Exam 3 Flashcards
Knee Complex
- femoral tibial joint
- patella femoral joint
- within one joint capsule
Distal Femur
- medial and lateral condyles
- intercondylar fossa
- medial and lateral epicondyles
- medial and lateral supracondylar lines
- adductor tubercle
- popliteal surface
- patella articulating surface
Femoral Condyles
- two weight bearing condyles covered with articular cartilage
- separated posteriorly by the intercondylar (femoral) notch: provides area for cruciate ligaments to pass
- separated anteriorly by trochlear groove: the articulating surface with the patella
Femoral Epicondyles
- lateral: proximal attachment for LCL and origin for gastrocnemius
- medial: insertion adductor magnus, proximal attachment for MCL, extends further than lateral
Trochlear Groove
- lies superior to medial and lateral condyles
- articulation site for patella
- lateral trochlear surface has increased height to prevent patella from excessively gliding lateral during knee extension-less likely to dislocate patella due to slight valgus force at our knees
How do ACL and PCL run?
- ACL: superior, posterior and lateral
- PCL: superior, anterior, and medial
- cross each other in an angled way
Proximal Tibia: Landmarks
- medial and lateral condyles are flat on top
- intercondylar eminence (point of bone that sticks up in middle) attachment for ACL, PCL, and horns of medial and lateral menisci
- tibial plateaus
- gerdy’s tubercle: between tibial tuberosity and head of fibula
- pes anserine
- tibial tuberosity: attachment for patellar tendon
- soleal line: soleus, popliteus, tibialis posterior, flexor digitorum longus
Proximal Tibia: Functions
- transfers weight across knee to ankle
- the flat plateaus articulate with femoral condyles
- separated by intracondylar eminences (tibial spines)
- attachment of cruciate ligaments and menisci
- plateaus densely covered with articular cartilage
Menisci of Knee
- medial is more C shaped (attaches to deep portion of MCL-semimembranosus sends attachments to posterior horn) and lateral is more O shaped (no attachment to LCL)
- medial tibial condyle is larger and articulates with more of femur
- wedge shaped fibrocartilage-improves joint congruency and stability and helps maintain joint space (load bearing and shock absorbing)
- attached along periphery of tibial plateaus to medial and lateral superior facets by coronary ligaments
- anchored at horns (on eminences)
- blood supply only to periphery of outer 1/3-none on inner so nutrition comes from synovial fluid
- do not attach to femur
Anterior Knee
- most distal fibers of VM extend further than VL
- VMO pulls patella up and out because it tends to drift laterally
- retinaculum that stabilizes your patella is more stable/thicker/stronger laterally than medially
Patella
- sesamoid bone of quadriceps
- apex inferiorly
- posterior surface is covered with articular cartilage in your body
- does not articulate with tibia-only femur
- posterior surface articulates with trochlear groove through facets
- articular cartilage here is thickest in the body
- odd facet is only in contact with femur when you’re in a deep squat
Articular Capsule
- largest synovial capsule in body
- superiorly attaches to femur above femoral condyles and intercondylar fossa
- inferiorly attaches to proximal tibia and periphery of patella
- cruciate ligaments are extra-synovial but intra-articular (inside capsule, outside synovial lining-so they don’t get bathed in synovial fluid)
- capsule allows passage of popliteus muscle posteriorly
- infrapatellar fat pad
- suprapatellar bursa
Knee Retinaculum
- fibrous tissue that has been described as extension of vastus medialis and vastus lateralis into patella and from patella into medial and lateral sides of tibial condyles
- hold patella in place
- medial and lateral portions
- IT band and lateral retinaculum interconnect so patella is very stable laterally
What’s in the intercondylar region?
- 6 structures
- ACL
- PCL
- horns of meniscus
Cruciate Ligaments
- within joint capsule but outside synovial cavity
- anterior cruciate: anterior intercondylar area of tibia; runs superior, posterior, and lateral to posterior medial side of lateral femoral condyle
- posterior cruciate: posterior intercondylar area of tibia; runs superior, anterior, and medial to anterior lateral side of medial femoral condyle
- ACL becomes taut in extension
- PCL becomes taut in flexion
Medial Collateral Ligament
- broad and flat (makes it harder to tear completely) from medial epicondyle of femur to medial condyle of tibia
- deep fibers attach to medial meniscus
Lateral Collateral Ligament
- cord like from lateral epicondyle to fibular head
- popliteus runs under and biceps femoris tendon splits around LCL-supports knee in varus force
- IT Band also supports knee in varus force also on lateral side
Oblique Popliteal Ligament
- expansion of semimembranosus: comes up and run laterally; strengthens capsule posteriorly (runs same way as popliteal muscle)
- taut in hyperextension
Arcuate Ligament
- runs along posterior aspect of fibular head
- runs superior and medial over popliteus from lateral side and blends with posterior part of joint capsule
- taut in hyperextension
What muscles cross knee joint?
