Anatomy Flashcards
1
Q
Elbow stabilisers
A
Primary static stabilizers
- ulnohumeral joint (coronoid)
- medial (ulnar) collateral ligament (MCL)
- anterior,
- posterior and
- transverse bundles
- the MCL provides resistance to valgus and distractive stresses primary restraint to valgus stress in maximal elbow flexion transverse bundle of MCL
- lateral collateral ligament complex
- radial collateral ligament (RCL)
- lateral ulnar collateral ligament (LUCL) function - primary restraint to varus and external stress during full arc of elbow motion origin - - crista supinatoris of
- accessory collateral ligament
- annular ligament - provides stability to the proximal radioulnar joint anatomy
- Secondary static stabilizers
- radiocapitellar joint - this functions as an important constraint to valgus stress the radial head provides approximately 30% of valgus stability this is most important at 0-30 deg of flexion/pronation capsule greatest contribution the capsule on stability occurs with the elbow extended origins of the flexor and extensor tendons
- Dynamic stabilizers includes muscles crossing elbow joint
- anconeus
- brachialis
- triceps
- biceps they provide compressive stability
2
Q
Space of Poirier
A
- center of a double “V” shape convergence of ligaments central weak area of the wrist in the floor of the carpal tunnel at the level of the proximal capitate between the volar radioscaphocapitate ligament and volar long radiolunate ligament (radiolunotriquetral ligament)
- wrist palmar flexion - area of weakness disappears
- wrist dorsiflexion - area of weakness increases in perilunate dislocations, this space allows the distal carpal row to separate from the lunate in lunate dislocations, the lunate escapes into this space
3
Q
Radial Nerve anatomy
A
- The biggest and terminal branch of the posterior cord of brachial plexus . C5-T1 , ·
- Leaves the brachial plexus through triangular interval along with profunda brachii artery
- Passing posteriorly it gives branches in the axilla, to the long and lateral head of triceps
- Passes posteriorly through the spiral grove, gives branches to the triceps medial head,
- Then it passes from medial to lateral posteriorly along piercing the lateral intermuscular septum, to become anterior structure,
- Passing down to the elbow between brachialis and brachioradialis supplying the lateral part.
- It passed down to the elbow giving a branch to both brachialis and brachioradialis and anconeus
- It then divides into PIN and superficial radial nerve. · PIN dives down between two heads of the supinator · Superficial radial nerve passes under the cover of brachioradialis with the radial artery and supplying the skin over the dorsum of first webspace. ·
- PIN – 9 muscle , ECRB, SUPINATOR, ECU, EDM, EDC, APL, EPB, EPL, EIP
4
Q
Median nerve
A
- Medial and lateral cord of brachial plexus by medial and lateral root , C5 –T1
- In the arm no branches ·
- Below the elbow – 4 branches – common flexors , FDS, FCR, PT, PL, · Passess between two heads of PT – AIN – FDP to index and middle finger, FPL, PQ ·
- Then passess down to the wrist – between FDS and FDP · Just 5 cm before the wrist Palmar cutaneous branch supplying the skin over the thenar eminence before it passes in the carpal tunnel
- Within the carpal tunnel it is the most superficial structure, sitting with 4 FDP tendon and 4 FDS tendon ( 34 and 25 ) FPL and the most radial structure in the carpal tunnel and median nerve is the most superficial structure,
- Recurrent motor branch after leaving the carpal tunnel.
- Variation
- within the carpal tunnel
- through the flexor retinaculum ( Trans ligamentous )
- before the carpal tunnel – pre ligamentous o
- Supplies 3 muscle in thenar eminence ( LOAF muscles) -
- Opp polices,
- Abd Poll Bre
- superficial head of FPB. ( Deep head supplied by ulnar nerve )
- Sensory branch to radial 3 ½ digits
- Lateral two lumbricals
5
Q
Ulnar nerve
A
- medial cord of brachial plexus C8 T1
- No branches to the upper arm
- Passes through the cubital tunnel, passes through the medial intermuscular septum, dives down between two heads of FCU
- It passes down to the wrist giving dorsal cutaneous branch before the Gyuns canal and passes through the Guyon’s canal with the ulnar artery, where it could be potentially injured or compressed ·
- It supplies all the small muscle of hand except the LOAF muscle
- Sensation to ulnar 1 ½ digits · Compression at cubital tunnel or Guyon’s canal
6
Q
leg cross section
A
7
Q
A
8
Q
A
9
Q
A
10
Q
Sciatic nerve L4-S3
- Arises from the ventral rami of L4-S3 and descends through the greater sciatic foramen to enter the gluteal region, emerging from below the piriformis more laterally than the inferior gluteal and pudendal vessels
- It descends through the posterior compartment of the thigh and ends by dividing into tibial and CPN, usually just above popliteal fossa
- The nerve lies on the ischium, superior gemellus, obturator internus, inferior gemellus, quadriceps femoris and adductor magnus
- It is overlaid by the LHB
- It does not supply any structure in the gluteal region
A
11
Q
cpn L4-S2
- The smaller terminal branch of sciatic nerve
- It begins just above the apex of the popliteal fossa and descends underneath the medial border of biceps femoris
- It crosses plantaris, lateral head of gastrocnemius, popliteus inside the knee joint capsule and the fibular origin of soleus
- It leaves the fossa, passing into PL where it divides into superficial and deep peroneal nerves
- Before dividing, the nerve gives off 5 branches:
- Cutaneous branches:
- ¡Lateral sural cutaneous nerve (upper lateral half skin)
- ¡Peroneal communicating nerve
