Randomized, double blinded comparative trial of intradermal injections of lignocaine versus N-saline around the knee to relieve pain in patients awaiting total knee replacement.
OBJECTIVE
We report a randomized, double-blinded comparative study assessing the efficacy of local anesthetic with N-saline intradermal blocks around the knee to reduce pain and improve patient satisfaction while waiting for a total knee joint replacement.


METHODS
Patients were offered involvement in this study while on the hospital waiting list for a knee replacement. Eligible patients, after completing a prestudy assessment, received an average of 6.3 (range: 1 to 10) intradermal injections of 0.5 mL either saline or 1% lignocaine injections into tender points around the knee. Patients were assessed at 2 hours and 1 week after the injections. Pain was assessed using 0 to 100 visual analog pain scale. Global perceived effect (satisfaction) was measured on a 7-point Likert scale.


RESULTS
Thirty-two of 34 patients attended at 1-week assessment, 24 (75%) felt that they were improved, and 8 (25%) considered they were unchanged or worse. In both the saline and lignocaine groups, 12 of 16 patients felt that they had improved. N-saline proved as effective as lignocaine in reducing knee pain when injected intradermally. Seventy-five percent of patients were improved at 1 week.
Loughnan
Terence Edward
TE
Department of Anaesthesia and Pain Management, Peninsula Health, Frankston, Victoria, Australia. terence.loughnan@pmed.monash.edu.au
Taverner
Murray G
MG
Webb
Ashley
A
D000779:Anesthetics, Local / Q000008:administration & dosage; D018771:Arthralgia / Q000188:drug therapy* / Q000209:etiology* / Q000517:prevention & control*; D019645:Arthroplasty, Replacement, Knee; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D007271:Injections, Intradermal; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D020370:Osteoarthritis, Knee / Q000150:complications / Q000628:therapy; D010147:Pain Measurement / Q000187:drug effects*; D012965:Sodium Chloride / Q000008:administration & dosage*; D016896:Treatment Outcome
D000779:Anesthetics, Local; D012965:Sodium Chloride; D008012:Lidocaine