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Preemptive Femoral Nerve Block Could Reduce the Rebound Pain After Periarticular Injection in Total Knee Arthroplasty
The Journal of Arthroplasty xxx (2016) 1e5
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Original article
Preemptive Femoral Nerve Block Could Reduce the Rebound Pain After Periarticular Injection in Total Knee Arthroplasty Yoon Seok Youm, MD a, Sung Do Cho, MD a, *, Hye Yong Cho, MD a, Chang Ho Hwang, MD b, Seung Hyun Jung, MD a, Kwang Ho Kim, MD a a b
Department of Orthopedic Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea Department of Physical Medicine and Rehabilitation, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
a r t i c l e i n f o
a b s t r a c t
Article history: Received 28 October 2015 Received in revised form 1 February 2016 Accepted 2 February 2016 Available online XXX
Background: We evaluated the effectiveness of postoperative pain management using intraoperative periarticular injection (PAI) and/or electromyography-guided preoperative femoral nerve block (FNB) in knees undergoing total knee arthroplasty (TKA). Methods: This study included 90 patients (90 knees) who underwent primary TKA. Thirty patients received a single injection of electromyography-guided FNB, 30 received intraoperative PAI, and 30 received both. Pain at rest and while moving was evaluated by a visual analog scale (VAS) at 0, 4, 8, 24, and 48 hours. Postoperative range of motion, time to walking, amount of opioid consumption, and complications were analyzed. Results: VAS immediately after surgery was significantly higher in the FNB group than in the PAI and combined groups, but did not differ significantly in the latter 2 groups. VAS after 4 and 8 hours showed similar results. VAS after 24 hours was significantly higher in the PAI than in the FNB and combined groups. After 48 hours, there were no differences among the 3 groups. Total opioid consumption was lower in the combined than in the FNB and PAI groups. Postoperative range of motion and time to walking were similar in the 3 groups. Conclusion: PAI was more effective than FNB during the early (0-8 hours) postoperative period after TKA. Patients treated with PAI, however, experienced rebound pain at 24 hours. The combination of PAI and FNB may provide greater postoperative pain management than either alone for the first 24 hours after TKA. © 2016 Elsevier Inc. All rights reserved.
Keywords: total knee arthroplasty periarticular injection femoral nerve block pain management rebound pain
Appropriate pain control after total knee arthroplasty (TKA) can enhance early functional recovery and improve patient satisfaction. Multimodal pain control regimens include oral or parenteral analgesics, nerve blockers, intravenous patient controlled analgesia (PCA) and periarticular injection (PAI) [1-3]. Because it is associated with fewer side effects than systemic opioids, continuous femoral nerve block (FNB) is frequently used to control postoperative pain after TKA. However, blocking of the femoral nerve may impair quadriceps muscle strength and increase the risk of infection. A single injection of FNB is easier to perform, less costly, and has
fewer complications than continuous FNB. Electromyography (EMG)-guided single injection FNB may provide better postoperative analgesia and a greater reduction in the demand for pain killers than FNB using traditional nerve stimulators [4]. PAI has also been reported to be effective in controlling immediate postoperative pain without the systemic side effects associated with systemic opioids [2,5-7]. Studies comparing PAI and FNB have yielded conflicting results about the superior efficacy of each [8-10]. This study, therefore, compared the effectiveness of intraoperative PAI and/or EMG-guided preoperative FNB in postoperative pain management of patients undergoing TKA.
No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2016.02.006. * Reprint requests: Sung Do Cho, MD, Department of Orthopedic Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, 290-3 Jeonha-dong, Dong-gu, Ulsan, 682-714, Korea.
Materials and Methods
http://dx.doi.org/10.1016/j.arth.2016.02.006 0883-5403/© 2016 Elsevier Inc. All rights reserved.
