Study: NCT02801799

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Varying infusion rates of Ropivacaine 0.2%
Description: Participants will receive one nerve catheter adjacent to the common peroneal nerve (trial day 1) and adjacent to the sciatic nerve (trial day 2). Each catheter will be randomly allocated to one of five infusion groups. All peroneal nerve catheters will receive the same volume of ropivacaine 0.2%. All the sciatic nerve catheters will receive the same volume of ropivacaine 0.2%.~The only inter-group variable will be the infusion rate. The fixed volume of ropivacaine will be determined in a separate study ('The Volume Study'), which is also part of the project: 'A novel technique for reliable, precise and safe postoperative management'.~The largest volumes tested in The Volume Study are 30 mL for the sciatic nerve and 20 mL for the common peroneal nerve. Therefore the highest volume for the two intervention days cannot exceed 30 mL (150 mg of ropivacaine).~We will ensure constant infusion rate and precise delivery of LA by using an electronic infusion pump and a nerve catheter.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Varying infusion rates of Ropivacaine 0.2%
Description: Participants will receive one nerve catheter adjacent to the common peroneal nerve (trial day 1) and adjacent to the sciatic nerve (trial day 2). Each catheter will be randomly allocated to one of five infusion groups. All peroneal nerve catheters will receive the same volume of ropivacaine 0.2%. All the sciatic nerve catheters will receive the same volume of ropivacaine 0.2%.~The only inter-group variable will be the infusion rate. The fixed volume of ropivacaine will be determined in a separate study ('The Volume Study'), which is also part of the project: 'A novel technique for reliable, precise and safe postoperative management'.~The largest volumes tested in The Volume Study are 30 mL for the sciatic nerve and 20 mL for the common peroneal nerve. Therefore the highest volume for the two intervention days cannot exceed 30 mL (150 mg of ropivacaine).~We will ensure constant infusion rate and precise delivery of LA by using an electronic infusion pump and a nerve catheter.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Varying infusion rates of Ropivacaine 0.2%
Description: Participants will receive one nerve catheter adjacent to the common peroneal nerve (trial day 1) and adjacent to the sciatic nerve (trial day 2). Each catheter will be randomly allocated to one of five infusion groups. All peroneal nerve catheters will receive the same volume of ropivacaine 0.2%. All the sciatic nerve catheters will receive the same volume of ropivacaine 0.2%.~The only inter-group variable will be the infusion rate. The fixed volume of ropivacaine will be determined in a separate study ('The Volume Study'), which is also part of the project: 'A novel technique for reliable, precise and safe postoperative management'.~The largest volumes tested in The Volume Study are 30 mL for the sciatic nerve and 20 mL for the common peroneal nerve. Therefore the highest volume for the two intervention days cannot exceed 30 mL (150 mg of ropivacaine).~We will ensure constant infusion rate and precise delivery of LA by using an electronic infusion pump and a nerve catheter.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Varying infusion rates of Ropivacaine 0.2%
Description: Participants will receive one nerve catheter adjacent to the common peroneal nerve (trial day 1) and adjacent to the sciatic nerve (trial day 2). Each catheter will be randomly allocated to one of five infusion groups. All peroneal nerve catheters will receive the same volume of ropivacaine 0.2%. All the sciatic nerve catheters will receive the same volume of ropivacaine 0.2%.~The only inter-group variable will be the infusion rate. The fixed volume of ropivacaine will be determined in a separate study ('The Volume Study'), which is also part of the project: 'A novel technique for reliable, precise and safe postoperative management'.~The largest volumes tested in The Volume Study are 30 mL for the sciatic nerve and 20 mL for the common peroneal nerve. Therefore the highest volume for the two intervention days cannot exceed 30 mL (150 mg of ropivacaine).~We will ensure constant infusion rate and precise delivery of LA by using an electronic infusion pump and a nerve catheter.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Varying infusion rates of Ropivacaine 0.2%
Description: Participants will receive one nerve catheter adjacent to the common peroneal nerve (trial day 1) and adjacent to the sciatic nerve (trial day 2). Each catheter will be randomly allocated to one of five infusion groups. All peroneal nerve catheters will receive the same volume of ropivacaine 0.2%. All the sciatic nerve catheters will receive the same volume of ropivacaine 0.2%.~The only inter-group variable will be the infusion rate. The fixed volume of ropivacaine will be determined in a separate study ('The Volume Study'), which is also part of the project: 'A novel technique for reliable, precise and safe postoperative management'.~The largest volumes tested in The Volume Study are 30 mL for the sciatic nerve and 20 mL for the common peroneal nerve. Therefore the highest volume for the two intervention days cannot exceed 30 mL (150 mg of ropivacaine).~We will ensure constant infusion rate and precise delivery of LA by using an electronic infusion pump and a nerve catheter.