- quadriceps
- popliteus
- gastrocnemius
- gracilis
- hamstrings
- plantaris
- sartorius
- semimembranosus
- IT band
Nerves of Popliteal Region
- sciatic splits into tibial and common fibular above knee
- tibial goes straight behind knee
- common fibular wraps behind neck of fibula and splits into superficial and deep fibular nerves
Popliteal Artery
- continuation of femoral at adductor hiatus
- passes through popliteal fossa
- branches to knee joint and ends by dividing into anterior and posterior tibial arteries
- ends as it goes under popliteus muscle
- branches: superior, medial, and inferior geniculate arteries, medial and lateral to knee supplying cruciate ligaments and synovial membrane
- splits into medial plantar and lateral plantar arteries behind medial malleolus
Interosseous Membrane
- runs from fibula inferior and medially to tibia
- tensile force through IO membrane to transfer force to tibia because fibula doesn’t articulate with femur
- ties fibula and tibia together
Lower Leg Compartments
- anterior
- lateral
- posterior superficial
- posterior deep
- each surrounded by strong layers of fascia
- know which compartment the muscles are in
Posterior Lower Leg Muscles
- superficial: gastroc, soleus, plantaris
- deep: flexor hallucis longus, flexor digitorum longus, tibialis posterior
Lower Legs, Medial/Lateral Beginning and Ending Points
- one that finishes most medial (flexor hallucis longus) starts most lateral in deep leg compartment
- one that ends most lateral (extensor digitorum) ends most medial
- tibialis posterior is in middle
Arteries of Posterior Lower Leg
- posterior tibial artery: from popliteal artery (after popliteal muscle and popliteal artery becomes posterior tibial artery)
- travels to foot under flexor retinaculum
- supplies posterior compartment
- fibular artery: branches from posterior tibial and descends in posterior compartment along intermuscular septum, perforating branches to lateral compartment but artery never goes into compartment
Lateral Compartment Muscles
- fibularis longus
- fibularis brevis
Tibial Nerve in Lower Leg
- innervation to: popliteus, gastroc, soleus, plantaris, FHL, FDL, and tibialis posterior
- becomes medial and lateral plantar nerves in foot
- sensory branches: sural (all sensory) from tibial and common fibular nerves-supply posterior and lateral leg
Superficial Fibular Nerve
- travels around neck of fibula then cuts into lateral compartment to supply it
- between fibularis longus and brevis
- innervates fibularis longus and brevis
- sensory to distal anterior surface of leg and dorsum of foot
PICTURES
- especially in Posterior leg power point
- look at one you drew as well
Fibula
- upper end=head
- apex=styloid process
- articular facet for tibia
- neck
- body
- lower end=lateral malleolus
Proximal (Superior) Tibiofibular Joint
- arthrodial joint between lateral condyle and head of fibula
- single facet on fibular head articulates with tibia
- covered with articular cartilage and connected by joint capsule and anterior and posterior ligaments
- synovial
Tibiofibular Syndesmosis
- distal tibia and fibular form osseous part of syndesmosis linked by: distal anterior and posterior tibiofibular ligament, transverse ligament (extension of IOM-internal to joint), interosseous ligament (extension of IOM-internal to joint)
- nerves go around side, but artery and vein go through membrane
- distal tib-fib joint is syndesmosis: fibrous joint fibers attach directly from tibia to fibula (should be no motion down low and only a tiny bit of gliding at top
Syndesmotic or High Ankle Sprain
- estimated 1-11% of all ankle sprains
- due to widening of ankle mortise as a result of increased length of syndesmotic ligaments after acute ankle sprain
- 40% of patients still have complaints of ankle instability 6 months after ankle sprain
- tibia and fibula spread and now joint is unstable
Deep Fibular Nerve
- begins as branch of common fibular nerve
- passes deep to EHL and anterior to IOM
- travels around neck of fibula then cuts into anterior compartment to supply it
- travels with anterior tibial artery down the middle of leg
- divides into lateral and medial branches at ankle
- supplies all 4 muslces in anterior compartment: tibialis anterior, EDL, EHL, fibularis tertius
- does sensory of web space between toes 1 and 2
Injury to Deep Fibular Nerve
- most common LE neuropathy
- damage can result from: lateral knee injury, inflammation, ischemia, diabetes
- foot drop is often consequence: people drag toes because they can’t dorsiflex ankle
Saphenous Nerve
- cutaneous nerve of anterior compartment
- largest cutaneous branch of femoral nerve
- passes along tibial side of leg with great saphenous vein
- descend behind medial border of tibia
Blood Supply of Lower Leg
- popliteal artery ends with two terminal branches
- anterior tibial artery supplies anterior compartment
- posterior tibial artery supplies posterior compartment
Anterior Tibial Artery
- supplies anterior compartment
- smaller terminal branch
- passes anteriorly through IOM and along anterior tibia
- travels between tibialis anterior and EHL (deep fibular nerve can travel with anterior tibial artery)
