First Carpometacarpal Joint Injection – Technique and Tips

By Chris Faubel, MD —

Indications

• First carpometacarpal (CMC) joint painful osteoarthritis
  • ICD-9 codes:
    • 715.14 “osteoarthrosis, localized, primary, hand”
    • 719.44 “pain in joint, hand”
  • ICD-10 codes:
    • M18.0 “primary arthrosis of first carpometacarpal joint, bilateral“
    • M18.1 “primary arthrosis of first carpometacarpal joint, unilateral“
    • M25.54 “pain in a joint, hand”

CPT code: 20600 “Arthrocentesis, aspiration and/or injection; small joint or bursa (eg, fingers, toes)”

Materials Needed

• Pen – clicking type
• Gloves – non-sterile
• Alcohol swabs (or povidone-iodine)
• Band-aid
• Tuberculin needle/syringe OR 1-ml syringe with 25-gauge 5/8″ needle (depending on body habitus)
• Injectate
  • 0.5-ml of 40mg/ml Depo-Medrol or Kenalog
  • 0.5-ml of 1% lidocaine

Technique / Procedure Steps

1. Always start with informed consent from the patient, and then a time-out to verify correct patient and injection site.
2. Mark the injection site with the pen tip in order to leave an impression in the skin (see pic above).
3. Perform the Allen’s test (to make sure patient has sufficient circulation in the hand from both the radial and ulnar arteries).
4. Clean the skin thoroughly with as many alcohol swabs as needed (usually only one is needed).
5. Patient position: Perform lying supine or seated with the radial side of the wrist up.
6. With the tuberculin needle/syringe, enter the skin about 45-degrees to the skin.  If bony resistance is met, redirect the needle until the entire 1/2″ or 5/8″ is inside the joint.  Note: Ultrasound may be needed if extensive osteophytes make it difficult to find an entry path.
7. Aspirate to make sure you’re not in any vessel.
8. After negative aspiration, inject the full contents of the syringe, unless lots of resistance is met (means intratendinous needle tip position).  Withdraw very slightly, or reposition completely, and try again.
9. Withdraw the needle after syringe if fully empty, and apply band-aid.

Tips

• Finding the injection site
  • Can palpate the joint space between the trapezoid and the 1st metacarpal bone with your nail.
  • Distracting the thumb distally may help to open the space.
• Numbing the skin
  • Find out all about “Taking the Sting Out” (of injections) by going here.
  • Since I use a tiny tuberculin needle, most patients have no problem with the injection and don’t need any extra lidocaine skin wheal or freezing spray.
    • I tell them numbing the skin with lidocaine will probably hurt more than the actual injection.
• After the injection
  • Have the patient move their thumb around a few times while you throw away supplies.
  • Then, re-mobilize the 1st CMC joint so they can see the immediate results of the lidocaine.
  • Explain to the patient that the lidocaine will wear off in an hour or so, and that they will be back to their normal pain until the steroids start kicking in (anywhere from 1-7 days).
  • May also ask the patient to not do much activity with that thumb for 12-24 hours.