Digital Nerve Block – Indications, Techniques, and Safety Tips

Last Updated on June 3, 2025

Digital nerve blocks are a reliable and commonly used method to provide anesthesia for procedures involving the fingers or toes. The digital blocks anesthetize the entire digit by targeting the nerves supplying it.

These blocks are especially useful for laceration repair, nail bed injuries, fracture manipulation, and abscess drainage.

The technique is performed using small volumes of local anesthetic injected around the base of the digit, effectively numbing both palmar/plantar and dorsal surfaces.

A proper understanding of the cutaneous nerve supply and the technique procedure is essential to ensure effective anesthesia and avoid complications such as ischemia or nerve damage.

Digital blocks are typically indicated for procedures distal to the metacarpophalangeal or metatarsophalangeal joints and are widely used in both emergency and outpatient surgical settings.

Relevant Anatomy for Digital Nerve Block

Each digit of the hand and foot is innervated by four digital nerves- two palmar (or plantar) and two dorsal branches. These nerves originate from major peripheral nerves and provide complete cutaneous sensory innervation to the digits.

Hand

The sensory supply to the fingers is derived from the median, ulnar, and radial nerves:

• Median nerve: Supplies the palmar aspect of the thumb, index, middle, and radial half of the ring finger, including the nail beds.
• Ulnar nerve: Supplies the palmar and dorsal aspects of the little finger and ulnar half of the ring finger.
• Radial nerve: Supplies the dorsum of the thumb and proximal dorsal aspects of the index and middle fingers (not the fingertips).

Each finger typically receives:

• Two palmar digital nerves – supplying the volar aspect and nail bed.
• Two dorsal digital nerves – supplying the proximal dorsum of the finger.

Foot

The toes receive sensory innervation via branches of the tibial and common peroneal (fibular) nerves:

• Tibial nerve: Its medial and lateral plantar nerves give palmar/plantar digital branches.
• Common peroneal nerve: Superficial peroneal and deep peroneal nerves give dorsal digital nerves.

As with the hand, each toe is innervated by:

• Two plantar digital nerves supply the sole side and nail bed.
• Two dorsal digital nerves supply the dorsum.

Clinical Note: The nail bed receives its sensory supply from the palmar or plantar nerves, which is why proper anesthetic deposition on these sides is essential even for dorsal procedures like nail avulsion.

Indications of Digital Nerve Block

A digital nerve block is indicated for any procedure involving a finger or toe where local infiltration would be insufficient, technically difficult, or excessively painful. These blocks are ideal for achieving complete anesthesia distal to the metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joints.

Common clinical indications include:

• Repair of large or deep lacerations on the digit
• Nail bed injuries and nail avulsion procedures
• Ingrown toenail removal
• Drainage of paronychia or felon
• Reduction or splinting of digital fractures and dislocations
• Foreign body removal from the digit
• Excision of digital warts or soft tissue lesions

Some clinicians also prefer digital blocks over local infiltration for better pain control and less tissue distortion in the operative field

Contraindications

Contraindications to Digital Block

While digital nerve blocks are generally safe, certain conditions warrant caution or complete avoidance to prevent complications.

Absolute Contraindications

• Compromised digital circulation
  (e.g., severe peripheral vascular disease, Raynaud’s phenomenon, crush injury)
• Infection at the intended injection site
• Known allergy to local anesthetic agents

Relative Contraindications

• Coagulopathy or patients on anticoagulants (increased risk of hematoma)
• Pre-existing neurologic deficit in the digit (risk of masking worsening symptoms)

Important: The use of epinephrine-containing solutions is contraindicated in digital blocks due to the risk of vasospasm and ischemic necrosis.

Equipment

Basic Supplies

• Sterile gloves and sterile drapes
• Antiseptic solution (e.g., povidone-iodine or chlorhexidine)
• Sterile gauze pads and adhesive bandages
• Alcohol swabs (optional for additional skin prep)

Injection Equipment

• Syringe (5–10 mL)
• 18-gauge needle for drawing up the anesthetic
• 25–30-gauge needle for infiltration (smaller gauge preferred to reduce pain)

Local Anesthetic Agents

• Lidocaine (1% or 2%) – rapid onset, shorter duration (~1–2 hours)
• Bupivacaine (0.25% or 0.5%) – slower onset, longer duration (~4–8 hours)
• Procaine – older agent, less commonly used today

Note: Always use plain anesthetic without epinephrine to avoid digital ischemia.

