KNEE
Two continuous femoral nerve block strategies after TKA
Won Sik Choy
•
Sang Ki Lee
•
Kap Jung Kim
•
Byoung Sub Kam
•
Dae Suk Yang
•
Kyoung Wan Bae
Received: 15 November 2010 / Accepted: 4 April 2011 / Published online: 12 April 2011
Ó Springer-Verlag 2011
Abstract
Purpose The purposes of this study were to compare the
pain score, systemic opioid consumption, and range of
motion (ROM) between the group where the use of con-
tinuous femoral nerve block (CFNB) was discontinued on
postoperative day 3 (POD 3) and the group where it was
discontinued on POD 7 within an established clinical
pathway for postoperative recovery after total knee
arthroplasty (TKA) and to assess the treatment-related side
effects and complications, as well as the functional status
of these two groups of patients at 2 years after surgery.
Methods This prospective, randomized, double-blinded
trial compared the analgesic efficacy and the functional
outcomes between group A (n = 30) where continuous
femoral nerve block was performed until POD 3 (discon-
tinued prior to the initiation of range of motion (ROM)
exercises) and group B (n = 33), where the continuous
femoral nerve block was performed until POD 7 (discon-
tinued during the ROM exercise) after TKA.
Results The resting pain scores of group B were lower
than those of group A but there was no significant differ-
ence between the two groups (n.s., P = 0.387). However,
the peak pain scores during ROM exercise, beginning on
POD3 through to POD14, were significantly lower in group
B than in group A (P = 0.001). The cumulative morphine
IV-PCA requirements through the POD 2 were similar in
the two groups (n.s., P = 0.811). However, the cumulative
oral oxycodone consumption during hospitalization was
significantly lower in group B than in group A,
P \ 0.0001. Group B showed significantly greater satis-
faction with their method of analgesia than group A
(P = 0.001). Group A scored 2.0 (2.0–3.0), whereas group
B scored 1.0 (1.0–2.0). At 2 years, there was no significant
difference in the functional outcomes (the knee flexion and
extension angle, the Knee Society Score, and WOMAC
pain, stiffness, and function scale).
Conclusion The study group who received 7-day con-
tinuous femoral nerve block after TKA showed superior
analgesia and higher patient satisfaction during the hospital
stay than those given 3-day continuous femoral nerve
block. Despite the additional time, effort and cost to place
and manage continuous femoral nerve catheters, the 7-day
continuous femoral nerve block can be recommended as an
effective and safe regional component of a multimodal
analgesia strategy after TKA.
Level of evidence II.
Keywords Continuous femoral nerve block Á
Total knee arthroplasty Á Functional outcomes
Introduction
The increased incidence of osteoarthritic disease and number
of elderly people has led to a gradual increase in the use of
TKA, which is one of the most successful orthopedic pro-
cedures for improving the health-related quality of life.
However, postoperative pain after TKA is often severe and
may hinder participation in early intensive physical therapy,
which is considered one of the most important factors for
optimal postoperative knee rehabilitation [18]. A range of
techniques have been used to provide postoperative anal-
gesia, which include non-steroidal anti-inflammatory
drugs (NASIDs), patient-controlled analgesia (PCA) with
W. S. Choy Á S. K. Lee (&) Á K. J. Kim Á
B. S. Kam Á D. S. Yang Á K. W. Bae
Department of Orthopedic Surgery, Eulji University College of
Medicine, 1306 Dunsan-dong, Seo-gu, Daejeon 302-799, Korea
e-mail: sklee@eulji.ac.kr
123
Knee Surg Sports Traumatol Arthrosc (2011) 19:1901–1908
DOI 10.1007/s00167-011-1510-4