This study prospectively enrolled 90 patients (90 knees) who underwent unilateral TKA for osteoarthritis from March 2014 to March 2015. Patients were excluded if they had undergone bilateral
2
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5
or revision arthroplasty, had a neurologic disorder or coagulopathy, were older than 80 years, were hypersensitive to local anesthetics, were unable to understand pain scales or use PCA, or refused to provide inform consent (Fig. 1). The study protocol was approved by the institutional review board of our institution, and all patients provided written informed consent. All operations were performed by the same surgeon under general anesthesia. A midline skin incision was made followed by limited medial parapatellar arthrotomy and traditional sequential medial release. The anterior and posterior cruciate ligaments were removed from all knees. Distal femoral and proximal tibial cuts were made using intramedullary and extramedullary alignment guides, respectively. Balances of the medial/lateral ligaments and flexion/extension gaps were adjusted to confirm the absence of abnormal findings on valgus/varus stress tests, the ability to achieve full knee extension, and the absence of medial/lateral laxity or lift off of a trial component during flexion. The femoral and tibial components in all patients were fixed with cement. Immediately after surgery, patients were allowed to start quadriceps strengthening exercises and active straight leg raising as instructed before surgery. Patients started continuous passive motion exercises on the first postoperative day and progressive weight bearing with the assistance of a walker or cane as soon as possible. Patients were randomized using a computer-generated sequence into 3 groups. Thirty patients received a single EMGguided injection of FNB, 30 received intraoperative PAI, and 30 received both FNB and PAI. Patients in the FNB group received a single injection of ropivacaine. Patients were placed in the supine position, and the femoral artery was palpated below the inguinal ligament. A 7-mm, 22-gauge, Teflon-coated, electrically conductive, double-lumen, beveled cannula (Myojet disposable hypodermic needle electrode; TECA Accessories, New York, NY) was inserted
just lateral to the femoral artery and into the iliopsoas muscle. This cannula enabled both femoral nerve stimulation and injection of local anesthetic. A recording electrode was placed on the skin above the motor point of the vastus medialis to detect the maximum electrical signal for muscle contraction. The femoral nerve was located by nerve stimulation for 0.2 ms at a frequency of 1 Hz and an intensity of 5 mA while monitoring the change in amplitude of the electrical signal. Once the electrical signal was found, the stimulation intensity was reduced stepwise by moving the cannula back and forth and from side to side until the highest amplitude could be induced by a stimulation intensity <0.5 mA. After the aspiration test showed no evidence of blood, 10 mL of 0.375% ropivacaine was injected. The correct level of analgesia was confirmed by monitoring the disappearance of the electrical signal after stimulation with an intensity of 5 mA shortly after injection and by assessing the integumentary sensation in the dermatome of the femoral nerve by pinprick tests. Patients in the PAI group received injections of 50 mL of solution, including 40 mL of 0.75% ropivacaine, 7.5-mg morphine sulfate, 0.3-mg epinephrine, 40-mg methyl prednisolone, 30-mg ketorolac, 500-mg cefoxitin, and additional normal saline. Using a 50-mL syringe, this solution was injected into the medial/lateral/ posterior joint capsule and periosteum and around the incision site of the joint capsule before fixation of implants (Fig. 2). Subcutaneous tissue was not injected to avoid skin necrosis. To supplement both analgesic regimens, all patients received 400-mg celecoxib, 325-mg acetaminophen þ 37.5-mg tramadol, and 75-mg pregabalin in the evening on the day before surgery. Postoperative pain was controlled by intravenous PCA (1600-mg fentanyl þ 80-mg nefopam) and twice daily administration of celecoxib 200 mg, acetaminophen 325 mg þ tramadol 37.5 mg, and pregabalin 75 mg. Intravenous morphine (0.05-0.1 mg/kg) was used for the treatment of severe pain.
Fig. 1. Flow diagram of this study. EMG, electromyography; FNB, femoral nerve block; PAI, periarticular injection.
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5
3
Fig. 2. Diagram showing intraoperative periarticular injection into the (A) posterior capsule, (B) medial periosteum and capsule, (C) lateral periosteum and capsule, and (D) soft tissues around the incision.
Clinical Evaluations Age, gender, and body mass index were assessed preoperatively. Pain at rest and while moving was evaluated using a visual analog scale (VAS) preoperatively and 0, 4, 8, 24, and 48 hours postoperatively. Range of motion after 1, 2, and 6 weeks and 3 months, amount of opioid consumption for the first 72 hours postoperatively, time to walking, and complications were compared in the 3 groups. Statistical Analysis An a priori power analysis was performed to determine the appropriate number of patients required to detect differences in clinical results. With an analysis of variance design and a ¼ 0.05, at least 22 patients in each group were needed to provide 80% power for analysis. Therefore, this study included 30 patients per group. Clinical parameters were compared by analysis of variance and post hoc analysis. All statistical analyses were performed using commercially available software (SPSS, Chicago, IL), with P values <.05 considered statistically significant. Results Preoperative demographics did not differ among the 3 groups (Table 1). Mean resting/active VAS immediately after surgery was
Table 1 Preoperative Demographics. Variables
Group 1
Group 2
Group 3
P Value
Knees Mean age (y) Gender(male:female) Mean body mass index (kg/m2)
30 68.0 4:26 25.7
30 69.5 3:27 24.2
30 67.5 4:26 26.8
.387 .902 .295
significantly higher in the FNB (57.9/73.0) than in the PAI (51.3/54.6) and combined treatment (51.9/54.7) groups (P ¼ .016), but did not differ significantly in the latter 2 groups (P ¼ .980). Similar results were observed after 4 and 8 hours (Table 2). Mean resting/active VAS after 24 hours was significantly higher in the PAI (52.4/62.1) than in the FNB (43.6/53.8) group and combined treatment (42.2/46.7) groups (P ¼ .008). After 48 hours, however, there were no differences among the 3 groups (Fig. 3). Mean total opioid consumption for the first 72 hours postoperatively was significantly lower in the combined treatment group (64.8 mg) than in the FNB (75.7 mg) and PAI (79.1 mg) groups (P ¼ .015). There were no differences among the 3 groups in postoperative range of motion and time to walking (Tables 3 and 4). One patient in the PAI group experienced immediate postoperative temporary peroneal nerve palsy, which spontaneously resolved after several hours. None of the patients in the 3 groups experienced infection or skin necrosis. Discussion This study showed that PAI was more effective than FNB for early (0-8 hours) postoperative pain relief after TKA. However, patients receiving PAI experienced rebound pain 24 hours after TKA. Collectively, these results indicate that the combination of PAI
Table 2 Resting/Active Visual Analog Scale. Postoperative Times
Group 1 Group 2 Group 3 P Value (Resting/Active) (Resting/Active) (Resting/Active)
Immediate postoperative 4h 8h 24 h 48 h
57.9/73.0
51.3/54.6
51.9/54.7
.016
48.7/54.4 44.9/49.3 43.6/53.8 35.5/46.5
41.4/44.1 33.9/38.1 52.4/62.1 32.6/37.5
41.9/46.7 33.1/37.3 42.2/46.7 35.7/42.5
.000 .000 .008 .621
4
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5 Table 4 Time to Walking.