Agent	Conc.	Max Dose (without epinephrine)	Onset	Duration of Action	Notes
Lidocaine	1- 2%	4.5 mg/kg (max ~300 mg)	2–5 minutes	1–2 hrs	Most used, rapid onset
Bupivacaine	0.25% or 0.5%	2.5 mg/kg (max ~175 mg)	5–10 minutes	4–8 hrs	Long-acting, slower onset
Mepivacaine	1% or 2%	4.5 mg/kg (max ~300 mg)	3–5 minutes	2–3 hrs	Intermediate option
Procaine	1%	7 mg/kg (max ~500 mg)	5–10 minutes	0.5–1 hr	Rarely used

Techniques of Digital Block

Several techniques can be used to administer a digital nerve block, each with specific clinical applications depending on the digit involved, patient comfort, and extent of anesthesia required.

Common techniques

• Web-Space Block – most commonly used, less painful, effective for fingers and smaller toes
• Transthecal Block – commonly used for fingers, especially when dorsal access is limited
• Three-Sided Digital Block – preferred for large toes (e.g., great toe)
• Four-Sided Ring Block – complete circumferential anesthesia; higher risk of ischemia
• Wing Block – used for nail bed procedures, particularly in fingers

The following things should be kept in mind

• Follow standard sterile precautions in all procedures
• Do not use epinephrine or adrenaline
• Use the smaller needle for injections. This leads to less pain.
• Use an appropriate amount for the space available
• Anesthesia of the great toe is more difficult and typically needs 3-sided/4-sided ring blocks.
• Take care not to inject intravascularly. Aspirate before each injection and avoid piercing the side opposite to the entry skin.

Web-Space DigitalNerve Block

The web-space block is a simple and well-tolerated technique, most commonly used for finger and toe procedures, except for the great toe.

It is the least painful of all digital nerve blocks and provides the right level of anesthesia.

Position

• Hand: palm down on a flat sterile surface
• Toe: The Foot is kept on a flat sterile surface, sole facing down

Steps

• Prepare the area using antiseptic (e.g., betadine), then apply sterile drapes.
• Load the syringe with the chosen anesthetic and attach a 25–30G needle.
• Identify the web space just distal to the metacarpophalangeal (MCP) join (metatarsophalangeal joint in the foot)
• Insert the needle on the dorsal side of the web space, angling toward the volar side.
• Inject 1–1.5 mL of anesthetic slowly as the needle advances toward the palmar aspect.
• Avoid piercing through the volar skin; if resistance is encountered, stop and adjust.
• Withdraw the needle and repeat the procedure on the opposite web space of the same digit.

Note: This technique anesthetizes both dorsal and palmar digital nerves via diffusion through loose areolar tissue of the web space.

This method is effective in toes also except the great toe.

Transthecal Digital Nerve Block

The transthecal block targets the flexor tendon sheath, allowing the anesthetic to spread distally and anesthetize the digital nerves. It is especially effective for procedures involving the index and middle fingers.

Position

• Hand: placed palm-up on a sterile field

Steps

• Prepare the hand with antiseptic and drape it in a sterile fashion.
• Identify the distal palmar crease corresponding to the affected finger.
• Palpate the flexor tendon and locate the entry point just distal to the metacarpophalangeal (MCP) joint.
• Insert a 25- or 27-gauge needle at a 45-degree angle to the skin, directed proximally toward the tendon sheath.
• Advance the needle slowly, you may feel a “give” as you enter the sheath.
• Inject 1–2 mL of local anesthetic slowly. If resistance is high, withdraw slightly and reposition.
• Apply gentle pressure proximal to the injection site to encourage distal flow of anesthetic.

Modified Transthecal Technique

• Insert the needle vertically (90°) at the palmar metacarpophalangeal crease.
• Advance until you contact the bone (proximal phalanx), then withdraw slightly.
• Inject the anesthetic as the needle is slowly withdrawn.
• Use the other hand to keep the pressure just proximal to the injection site so that the flow is directed distally.

Note: This method is slightly more painful than web-space injection due to the confined space, but offers excellent anesthesia with a single needle stick.

