Week 9 Wrist Flashcards
function of the wrist complex
wrist - allow 2 degrees of freedom
- positioning of the hand
- stability for WB
- maintaining optimal length for the muscles responsible for grasp
radiocarpal joint
proximally, distally
proximally:
concave surface of radius, TFCC
distally:
convex surface of scaphoid, lunate and triquetrum
function of triangular fibrocartilage complex (TFCC)
- stabiliser of the ulnar carpal bones and distal radioulnar joint
- provides cushion/ load-bearing surface at the wrist joint during WB on hands or pushing
- WB: radius -80%, ulna -20%
role of wrist ligaments
- provide stability
- transfer forces through and across the carpal bones
- limit unwanted movements
describe midcarpal joint
- proximal row jointed losely, distal row is bound tightly by strong ligaments
- functional joint
wrist complex: midcarpal joint
- *lunate is the most commonly dislocated carpal bone *
- important role of scaphoid and proximal carpal row: acts as an ‘intercarpal bridge’
- implication: without the scaphoid and the central radio-luno-capitate link, the wrist would be unstable under compression loads
extrinsic wrist ligaments
- dorsal radiocarpal ligament
- palmar radiocarpal ligament
- radial collateral ligament
- ulnar collateral ligament
intrinsic wrist ligaments
- palmar ligaments
- dorsal intercarpal ligaments
wrist movement
- motion occurs simultaneously at radiocarpal and midcarpal joints
- this allows greater total ROM and more stable arc of motion in all planes
wrist complex AROM
degrees of wrist F, E, radial and ulnar deviation
wrist flexion: 65-80 degrees
wrist extension: 55-70 degrees
radial deviation: 15 degrees
ulnar deviation: 30 degrees
wrist extension movement
- proximal carpal bones
slides anteriorly and roll posteriorly - limit to extension: *palmar radiocarpal ligament *, dorsal lip of radius impinges on carpus
close packed position- as the palmar radiocarpal ligaments tighten, creating a sling across the scaphoid/ lunate, causing *proximal and distal rows to rotate together *
- damange to scapholunate/ lunotriquetral ligamnets = instability and decreased range and function at wrist
wrist flexion movement
slides posteriorly and rolls anteriorly- limit to flexion: tension dorsal radiocarpal ligaments, posterior capsule
wrist movement: radial deviation
-
roll radially and slide in ulnar direction(in both distal and proximal carpal rows) - also
moves anteriorly in proximal carpal row - anterior movement of proximal row occurs due to ‘pushing’ forces of contacting articular surfaces and ‘pulling’ forces sue to ligament tension
wrist movementL ulnar deviation
-
roll ulnar side and slide in radial side(in both the distal and proximal carpal bones) - also
moves posteriorlyin proximal carpal row - palmar ligaments play large role in guiding carpal movement
- highly variable and complex
if wrist extension was limited by stiffness, which accessory movement of the radiocarpal joint might you consider for mobilisation treatment?
PA glide extension
wrist musculature 手腕肌肉組織
wrist complex provides
- stable base for hand
- optimmal length-tension ratio of long finger muscles
wrist musculature: flexors
- 6 main muscles
- much stronger than extensors
- flexor retinaculum
~~~ - force in dependent on wrist extension
- finger flexion is modified by intrinsic muscles of the hand
~~~
why are extensors so important?`
stabilise and position the wrist for effective use of long finger flexors- contraction of long finger flexors causing wrist flexion torque at the same time = active insufficiency
- wrist extends as fingers flex to maintain length tension
functional position of the wrist
- **15-20 degrees extension and 10 degrees ulnar deviation **
- implications: stiff, painful, weak/ unstable wrist often assumes a posture that interferes 干擾 with the optimal length of finger muscles –> limits effectie hand function
- position for surgical fusion/ immobilisation due to injury
common mechanisms of wrist injury
- impact
- weight bearing
- twisting
- throwing
colles’ fracture
mechanism, diagnosis, management
- mechanism: fall on outstretched hand (extension)
- dinner fork deformity
- diagnosis: pain, swelling, restricted wrist ROM
- management:
- GAMP (general anesthetic manipulation or gap)
- non-displaced 無移位 or minimally displaced fractures with only monir comminution 粉碎性骨折, casted for 6/52 until bony union
- ORIF
- plate or pin fixation
- shorter period of immobilisation
- 3-4/52
- potential consequences 潛在後果:
- radial shortening –> wrist to OA and stiffness
epiphyseal fractures are common in children 6-10 years.
