Date post: | 08-Apr-2017 |
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The Leg
Presented by Dr. Maryna Kornieieva Asst. of Anatomy
• Orthopedic anatomy• Clinical anatomy• Radiologic anatomy
Leg: Orthopedic Anatomy
Proximal leg: bones
Anterior view: tibia(T) and fibula(F)
Posterior view: tibia(T) and fibula(F)
Medial tibial condyleMedial tibial condyle
Lateral tibial condyle
Tibial tuberosity(patellar ligament)
Intercondilar eminenceFibular Articular facet
Soleal line
Medial surface(subcutaneous)
Anterior border
Medial borderLateral border(interosseous)
Lateral surface Posterior surface
Head
Styloid process
Neck
TT
F
Proximal Tibiofibular Joint
The proximal TF joint is synovial and of little clinical consequence (opposed to the fibrous distal TF joint which is vital to ankle stability)
Proximal Tibiofibular Joint
Distal Tibiofibular Joint
Interosseous membrane
Type: synovial, plane, gliding joint
Type: fibrous joint
Movements: small amount
Movements: small amount
Articulation: lateral condyle of the tibia and the head of the fibula
Articulation: fibular notch at the lower end of the tibia and the lower end of the fibula.
Ligaments:
Anterior and posterior ligaments
Clinical notes
The fibular neck has the common peroneal (fibular) nerve running around it that may be injured by fracture, oedema or compression.
Tibial plateau fractures occur due to a fall from a height, direct trauma, valgus or varus injuries (usually valgus due to lateral trauma causing lateral condyle injury) and minor falls in an osteoporotic patient.
Anterior Intercondilar area
Posterior Intercondylar area
Tibial plateau
Intercondilar eminence
CT (MIP)
Clinical notes
The tuberosity may avulse anteriorly or fragment. It usually responds to conservative treatment.
Osgood-Schlatter’s disease -(epiphysitis) is due to avulsion and inflammation of the soft young tibial tuberosity epiphysis subject to the pull of the powerful quadriceps muscle.
Tibial shaft fractures
1) It is a weight-bearing bone with little surrounding muscle anteromedially (that would improve blood supply for healing).2) There are only skin and periosteum over the bone increasing the chance of an open fracture.3) The fibula may hold the ends of a tibial fracture apart, making healing less likely.
Transverse(hit by a car)
Spiral (torsion injury)
Oblique(direct trauma plus indirect
torsion)
Clinical notes: peripheral pulses must be checked early. If the foot is pale and pulseless, immediate temporary reduction is required.
Treatment: Conservative treatment may be used for stable fractures but otherwise, internal fixation by intramedullary nail or plate is used. Isolated tibial fractures may require fibular osteotomy.
Difficulties:
Distal leg: bones
Eversion injuries to the ankle may cause high fibula fractures (even at the fibular neck) due to sprining of the bone around the distal TF joint as the fulcrum.
Medial malleolus
PosteriorAnterior
Malleolar fossa
Tibialis posterior groove
Flexor hallucis longus groove
Distal TF joint
Peroneus longus groove
Add X-ray Ankle mortise
Lateral malleolus
Distal Tibiofibular JointThe bony mortise keeps the ankle joint very solid but depends on an intact distal tibiofibular joint (if it is not intact then there can be lateral shift of the talus).
Ligaments of the Distal TF joint:
Interosseous ligaments
Anterior inferior tibiofibular lig.
Posterior inferior tibiofibular lig.
Posterior talo-fibular ligament Anterior talo-
fibular ligamentCalcaneo-fibular lig
Clinical notes
Rotational ankle injuries do often cause malleolar fractures: medial one is stressed in hyperinversion, while lateral one – in hypereversion.
Cross-sectional computed tomography scan showing measurement of the anterior, central, and posterior width of the distal tibiofibular joint (normal).
Diastasis is complete disruption of the strong fibrous distal tibiofibular joint. It indicates significant trauma and unstable ankle (a serious injury). This allows lateral shift of the talus and needs fixation.
Leg: Clinical Anatomy
The Leg: regionsis the part of the lower limb between the knee and ankle joint
Anterior region of the leg Posterior region of the leg
Surface Anatomy of the LegAnterior region Posterior region
Superficial veinsLong (greater) saphenous vein forms in front of the medial malleolus and ascends up along the medial side of the lower limb till it opens into the femoral vein 3-4 cm below the inguinal ligament (saphenous hiatus).
