Week 5 content Flashcards
Describe the articulation of the sacroiliac joint.
Synovial joint, but only sacrum is lined with hyaline cartilage, and ilium is covered in fibrous cartilage
Both sacrum and ilium are irregularly shaped to help the bones interlock with each other
Strong joint capsule and the strongest ligaments in the body support it
Ear-shaped articulation surfaces
Less than 4 degrees of rotation
Compression helps to prevent shear
Name the ligaments of the SI joint.
Interosseus sacroiliac ligaments Posterior sacroiliac ligaments Anterior sacroiliac ligaments Iliolumbar ligament Sacrotuberous ligament Sacrospinous ligament
Describe the interosseus sacroiliac ligaments.
Massive, strong ligaments that unite the sacral and iliac tuberosities
Describe the posterior SI ligaments.
Composed of short and long fibers that connect the sacrum and ilium posteriorly. Blends with the sacrotuberous ligament. AKA long dorsal SI ligament
Most superficially placed
Describe the anterior SI ligaments.
Transverse fibers that support the anterior and inferior portion of the SI joint
Completes the joint capsule anteriorly
Describe the iliolumbar ligament.
Accessory ligament of the SI joint. Supports the L5-S1 joint
Describe the sacrotuberous ligament.
Helps support the SI joint by preventing nutation of the sacrum.
VERY important ligament in SI joint, works with sacrospinous
Longer, more posteriorly, exteriorly, and superficially placed compared to sacrospinous.
Describe the sacrospinous ligament.
Helps support SI joint by preventing nutation
VERY important for SI joint, works with sacrotuberous
Shorter and more anteriorly + deeply placed compared to sacrotuberous
Describe how the SI joint overcomes torque forces.
Weight of body coming down through the spine rotates sacrum anteriorly (nutation)
Ground reaction force through femur rotates ilium posteriorly, which further contributes to nutation.
Creates a locking mechanism to overcome torque
Describe how the SI joint overcomes shear.
Form and force closure - combination of angled joint surface to provide some form closure, and muscular activity of the LE to provide some force closure to counteract weight of body coming down through the spine
SI joint subject to shear forces d/t the vertical orientation of the joint facets, weight-bearing of the body, and gravity
T/F: SI dysfunction is usually a result of impaired load transfer through the SI joints.
True
Nutation of the sacrum is restrained by which ligament?
Sacrotuberous ligament
further enhanced by the action of biceps femoris attachment to ischial tuberosity
Counternutation of the sacrum is restrained by what ligament?
Long dorsal SI ligament
further enhanced by action of the latissimus dorsi through its attachment via the TLF
When is load transfer through the pelvic girdle most effective?
When sacrum is nutated or tilted forward at its superior aspect
What muscles contribute to compression of the SI joint anteriorly and posteriorly?
Latissimus dorsi via the TLF and its contralateral gluteus maximus (posteriorly)
Internal and external obliques (anteriorly)
Describe the classification and articulation of the hip joint.
Synovial joint - ball and socket
Articulation of the head of the femur and the acetabulum of the ox coxae
Describe the acetabulum.
Deepened by the acetabular labrum, which attaches to the bony rim and the transverse acetabular ligament, which spans the acetabular notch, creating the acetabular foramen, which provides passage of blood vessels and nerves to the joint cavity
Describe the femur as it relates to the hip joint.
Attached to the transverse acetabular ligament and the acetabular labrum via the ligament of the head of the femur (AKA ligamentum teres femoris)
Attachment of the ligament is marked on the femur by a small depression called the fovea capitis, where there is no articular cartilage.
Describe how the hip joint ligaments aid in compression of the head of the femur into the acetabulum.
The iliofemoral, pubofemoral, and ischiofemoral ligaments all restrain hip extension by becoming taut in extension, winding around the femur and compressing it into the acetabulum
Loose-packed joint position: ligaments are straight and loose
Close-packed: ligaments are wound and taut in hip extension
Describe the angle of Wiberg.
Shows how much of the acetabular rim surrounds the head of the femur
Made with the line of vertical weight bearing the the plane of the acetabular rim
Normally 25-40 degrees
Name the ligaments of the hip joint capsule.
Iliofemoral ligament (Y ligament)
Ischiofemoral ligament
Pubofemoral ligament
Zona orbicularis
Describe the iliofemoral ligament.
AKA the Y ligament
Extends from AIIS and acetabular rim to the intertrochanteric line
Taut in extension and prevents hyperextension of the hip in standing.
Describe the ischiofemoral ligament.
Extends from acetabulum posteriorly and spirals superolaterally to the neck of the femur and greater trochanter.
Becomes taut in extension and helps prevent hyperextension
Describe the pubofemoral ligament.
Extends from the pubic part of the acetabulum and superior ramus to the lower part of the intertrochanteric line.
