The most useful method to manage pain after major ankle surgery is infusion of local
analgesics with a catheter close to the sciatic nerve.
Sensation from the ankle are carried by three nerves: The tibial and peroneal nerve (unified
in the sciatic nerve) and the saphenous nerve.
Study purpose is to test whether continuous infusion of local analgesics by saphenous nerve
catheter provide a better treatment of pain in comparison with a single injection nerve
block. In addition cost-effectiveness of the two methods are compared.
The 50 patients of the trial are randomized in clusters of ten. We intend to do a preliminary
analysis of the data from the first 40 patients. However, it is not an interim analysis.
Fifty patients will be included independent of the result of the preliminary analysis. The
random allocation of the last 10 patients will also be double-blinded.