- ¡Recurrent genicular nerve(skin over patella)
- Articular branches:
- ¡Superior and inferior genicular nerves
- The CPN supplies no mm
-
A
12
Q
DPN L4-S2
- It begins within PL and winds around the fibular neck deep to EDL
- It enters the anterior compartment by piercing the IOM and descends between EDL and ATT lateral to the anterior tibial vessels
- In the middle of the leg the DPN lies on the IOM between ATT and EH
- At the lower part of the tibia, EHL crosses over the nerve so that 2 mm lie on either side of the nv bundle (ATT, Ehl medially and EDL, PT laterally)
- It supplies the mm of the extensor compartment of the leg: EDL, EHL, PT and EDB
A
13
Q
sPN L4-S2
- It begins in the substance of PL on the lateral side of fibular neck
- It descends first between PL and EDL
- It supplies PL and PB and pierces the deep fascia in the distal 1/3 of the leg
- It divides into medial and lateral cutaneous branches
- Medial branch: skin on the distal part of the anterior leg, skin on the dorsum of the foot (except the 1st web space), the medial side of the big toe and adjacent sides of the 2nd and 3rd toes
- Lateral branch: skin of the dorsum of the foot and adjacent sides of the 3rd, 4th and 5th toes
A
14
Q
Tibial Nerve L4-S2
- It is the terminal branch of sciatic nerve
- It begins just above the popliteal fossa, descends almost vertically through the fossa, lying first on the lateral side of the popliteal artery, then posterior to it and finally medial to it
- The popliteal vein lies between the nerve and artery throughout its course
- At the lower border of the popliteus it passes deep to the tendinous arch of the soleus accompanied by the tibial vessels
- It runs straight down the midline of the calf, deep to soleus, lying on the fibular aponeurosis of FDL
- The nerve accompanies the posterior tibial artery and lies first on its medial side, then crosses posterior to it and finally lies on its lateral side
- It leaves the posterior compartment of the leg under the flexor retinaculum behind the medial malleolus and then divides into the medial and lateral plantar nerves
- The tibial nerve innervates all the mm of the foot except for the EDB (peroneal nerve)
A
15
Q
sural Nerve S1-S2
A
- It descends on the posterior surface of gastrocnemius and unites with the peroneal communicating nerve
- It runs down alongside the saphenous vein behind the lateral malleolus and ends on the lateral side of the little toe
- It is sensory to the posterolateral 1/3 of the leg, the lateral part of the foot and heel and the lateral side of the 5th toe
17
Q
- Flexor retinaculum: it is the distal continuation of 2 sheets of fascia: the deep fascia of the forearm and the fascia over FDS. These 2 sheets come together and later become continuous with the palmar aponeurosis
- Functions of the retinaculum:
- ¡Acts as a protracting and restraining device which is essential to stop bowstringing of the long tendons
- ¡It gives partial insertion to some mm (PL, FCU)
- ¡It gives partial origin to some mm (thenar and hypothenar)
- Attachments:
- ¡Medial: pisiform, hook of hamate
- ¡Lateral: tubercle of scaphoid, ridge of trapezium
- A series of structures pass superficial to the retinaculum into the hand. The most important medial to lateral are:
- ¡FCU (attached to pisiform)
- ¡Ulnar nerve and vessels (close to pisiform)
- ¡Palmar cutaneous branches of the ulnar nerve
- ¡PL (middle of retinaculum)
- ¡Palmar cutaneous branch of the median nerve
A
18
Q
Talus blood supply
- Head: has a large distal articular surface which has 2 facets:
- Medial and lateral
- The inferior surface of the body has 2 articular surfaces:
- Posterior calcaneal and middle calcaneal surface
- ¡The main blood supply is the “artery of the tarsal canal” arising from the posterior tibial artery 1cm proximal to the division into the medial and lateral plantar arteries; it continues to the lateral part of the sinus tarsi where it anastomoses with the artery of the tarsal sinus forming a vascular sling under the talar neck
- ¡A branch of the artery of the tarsal canal known as the deltoid branch supplies the medial aspect of the talar body
- ¡Dorsalis pedis supplies the superior aspect of the talar neck and gives off the artery of the tarsal sinus
- ¡Peroneal artery gives off small branches which form a plexus posteriorly with branches of the posterior tibial artery
A
- Sinus tarsi:
- It is bounded by the talus and calcaneum, the talocalcaneonavicular joint anteriorly and posterior facet of the subtalar joint posteriorly
- ¡It is medially continuous with the much narrower tarsal canal
- ¡It contains the cervical ligament, the 3 roots of the inferior extensor retinaculum and the interosseous talocalcaneal ligament
- ¡Both the sinus and the canal contain blood vessels (nutrition of talus) and nerves
- Anterior tibial artery:
- It supplies structures in the extensor compartment of the lower leg; it descends on the IOM and crosses the lower tibia at the ankle joint midway between the malleoli; initially, it lies between ATT (medially) and EDL (laterally), then between ATT and EHL; the DPN is initially lateral to the artery but passes anterior to it before again becoming lateral
- Posterior tibial artery:
- ¡Lies above travelling downwards on PTT, FDL, the tibia and the ankle joint; it lies deep to gastrocnemius, soleus, flexor retinaculum and abductor hallucis; it ends under the flexor retinaculum by dividing into medial and lateral plantar arteries
- Dorsalis pedis artery:
- ¡It is a direct continuation of the anterior tibial artery; it begins midway between the malleoli and runs anteromedially, deep to the inferior extensor retinaculum between EHL and EDL tendons
