First Dorsal Compartment Injection (De Quervain's)

Treats

• De Quervain's tenosynovitis (APL/EPB)

Pre-procedure checklist

• Confirm patient identity (two identifiers)
• Confirm procedure, side, and site
• Review allergies and anticoagulation
• Confirm informed consent — DISCUSS subcutaneous fat atrophy and skin depigmentation risk at the radial styloid
• Pre-scan: identify APL/EPB tendons, septum (if present), superficial radial nerve branches, radial artery
• Time-out immediately before needle entry

Positioning

• Seated or supine; forearm neutral; thumb up

Probe

• High-frequency linear probe (6-13 MHz)

Landmarking — find the view

• Visual Cue: 'Two eyes in one socket' — identify the APL and EPB tendons together in short-axis over the radial styloid.
• Slide the probe slightly proximal and distal to identify any vertical septum (a wall) between the tendons.
• Check for any small fluid collections or 'halo' around the pair.
• Map the superficial radial nerve branches — they are frequently very close to the entry site.
• Identify the radial artery on the volar side — DO NOT use a volar trajectory.

The correct ultrasound view

• Two tendons within sheath; septum visible if present

Needle corridor

• Dorsal in-plane approach (after rotating the probe into long-axis along the tendons): enter from the dorsal/dorsoradial aspect distal-to-proximal, advancing into the sheath superficial to the APL/EPB tendons. AVOID any volar trajectory — the radial artery lies on the volar side of the radial styloid.

1. 1Dorsal in-plane entry into the sheath; inject ≤ 1.5 mL total; ensure spread around BOTH tendons.
2. 2If a septum is present, perform TWO separate injections — one in the APL sub-sheath and one in the EPB sub-sheath. A single injection into the APL alone is the most common cause of treatment failure.
3. 3STOP IMMEDIATELY if the patient reports electric, shooting, or paresthetic sensations along the dorsoradial hand or thumb.

Tips

• Always identify the superficial radial nerve first and adjust approach.
• Use a short 27G needle for better control in this superficial space — but only with non-particulate steroid (27G can clog with triamcinolone suspension).
• Counsel patient about subcutaneous fat atrophy and depigmentation risk at the radial styloid (well-documented particulate steroid complication).
• Limit to 1-2 steroid injections per year at this site.

Supplies

• 3 mL Syringe
• 27G 0.5" or 1" Needle (use ≥ 25G if injecting triamcinolone — particulate can clog 27G)
• 18G Drawing Needle
• 1% Lidocaine (0.5-1 mL)
• Dexamethasone 4 mg (PREFERRED — non-particulate, no fat atrophy risk near SRN) OR triamcinolone 10-20 mg
• Alcohol Swabs (vial tops)
• Betadine/Chloraprep
• Sterile Gloves
• Sterile 4x4 Gauze Pads
• Sterile Towels & Drapes
• Adhesive Bandage (Band-Aid)
• Washcloth/Towel (gel cleanup)
• Needle Disposal Safety Cap
• Sterile probe cover & gel

Post-procedure

• Apply a clean dressing; remove after 24 hours.
• Local anesthetic relief for 1-4 hours; steroid begins 24-72 hours.
• Steroid 'flare' in 2–10% — manage with ice and acetaminophen.
• Rest the thumb 24-48 hours; brief thumb spica splint optional for 1 week.
• Return for: spreading redness, swelling, fever, disproportionate pain, OR new skin depigmentation/dimpling at the injection site.
• Diabetics: expect 50-100 mg/dL glucose rise for 3-5 days.
• Maximum 1-2 injections per year at this site.