extracapsular Ligament
Arises posterior to the fibular head and passes over the tendon of popliteus, the spreads over the posterior aspect of the joint, blending with the capsule.
Supports the knee posteriorly.
Knee Joint: Ligaments
Oblique Popliteal
Extracapsular Ligament
Recurrent expansion of the tendon of semimembranosus posteriorly
Arises posterior to the medial condyle and passes superolaterally toward the lateral femoral condyle
Blends with the central part of the posterior aspect of the joint capsule
Spans the intracondylar fossa of the femur
Reinforces the posterior aspect of the joint
Knee Joint: Ligaments
TCL
Extracapsular Ligament
TCL = Tibial collateral ligament
Flat band that extends from the medial femoral condyle to the medial condyle and surface of the tibia
At the midpoint, its deep fibers attach to the medial meniscus
Reinforces the medial aspect of the joint
Resists valgus forces (lateral to medial); Genu valgum will put stress on TCL
WEAKER than FCL
Knee Joint: Ligaments
FCL
Extracapsular Ligament
FCL = Fibular Collateral Ligament
Cord-like structure that extends from the lateral femoral condyle to the lateral surface of the fibular head
Tendon of Popliteus passes deep to it, separating it from the lateral meniscus.
Reinforces the lateral aspect of the knee joint
Taut in full extension
Varus forces will place stress on FCL (forces going medial to lateral) therefore having genu varus stresses FCL
Knee Joint: Ligaments
Cruciate Ligaments (Overview)
Located within the joint capsule but outside of the synovial cavity
Primary rotary stabilizers of the knee
Both ligaments have an anteromedial and a posterolateral part so both are taut regardless of where you move the knee
Named for where they attach on the tibia
Knee Joint: Ligaments
ACL
Intracapsular Ligament
Extends from the anterior intercondylar area of the tibia to the posterior part of the medial side of the lateral femoral condyle
Resists posterior displacement of the femur on the tibia (and anterior displacement of the tibia on the femur) as well as knee hyper extension.
It is slack in flexion and taut in extension, thogh it is always at least partially taught
It is the weaker of the 2 cruciate ligaments and has weaker blood supply.
Knee Joint: Ligaments
PCL
Intracapsular Ligament
PCL = Posterior Cruciate ligament
Extends from the posterior intercondylar area of the tibia and passes superiorly and anteriorly on the medial side of the ACL to attach to the anterior part of the lateral surface of the medial condyle of the femur
Resists anterior displacement of the femur on the tibia or posterior displacement of the tibia on the femur (like in walking downhill) and resists knee hyper extension
Taut in flexion and slack in extension
Stronger of the 2 cruciate ligaments
Knee Joint: Menisci
Overview
Wafers of fibrocartilage on the articular surface of the tibia
Aid in lubrication, nutrition, shock absorption, and joint congruency; reduce friction during movement
the inner 2/3 are avascular and the outer 1/3 is vascualrized
They cary 40 - 70 percent of the load across the knee
When you squat down (as you flex your knees) the menisci move posteriorly; the lateral one moves more than the medial one
Knee Joint: Menisci
Medial Meniscus
C shaped
On the medial articular surface of the tibia (tibial plateau)
Larger and less mobile of the 2 menisci
It is thicker posteriorly than anteriorly
Anterior and Posterior horns attach to the anterior and posterior intercondylar areas respectively
It is firmly adhered to the deep fibers of MCL
Knee Joint: Menisci
Lateral Meniscus
O shaped
On the lateral tibial plateau
Smaller and more mobile
More equal in thickness throughout
Its horns attache to the intercondylar areas of the tibia (the are closer together
It is separated from the FCL by the popliteus tendon and is therefore more mobile and less likely to be injured
Knee Joint: Ligaments
Posterior Meniscofemoral Ligament
Intracapsular ligament
Joins the lateral meniscus to the PCL and the medial condyle of the femur
only found in about 70% of knees
Knee Joint: Ligaments
Coronary Ligament
Portion of the joint capsule extending from the margins of the menisci to the periphery of the tibial condyles.