It is taut in extension and abduction and helps
prevent excessive abduction
Describe the zona orbicularis.
Capsular fibers that encircle the neck of the femur, cinching down the capsule around the neck of the femur
Thickening of joint capsule that creates an O-ring around the neck
Describe the bursae of the hip joint.
Anteriorly: bursa under the tendon of the iliopsoas
Posteriorly: bursa for tendon of obturator externus
Describe the blood and nerve supply to the hip joint.
Blood - medial and lateral circumflex arteries from profunda femoris, artery to the head of the femur (from obturator artery via acetabular branch in ligamentum teres femoris)
Innervation - femoral, obturator, superior gluteal, nerve to quadratus femoris
What are important functions of the sacrospinous ligament?
Restricting nutation of the sacrum and creating the greater and lesser sciatic notches
Which ligament is best positioned to restrain counternutation?
Long dorsal SI ligament
What movement does the iliofemoral ligament limit?
Hip extension
What is the close packed position of the hip and why?
Full hip extension, because this position draws the strong ligaments of the joint tight, resulting in stability
What structure spans the acetabular notch and creates the acetabular foramen?
Transverse acetabular ligament - consists of strong, flattened fibers which cross the acetabular notch and convert it into a foramen through which the nutrient vessels enter the joint
A football player cuts and turns while running and experiences sudden pain in his knee which makes him fall and is unable to continue playing d/t severe pain and swelling. What components of his knee are at greatest risk for injury?
ACL, MCL, medial meniscus (unhappy triad)
What structure attaches on the tuberosity on the base of the 5th metatarsal?
Tendon of peroneus brevis
Describe the articulation of the knee joint.
Synovial joint of hinge variety with small amount of rotation; largest + most superficial joint
Articular surface of the femur is larger than the surface for the tibia, so some sliding must occur with the femur to maintain contact with the tibia
Strong fibrous capsule
Describe the Q angle.
For evaluating tibiofemoral alignment and the level of varus/valgus stress
Angle between ASIS to patella and tibial tuberosity to patella
Normal: 12-20 with men being on the lower end and women being on the higher end
> 20 would be valgus and <12 would be varus
Describe the extracapsular ligaments of the knee.
Patellar ligament - continuation of quadriceps tendon, strengthens the anterior capsule of the knee
Fibular (lateral) collateral ligament - lateral femoral epicondyle to lateral surface of fibular head; only partially fused with capsule on superior end
Tibial (medial) collateral ligament - medial femoral epicondyle to medial tibia; blends completely with capsule
Arcuate ligament - posterior lateral femoral epicondyle to intercondylar area of tibia; strengthens posterior capsule, Y-shaped
Oblique popliteal ligament - expansion of the semimembranosus muscle, strengthens posterior capsule
Describe how to differentiate between the arcuate and oblique popliteal ligaments.
The arcuate ligament forms an arc over the popliteus tendon and allows it to pass under and be guided between the LCL and the joint capsule to insert into the lateral femoral epicondyle
The oblique popliteal ligament runs parallel to the popliteus muscle
Describe the capsular bursae of the knee.
Suprapatellar - expansion of synovial capsule between the femur and quadriceps tendon; ABOVE patella
Popliteus - expansion of the synovial capsule between the popliteus and lateral tibial condyle (sits underneath popliteus tendon)
Gastrocnemius - expansion of synovial capsule between medial head of gastroc and femur (there is also one under the lateral head)
Subcutaneous prepatellar - between the skin and patella; BEFORE the patella
Subcutaneous infrapatellar - between skin and tibial tuberosity; BELOW patella
Deep infrapatellar - between patellar ligament and tibia
Describe the anterior intracapsular ligament of the knee.
Anterior cruciate ligament - arises from anterior intercondylar area of tibia and extends superiorly, posteriorly, and laterally to attach to the posterior medial side of the lateral femoral condyle
Extrasynovial - synovial capsule lines the fibrous capsule of the knee joint except posteriorly where it is reflected around the cruciate ligaments
Prevents posterior displacement of the femur on the tibia (ANTERIOR DISPLACEMENT OF THE TIBIA ON THE FEMUR) and hyperextension of the knee joint
Describe the posterior intracapsular ligament of the knee.
Posterior cruciate ligament - arises from posterior intercondylar area of tibia and passes superiorly and anteriorly on the medial side of the ACL to the anterior lateral side of the medial femoral condyle
Prevents anterior displacement of the femur on the tibia (POSTERIOR DISPLACEMENT OF THE TIBIA); main stabilizer of the flexed knee during gait
Describe the menisci.
