trochlea arc of articular cartilage, how many degrees?
distal humerus articular surface: rotation? tilt? varus/valgus?
5 degrees IR 30 deg anterior tilt valgus 6-8 deg
what is the carrying angle of the elbow? (definition and value)
angle between long axis of humerus and long axis of ulna. 10-15 deg in males, 15-20 deg in females (valgus)
radial head safe zone: defintion and importance
arc between lister's tubercle and radial styloid - roughly 90 degree arc. safe placement of screws to avoid impingement
radius anatomic bowing: in what plane(s) and how much? where is the apex of curvature?
coronal, 10 deg, apex mid-radius (radial side) saggital, 4.7 degrees, apex dorsal, proximal shaft
anteromedial facet of coronoid: how much is unsupported by ulnar metaphysis?
PUDA: what is it and how much?
proximal ulna dorsal angulation 5.7degrees apex dorsal, about 47mm from tip of olecranon
what attaches to the coronoid tip?
LCL complex of elbow: name the components, origins, insertions
LUCL: lat epicondyle to supinator crest
LRCL: lat epicondyle to annular ligament
annular ligament - from margins of sigmoid notch of proximal ulna
MCL complex of elbow: name the components
anterior bundle of the MCL of elbow: name the components. When is each component most susceptible to injury?
anterior, central posterior BANDS
anterior: in elbow extension
posterior: in elbow flexion
central:iosmetric, doesnt matter
what provides elbow valgus stability? at what ROM?
intrinsic bony restraint: <20 or >120 degrees
anterior bundle of MCL: from 20-120 degrees
list the elbow primary stabilizers
list the elbow secondary stabilizers
CEO and CFO
name the primary and secondary stabilizers to axial loading of the forearm
primary: radial head
secondary: TFCC, IOM
the forearm IOM: which part is most important?
central part. the middle ligamentous complex.
name all forearm muscles innervated by the median n., its origin and insertion
(excluding the ones innervated by the AIN)
pronator teres: from CFO to lateral radius
FCR: from CFO to base of MT2 and 3
palmaris longus: from CFO to flexor retinaculum
FDS: from CFO to base of middle phalanges 2-5
name all the forearm muscles supplied by the AIN, origins and insertions
FDP (radial 2 digits): proximal ulna and IOM to base of distal phalanges 2-5
FPL: proximal radius/IOM to base of distal phalanx of thumb
PQ: medial distal ulna to lateral distal radius
explain gantzer's accessory FPL and clinical significance
accessory head of FPL sometimes found
can cause compression of AIN
what muscles make up the mobile wad? Origins, insertions, innervation
BR: lateral supracondylar ridge to radial styloid - radial n
ECRL: lateral supracondylar ridge to dorsal base of MC2-radial n
ECRB: lateral epicondyle to dorsal base of MC3 - PIN
list the superficial extensors of the forearm: origins, insertions, innervation
anconeus - lCEO to olecranon. radial n
EDC - CEO to extensor hood. PIN
EDM - CEO to extensor hood. PIN
ECU - CEO to dorsal base of MC5. PIN
deep extensors of the forearm. origins, insertions, innervation
supinator. origin=LCL, lateral epicondyle, supinator crest. insertion=radial shaft. PIN
APL - from proximal ulna/radius/IOM to base of 1st prox phalanx. PIN
EPB - from proximal radius/IOM to base of proximal phalanx of thumb
EPL - from proximal ulna/IOM to thumb distal phalanx. PIN
EIP - from distal ulna/IOM to extensor hood. PIN
list the contents of each wrist extensor compartment
1: APL, EPB
2: ECRL, ECRB
4: EDC, EIP (PIN lies outside the compartment, deep to it)
describe the path of the radial artery from start to finish including all its main branches
brachial artery in antecubital fossa branches into radial artery
radial artery gives off recurrent branch right away, just distal to biceps tendon. This travels backwards between BR and brachialis (alongside the radial n)
radial a continues at proximal forearm between BR and pronator teres. It stays under BR (between deep and superficial flexors)
at wrist it gives off superficial palmar branch, which pierces the thenar eminence and enters the palm
then the rest of the radial a turns laterally and enters snuffbox, then pierces between the two heads of the first dorsal interosseus
then it goes between the two heads of the adductor pollicis anteriorly, and then becomes the DEEP palmar arch
describe the path of the ulnar artery form start to finish
brachial a branches in antecubital fossa into ulnar a
lies deep to pronator teres
ulnar a gives off common interosseous artery which branches into the anterior and posterior IO artery - these pass on either side of the IOM. the posterior IO artery passes through a hole at proximal end of IOM to get to dorsal side. anterior IO artery travels with AIN. posterior IO artery goes down to the wrist between superficial and deep extensors, where it runs with the PIN under the 4th compartment.
ulnar a then continues between FDP and FDS. proximally it runs alongside median n (but median n dives between heads of pronator teres)
distally at wrist, travels with ulnar n between FDS and FCU tendons (along with ulnar n)
enters guyons canal - artery stays medial to n
becomes superficial palmar arch
describe the path of the median n from the elbow to the end, including the AIN
lies medial to brachial artery in arm, enters antecubital fossa and passes between heads of pronator teres
runs between FDP and FDS (same plane as ulnar n, ulnar a)
then emerges between FDS and FPL, gives off palmar cutaneous branch
then enters the carpal tunnel, then divides to the fingers
AIN branches from median n at variable point as it passes between pronator teres heads. Lies on IOM between FDP and FPL. travels with Anterior IO artery. terminates at PQ
what is AIN syndrome? how does it present?
AIN compression neuropathy or neuritis
presents with weakness of things supplied by AIN: FPL, FDP2 and FDP3, normal sensory function.
explain the supracondylar process and the ligament of struthers. clinical significance?
rare residiual supracondylar process on ulnar side of distal humerus
vistigial fibrous band connects it to medial epicondyle=ligament of struthers
median n passes deep to it.
it can cause median n compression
distinguish from pronator and AIN syndrome by also having pronator weakness
list the sites of median n compression including AIN
supracondylar process/ligament of structers
gantzer's accessory FPL
describe the path of the ulnar nerve from the upper arm to the end
travels along anterior aspect of medial IM septum in upper arm, piercing it to the posterior side via arcade of struthers (8-10cm prox to medial epicondyle), then travels up against medial triceps head.
goes behind medial epicondyle, enters cubital tunnel
exits tunnel, passing into forearm between heads of FCU
penetrates deep flexor-pronator aponeurosis
travesl between FDS and FDP along with ulnar a (ulnar to it)
emerges between FDS and FCU tendons at wrist, enters guyon's canal
bifurcates in the hand in guyon's canal into 3 zones:
zone 1: proximal to bifurcation - affects both sensory/motor
zone 2: deep motor branch only (supplying intrinsics)
zone 3: sensory branch - supplies ulnar side of hand