Wrist Arthroscopy

Diagnostic vs Therapeutic

Diagnostic
- Assess tears of TFCC
- Chondral damage to carpus
- Chronic wrist pain of unknown Diagnosis
Therapeutic
- Distal radial & carpal Fracture
  - Aid in ORIF distal radius fracture with mini-open procedure
  - Percutaneous pinning of scaphoid
- Ligament tears
  - Scapho-lunate instability
  - Luno-triquetral instability
- Debride TFCC tears
- Synovectomy
- Removal of loose bodies
- Wrist lavage
- Arthrofibrosis

Tourniquet
Traction
- essential for visualisation
- Traction tower & finger traps to 2 or 3 digits (usually IF & MF)
- If don't have tower use shoulder holder & wt suspended off traps
- Overhead or traction device – so that elbow lies just off the table
- 10lb wt
2.7 mm scope
- essential
- 2.7mm or 2.9mm 30° or 70° scope
- 1.9mm scope also available for DRUJ, thumb CMCJ/ STTJ, MCPJ
Infuse NS 1st
Small joint instrumentation as well

Named according to interspace through which they pass
Most common
- 3-4 portal
- 4-5 portal
- 6-R portal
- 6-U portal
3-4 Portal
- Feel Lister's tubercle
- 1cm distal is soft spot between extensor compartments 3 & 4
4-5 Portal
- Roll finger over mobile 4th compartment to feel soft spot
- Is slightly proximal to 3-4 because of slope of radius
6-R & 6-U
- Named after their position about ECU
Then
- Insuflate wrist with 3-5ml N/Saline into radiocarpal joint
- All portal incisions longitudinal to protect extensors
- Only incise skin
- Use blunt trocars to avoid radial n injury
- Pass trocar at 30-40° passing volar to conform to shape of radius
Midcarpal Portals
- Two portals to view S-shaped midcarpal joint
- Made 1cm distal to 3-4 & 4-5 portals
- In soft spot between capitate & scaphoid
3-4 portal is primary viewing portal
4-5 or 6-R main working portal
6-U is inflow portal
Outflow usually through IV tubing attached to scope

Start at radial styloid & scaphoid
Work radial to ulnar
Identify RadioScaphoCapitate Ligament & immediately beside is Long Radiolunate Ligament (extremely wide usually 3x width of RSCL)
Next is Short RadioLunate Ligament (often see blood vessels along this ligament)
Distal to short ligament is Scapholunate Lig
Examine from membranous proximal portion to thicker dorsal ligamentous portion
Follow ulnarly along lunate & its fossa to TFCC
Articular disk should be taut like a trampoline (actual ballottment with probe should give same feeling = Trampoline test)
Examine for tears » central or peripheral if not taut
Don't be caught out by ulnar styloid recess is normal finding at base of styloid not a tear
Then to triquetrum
Must probe both scapholunate joint & lunotriquetral joint for instability
Next move to midcarpal joint with scope & probe using both midcarpal portals
Most prominant feature is curve of head of capitate
Reverse look & view scapholunate joint & lunotriquetral joint
STTJ can be seen by passing completely radially

Must look from radiocarpal & midcarpal joints
Both joint ligaments should be tight & concave
Can do “poor man's arthrogram”
- Ie inflow in RCJ outflow in MCJ
- If flow then have tear in ligament

I. Attenuation or haemorrhage within ligament
- No step
- Treatment cast immobilisation
II. Incongruency or step-off in midcarpal space
- Treatment a/scopic pinning
- Use K wire as joystick to reduce
III. Step-off on both sides
- Probe may be passed between bones
- Treatment a/scopic or open repair
IV. Gross instability
- Treatment open repair

Critical tolerance for articular incongruity = 2mm
Recent evidence now say 1mm
A/scopic assisted helps to achieve congruity
Also now are seeing high incidence of scapholunate & lunotriquetral ligament injuries
Technique
- Usually wait 2-7/7 for bleeding
- Usual set up
- 3-4 visual portal, 4-5 or 6-R as working portals,6-U as inflow
- Occasionally use 1-2 portal
- Use K-wires placed under I-I control to joystick fragments as well as small pick etc through working portal
- Wire fixation as per usual once reduction obtained
- If see die punch have to open