They help hold the menisci in place
Knee Joint: Ligaments
Transverse Ligament of the Knee
Runs between the anterior horns of the lateral and medial menisci, crossing the anterior intercondylar area
Tethers the menisci together during movement, and helps prevent the anterior horns of the menisci form moving forward when the knee is being extended.
Only found in about 58% of knees.
Knee Joint: Movements
Primary Movement
Screw Home Mechanism
Primary movement it flexion/extension
Because the lateral femoral articular surface is smaller than the medial articular surface, the lateral part comes in to full extension first, and some rotation is required to bring the medial side of the knee into full extension.
Screw home mechanism:
To lock the knee in a CKC, as the knee comes into extension, the femur passively rotates medially to bring the medial side of the knee into full extension; no help from muscles is required.
To unlock the knee in a CKC, the popliteus muscle contracts to rotate the femur laterally on the tibia about 5 degrees.
To lock the knee in an OKC, the tibia passively rotates laterally on the femur.
To unlock the knee in an OKC, the popliteus contracts to actively rotate the tibia medially on the femur
Knee Joint: Arteries
Descending Genicular branch of femoral artery
Descending branch of lateral circumflex femoral artery
Popliteal artery (gives off genicular branches)
Superior Medial and Lateral Genicular Arteries
Middle Genicular Artery
Inferior Medial and Lateral Genicular Arteries
Reccurrent branches of Anteiror Tibial, Posterior Tibial, and Circumflex Fibular arteries
Knee Joint: Bursae
Bursae of the Anterior Knee
Suprapatellar Bursa:
Continuous with the synovial membrane; lies between the quadriceps tendon and the anterior femur
Subcuatneous Prepatellar:
Between the skin and the patella bone
Subcutaneous Infrapatellar:
Between the skin and the patellar ligament
Deep Infrapatellar:
Lies between the patellar ligament and the tibia
Knee Joint: Bursae
Bursae of the Posterior Knee
Popliteus Bursa:
Continuous with the synovial membrane; lies between the popliteus tendon and the lateral condyle of the tibia
Semimembranosus Bursa:
Lies between the semimembranosus tendon and the medial head of gastrocnemius
Gastrocnemius Bursa:
deep to the proximal attachment of the tendon of the medial head of gastrocnemius
Anserine Bursa:
Separates the 3 tendons that attach at the pes anserine from the medial tibia and the TCL
Proximal Tibiofibular Joint
Joint Type
Articulation
Ligaments and Capsule
Movement
Type: Plane type synovial
Articulation: between the head of the fibula and the lateral condyle of the tibia
Ligaments and capsule: has an articular capsule that is strengthened by anterior and posterior ligaments
Movements: Slight upward movement of the fibula occurs with ankle plantarflexion as the wider anterior part of the talus moves up into the mortise of the ankle at the distal tibiofibular joint. We feel this movement more at the proximal than at the distal joint because the integrity of the mortise must be maintained.
