Upper Limb Key Anatomy
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- Borders:
- It is a triangular anatomic area in the anterosuperior aspect of the shoulder, which is defined by the coracoid process at its base, superiorly by the anterior margin of the supraspinatus tendon, and inferiorly by the superior margin of the subscapularis tendon
- Contents = biceps tendon, CHL, SGHL
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- Spaces and Intervals of the Shoulder
- Triangular space — Contains circumflex scapular artery
- Quadrangular space — Contains axillary nerve and posterior circumflex humeral artery
- Triangular interval — Contains radial nerve and profunda brachii
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- Normal ratio is 2:1 glenohumeral joint to scapulothoracic movement
- Failure of mechanics in either component will lead to impingement
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- 7 structures: 4 ligaments and 3 muscles
- 3 muscles: Pectoralis minor, short head of biceps, coracobrachialis
- 4 ligaments: CAL, CCL, CHL, Transverse scapular ligament (covers suprascapular notch for suprascapular nerve)
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- Consists only of the short head of biceps and coracobrachialis
- Pectoralis minor is not part of the conjoint tendon
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- Boundaries: Pronator teres, brachioradialis, transepicondylar line
- Contents: Biceps tendon, artery, nerve (TAN; nerve most medial)
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- The axillary nerve branches from the posterior cord (C5 - T1)
- Descends in the axilla posterior to the axillary artery and anterior to the subscapularis
- It emerges from the axilla at the lower border of the subscapularis, traversing the quadrangular space
- Divides into 3 terminal branches:
- Articular branch — supplies the glenohumeral joint
- Posterior terminal branch — innervates posterior deltoid and teres minor; also supplies skin over the inferior deltoid as the upper lateral cutaneous nerve of the arm
- Anterior terminal branch — winds around the surgical neck of the humerus to innervate the anterior aspect of the deltoid muscle; terminates with cutaneous branches to the anterior and anterolateral shoulder
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- Divided by the pectoralis minor into 3 parts - STL, SAP:
- 1st part: Superior thoracic artery
- 2nd part: Thoracoacromial, lateral thoracic artery
- 3rd part: Subscapular artery (gives rise to circumflex scapular artery), posterior and anterior humeral circumflex
Hip Anatomy
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- Inguinal ligament superiorly, Adductor Longus medially, Sartorius laterally
- Contents: VAN - Vein, Artery, Nerve
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- L2/3/4 - femoral nerve
- L4/5/S1 - Superior gluteal
- L5/S1/S2 - inferior gluteal
- L4/5/S1/S2 - sciatic nerve
- Implications of this info is in foot drop. How to differentiate CPN vs L5? Check other nerves supplied by same roots:
- Tibial nerve - posterior tibialis
- Superior gluteal - check hip abduction
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- Think of it as nerves and their associated structures (if any)
- The 2 structures exiting from the greater sciatic notch go around the sacrospinous ligament and enter the lesser sciatic foramen
- Greater sciatic foramen -
- Above piriformis - Superior gluteal nerve and artery
- Below piriformis - 5 nerves and associated
- 1. Sciatic nerve
- 2. Inferior gluteal nerve (+ artery)
- 3. Nerve to QF
- 4. Nerve to OI (+ OI tendon) [Re-entrance]
- 5. Pudendal nerve (+ internal pudendal artery) [re-entrance]
- Lesser sciatic foramen -
- Nerve to OI (+OI tendon)
- Pudendal nerve (+internal pudendal artery)
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- Main blood supply is the Medial Femoral Circumflex Artery
- MFCA + LFCA + superior gluteal artery + inferior gluteal artery = Extra-capsular ring ➔ Ascending cervical arteries (aka Retinacular arteries) ➔ Intracapsular ring ➔ Penetrates head and gives rise to epiphyseal artery network
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- Based on Seminal paper by Trueta in 1957 cadaveric study:
- Birth to 3 years = Metaphysial artery and Lateral epiphyseal artery
- 4yr - 8yr = Lateral epiphyseal artery sole blood supply, metaphysial vessels diminish (unable to penetrate through physis)
- 8yr - Puberty = Lateral epiphyseal + Ligamentum teres
- Puberty to adulthood = Lateral epiphyseal + ligamentum teres + metaphysial artery
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- Piriformis - nerve to piriformis