Three-Sided Digital Nerve Block

The three-sided digital nerve block is typically used for the great toe, which often requires a more extensive anesthetic approach due to its larger size and deeper nerve distribution.

This technique typically provides sufficient anesthesia without the need for a plantar injection, thereby reducing pain.

Position

• The foot is placed on a flat sterile surface with the plantar surface down.

Steps

1. Medial Injection
   • Insert a 25–27G needle at the medial side of the toe, just distal to the metatarsophalangeal (MTP) joint.
   • Advance the needle slightly toward the plantar surface (without piercing it).
   • Inject 1–1.5 mL of anesthetic while advancing through subcutaneous tissue.
   • Withdraw and redirect laterally under the skin in the same medial web space to cover a wider field.
2. Lateral Injection
   • Repeat the same procedure on the lateral side of the toe, mirroring the medial injection.
3. Dorsal Injection
   • Insert the needle dorsally at the base of the toe, between the previous medial and lateral points.
   • Inject 1 mL of anesthetic transversely to block the dorsal digital nerves.

Four-Sided Ring Block

It is an extension of 3 sided block.

After completion of the above three steps, the needle is inserted at the lateral aspect of the digit on the plantar side and advanced it medially as the anesthetic is slowly injected. This method is not preferred because of the risk of ischemic complications.

Wing Block Procedure

The wing block is a specialized technique used primarily for procedures involving the distal part of the digit, such as nail bed repair, nail avulsion, or nail fold injuries.

It targets the nerve fibers around the proximal nail fold, providing localized anesthesia without affecting the entire digit.

Position

• Hand or foot placed with the volar or plantar surface down (dorsum facing up).

Steps

• Identify the intersection point between the lateral nail fold and the proximal nail fold.
• Insert a 25–30G needle at a 45-degree angle to the skin, about 3 mm proximal to the intersection point, with the needle tip pointing toward the nail matrix.
• Inject a small volume (0.5–1 mL) of anesthetic along the proximal nail fold.
• Withdraw the needle slightly, redirect it toward the lateral nail fold, and inject along that plane.
• Repeat the procedure on the opposite side of the nail if needed, using the same technique.

Unlike web-space blocks, the wing block delivers anesthesia directly into the subcutaneous tissue around the nail bed, offering faster, localized effect. However, this technique can be more painful due to tighter tissue planes and is less commonly used.

Complications and Precautions

Digital nerve blocks are generally safe when performed correctly, but they are not without risk. Understanding potential complications and necessary precautions is essential to minimize harm and ensure effective anesthesia.

Complications

• Pain at the injection site can be minimized with smaller-gauge needles and slow infiltration
• Hematoma, especially if inadvertent vessel puncture occurs
• Infection – rare with proper aseptic technique
• Inadequate anesthesia – due to incorrect technique, anatomical variation, or underdosing
• Intravascular injection can lead to systemic toxicity (e.g., CNS or cardiac effects)
• Nerve injury – direct trauma from the needle may cause transient or rarely permanent sensory changes
• Digital ischemia or necrosis, especially if:
  • Epinephrine-containing solutions are mistakenly used
  • Multiple circumferential injections lead to excessive pressure
  • Preexisting vascular insufficiency is present

Precautions

• Always aspirate before injection to rule out intravascular placement.
• Use the smallest effective volume of anesthetic (typically 3–5 mL total per digit).
• Avoid epinephrine or any vasoconstrictive additives.
• Document neurovascular status before and after the block.
• Avoid injecting into infected tissue, which may spread the infection or render the block less effective.

In patients with compromised circulation or peripheral vascular disease, consider alternative pain management strategies.

References

• Napier A, Howell DM, Taylor A. Digital Nerve Block. [Updated 2024 Feb 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526111/
• Borbón TY, Qu P, Coleman-Satterfield TT, Kearney R, Klein EJ. Digital nerve blocks: A systematic review and meta-analysis. J Am Coll Emerg Physicians Open. 2022 Jul 1;3(4):e12753. [PubMed]
• Antevy PM, Zuckerbraun NS, Saladino RA, Pitetti RD. Evaluation of a transthecal digital nerve block in the injured pediatric patient. Pediatr Emerg Care. 2010 Mar;26(3):177-80. [PubMed]