Short (lesser) saphenous vein forms behind the lateral malleolus and goes toward the popliteal fossa, there it tributes into the popliteal vein.
There are numerous perforating veins (30-40) connecting superficial veins with the deep along their way. The valves inside the perforating veins allow one-directed blood flow (from superficial veins to the deep).
The vascular wall of the superficial veins is thin and is able to resist only the minimal blood pressure. In case of development of venous hypertension, the wall dilates and become tortures. This state is known as varices, or varicose disease.
Compartments of the legDeep fascia attaches to the periosteum of the anterior and medial borders of the tibia
Anterior Crural Intermuscular Septum
Posterior Crural Intermuscular Septum
Investing Deep Fascia
Transverse Intermuscular Septum
Transverse intermuscular septum separates superficial and deep muscles of the posterior compartment and gives rise to retinacula around the ankle.
Leg: compartments
Muscles:
1. tibialis anterior,
2. extensor digitorum longus,
3. extensor hallucis longus,
4. peroneus tertius;
Blood supply: Anterior tibial artery
Nerve supply: Deep peroneal nerve
Superficial muscles:
1. gastrocnemius,
2. plantaris, and
3. soleus
Deep muscles:
Popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior.
Blood supply: Posterior tibial artery
Nerve supply: Tibial nerve
Anterior Compartment (AC) Posterior Compartment (PC) Lateral Compartment (LC)
Muscles: 1. Peroneus longus, 2. Peroneus brevis;
Blood supply: Perforating branches from the fibular (peroneal) artery
Nerve supply: Superficial fibular (peroneal) nerve
AC muscles: Tibialis AnteriorOrigin:Lateral surface ofshaft of tibia andinterosseousmembrane.
Insertion:Medial cuneiform and base of 1st metatarsal bone.
Nerve Supply:Deep peronealnerve
Action:Extends foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; holds up medial longitudinal arch of foot.
Extensor Digitorum Longus
Action:Extends toes; extends footat ankle joint
Insertion:Extensor expansion of lateralfour toes
Origin: Anterior surface ofshaft of fibula
Nerve Supply:Deep peroneal nerve
Extensor Hallucis Longus
Action:Extends big toe; extendsfoot at ankle joint; invertsfoot at subtalar andtransverse tarsal joints
Insertion:Base of distal phalanx ofgreat toe
Origin:Anterior surface of shaft of fibula
Nerve Supply: Deep peronealnerve
Peroneus (Fibularis) TertiusOrigin:Anterior surface ofshaft of fibula
Insertion:Base of 5th metatarsal bone
Nerve Supply:Deep peronealnerve
Action: Extends foot at ankle joint; everts foot at subtalar and transverse tarsal joints.
Anterior compartment: vessels
Anterior Tibial Artery arises from the popliteal artery within the cruropopliteal canal.
It quits the canal via the anterior outlet (the opening in interosseous membrane) and descends to the foot with the deep fibular nerve.
Branches:1) Anterior tibial
recurrent artery (ascends to the genicular anastomosis);
2) Muscular branches;
3) Anterior (medial and lateral) malleolar arteries (descend to the ankle).
It continues with the dorsal artery of foot.
Anterior compartment: nervesDeep fibular nerve
It one of the two divisions of the common fibular nerve.
Course: It passes through the anterior crural intermuscular septum and descends toward the ankle deep to the extensor digitorum longus.Supplies:
On the leg - all muscles of the anterior compartment;On the foot - extensor digitorum brevis, first two dorsal interossei muscles, + the skin between the great and second toes.
Deep Fibular Nerve Injury
The deep fibular nerve could be damaged as a part of the common peroneal nerve, because last one is extremely vulnerable to injury as it winds around the neck of the fibula.
Injury to the common peroneal nerve (as well as the deep fibular itself) causes foot drop.
Anterior Compartment of the Leg Syndrome
Compartment syndrome occurs with a rise in pressure within a compartment due to many causes but often unrecognized trauma. Symptoms: • Progressive ischemic pain;• Numbness and
paraesthesia;• Swelling and induration in
the leg;• Pale foot.
