Indications

• TFCC tear
• Carpal ligament injury
• Carpal instability (specialist scan)

Patients must be referred by a consultant orthopaedic surgeon with vetting by consultant radiologist.

Positioning

• Superman position or hand by side if not tolerated. Hand by side only works in a slim patient, as the coil must be as near to the magnetic isocentre as possible.
• Allow patient plenty of time to find comfortable position
• Encourage flexed elbow and relaxed shoulder extension rather than extreme positions
• Movement artefact is a problem due to patient discomfort in the superman position

Arthrography guidance

• Can be injected under fluoroscopic or ultrasound guidance for TFCC or cartilage indications
• Fluoroscopy should be used for suspected ligament injury or carpal instability so that dynamic assessment can be carried out

General arthrogram technique (fluoroscopy)

1. Sit patient at end of fluoro table and place wrist on 15deg wedge to correct radial angle. Place wrist in comfortable ulnar deviation.
2. Screen and adjust position ensuring that radiocarpal joint space is well visualised in profile
3. Inject onto central/proximal scaphoid, or with minimal radial needle inclination at the joint capsule
4. Inject only 0.5ml of contrast to confirm position, more risks contaminating approach if not correctly sited
5. Once spread is observed through wrist joint, swap to Magnevist. It is recommended that 3mL are decanted from the pre-mixed syringe into a small syringe.

If you use extension tubing, prime and remove air bubbles meticulously before injecting. For this reason it is not recommended that you use tubing. Not using tubing also gives you the benefit of the “lava lamp sign” to confirm correct intra-articular position before contrast injection.

Carpal instability arthrography (fluoroscopy only)

Follow the initial steps as above until the first 0.5mL of contrast has been injected into the radiocarpal joint

• Screen the joint moving from radial through ulnar deviation observing:
  • Carpal bone movements and relations
  • Migration of contrast across wrist, through ligament spaces and into the distal radioulnar joint
• Inject more contrast to fill the wrist (~3mL) as confirmed with backfilling of the directly applied syringe
• Take radiographic exposures of the wrist in:
  • Neutral position
  • Radial deviation
  • Ulnar deviation

MRI Scan

• FOV to cover from 2cm proximal to wrist joint line to bases of metacarpals
• High resolution hand and wrist coil