position of safe immobilisation
POSI of colles’ fracture
- wrist 20-30 degrees extension and slight ulnar deviation
- MCP joints: 45-70 degrees flexion
- IP joints: extension volar plate taut
- flexion for prolonged period = contractures of volar plate
**- thumb: 45 degrees abduction **
opposite to colles’ fracture
smith’s fracture
- mechanism: backward fall on the palm of an outstrected hand (flexion)
- classification:
- type I: extra articular
- type II: crosses into the dorsal articular surface
- type III: enters radiocarpal joint
scaphoid fracture
- mechanism: fall on outstretched hand (wrist extension and radial deviation)
- diagnosis: pain on wrist and thumb movement (tender snuffbox palpation)
- can be missed on x-ray in early stages - may not show for 10-14 days (need to repeat X-rays or CT scans)
- management: cast including thumb for 6-12 weeks (unstable fractureL internal fixation)
- complications: non union 骨折不癒合, avascular necrosis 缺血性壞死 due to poor blood supply, wrist instability
- physio aims: same as colles
gaining ROM post fracture
- focus on AROM
- **no overpressure **
- be very **wary 警惕 of pain at # site **
- **be careful of added resistance **
- no strength testing/ strength exercises until # union
lunate fractures
- mechanism: wrist hyperextension
- surgery required
ligament injuries of the wrist
- scapholunate ligament tear –> results in ‘Terry Thomas sign’
- Watson’s test –> positive if pain
- conservative or surgical management –> decrease ROM wrist complex
conservative management: eg: muscular strengthening, proprioceptive training, and coordination training
triangular fibro-cartilage complex (TFCC)
- *major stabiliser of ulna and carpus and distal R-U joint *
-** common site of ulnar wrist pain ** - mechanism: high compressive loads with ulnar deviation
- MRI
- surgery: shorten ulna
**carpal tunnel syndrome (CTS) **
causes, sings and symptoms, special tests, management
- neuropathy due to compression of median nerve in carpal tunnel
- common causes: gripping, overuse of wrist/ finger flexors (typing)
- conditions with increased fluid retention eg: pregnancy, lymphoedema
- signs and symptoms: numbness and pain in palmar aspect lateral 3.5 fingers, wrist and hand weakness - thumb (median nerve), worse through night and in morning, eased with activity, wasting of thenar muscles (thumb)
- special tests: Tinel’s sign, Phalen’s sign (wrist in full flexion for 30-60 seconds), nerve conduction tests of medial nerve
- management: convervative (RICE, NSAIDS), surgical (decompression of carpal tunnel)
more common in women 40-60 years old
6 steps that causes CTS
step 1: increase pressure in carpal tunnel
step 2: reduce blood to median nerve
step 3: reduce oxygen to nerve
step 4: inflammation of perinurium
step 5: blocking of neural transmission/ axoplasmic transport
step 6: atrophy of median nerve
De Quervain’s Tenosynovitis
signs and symptoms, diagnosis, management, complications
- **tendinopathy of ther APL and EPB tendons **
- signs and symptoms: pain, swelling, history of repetitive forceful gripping coupled with ulna deviation - most cases
- diagnosis: Finkelstein’s test (ulnar deviation of the wrist with the fist closed over the flexed thumb, positive if pain)
- management: decrease pain/ inflammation, increase flexibility EPB/ APL (massage and stretch), increase strength EPB/ APL (use eccentric and concentric with caution)
- complications: painful scars, tendon adhesions, subluxation of tendons
corticosteroid injections are often required, if these treatments fail, surgical release maybe necessary
wrist injuries - aims of physio management
- increase/ restore joint ROM
- increase/ restore muscle length, strength
- increase/ resotre function (gross motor and fine motor)
- proprioceptive retraining
- decrease pain/ swelling