Able to walk >3 m (d, mean)
Fig. 3. PAI alone and FNB þ PAI were more effective for pain control than FNB alone for the first 8 hours after surgery. At 24 hours, however, FNB alone and FNB þ PAI were more effective than PAI alone.
and FNB was the most effective method of reducing pain for the first 24 hours after TKA. Administration of systemic opioids remains one of the most effective and basic pain control methods after TKA. However, opioids have numerous adverse effects on the respiratory, circulatory, urinary, gastrointestinal, and nervous systems [11-14]. Multimodal pain management may reduce these side effects while still providing effective pain control. These methods involve the use of multiple agents that act at different steps of the pain pathway and include spinal or epidural analgesia, nerve blockers, preemptive oral analgesia, intraoperative PAI and postoperative oral or parenteral analgesia [15,16]. Several reports have compared continuous FNB and intraoperative PAI. For example, intraoperative PAI resulted in significantly lower pain scores during activity and lower consumption of opioids on the first postoperative day than continuous FNB [8]. In addition, average pain on movement was found to be lower with PAI than with FNB [5]. Although both PAI and FNB provided good analgesia after TKA, PAI may be superior, as it is less costly and easier to perform. In our study, pain scores for the first 8 hours after TKA were lower in the PAI and combined (FNB þ PAI) groups than in the FNB group, indicating that PAI was more effective than FNB during this early (0-8 hours) postoperative period. No differences were observed between the PAI and combined treatment groups, indicating that the effects of these 2 agents were not synergistic, with the effects of FNB masked by those of PAI. FNB may be less effective than PAI during the early postoperative period because the posterior part of the knee is innervated by the sciatic nerve. Thus, injection into the posterior portion of the knee may be important in controlling immediate postoperative pain and enhancing patient satisfaction. In contrast to these findings, pain scores 24 hours postoperatively were significantly lower in the FNB and combined groups than in the PAI group, indicating that FNB was more effective than PAI at this time point. PAI likely resulted in the dispersion of administered drugs and their infiltration into multiple sites. Moreover, circulation around the capsule and periosteum was better at 24 hours than earlier. The relatively higher pain scores in the PAI group at 24 hours may have been due to the faster washout
Table 3 Postoperative Range of Motion. Postoperative Periods
Group 1
Group 2
Group 3
P Value
1 2 6 3
103.2 126.4 132.2 135.3
106.5 127.6 135.3 136.4
105.0 125.7 135.6 137.2
.315 .771 .361 .424
wk wk wk mo
Group 1
Group 2
Group 3
P Value
3.2
3.2
3.1
.610
of drugs with PAI than with FNB. Moreover, patients in the PAI group had higher pain scores after 24 hours than after 8 hours postoperatively with this rebound pain also due to faster washout of drugs in this group. Pain scores were lower in the combined than in the PAI group, indicating that the FNB could reduce this rebound pain. Indeed, several studies have reported that PAI was effective but short acting. For example, intraarticular injection of morphine and bupivacaine resulted in a modest short-term reduction in pain scores compared with placebo (saline) with the difference statistically significant only at 4 hours [6]. Another study found that PAI provided better pain control during the immediate postoperative period, but only while patients were in the postanesthesia care unit [7]. Moreover, patients who received PAI were found to have lower VAS scores for pain only during activity in the postanesthetic care unit and 4 hours after surgery [2]. In this study, PAI included ropivacaine, morphine sulfate, epinephrine, methyl prednisolone, and ketorolac. Ropivacaine is a long-acting local anesthetic with potency similar to bupivacaine, although ropivacaine is less likely to cause cardiovascular toxicity [17]. None of the patients in this study reported ropivacaine-related complications. A comparison of intraarticularly and systemically administered nonsteroidal anti-inflammatory drugs, including ketorolac showed a statistically significant effect in favor of intraarticular nonsteroidal anti-inflammatory drugs [18]. Opioid receptors have been identified on peripheral processes of sensory neurons. Moreover, tissue damage stimulates the expression of peripheral opioid receptors, likely resulting in a concomitant increase in their function [19]. Steroids were administered to reduce inflammatory reactions. EMG-guided single injection FNB can provide better pain relief than traditional administered FNB in patients undergoing TKA, as well as reducing the consumption of analgesics, suggesting that the EMG-guided approach may prove more efficacious in localizing nerves [4]. The failure rate of FNB was reported to be about 5%, and femoral nerve injury may occur during the procedure [20,21]. However, none of the patients in this study experienced any complications. There were no differences among the 3 groups of patients in postoperative range of motion and time to walking. This may have been due to both FNB and PAI having a relatively short duration of analgesic activity. However, total opioid consumption was lower in the combined group than in the FNB and PAI groups, suggesting that combinations of FNB and PAI may be more effective in controlling immediate postoperative pain than either alone. Moreover, patients treated with PAI alone experienced rebound pain 24 hours after TKA. These findings indicate that PAI should be administered together with FNB, rather than alone, to avoid rebound pain. The limitations of this study included the relatively small number of patients and the lack of measurement of pain VAS 12 hours after TKA. Another limitation may be the poor standardization of other factors affecting pain induction, such as duration of surgery and amounts of opioids and pain killers administered during surgery. Also, all operations were performed under general anesthesia instead of regional anesthesia. PAI was more effective than FNB during the early (0-8 hours) period after TKA but showed rebound pain after 24 hours. The combination of PAI and FNB may enhance postoperative pain management for the first 24 hours after TKA.
