Pain management in outpatient knee arthroscopy

Abstract

Knee arthroscopy is probably the most common orthopaedic procedure performed. The objective of this thesis was to compare local anaesthesia with other used anaesthetic techniques for outpatient knee arthroscopy. The choice of postoperative local anaesthetic and the general postoperative pain pattern and management, as well as the general outcome were evaluated. Totally 642 patients were involved in three prospective randomized studies and one follow-up.

In the first study patients were randomly allocated to either local (LA) (n=200), general (GA) (n=100) or spinal (SA) (n=100) anaesthesia. All patients were assessed and made self-assessments during the day of surgery and postoperatively. The surgeons were asked to grade the technical difficulty of the arthroscopic procedure on a VAS scale, and they also reported if the allocated anaesthesia was optimal, or, if not, which technique they would have preferred.

In the second study 120 patients were studied comparing levobupivacaine 2.5 mg/ml (n=40), levobupivacaine 5 mg/ml (n=40), and lidocaine 10 mg/ml with adrenaline (n=40), administered intra-articularly at the end of surgery performed under light GA. Primary study endpoint was the need for any analgesics during the first 24 postoperative hours. In the third study 122 patients were randomised to either a NSAID (lornoxicam) (n=61), or a coxib (rofecoxib) (n=61) postoperatively after surgery in GA. Pain ratings and need for rescue medication were followed for four consecutive days. The fourth study is a questionnaire follow-up, six months after surgery, of all the enrolled patients in the first study.

Results: Ninety percent of the LA patients were satisfied with the procedure, although they stated statistically more intraoperative pain than the GA and SA patients. In 5 % of the LA patients the surgeon reported technical difficulties. If excess synovitis was present, LA did not seem to provide sufficient anaesthesia for surgery. Levobupivacaine 5 mg/ml was found to be an effective postoperative local anaesthetic in outpatient knee arthroscopy, providing superior postoperative analgesia as compared to lidocaine or a lower concentration of levobupivacaine. Twenty-five percent required, however, further analgesics during the first 24 hours after surgery. There was no difference in need for rescue analgesia (50 %), pain rating or side-effect profile between the patients receiving either a conventional NSAID or a selective cox-II-inhibitor. No repeat arthroscopies occurred in the SA or GA groups, three occurred in the LA group. The clinical course was altered by the repeat arthroscopy in only one case. There was no difference in the satisfaction rate between the anaesthesia groups six months after surgery.

Summary and conclusion: LA is a valid alternative to GA, or SA for outpatient knee arthroscopy in a selected group of motivated patients. The use of a long-acting local anaesthetic (levobupivacaine 5 mg/ml) intra-articularly, given immediately postoperatively, reduces experienced pain 24 hours after surgery. Still this must be combined with the access to oral analgesics for the coming 2-3 days in order to manage pain. We found no evidence for using the more expensive coxibes for the postoperative pain management. The choice of anaesthesia does not influence the frequency of repeat arthroscopy, satisfaction with the procedure, or recovery six months after surgery.