Wrist Instabilities

Question 1

Carpal instability

Answer 1

dislocation or loss of contact between bones of the distal carpal row over the proximal carpal row in relation to the radioulnar joint

Question 2

Radioulnar motion - radial deviation

Answer 2

distal row - radial

proximal row - ulnar

Question 3

Radioulnar motion - ulnar deviation

Answer 3

distal row - ulnar

proximal row - radial

Question 4

DTM

Answer 4

Dart Throwing Motion

involves a combination of wrist extension in radial deviation and flexion with ulnar deviation

Question 5

DTM and SLIL

Answer 5

DTM pattern produces minimal elongation and thus minimal tension the the volar and dorsal SLIL

Question 6

Load distribution on the carpus during gripping

Answer 6

80% on the radiocarpal joint
20% on the ulnocarpal region

of the 80% radial load: 60% on scaphoid and 40% on lunate

Question 7

Stages of scapholunate instability (3)

Answer 7

1. predynamic instability
2. dynamic instability
3. static instability

Question 8

Pre-dynamic instability

Answer 8

earliest sign of SLIL pathology
SL membrane attenuated or partially torn, producing abnormal motion between the scaphoid and the lunate
produces wrist synovitis and pain

Question 9

Dynamic instability

Answer 9

ligamentous tears of either the palmar and/or dorsal portions of SLIL

Question 10

Static instability

Answer 10

SL gap can be seen on radiograph (>3mm abnormal)
SL angle greater than 60-70 deg on lateral radiograph
lunate rotated dorsally (DISI)

Question 11

Signs and symptoms SL injury

Answer 11

• typically result of a FOOSH
• acute injury present with painful and swollen wrist
• with time, pain becomes more localized of the SL ligament dorsally
• Terry Thomas sign
• signet ring sign
• DISI deformity
• degenerative changes to radial styloid and capitolunate joint

Question 12

Pre-dynamic and dynamic instability therapeutic management

Answer 12

• cast immobilization 7-10 days
• prefabricated orthosis to be used during aggravating activities for additional 2-6 weeks
• AROM exercises/DTM
• once pain free, orthosis discontinued and strengthening exercises as tolerated 10 weeks and beyond
• most resolve within 6 months without surgical intervention

Question 13

Static SL dissociation therapeutic management

Answer 13

?

Question 14

Signs and symptoms LT injury

Answer 14

• typically occurs secondarily to injury to ulnar side of wrist
• pain over the ulnar aspect of their wrist that is exacerbated by power grip and ulnar deviation
• VISI deformity
• lateral radiograph: lunate more palmarly flexed
• normal SL angle

Question 15

Midcarpal instability

Answer 15

instability between the proximal and distal carpal rows

can be intrinsic or extrinsic

Question 16

Intrinsic MCI

Answer 16

characterized by generalized wrist ligament laxity outside of the carpus
can be classified as dorsal, palmar, or combined

Question 17

Extrinsic MCI

Answer 17

secondary to bone abnormalities outside of the carpus like radius fracture malunions and extrinsic ligament injuries found in association with ulnar minus variance

Question 18

Signs and symptoms MCI

Answer 18

sense of wrist instability, significant wrist pain, an abrupt painful click/clunk/snap during wrist motion, and weakness with gripping

Question 19

DISI

Answer 19

dorsal intercalated segment instability

lunate dorsiflexed 15 degrees or greater in relation to capitate

Question 20

VISI

Answer 20

volar intercalated segment instability
volar rotatoion of the scaphoid and lunate can be seen on lateral radiograph
capitolunate angle of greater than 30 degrees

Question 21

Op/NonOp management of wrist ligament injury

Answer 21

1. edema and pain control
2. maintenance of ROM to uninvolved joints
3. initiation of controlled, protected mobilization to the uninvolved structures
4. avoidance of exercise or activity that may compromise tissue healing or place undue load to healing/repaired structures
5. overall achievement of stable wrist with functional ROM

Question 22

Functional wrist ROM

Answer 22

5 degrees flexion
30 degrees extension
10 degrees radial deviation
15 degrees ulnar deviation