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5
Appendix A. Supplementary Data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.arth.2016.02.006.
References 1. Vendittoli PA, Makinen P, Drolet P, et al. A multimodal analgesia protocol for total knee arthroplasty. A randomized, controlled study. J Bone Joint Surg Am 2006;88:282. 2. Busch CA, Shore BJ, Bhandari R, et al. Efficacy of periarticular multimodal drug injection in total knee arthroplasty. A randomized trial. J Bone Joint Surg Am 2006;88:959. 3. Andersen LO, Husted H, Otte KS, et al. High volume infiltration analgesia in total knee arthroplasty: a randomized, double-blind, placebo-controlled trial. Acta Anaesthesiol Scand 2008;52:1331. 4. Youm YS, Cho SD, Hwang CH. Prospective, double-blind, randomized controlled trial of electrophysiologically guided femoral nerve block in total knee arthroplasty. Ther Clin Risk Manag 2013;9:107. 5. Affas F, Nygards EB, Stiller CO, et al. Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block. Acta Orthop 2011;82(4):441. 6. Mauerhan DR, Campbell M, Miller JS, et al. Intra-articular morphine and/or bupivacaine in the management of pain after total knee arthroplasty. J Arthroplasty 1997;12:546. 7. Lombardi Jr AV, Berend KR, Mallory TH, et al. Soft tissue and intraarticular injection of bupivacaine, epinephrine, and morphine has a beneficial effect after total knee arthroplasty. Clin Orthop Relat Res 2004;428:125. 8. Toftdahl K, Nikolajsen L, Haraldsted V, et al. Comparison of peri- and intraarticular analgesia with femoral nerve block after total knee arthroplasty: a randomized clinical trial. Acta Orthop 2007;78(2):172.
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9. Yadeau JT, Goytizolo EA, Padgett DE, et al. Analgesia after total knee replacement: local infiltration versus epidural combined with a femoral nerve blockade: a prospective, randomised pragmatic trial. Bone Joint J 2013;95:629. 10. Carli F, Clemente A, Asenjo JF, et al. Analgesia and functional outcome after total knee arthroplasty: periarticular infiltration vs continuous femoral nerve block. Br J Anaesth 2010;105:185. 11. Arunasalam K, Davenport HT, Painter S, et al. Ventilatory response tomorphine in young and old subjects. Anaesthesia 1983;38:529. 12. Coda BA, Hill HF, Hunt EB, et al. Cognitive and motor function impairments during continuous opioid analgesic infusions. Hum Psychopharmacol 1993;8: 383. 13. Duthie DJ, Nimmo WS. Adverse effects of opioid analgesic drugs. Br J Anaesth 1987;59:61. 14. Lowenstein E, Whiting RB, Bittar DA, et al. Local and neurally mediated effects of morphine on skeletal muscle vascular resistance. J Pharmacol Exp Ther 1972;180:359. 15. Parvizi J1, Miller AG, Gandhi K. Multimodal pain management after total joint arthroplasty. J Bone Joint Surg Am 2011;93:1075. 16. Maheshwari AV, Blum YC, Shekhar L, et al. Multimodal pain management after total hip and knee arthroplasty at the Ranawat Orthopaedic Center. Clin Orthop Relat Res 2009;467:1418. 17. Mather LE, Copeland SE, Ladd LA. Acute toxicity of local anesthetics: underlying harmacokinetic and pharmacodynamic concepts. Reg Anaesth Pain Med 2005;30(6):553. 18. Rømsing J, Møiniche S, Ostergaard D, et al. Local infiltration with NSAIDs for postoperative analgesia: evidence for a peripheral analgesic action. Acta Anaesthesiol Scand 2000;44:672. 19. Stein C, Schafer M, Machelska H. Attacking pain at its source: new perspectives on opioid. Nat Med 2003;9(8):1003. 20. Gurnaney H, Ganesh A, Cucchiaro G. The relationship between current intensity for nerve stimulation and success of peripheral nerve blocks performed in pediatric patients under general anesthesia. Anesth Analg 2007;105:1605. 21. Sharma S, Iorio R, Specht LM, et al. Complications of femoral nerve block for total knee arthroplasty. Clin Orthop Relat Res 2010;468:135.