2 fibrocartilaginous discs that deepen the shallow articular fossae of the tibia, allowing for congruency in knee joint
Medial meniscus - C shaped, firmly attached to the MCL, attached along the periphery of the tibial condyle by the coronary ligaments
Lateral meniscus - O shaped, attached to the tibial condyles via coronary ligaments; separated away from the LCL by the tendon of popliteus; posterior meniscofemoral ligament is a strong tendinous extension of the lateral meniscus that attaches to the PCL and medial tibial condyle
Describe blood supply to the menisci.
Lateral third of each meniscus is well supplied (red zone), while medial third is not well supplied (white zone)
Middle third is considered a pink zone with some blood supply
Describe the blood supply and innervation of the knee joint.
Blood - genicular branches from popliteal artery
Innervation - obturator, femoral, tibial, common peroneal nerves
Describe the main articulation of the ankle joint.
Talocrural joint - articulation of the tibia and fibular with the talus
Synovial joint of the hinge variation
More stable in dorsiflexion than plantarflexion d/t talus being wider anteriorly than posteriorly
Tibia articulates with the talus in 2 places
- inferior surface forms the roof of the malleolar mortice, transferring the body’s weight to the talus
- medial malleolus articulates with medial surface of the talus
Describe the other joints of the foot.
Subtalar joint - talocalconeal articulation
Transverse tarsal joint - made up of calcaneocuboid and talonavicular joints
Lisfranc joint - midfoot joint between the metatarsals and cuboid/cuneiforms
Describe the lateral collateral ligaments of the ankle joint.
3 ligaments that attach the lateral malleolus to the talus and calcaneus
Anterior talofibular ligament (ATFL) - lateral malleolus to neck of the talus
Posterior talofibular ligament (PTFL) - lateral malleolus to lateral tubercle of the posterior process of talus
Calcaneofibular ligament (CFL) - lateral malleolus tp lateral calcaneus
What ligaments are damaged in ankle sprains grades 1-3?
Grade 1 - only ATFL
Grade 2 - ATFL and CFL
Grade 3 - ATFL, CFL, and PTFL
Describe the medial collateral ligaments of the ankle joint.
AKA deltoid ligament; consists of 4 parts that attach the medial malleolus to the talus, calcaneous, and navicular
Tibionavicular ligament (TNL)
Anterior tibiotalar ligament (ATTL)
Posterior tibiotalar ligament (PTTL)
Tibiocalcaneal ligament (TCL)
Describe the medial collateral ligaments of the ankle joint.
AKA deltoid ligament; consists of 4 parts that attach the medial malleolus to the talus, calcaneous, and navicular
Describe the blood and nerve supply to the ankle joint.
Blood - malleolar branches of the peroneal, anterior tibial, and posterior tibial arteries
Innervation - derived from saphenous, tibial, sural, superficial, and deep peroneal nerves
What are the most important intertarsal joints?
Subtalar (talocalcaneal) joint
Transverse tarsal joint (calcaneocuboid and talonavicular joints)
Describe the navicular drop test.
Positive - significant change in navicular tuberosity height from NWB (seated) to WB (standing on foot); indicative of insufficient arch/fallen arch
Describe the articulation of the subtalar joint.
Synovial
Articulation of the talus and calcaneus
Permits inversion and eversion of the foot
Describe the transverse tarsal joint.
AKA midtarsal joint; consists of 2 separate joints
Talocalcaneonavicular joint and calcaneocuboid joint
Describe the talocalcaneonavicular joint and its ligament.
Synovial ball and socket
Supported by the plantar calcaneonaviclar ligament (spring ligament) which extends from the sustentaculum tali to the posterior surface of the navicular; important in maintaining longitudinal arch of foot and completes the socket for the head of the talus
Describe the calcaneocuboid joint and its associated ligaments.
Synovial
Long plantar ligament - plantar surface of calcaneus to cuboid and metatarsal heads 2-4; forms a tunnel for passing tendons and supports longitudinal arch
Short plantar ligament - AKA plantar calcaneocuboid ligament; plantar surface of calcaneus to cuboid, assists with longitudinal arch support
Describe the dorsal support to the transverse tarsal joint.
Supported dorsally by the bifurcated ligament (calcaneocuboid and calcaneonavicular ligaments) and the dorsal talonavicular ligament
Where does flexion and extension occur in the forefoot?
In the metatarsophalangeal and interphalangeal joints
Bones of the foot proximal to the MTP joints are united by what?
Dorsal and plantar ligaments
Bones of the MTP and IP joints are united by what?
Lateral and medial collateral ligaments
Describe blood and nerve supply to the foot joints.
Blood - medial and lateral plantar arteries from posterior tibial artery, dorsalis pedis and arcuate arteries from anterior tibial artery
Innervation - medial and lateral plantar nerves from tibial nerve, medial and intermediate dorsal cutaneous nerves from superficial peroneal nerve, deep peroneal n.
Inversion and eversion of the foot occur at which joints?
Subtalar and midtarsal joints
Push-off during gait comes from which joints in the foot?
MTP and IP joints
