Recommended Corticosteroid and Lidocaine Combination for Trigger Finger of the 5th Digit
Use triamcinolone 40 mg (1 mL) alone without lidocaine for trigger finger injection into the 5th digit, as this approach results in significantly less injection pain while maintaining therapeutic efficacy. 1
Corticosteroid Selection and Dosing
Triamcinolone acetonide 40 mg (1 mL) is the evidence-based corticosteroid of choice for trigger finger injection, demonstrated in multiple randomized controlled trials 2, 1, 3, 4
The injection should be administered into the flexor tendon sheath of the affected digit 5, 2
The Lidocaine Controversy: Evidence Against Routine Use
Recent high-quality evidence challenges the traditional practice of adding lidocaine to corticosteroid injections:
A 2021 randomized, double-blind controlled trial found that adding 1% lidocaine with epinephrine to triamcinolone significantly increased injection pain (VAS 3.5 vs 2.0, p<0.05) compared to triamcinolone with saline placebo 1
Despite the increased pain, there was no difference in treatment success rates between groups with or without lidocaine 1
Using corticosteroid alone is simpler, more efficient, safer (single drug reduces potential complications), and less painful 1
When Lidocaine May Be Considered
If you choose to use local anesthetic despite the evidence, consider these parameters:
Use 0.5 mL of 1% lidocaine without epinephrine if anesthesia is deemed necessary 2
Note that older Cochrane reviews showed corticosteroid plus lidocaine was superior to lidocaine alone (RR 3.15, NNT=3), but this compared against lidocaine monotherapy, not corticosteroid monotherapy 3, 4
Safety Considerations for Digital Injections
The historical concern about epinephrine causing digital necrosis has been definitively refuted:
Multiple systematic reviews and randomized controlled trials confirm that epinephrine is safe for use in digits with no reported cases of necrosis 6
The American Academy of Dermatology gives a Grade A recommendation (Level I-II evidence) for the addition of epinephrine to local anesthesia on digits 6
If using lidocaine with epinephrine, employ the lowest effective concentration to provide adequate anesthesia 6
Dosing Limits and Toxicity Prevention
Maximum safe lidocaine doses must be respected:
Without epinephrine: 4.5 mg/kg in adults 7
With epinephrine: 7.0 mg/kg in adults 7
Do not use lidocaine within 4 hours of other local anesthetic interventions to prevent cumulative toxicity 7
Early toxicity signs include circumoral numbness, facial tingling, slurred speech, and tinnitus 7
Practical Injection Technique
For optimal results:
Consider ultrasound guidance for precise tendon sheath placement 2
Total injection volume should be 1-2 mL maximum (either triamcinolone 40 mg alone in 1 mL, or triamcinolone 40 mg in 1 mL plus 0.5-1 mL lidocaine if chosen) 2, 1
Treatment success can be expected in approximately 60-70% of cases at 4 weeks, with effects potentially lasting up to 4 months 3, 4
Common Pitfalls to Avoid
Avoid reflexively adding lidocaine based on outdated practice patterns—the 2021 evidence shows it increases pain without improving outcomes 1
Do not avoid epinephrine in digits due to the debunked necrosis myth—it is safe and provides hemostasis and prolonged anesthetic effect if you do use lidocaine 6
Do not exceed maximum lidocaine doses when combining with other local anesthetic procedures 7
Counsel patients that the injection itself causes brief discomfort, but this is actually less painful without lidocaine than with it 1