- Gemellus Superior - nerve to OI
- OI - nerve to OI
- Gemellus Inferior - nerve to QF
- QF - nerve to QF
Knee Anatomy
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- Layer 1 = ITB and biceps femoris
- CPN in between layers 1 and 2
- Layer 2 = Patellar retinaculum and Lateral patellofemoral ligament
- Layer 3 [=PLC] =
- Superficial = LCL, ALL;
- Lateral geniculate artery between superficial and deep layers
- Deep = Popliteofibular ligament, Popliteus, capsule, arcuate ligament
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- Layer 1 = Sartorius
- Pes Anserinus is between Layers 1 and 2
- Layer 2 = Superficial MCL, MPFL, Posterior oblique ligament
- Layer 3 = Deep MCL, capsule, coronary ligaments
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- 3 main structures = LCL, Popliteofibular Ligament, Popliteus tendon; the rest are secondary
- PLC consists of both dynamic and static stablizers
- Static (4 ligaments) = LCL, popliteofibular ligament, flabellofibular ligament, arcuate ligament
- Dynamic (3) = Popliteus, biceps femoris and lateral head of gastroc
- + posterolateral capsule
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- Static and dynamic stabilizers
- Static - (4) ligaments - sMCL, dMCL, Posterior Oblique Ligament, Oblique popliteal ligament
- Dynamic - (2)semimembranosus, medial head of gastrocnemius
- + Posterior horn of medial meniscus
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- Tibioperoneal trunk ➔ PTA and PPA
- ATA branches off first
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- AVN - artery, vein, nerve (artery is deepest)
- Boundaries - diamond
- Popliteal artery bifurcations genicular arteries; Anterior tibial, posterior tibial which gives peroneal artery
- Vein tributuries - short saphenous vein drains into politeal vein
- Nerve branches - sural nerve following small saphenous vein
Ankle Anatomy
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- ATFL, PTFL, CFL
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- Deep Deltoid ligaments (2) = Deep posterior Tibiotalar ligament, Deep Anterior Tibiotalar ligament, [Deep deltoid = TT ligaments]
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- 'Constant fragment' – Anteromedial fragment consisting of sustentaculum tali and middle facet. FHL runs under
- 3 ligaments attach to sustentaculum tali = tibiocalcaneal ligament, talocalcaneal, calcaneonavicular (spring ligament)
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- AITFL, PITFL, ITL (inferior transverse ligament posteriorly), IOL, Accessory Anterior inferior Tibiofibular ligament (Accessory AITFL) aka Bassett's ligament
Hand Anatomy
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- Boundaries - 1st and 3rd extensor compartments, floor is scaphoid, proximal is radial styloid, apex is base of thumb
- Contents = Radial artery, Cephalic vein
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- Ulnar artery - 80% of hand
- Forms superficial palmar arch and deep palmar arch
- Radial artery - 20%
- Gives off superficial palmar branch → becomes superficial arch which anastomoses with ulnar artery
- Becomes the deep palmar branch → becomes deep palmar arch
- Deep palmar arch mainly from Radial artery [Kaplan's Line]
- Superficial palmar arch mainly from ulnar artery
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- Proximal transverse arch - Rigid, formed by proximal carpal bones
- Distal Transverse arch - Flexible; formed by the metacarpal heads
- Longitudinal arch - Flexible
- Purpose of arches is to allow hand to conform to objects being held to increase stability
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- 3 palmar unipennate interosseous - PAD adductors (3 only because thumb has adductor pollicis)
- 4 dorsal bipennate interosseous - DAB abductors
- Both interosseous muscles arise from metacarpals and attach to lateral bands
- Lumbrical muscles originate from radial aspect of FDP tendons and attach to radial aspect of lateral bands of extensor expansion - they are the only muscles that originate and insert on tendons
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- Can be described with the Lichtman Oval theory
- Distal carpal row - fixed unit due to strong interosseous ligaments; acts as one unit
- Proximal carpal row - No tendon attachments; "intercalated segment" between radius, ulna and distal carpal row
- The apex of the oval is the capitate and the base of the oval is the lunate which acts as an intercalated torque converter between the scaphoid and the triquetrum
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Bind them on your heart always; tie them around your neck. Proverbs 6:21