The Effect of Liposomal Lidocaine on Perceived Pain in Children During Percutaneous Interosseous Pin Removal in the Outpatient Setting

The removal of smooth, percutaneous pins (Perc Pins), which are used for fracture fixation, occurs once adequate bone healing has taken place. At the Stollery Children's Hospital (SCH), this frequently performed procedure is currently done without anesthetic, making it a painful and uncomfortable experience for the child and their caregiver(s). Liposomal Lidocaine is a relatively new effective and "needle-free" topical anesthetic. The investigators were interested in examining its effectiveness in pain reduction in children undergoing Perc Pin removal. Objective: To determine if Liposomal Lidocaine is effective in reducing pain in a pediatric population undergoing Perc Pin removal compared to a placebo. Hypothesis: The investigators hypothesize that Liposomal Lidocaine would significantly reduce pain during Perc Pin removal compared to a placebo. Research Design: This was a triple-blinded, randomized placebo-controlled clinical trial with 281 patients (140 patients each in the Maxilene and 141 in the Placebo groups). Pain measurements, using the Oucher Scale (children) and a 10-cm Visual Analog Scale (parents and caregivers) were collected prior to randomization and immediately after Perc Pin removal. Data was analyzed using a Student's t-test and the Wilcoxon signed ranks test.

• Drug: Liposomal Lidocaine
  4% Liposomal Lidocaine
  Other Name: Maxilene
• Drug: Placebo
  Tubes were visually identical to the Liposomal Lidocaine tubes.

• Experimental: Liposomal Lidocaine group
  Patients in this groups received 4% Liposomal Lidocaine that was applied to the area immediately surrounding the pin site(s) and was covered with an opaque Tegaderm dressing
  Intervention: Drug: Liposomal Lidocaine
• Placebo Comparator: Placebo Group
  This group received a placebo that was applied to the area immediately surrounding the pin site(s) and was covered with an opaque Tegaderm dressing.
  Intervention: Drug: Placebo

Inclusion Criteria:

• Children between 3 and 16 years of age (i.e. up to but not including the 17th birthday) who present to the Pediatric Plaster Room at the SCH for Perc Pin removal were eligible for inclusion in this study.

Exclusion Criteria:

• Any patient with Perc Pins that are threaded (not smooth), as these pins require a more difficult removal process, oftentimes in the operating room instead of the orthopedic clinic.
• Infection around the Perc Pins: This is considered a relative contraindication to the use of topical anesthetic as it is usually less effective in this situation.
• Any parents/patients unable to exhibit understanding of the Oucher/VAS -- due to language barriers or developmental delay in the patient (e.g. severe cerebral palsy).
• The presence of an open wound in the vicinity of the pins that could not be excluded from the area to which the topical anesthetic cream is to be applied.
• Present use of analgesic or anxiolytic medications (within 24 hours prior to pin removal)
• Known allergies or adverse reactions to Maxilene