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Original article
Preemptive Femoral Nerve Block Could Reduce the Rebound Pain After Periarticular Injection in Total Knee Arthroplasty Yoon Seok Youm, MD a, Sung Do Cho, MD a, *, Hye Yong Cho, MD a, Chang Ho Hwang, MD b, Seung Hyun Jung, MD a, Kwang Ho Kim, MD a a b
Department of Orthopedic Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea Department of Physical Medicine and Rehabilitation, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
a r t i c l e i n f o
a b s t r a c t
Article history: Received 28 October 2015 Received in revised form 1 February 2016 Accepted 2 February 2016 Available online XXX
Background: We evaluated the effectiveness of postoperative pain management using intraoperative periarticular injection (PAI) and/or electromyography-guided preoperative femoral nerve block (FNB) in knees undergoing total knee arthroplasty (TKA). Methods: This study included 90 patients (90 knees) who underwent primary TKA. Thirty patients received a single injection of electromyography-guided FNB, 30 received intraoperative PAI, and 30 received both. Pain at rest and while moving was evaluated by a visual analog scale (VAS) at 0, 4, 8, 24, and 48 hours. Postoperative range of motion, time to walking, amount of opioid consumption, and complications were analyzed. Results: VAS immediately after surgery was significantly higher in the FNB group than in the PAI and combined groups, but did not differ significantly in the latter 2 groups. VAS after 4 and 8 hours showed similar results. VAS after 24 hours was significantly higher in the PAI than in the FNB and combined groups. After 48 hours, there were no differences among the 3 groups. Total opioid consumption was lower in the combined than in the FNB and PAI groups. Postoperative range of motion and time to walking were similar in the 3 groups. Conclusion: PAI was more effective than FNB during the early (0-8 hours) postoperative period after TKA. Patients treated with PAI, however, experienced rebound pain at 24 hours. The combination of PAI and FNB may provide greater postoperative pain management than either alone for the first 24 hours after TKA. © 2016 Elsevier Inc. All rights reserved.
Keywords: total knee arthroplasty periarticular injection femoral nerve block pain management rebound pain
Appropriate pain control after total knee arthroplasty (TKA) can enhance early functional recovery and improve patient satisfaction. Multimodal pain control regimens include oral or parenteral analgesics, nerve blockers, intravenous patient controlled analgesia (PCA) and periarticular injection (PAI) [1-3]. Because it is associated with fewer side effects than systemic opioids, continuous femoral nerve block (FNB) is frequently used to control postoperative pain after TKA. However, blocking of the femoral nerve may impair quadriceps muscle strength and increase the risk of infection. A single injection of FNB is easier to perform, less costly, and has
fewer complications than continuous FNB. Electromyography (EMG)-guided single injection FNB may provide better postoperative analgesia and a greater reduction in the demand for pain killers than FNB using traditional nerve stimulators [4]. PAI has also been reported to be effective in controlling immediate postoperative pain without the systemic side effects associated with systemic opioids [2,5-7]. Studies comparing PAI and FNB have yielded conflicting results about the superior efficacy of each [8-10]. This study, therefore, compared the effectiveness of intraoperative PAI and/or EMG-guided preoperative FNB in postoperative pain management of patients undergoing TKA.
No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2016.02.006. * Reprint requests: Sung Do Cho, MD, Department of Orthopedic Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, 290-3 Jeonha-dong, Dong-gu, Ulsan, 682-714, Korea.
Materials and Methods
http://dx.doi.org/10.1016/j.arth.2016.02.006 0883-5403/© 2016 Elsevier Inc. All rights reserved.
