Ultrasound-guided Blocks for Ambulatory Knee Arthroscopy

In this study, we wish to investigate the effect of ultrasound (US) -guided block of the saphenous nerve (SN) and the posterior branch of the obturator nerve (ONP) on postoperative pain and the use of opioids (morphine-like pain medicine) in the first 24 hours following ambulatory knee arthroscopy. We wish to investigate the analgesic effect of these two blocks compared to placebo (injection of local anesthetic with known pain blocking properties compared with injection of a saline solution), when used as a supplement to conventional oral analgesics. We hypothesize that patients receiving the active treatment may experience less pain during the first 24 hours after their operation than patients receiving the placebo treatment, and possibly require less opioid analgesics, experience less opioid related side effects and have a higher function level in this period than patients receiving the placebo treatment.