Superficial Radial Nerve Injection

Other Names

• Superficial Radial Nerve Injection
• Wartenberg's Syndrome Injection

---

Illustration of course of the superficial branch of the radial nerve

Illustration of the superficial branch of the radial nerve (click to enlarge).

Background

Key Points

• Use a high frequency, linear transducer
• Needle: 25- to 27-gauge, 1.0- to 1.5 inch needle

Anatomy of the Superficial Branch of the Radial Nerve

• Purely sensory branch of the radial nerve
  • Innervation of the dorsal lateral side of hand, proximal dorsal surface of thumb, index and half of middle finger
• Originates in the cubital fossa
• Courses down the forearm, lateral to the radial artery
• Concealed between brachioradialis, pronator teres
• About 7 cm proximal to wrist, pierces deep fascia, passes over anatomic snuffbox to dorsum of hand

Palpation Guidance vs Ultrasound Guidance

• This procedure can not reliably be performed with palpation guidance

---

Indications

• Wartenberg Syndrome

---

Contraindications

• Absolute
  • Anaphylaxis to injectates
  • Overlying cellulitis, skin lesion or systemic infection
• Relative
  • Can be treated with less invasive means
  • Hyperglycemia or poorly controlled diabetes
  • Lack of symptom improvement with previous injection

---

A and B. Short-axis view of the dorsal wrist, just radial to Lister’s tubercle. Note the different positions of the nerves in relation to the first and second dorsal compartment and overlying vessel. Arrow, superficial branch of the radial nerve; 1st, first dorsal wrist compartment; 2nd, second dorsal wrist compartment; R, radius; V, vein.

Probe and needle position for short axis, out of plane approach

Probe and needle position for short axis, in plane approach

Procedure

Equipment

• Sterile prep (i.e. chloraprep, chlorhexidine, iodine, etc)
• Gloves
• Needle: typically 21-25 gauge, 1.5 inch
• Syringe: 5-10 mL
• Gauze
• Ethyl Chloride
• Bandage
• Injectate
  • Local anesthetic
  • Corticosteroid
• Sterile probe cover

Ultrasound Findings

• The superficial radial nerve is very small
  • Can be difficult to find
  • Best seen in short axis
• Most easily located over radial wrist, just superficial to 1st and 2nd dorsal compartments
• Technique
  • Find listers tubercle in short axis
  • Slowly slide radially, brining the 1st and 2nd dorsal compartments into view
  • Nerve lies in a small superficial fascia between the two compartments
• Can track proximally
  • Slowly slide in short axis up the forearm
  • Will come to the intersection of the 1st and 2nd dorsal compartments
  • Nerve moves away from tendons

Technique: Short Axis, Out of Plane

• Patient Position
  • Patient is seated on opposite side of the table from the proceduralist
  • Hand wrist on table, radial side facing up
• Transducer position
  • Short axis
• Needle Approach/ Orientation
  • Out of plane
  • Step-wise technique distal to proximal
• Target
  • Superficial radial nerve
• Pearls and Pitfalls
  • Can rotate to long axis once needle is at target
  • Recommend identifying nerve more proximally and tracing it distally
  • The nerve is extremely superficial
  • Apply gentle pressure, too much will make identification difficult

Technique: Short Axis, In Plane

• Patient Position
  • Patient is seated on opposite side of the table from the proceduralist
  • Hand wrist on table, radial side facing up
• Transducer position
  • Short axis
• Needle Approach/ Orientation
  • In plane
  • Dorsal to volar
• Target
  • Superficial radial nerve
• Pearls and Pitfalls
  • Can visualize nerve during entire procedure
  • Easier to get under nerve, more difficult to hydrodissect
  • Careful to avoid other vascular structures

---

Aftercare

• No significant restrictions
• Can augment with ice, NSAIDS
• Consider temporary thumb spica splint after procedure

---

Complications

• Skin: Subcutaneous fat atrophy, skin atrophy, skin depigmentation
• Painful local reaction
• Infection
• Hyperglycemia
• Tendon, nerve or blood vessel injury

---

See Also

• Procedures Main
• Ultrasound Main
• Wrist Pain Main

---