This study prospectively enrolled 90 patients (90 knees) who underwent unilateral TKA for osteoarthritis from March 2014 to March 2015. Patients were excluded if they had undergone bilateral
2
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5
or revision arthroplasty, had a neurologic disorder or coagulopathy, were older than 80 years, were hypersensitive to local anesthetics, were unable to understand pain scales or use PCA, or refused to provide inform consent (Fig. 1). The study protocol was approved by the institutional review board of our institution, and all patients provided written informed consent. All operations were performed by the same surgeon under general anesthesia. A midline skin incision was made followed by limited medial parapatellar arthrotomy and traditional sequential medial release. The anterior and posterior cruciate ligaments were removed from all knees. Distal femoral and proximal tibial cuts were made using intramedullary and extramedullary alignment guides, respectively. Balances of the medial/lateral ligaments and flexion/extension gaps were adjusted to confirm the absence of abnormal findings on valgus/varus stress tests, the ability to achieve full knee extension, and the absence of medial/lateral laxity or lift off of a trial component during flexion. The femoral and tibial components in all patients were fixed with cement. Immediately after surgery, patients were allowed to start quadriceps strengthening exercises and active straight leg raising as instructed before surgery. Patients started continuous passive motion exercises on the first postoperative day and progressive weight bearing with the assistance of a walker or cane as soon as possible. Patients were randomized using a computer-generated sequence into 3 groups. Thirty patients received a single EMGguided injection of FNB, 30 received intraoperative PAI, and 30 received both FNB and PAI. Patients in the FNB group received a single injection of ropivacaine. Patients were placed in the supine position, and the femoral artery was palpated below the inguinal ligament. A 7-mm, 22-gauge, Teflon-coated, electrically conductive, double-lumen, beveled cannula (Myojet disposable hypodermic needle electrode; TECA Accessories, New York, NY) was inserted
just lateral to the femoral artery and into the iliopsoas muscle. This cannula enabled both femoral nerve stimulation and injection of local anesthetic. A recording electrode was placed on the skin above the motor point of the vastus medialis to detect the maximum electrical signal for muscle contraction. The femoral nerve was located by nerve stimulation for 0.2 ms at a frequency of 1 Hz and an intensity of 5 mA while monitoring the change in amplitude of the electrical signal. Once the electrical signal was found, the stimulation intensity was reduced stepwise by moving the cannula back and forth and from side to side until the highest amplitude could be induced by a stimulation intensity <0.5 mA. After the aspiration test showed no evidence of blood, 10 mL of 0.375% ropivacaine was injected. The correct level of analgesia was confirmed by monitoring the disappearance of the electrical signal after stimulation with an intensity of 5 mA shortly after injection and by assessing the integumentary sensation in the dermatome of the femoral nerve by pinprick tests. Patients in the PAI group received injections of 50 mL of solution, including 40 mL of 0.75% ropivacaine, 7.5-mg morphine sulfate, 0.3-mg epinephrine, 40-mg methyl prednisolone, 30-mg ketorolac, 500-mg cefoxitin, and additional normal saline. Using a 50-mL syringe, this solution was injected into the medial/lateral/ posterior joint capsule and periosteum and around the incision site of the joint capsule before fixation of implants (Fig. 2). Subcutaneous tissue was not injected to avoid skin necrosis. To supplement both analgesic regimens, all patients received 400-mg celecoxib, 325-mg acetaminophen þ 37.5-mg tramadol, and 75-mg pregabalin in the evening on the day before surgery. Postoperative pain was controlled by intravenous PCA (1600-mg fentanyl þ 80-mg nefopam) and twice daily administration of celecoxib 200 mg, acetaminophen 325 mg þ tramadol 37.5 mg, and pregabalin 75 mg. Intravenous morphine (0.05-0.1 mg/kg) was used for the treatment of severe pain.
Fig. 1. Flow diagram of this study. EMG, electromyography; FNB, femoral nerve block; PAI, periarticular injection.
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5
3
Fig. 2. Diagram showing intraoperative periarticular injection into the (A) posterior capsule, (B) medial periosteum and capsule, (C) lateral periosteum and capsule, and (D) soft tissues around the incision.
Clinical Evaluations Age, gender, and body mass index were assessed preoperatively. Pain at rest and while moving was evaluated using a visual analog scale (VAS) preoperatively and 0, 4, 8, 24, and 48 hours postoperatively. Range of motion after 1, 2, and 6 weeks and 3 months, amount of opioid consumption for the first 72 hours postoperatively, time to walking, and complications were compared in the 3 groups. Statistical Analysis An a priori power analysis was performed to determine the appropriate number of patients required to detect differences in clinical results. With an analysis of variance design and a ¼ 0.05, at least 22 patients in each group were needed to provide 80% power for analysis. Therefore, this study included 30 patients per group. Clinical parameters were compared by analysis of variance and post hoc analysis. All statistical analyses were performed using commercially available software (SPSS, Chicago, IL), with P values <.05 considered statistically significant. Results Preoperative demographics did not differ among the 3 groups (Table 1). Mean resting/active VAS immediately after surgery was
Table 1 Preoperative Demographics. Variables
Group 1
Group 2
Group 3
P Value
Knees Mean age (y) Gender(male:female) Mean body mass index (kg/m2)
30 68.0 4:26 25.7
30 69.5 3:27 24.2
30 67.5 4:26 26.8
.387 .902 .295
significantly higher in the FNB (57.9/73.0) than in the PAI (51.3/54.6) and combined treatment (51.9/54.7) groups (P ¼ .016), but did not differ significantly in the latter 2 groups (P ¼ .980). Similar results were observed after 4 and 8 hours (Table 2). Mean resting/active VAS after 24 hours was significantly higher in the PAI (52.4/62.1) than in the FNB (43.6/53.8) group and combined treatment (42.2/46.7) groups (P ¼ .008). After 48 hours, however, there were no differences among the 3 groups (Fig. 3). Mean total opioid consumption for the first 72 hours postoperatively was significantly lower in the combined treatment group (64.8 mg) than in the FNB (75.7 mg) and PAI (79.1 mg) groups (P ¼ .015). There were no differences among the 3 groups in postoperative range of motion and time to walking (Tables 3 and 4). One patient in the PAI group experienced immediate postoperative temporary peroneal nerve palsy, which spontaneously resolved after several hours. None of the patients in the 3 groups experienced infection or skin necrosis. Discussion This study showed that PAI was more effective than FNB for early (0-8 hours) postoperative pain relief after TKA. However, patients receiving PAI experienced rebound pain 24 hours after TKA. Collectively, these results indicate that the combination of PAI
Table 2 Resting/Active Visual Analog Scale. Postoperative Times
Group 1 Group 2 Group 3 P Value (Resting/Active) (Resting/Active) (Resting/Active)
Immediate postoperative 4h 8h 24 h 48 h
57.9/73.0
51.3/54.6
51.9/54.7
.016
48.7/54.4 44.9/49.3 43.6/53.8 35.5/46.5
41.4/44.1 33.9/38.1 52.4/62.1 32.6/37.5
41.9/46.7 33.1/37.3 42.2/46.7 35.7/42.5
.000 .000 .008 .621
4
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5 Table 4 Time to Walking.