Distal Tibiofibular Joint
Joint Type
Articulation
Ligaments and Capsule
Movement
Type: Fibrous Joint (syndesmosis)
Articulation: fibular notch of the tibia with the medial surface of the distal fibula
Ligaments:
- Interosseous Ligament (continuous with interosseous membrane)
- Anterior and posterior ligaments (posterior ligament has a transverse part that runs between the malleoli forming part of the posterior wall of the mortise of the ankle)
Ankle (Talocrural) Joint
General Characteristics
Articulations
Ligaments (list)
Movements
General Characteristics: Hinge type synovial joint
Joint is formed by the medial malleolus of the tibia, the lateral malleolus of the fibula, and the pulley shaped trochlea of the talus. the fibula is NOT WEIGHT BEARING
The malleoli, along with the inferior transverse part of the posterior tibiofibular ligament form a socket (mortise) into which the trochlea of the talus fits
Articulations:
Between the distal ends of the tibia and fibula (malleoli) and the superior part of the talus
Medial surface of the lateral malleolus articulates with the lateral surface of the talus
Lateral Surface of the medial malleolus articulates with the medial surface of the talus
Ligaments: LCL of the ankle, composed of 1. Anterior talofibular 2. Posterior Talofibular 3. Calcaneofibular **Fibula is a smaller bone so it comes last in the name
MCL of the ankle (aka deltoid ligament) composed of:
- Tibionavicular
- Tibiocalcaneal
- Posterior Tibiotalar
- Anterior Tibiotalar
* *tibia is a larger bone and it forms the malleolus on this side so it comes first in the name
Movements: Dorsiflexion and Plantarflexion (joint is most stable in Dorsiflexion b/c the wider part of the talus is in the mortise)
Important Intertarsal Joints (2)
Subtalar:
Articulation of the inferior surface of the talus with the sustentaculum tali of the calcaneus
Transverse tarsal:
Made up of adjacent talonavicular and calcaneocuboid joints
Ligaments of the Intertarsal Joints: MCL and LCL of the ankle
Anchor the talus onto the calcaneus and the navicular
Ligaments of the Intertarsal Joints: Talocalcaneal Interosseous Ligament
Anchors the talus to the Calcaneus
Ligaments of the Intertarsal Joints: Spring Ligament
Aka Plantar calcaneonavicular ligament
Deep to Tibialis Posterior Tendon
Supports the head of the talus, which is the keystone of the medial longitudinal arch; holds the talus in place
Prevents downward displacement of the talus between the calcaneus and the navicular
Ligaments of the Intertarsal Joints: Long Plantar Ligament
On the lateral side of the foot
supports the calcaneocuboid joint
Ligaments of the Intertarsal Joints: Short Plantar ligament
comes out medially just deep to the long plantar ligament
also supports the calcaneocuboid joint
Movements of the Intertarsal Joints
Inversion:
Occurs primarily at the subtalar joint, and is associated with forefoot supination and adduction at the transverse tarsal joint
Eversion:
Occurs primarily at the subtalar joint and is associated with abduction and forefoot pronation at the transverse tarsal joint
Tarsometatarsal Joints
Articulation
Movement
Articulation of the cuboid and 3 cuneiforms with the bases of the metatarsals
Ligaments are Dorsal , Plantar, and Interosseous
Very little movement; slight gliding
Intermetatarsal Joints
Articulation
Movement
Articulations between adjacent metatarsals
Ligaments are Dorsal , Plantar, and Interosseous
Little individual movement
Metatarsophalangeal Joint
Between heads of metatarsals and bases of proximal phalanges
Have collateral ligaments and strong reinforcing plantar ligaments
Movement:
Flexion/Extension
Abduction/Adduction
Interphalangeal Joints
heads of proximal phalanges articulate with bases of distal phalanges
Have collateral and plantar ligaments
Do flexion/extension
Arches of the Foot: Overview
Act as shock absorbers for supporting the weight of the body and propelling it forward
Make the foot adaptable to changes in surfaces and weight
They resist movement in the opposite direction of force
They are maintained by the shape of the bones, the plantar ligaments, the plantar aponeurosis, and the action of the muscles
Arches of the Foot: Medial Longitudinal Arch
Underneath the tendon of Tibialis Posterior
Composed of the Calcaneus, Talus (keystone of the arch supported by spring ligament), navicular, cuneiforms, and metatarsals (medial 3)
supported by the tendons of tibalis anterior, tibialis posteiror, and fibularis longus
Arches of the Foot: Lateral Longitudinal Arch
Much lower than the medial longitudinal arch
Composed of Calcaneus, Cuboid, and lateral 2 metatarsals
Arches of the Foot: Transverse arch
composed of the cuboid (laterally), cuneiforms, and metatarsals
supported by the fibularis longus tendon