- ends between malleoli where it becomes dorsalis pedis artery
Compartment Syndrome
- compression of nerves, blood vessels, and muscle due to bleeding or swelling
- leads to tissue death from lack of oxygenation due to blood vessels being compressed by raised pressure within compartment
- can be divided into acute, subacute, and chronic compartment syndrome
Compartment Syndrome Causes-Acute
- can be medical emergency
- blunt force trauma
- fracture
- vascular puncture
- crush injuries
- cast compression
Compartment Syndrome Causes-Chronic
- not usually medical emergency
- AKA chronic exertional compartment syndrome
- repetitive muscle use (cycling, soccer)
- arterial inflow out paces venous outflow and pressure builds
- eventually leads to ischemia
- subsides with rest
Flexor Retinaculum
- structures that go underneath are Tom Dick and A Very Nervous Harry
- tibialis posterior
- flexor digitorum
- posterior tibial artery
- posterior tibial vein
- tibial nerve
- flexor hallucis longus
Retinaculums
- 2 extensors
- 2 laterals
- 1 flexor
- synovial sheaths need to be able to slide underneath these smoothly
Bones of Foot and Ankle
- tarsals: talus, calcaneous, navicular, cuboid, cuneiforms (medial, lateral, middle)
- metatarsals: 5 bases are proximal, heads are distal, shafts are in middle
- phalanges: 1st toe has proximal and distal and 2-5 have proximal, middle, and distal
Lisfranc Fracture
-one or more MT displace from tarsus
Talus
- convex dome
- articulates with distal tibia and fibula (ankle mortis or ankle joint)
- neck
- head: articulates with navicular (part of trans tarsal joint)
- subtalar joint: articulates with calcaneus (inversion and eversion)
Calcaneus
- heel bone (part of trans tarsal joint)
- articulates with talus above and cuboid anteriorly
- tuberosity
- sustentaculum tali: medial (FHL tendon fits in groove) Identify this on a bone
Tarsal Articulations
- navicular: articulates with talus, cuboid and all 3 cuneiforms
- cuboid: articulates with calcaneous, navicular, lateral cuneiform and base of MT 4 and 5
- cuneiforms: articulate with bases of MT 1-3 and navicular
- metatarsals 1-5: 1-3 articulate with medial middle and lateral cuneiforms; 4 and 5 with cuboid
Talocrural Joint
- distal tibia/fibula with talus
- dorsiflexon/plantar flexon
Subtalar Joint
- talus with calcaneus
- inversion/eversion
Mid Tarsal (Transverse Tarsal) Joint
-navicular and cuboid with talus and calcaneous
Tarsometatarsal Joint
-3 cuneiforms and cuboid with bases of MTs
Plantar Surface Ligaments
- support the arches
- plantar aponeurosis
- long plantar ligament
- short plantar ligament
- spring ligament
Plantar Aponeurosis
- from calcaneal tuberosity and across bottom of foot
- crosses MTP joints to toes
- taut with extension of MTP joints
Long and Short Plantar Ligaments
- long: calcaneus to cuboid and base of MTs (deep, lateral)
- short: calcaneus to cuboid (deep, lateral)
Spring Ligament
- aka plantar calcaneonavicular ligament
- medial
Medial Collateral Ligament
- deltoid
- 4 parts that come together to act as one big fan shaped ligament
- anterior and posterior tibiotalar, tibiocalcaneal, tibionavicular
Lateral Collateral Ligament
- anterior talofibular
- calcaneofibular
- posterior talofibular
- usually sprain these from front to back
Even More Ligaments of Ankle and Foot
- collateral ligaments of MPT, PIP, DIP joints
- transverse metatarsal ligament
- plantar plates at MTP, PIP, DIP (same thing as volar plates-long flexor tendons can slide on them more easily)
- also have cruciate and annular ligaments and an extensor mechanism
4 Layers of Plantar Muscles
- flexor digitorum brevis, abductor hallucis, abductor digiti minimi
- quadratus plantae, lumbricals
- flexor hallucis brevis (2 heads), flexor digiti minimi brevis, adductor hallucis (2 heads)
- palmar interossei (3), dorsal interossei (4)
Dorsalis Pedis Artery
- branches off anterior tibail
- under extensor retinaculum between EHL and EDL
- divides into deep plantar artery: divides between 1st and 2nd MT and posterior to sole of foot
- and lateral tarsal artery: runs across dorsum of foot on lateral side and under extensor digitorum longus: swings out laterally as arcuate then medially and comes back to dorsalis pedis-forms archway
Nerves of Foot
- saphenous: sensory to skin on medial ankle and foot
- superficial fibular: dorsum of foot sensory
- deep fibular: motion to EDB and EHB and sensory to skin between 1 and 2 web space
- medial plantar: sensory to medial side of foot and medial 3 digits and motor to LAFF (lumbrical 1, abductor hallucis, flexor digitorum brevis, flexor hallucis brevis)
- lateral plantar: everything else on bottom of foot and sensory to lateral side of foot 4th toe split with medial plantar
- sural: sensory to skin on lateral foot and heel
- heel is done by tibial nerve before it splits
Archways of Foot
- plantar: lateral plantar and medial plantar
- dorsal: dorsalis pedis, lateral tarsal, arcuate
- off of dorsalis pedis is lateral tarsal, to arcuate, then back to dorsalis pedis
- on plantar side is posterior tibial which splits into lateral and medial which link up with each other
- deep branches link the two arches together