pathology Flashcards
What muscles are important to target with medial instability?
- flexor carpi ulnaris because of it proximity to the MCL
2. flexor digitorum superficialis because of it proximity and size
What is the most common direction of elbow dislocation?
posteriorlateral rotation of the ulna
How can the redial head cartilage become irritated without a compressive force?
- the capitellum has insufficent cartilage on the posterior surface to accommodate the radial head in extreme hyper extension
- can mimic lateral epicondyalgia
What type of trauma can occur with hyper flexion injury of the elbow?
- coronoid process can jam into the coronoid fossa
2. smaller biceps are more prone to injury
What is the typical mechanism for anterior radial head dislocations?
- the biceps can pull the radial head out of the annular ligament in a flexed pronated elbow position
- in this position you have the least amount of static stability and the radius is fulcroming on the ulna
What redial head pathology is often mistaken for lateral epicondylgia?
carlitage irritation from boney contact of the radial head during hyper extension
Why are children more prone to pulled elbows?
- smaller radial heads
- relatively greater plasticity of cartilage
- immature annular ligaments
How does a “pushed” elbow effect elbow function?
- radial head comes in contact with capitellum prematurely limiting extension
- also have greater compression of the TFCC during supination because of further functional shortening of the radius
What are some common pathologies that disrupt the median nerve?
- fractures of the humerus and distal radius
- dislocations of the elbow or lunate
- laceration of the anterior wrist
- compression at ligament of streuthers, pronator teres, FDS, AIS, carpal tunnel
How does median nerve injury entrapement at the ligament of struthers manifest?
- symptoms; vague pain in the forearm
- motor: pronator teres, FCR, PL, FDS, FDP, FPL, PQ, lumbricals 1 and 2, OP AbPB FPB (Key is FCR)
- sensory: Palmar cutaneous, palmar digital cutaneous
What are some common cuase of pronator teres syndrome?
- lacertus fibriosis or thickening
- hypertrophied PT
- fibrous bands in the muscle
What are the symptoms of the pronator teres nerve entrapment
MEDIAN
1symptoms: vague pain in the forearm
2. motor: (pronator teres), FCR, PL, FDS, FDP, FPL, PQ, lumbricals 1 and 2, OP AbPB FPB
3. sensory: Palmar cutaneous, palmar digital cutaneous
What differential would you expect with pronator teres nerve entrapment?
weakness with pronation with the elbow flexed because you remove pronator teres which should be working fine
What are the clinical finding with anterior interossseus syndrome?
MEDIAN
- motor: (pronator teres, FCR, PL, FDS), FDP, FPL, PQ, (lumbricals 1 and 2, OP AbPB FPB)
- sensory:
- symptoms: proximal forearm pain and weakness
- signs: weak pinch, unable to pinch tip to tip, but collapses into pulp to pulp, weak pronation with elbow flexed
What might you expect to find with CTS?
MEDIAN
- motor: (pronator teres, FCR, PL, FDS, FDP, FPL, PQ), lumbricals 1 and 2, OP AbPB FPB
- senory:palmar digital cutaneous
What makes up the carpal tunnel?
- medially- pisiform and hook of hamate
- lateral- scaphoid tuberosity and crest of trapezium
- floor- lunate and capitate
- roof transverse carpal ligament and palamer carpal ligament that make up the flexor retiinaculum
What are the most common entrapement sites for the radial nerve?
- upper arm or brachial plexus
- posterior interosseus
- radial tunnel
- cheiralgia parasthetica
What clinical findings might you expect with an upper radial nerve injury?
- symptoms: weakness with wrist and elbow extension, loss of wrist stability and inability to grasp
- sensory: limited secondary to overlap with other nerves
- motor: treceps anconeus, brachioradialis, ECRL BRANCHES deep radial ECRB and supinator, post interosseous ED, EDM, ECU, AbPL, EPN, EPL, EI
What clinical finding would you expect with a posterior interosseus entrapment?
- symptoms: poor wrist stability and loss of grasp, wrist drop, inability to abduct thumb
- sensory: none
- motor: (triceps anconeus, brachioradialis, ECRL BRANCHES deep radial ECRB) and supinator, post interosseous ED, EDM, ECU, AbPL, EPN, EPL, EI
What clincal findings would you expect with radial tunnel syndrome?
- symptoms:lateral elbow pain and tenderness over the PIN
2. motor: decrease ECRB or positive long finder test
how do you differentiate between lateral epicondalgia and radial tunnel syndrome?
- tenderness: RTS extensor mass LE lateral epicondyle
- type of pain: RTS dull LE sharp
- resisted supination: RTS painful LE not painful
- response to steriod injection: RTS none LE good
What is the primary site for radial nerve sensory loss?
dorsal web space between first and second web space