Able to walk >3 m (d, mean)
Fig. 3. PAI alone and FNB þ PAI were more effective for pain control than FNB alone for the first 8 hours after surgery. At 24 hours, however, FNB alone and FNB þ PAI were more effective than PAI alone.
and FNB was the most effective method of reducing pain for the first 24 hours after TKA. Administration of systemic opioids remains one of the most effective and basic pain control methods after TKA. However, opioids have numerous adverse effects on the respiratory, circulatory, urinary, gastrointestinal, and nervous systems [11-14]. Multimodal pain management may reduce these side effects while still providing effective pain control. These methods involve the use of multiple agents that act at different steps of the pain pathway and include spinal or epidural analgesia, nerve blockers, preemptive oral analgesia, intraoperative PAI and postoperative oral or parenteral analgesia [15,16]. Several reports have compared continuous FNB and intraoperative PAI. For example, intraoperative PAI resulted in significantly lower pain scores during activity and lower consumption of opioids on the first postoperative day than continuous FNB [8]. In addition, average pain on movement was found to be lower with PAI than with FNB [5]. Although both PAI and FNB provided good analgesia after TKA, PAI may be superior, as it is less costly and easier to perform. In our study, pain scores for the first 8 hours after TKA were lower in the PAI and combined (FNB þ PAI) groups than in the FNB group, indicating that PAI was more effective than FNB during this early (0-8 hours) postoperative period. No differences were observed between the PAI and combined treatment groups, indicating that the effects of these 2 agents were not synergistic, with the effects of FNB masked by those of PAI. FNB may be less effective than PAI during the early postoperative period because the posterior part of the knee is innervated by the sciatic nerve. Thus, injection into the posterior portion of the knee may be important in controlling immediate postoperative pain and enhancing patient satisfaction. In contrast to these findings, pain scores 24 hours postoperatively were significantly lower in the FNB and combined groups than in the PAI group, indicating that FNB was more effective than PAI at this time point. PAI likely resulted in the dispersion of administered drugs and their infiltration into multiple sites. Moreover, circulation around the capsule and periosteum was better at 24 hours than earlier. The relatively higher pain scores in the PAI group at 24 hours may have been due to the faster washout
Table 3 Postoperative Range of Motion. Postoperative Periods
Group 1
Group 2
Group 3
P Value
1 2 6 3
103.2 126.4 132.2 135.3
106.5 127.6 135.3 136.4
105.0 125.7 135.6 137.2
.315 .771 .361 .424
wk wk wk mo
Group 1
Group 2
Group 3
P Value
3.2
3.2
3.1
.610
of drugs with PAI than with FNB. Moreover, patients in the PAI group had higher pain scores after 24 hours than after 8 hours postoperatively with this rebound pain also due to faster washout of drugs in this group. Pain scores were lower in the combined than in the PAI group, indicating that the FNB could reduce this rebound pain. Indeed, several studies have reported that PAI was effective but short acting. For example, intraarticular injection of morphine and bupivacaine resulted in a modest short-term reduction in pain scores compared with placebo (saline) with the difference statistically significant only at 4 hours [6]. Another study found that PAI provided better pain control during the immediate postoperative period, but only while patients were in the postanesthesia care unit [7]. Moreover, patients who received PAI were found to have lower VAS scores for pain only during activity in the postanesthetic care unit and 4 hours after surgery [2]. In this study, PAI included ropivacaine, morphine sulfate, epinephrine, methyl prednisolone, and ketorolac. Ropivacaine is a long-acting local anesthetic with potency similar to bupivacaine, although ropivacaine is less likely to cause cardiovascular toxicity [17]. None of the patients in this study reported ropivacaine-related complications. A comparison of intraarticularly and systemically administered nonsteroidal anti-inflammatory drugs, including ketorolac showed a statistically significant effect in favor of intraarticular nonsteroidal anti-inflammatory drugs [18]. Opioid receptors have been identified on peripheral processes of sensory neurons. Moreover, tissue damage stimulates the expression of peripheral opioid receptors, likely resulting in a concomitant increase in their function [19]. Steroids were administered to reduce inflammatory reactions. EMG-guided single injection FNB can provide better pain relief than traditional administered FNB in patients undergoing TKA, as well as reducing the consumption of analgesics, suggesting that the EMG-guided approach may prove more efficacious in localizing nerves [4]. The failure rate of FNB was reported to be about 5%, and femoral nerve injury may occur during the procedure [20,21]. However, none of the patients in this study experienced any complications. There were no differences among the 3 groups of patients in postoperative range of motion and time to walking. This may have been due to both FNB and PAI having a relatively short duration of analgesic activity. However, total opioid consumption was lower in the combined group than in the FNB and PAI groups, suggesting that combinations of FNB and PAI may be more effective in controlling immediate postoperative pain than either alone. Moreover, patients treated with PAI alone experienced rebound pain 24 hours after TKA. These findings indicate that PAI should be administered together with FNB, rather than alone, to avoid rebound pain. The limitations of this study included the relatively small number of patients and the lack of measurement of pain VAS 12 hours after TKA. Another limitation may be the poor standardization of other factors affecting pain induction, such as duration of surgery and amounts of opioids and pain killers administered during surgery. Also, all operations were performed under general anesthesia instead of regional anesthesia. PAI was more effective than FNB during the early (0-8 hours) period after TKA but showed rebound pain after 24 hours. The combination of PAI and FNB may enhance postoperative pain management for the first 24 hours after TKA.