It is required urgent fasciotomy to avoid muscle necrosis and distal ischemia.
PC musclesSuperficial Deep
Gastrocnemius
Soleus
Plantaris
Tibialis Posterior
Popliteus
Flexor Digitorum LongusFlexor Hallucis Longus
GastrocnemiusOrigin:Lateral head fromlateral condyle offemur and medialhead from abovemedial condyle
Insertion:Via tendo calcaneus into posterior surface of calcaneum.
Nerve Supply: Tibial nerve
Action:
• Plantar flexes foot at ankle joint;
• flexes knee joint.
Soleus
Insertion:Via tendo calcaneusinto posterior surface of calcaneum
Action: Together with gastrocnemius andplantaris is powerful plantar flexor of ankle joint; providesmain propulsive force in walking and running
Nerve Supply: Tibial nerve
Origin:Shafts of tibia and fibula
Ruptured Tendo CalcaneusCommon in middle-aged tennis players
The rupture occurs at its narrowest part, about 5 cm above its insertion.
Symptoms:• Acute pain;• Impossible plantar flexion;• Palpable gape above calcaneus
N
The tendon should be sutured as soon as possible and the leg immobilized with the ankle joint plantar flexed and the knee joint flexed.
Plantaris
Nerve Supply:Tibial nerve
Action:Plantar flexes foot at ankle joint;flexes knee joint Origin:
Lateralsupracondylarridge of femur
Insertion:Posterior surface ofcalcaneum
Plantaris
PopliteusThe popliteus muscle arises inside the capsule of theknee joint and is inserted into the upper part of the posteriorsurface of the tibia.
The tendon separates the lateral ligament of the knee joint from the lateral meniscus so that the meniscus is not tethered to the ligament and is freer to move and adapt to the surfaces of the condyle of the femur and the tibia.
The popliteus muscle is responsible for “unlocking” the knee joint.
Tibialis Posterior
Nerve Supply:Tibial nerve
Origin: Posterior surfaceof shafts of tibiaand fibula andinterosseousmembrane
Action:Plantar flexes foot at anklejoint; inverts foot at subtalarand transverse tarsal joints;supports medial longitudinalarch of foot
Tibialis posterior groove
Flexor retinaculum
Insertion:Tuberosity of navicular boneand other neighboring bones
Tarsal TunnelBoundaries: Contents:
• Tibialis posterior tendon
• Flexor digitorum longus tendon
• Posterior tibial artery• Posterior tibial vein• Tibial nerve• Flexor hallucis longus
tendon
• roof: flexor retinaculum• floor: medial surfaces of the talus and calcaneus
Flexor Digitorum Longus
Nerve Supply:Tibial nerve
Action:
Flexes distal phalanges of lateral four toes; plantar flexes foot at ankle joint;
supports medialand lateral longitudinal arches of foot.
Origin: Posterior surface ofshaft of tibia
Insertion:Bases of distalphalanges oflateral four toes
L R
Flexor Hallucis LongusOrigin: Posterior surface ofshaft of fibula Nerve Supply:
Tibial nerve
Action:Flexes distal phalanx of big toe; plantar flexes foot at ankle joint; supports medial longitudinal arch of foot.
Insertion:
Base of distalphalanx of big toe.
L R
Posterior compartment: vesselsTibialis Posterior artery Peroneal (fibular) artery
Passes downward along the posterior surface of the tibialis posterior, accompanied by deep veins and the tibial nerve.Branches:• Peroneal artery• Muscular branches• Nutrient artery to the
tibia.• Anastomotic branches• Medial and lateral
plantar arteries
It descends behind the fibula, either within the substance of the flexor hallucis longus muscle or posterior to it.
• Muscular branches • Nutrient artery to the fibula• Anastomotic branches (ankle
joint)• Perforating branch (pierces
the interosseous membrane to reach the muscles of the lateral compartment of the leg).
Branches:
1 - a. poplitea; 2 - a. genu sup. lateralis; 3 - a. genu inf. lateralis; 4 - a. peronea (fibularis); 5 - rami malleolares tat.; 6 - rami calcanei (lat.); 7 - rami calcanei (med.); 8 - rami malleolares mediales; 9 - a. tibialis post.; 10 - a. genu inf. medialis; 11 - a. genu sup. medialis.
