Continuous femoral nerve block after total knee arthroplasty?
Article first published online: 15 APR 2009
© 2009 The Authors. Journal compilation © 2009 The Acta Anaesthesiologica Scandinavica Foundation
Acta Anaesthesiologica Scandinavica
Volume 53, Issue 7, pages 914–920, August 2009
How to Cite
KADIC, L., BOONSTRA, M. C., DE WAAL MALEFIJT, M. C., LAKO, S. J., VAN EGMOND, J. and DRIESSEN, J. J. (2009), Continuous femoral nerve block after total knee arthroplasty?. Acta Anaesthesiologica Scandinavica, 53: 914–920. doi: 10.1111/j.1399-6576.2009.01965.x
- Issue published online: 7 JUL 2009
- Article first published online: 15 APR 2009
- Accepted for publication 14 February 2009
Background: A continuous femoral nerve block is frequently used as an adjunct therapy after total knee arthroplasty (TKA). However, there is still debate on its benefits.
Methods: In this prospective, randomized study, patients received a basic analgesic regimen of paracetamol and dicloflenac for the first 48 h postoperatively. In addition, the study group received a continuous femoral nerve block. A morphine patient-controlled analgesia pump was also available as a rescue analgesic to all the patients. Patients' numeric rating scores for pain, the amount of morphine consumed and its side effects during the first 48 h were recorded. Knee flexion angles achieved during the first week were registered. Three months postoperatively, patients completed Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score.
Results: The study group (n=27) had less pain (P=0.0016) during the first 48 h, was more satisfied with the analgesia (P<0.001) and used less morphine (P=0.007) compared with the control group (n=26). Fewer patients were nauseated, vomited or were drowsy in the study group (P=0.001). Also, the study group achieved better knee flexion in the first 6 days after surgery (P=0.001), with more patients reaching 90° flexion than the control group. However, after 3 months, there were no significant functional differences between the groups.
Conclusion: A continuous femoral nerve block leads to better analgesia, less morphine consumption and less morphine-related side effects after TKA. Early functional recovery is improved, resulting in more patients reaching 90° knee flexion after 6 days. However, after 3 months, no significant functional benefits were found.