Y.S. Youm et al. / The Journal of Arthroplasty xxx (2016) 1e5
Appendix A. Supplementary Data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.arth.2016.02.006.
References 1. Vendittoli PA, Makinen P, Drolet P, et al. A multimodal analgesia protocol for total knee arthroplasty. A randomized, controlled study. J Bone Joint Surg Am 2006;88:282. 2. Busch CA, Shore BJ, Bhandari R, et al. Efficacy of periarticular multimodal drug injection in total knee arthroplasty. A randomized trial. J Bone Joint Surg Am 2006;88:959. 3. Andersen LO, Husted H, Otte KS, et al. High volume infiltration analgesia in total knee arthroplasty: a randomized, double-blind, placebo-controlled trial. Acta Anaesthesiol Scand 2008;52:1331. 4. Youm YS, Cho SD, Hwang CH. Prospective, double-blind, randomized controlled trial of electrophysiologically guided femoral nerve block in total knee arthroplasty. Ther Clin Risk Manag 2013;9:107. 5. Affas F, Nygards EB, Stiller CO, et al. Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block. Acta Orthop 2011;82(4):441. 6. Mauerhan DR, Campbell M, Miller JS, et al. Intra-articular morphine and/or bupivacaine in the management of pain after total knee arthroplasty. J Arthroplasty 1997;12:546. 7. Lombardi Jr AV, Berend KR, Mallory TH, et al. Soft tissue and intraarticular injection of bupivacaine, epinephrine, and morphine has a beneficial effect after total knee arthroplasty. Clin Orthop Relat Res 2004;428:125. 8. Toftdahl K, Nikolajsen L, Haraldsted V, et al. Comparison of peri- and intraarticular analgesia with femoral nerve block after total knee arthroplasty: a randomized clinical trial. Acta Orthop 2007;78(2):172.
5
9. Yadeau JT, Goytizolo EA, Padgett DE, et al. Analgesia after total knee replacement: local infiltration versus epidural combined with a femoral nerve blockade: a prospective, randomised pragmatic trial. Bone Joint J 2013;95:629. 10. Carli F, Clemente A, Asenjo JF, et al. Analgesia and functional outcome after total knee arthroplasty: periarticular infiltration vs continuous femoral nerve block. Br J Anaesth 2010;105:185. 11. Arunasalam K, Davenport HT, Painter S, et al. Ventilatory response tomorphine in young and old subjects. Anaesthesia 1983;38:529. 12. Coda BA, Hill HF, Hunt EB, et al. Cognitive and motor function impairments during continuous opioid analgesic infusions. Hum Psychopharmacol 1993;8: 383. 13. Duthie DJ, Nimmo WS. Adverse effects of opioid analgesic drugs. Br J Anaesth 1987;59:61. 14. Lowenstein E, Whiting RB, Bittar DA, et al. Local and neurally mediated effects of morphine on skeletal muscle vascular resistance. J Pharmacol Exp Ther 1972;180:359. 15. Parvizi J1, Miller AG, Gandhi K. Multimodal pain management after total joint arthroplasty. J Bone Joint Surg Am 2011;93:1075. 16. Maheshwari AV, Blum YC, Shekhar L, et al. Multimodal pain management after total hip and knee arthroplasty at the Ranawat Orthopaedic Center. Clin Orthop Relat Res 2009;467:1418. 17. Mather LE, Copeland SE, Ladd LA. Acute toxicity of local anesthetics: underlying harmacokinetic and pharmacodynamic concepts. Reg Anaesth Pain Med 2005;30(6):553. 18. Rømsing J, Møiniche S, Ostergaard D, et al. Local infiltration with NSAIDs for postoperative analgesia: evidence for a peripheral analgesic action. Acta Anaesthesiol Scand 2000;44:672. 19. Stein C, Schafer M, Machelska H. Attacking pain at its source: new perspectives on opioid. Nat Med 2003;9(8):1003. 20. Gurnaney H, Ganesh A, Cucchiaro G. The relationship between current intensity for nerve stimulation and success of peripheral nerve blocks performed in pediatric patients under general anesthesia. Anesth Analg 2007;105:1605. 21. Sharma S, Iorio R, Specht LM, et al. Complications of femoral nerve block for total knee arthroplasty. Clin Orthop Relat Res 2010;468:135.