To investigate the function of a novel catheter for continuous peripheral nerve blocks in the popliteal nerve: Two key issues are investigated 1) Successful primary placement and function of the catheter for continuous peripheral nerve blocks confirmed by a decrease in motor function following injection of local analgesics through the catheter; 2) The rate of displacement after standardized movement of the limb where the catheter for continuous peripheral nerve blocks is inserted.

Although peripheral nerve blocks are known to provide superior postoperative analgesia. Continuous peripheral nerve block (CPNB) are not used to the extent they deserve. This is predominantly due to variable success rates. Furthermore, the existing techniques for placing catheters for CPNBs are technically complicated and time consuming.4,5 Major problems include difficult insertion of the catheter tip past the needle, difficult visualization of catheter advancement, secondary displacement of the local anesthetic (LA) injection orifice(s) and limited possibility of repositioning the catheter once it has been left in situ. We have developed a new catheter for CPNBs to address and overcome these limitations.

Hence, the new catheter should primarily provide precise initial placement of the catheter, less risk of secondary displacement and a possibility to readjust the new catheter at any time point after initial placement. Furthermore, in-plane ultrasound (US) visualization during the entire procedure and during readjustment should be possible. The new catheter should also provide a simple and rapid technique with few components. Initial proof of concept studies in cadavers are promising with success rates close to 100 % both for initial placement and readjustment

Inclusion Criteria:

1. Male or female ≥18 years of age at Visit X.
2. ASA classification ≤ II
3. Written informed consent obtained from volunteer and ability for volunteer to comply with the requirements of the study.

Exclusion Criteria:

1. BMI ≥ 30
2. Previous or ongoing surgery, pain or other disability of investigated region.
3. Prescriptive drugs other than anti-contraceptive.
4. Sensory or neurologic deficits in the investigated region
5. Allergy to LA
6. Pregnancy, breastfeeding, or unwilling to practice birth control during participation in the study.-