Palpation of the posterior tibial artery
The point: posterior and inferior to the medial malleolus.
Goal: assessing a patient for peripheral vascular disease.
Deep Veins: Thrombosis
It passes rapidly to the heart and lungs, causing pulmonary embolism, which is often fatal.
DVT - is the formation of a blood clot (thrombus) within a deep vein, predominantly in the legs.
Non-specific signs may include pain, swelling, redness, warmness, and engorged superficial veins.
• Older age;• Major surgery and orthopedic surgery;• Inactivity and immobilization, as with orthopedic
casts, sitting, travel, bed rest, and hospitalization;• Trauma, minor leg injury, and lower limb amputation;• Blood disorders; and others.
Risk factors:
Tibial nerve
• Muscular branches: soleus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior.
• Cutaneous: The medial calcaneal branch supplies the skin over the medial surface of the heel.
• Articular branch to the ankle joint.• Medial and lateral plantar nerves
Branches on the leg:
The cutaneous innervation of the terminal branches of the sciatic nerve.
Tarsal Tunnel SyndromeSymptoms:• Pain and tingling in and around ankles and
sometimes the toes• Swelling of the feet• Painful burning, tingling, or numb sensations
in the lower legs. Pain worsens and spreads after standing for long periods; pain is worse with activity and is relieved by rest.
• Pain radiating up into the leg, and down into the arch, heel, and toes
• Pain along the Posterior Tibial nerve path• Burning sensation on the bottom of foot that
radiates upward reaching the knee• "Pins and needles"-type feeling and
increased sensation on the feet.
TT - is a compression neuropathy and painful foot condition in which the tibial nerve is compressed as it travels through the tarsal tunnel.
Definition:
Peroneus LongusOrigin: Lateral surface of shaft of fibula
Insertion:Base of 1stmetatarsaland the medialcuneiform
Nerve Supply: Superficialperoneal nerve
Action:Plantar flexes foot at ankle joint; everts foot at subtalar and transverse tarsal joints; supports lateral longitudinal and transverse arches of foot.
Peroneus Brevis
Action:Plantar flexes foot at ankle joint; everts foot at subtalar and transverse tarsal joint; supportslateral longitudinal arch of foot.
Origin:Lateral surface ofshaft of fibula
Nerve Supply:Superficialperoneal nerve
Insertion:Base of 5thmetatarsal bone
Tenosynovitis and Dislocation of the Peroneus Longus and Brevis Tendons
Tenosynovitis can affect the tendon sheaths of the peroneus longus and brevis muscles as they pass posterior to the lateral malleolus.
Tendons of peroneus longus and brevis may dislocate forward. For this condition to occur, the superior peroneal retinaculum must be torn.
PL – peroneus longus; PB – peroneus brevis; SPR – superior peroneal retinaculum; IPR – inferior peroneal retinaculum.
Lateral compartment: vesselsNumerous branches from the peroneal (fibular) artery, which passes through posterior compartment of the leg, pierce the posterior fascial septum, and supply the peroneal muscles.
NC-MRA (inflow inversion recovery) shows normal arterial vasculature of the lower extremities. PA, popliteal artery; AT, anterior tibial arteries; PT, posterior tibial arteries; and PER, peroneal arteries.
Nerves The superficial peroneal nerve is one of the terminal branches of the common peroneal nerve
Muscular: to the peroneus longus and brevis
Branches
Cutaneous: • lower part of the
front of the leg;• dorsum of the
foot;• dorsal surfaces of
the skin of all the toes (except the adjacent sides of the first and second toes and the lateral side of the little toe).
It arises in the substance of the peroneus longus muscle on the lateral side of the neck of the fibula, and then descends between the peroneus longus and brevis muscles.
Leg: Radiologic Anatomy
Sectional Anatomy of the Leg
T1-weighted axial image through the upper leg
(fatty tissues bright, fluids dark)
MRI
T2W axial MR image through the upper leg
Note increased signal of all the muscles, in all the compartments. This is edema. There is also some edema of the subcutaneous tissues. It is very unusual for a trauma, for example, to present with edema in all compartments. There are no fluid collections within the muscles, but notice the perifascial fluid collections.(fatty tissues dark, fluids bright)