Background: Bacterial colonization of peripheral nerve catheters is frequent, although infection is relatively rare. With central venous catheters, the tunneling of catheter into the subcutaneous tissue significantly decreases catheter colonization and catheter-related sepsis.

Purpose: The aim of this study is to evaluate the incidence of bacterial colonization in adult patients with femoral tunnelized perineural nerve catheters.

Methods: A total of 338 patients with femoral catheter will be included in the study. The patients will be randomized to be included in the control group (without tunnelling) or in the group with catheter tunneled 2-3 cm subcutaneously. After removal, catheter will be analyzed for colonization (primary outcome). Quantitative culture will be used as described by Brun-Buisson for intravascular catheters. The site of insertion will be monitored daily for any signs of infection (secondary outcome).

Perspective: To show the incidence of femoral perineural catheter colonization is low with subcutaneous tunneling

Inclusion Criteria:

• Patients scheduled to undergo scheduled orthopaedic surgery performed with a femoral perineural catheter

Exclusion Criteria:

• Age under 18 years
• Local nerve pathology
• Refusal to regional anaesthesia
• Major psychological disorder
• Major cardiac conduction disease
• Infection at the puncture site