THEKNE-01898; No of Pages 5 The Knee xxx (2014) xxx–xxx

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The Knee

Comparison of peripheral nerve block with periarticular injection analgesia after total knee arthroplasty: A randomized, controlled study Kazuhide Uesugi ⁎, Naoko Kitano, Tadashi Kikuchi, Miho Sekiguchi, Shin-ichi Konno Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, Fukushima, Japan

a r t i c l e

i n f o

Article history: Received 5 October 2013 Received in revised form 3 April 2014 Accepted 9 April 2014 Available online xxxx Keywords: Periarticular injection analgesia Total knee arthroplasty Peripheral nerve block Randomized study

a b s t r a c t Background: Pain after total knee arthroplasty (TKA) is usually severe. Recently, the usefulness of local periarticular injection analgesia (PAI) and peripheral nerve block (PNB) has been reported. We report a prospective blinded randomized trial of PAI versus PNB in patients undergoing primary TKA, in accordance with the CONSORT statement 2010. Methods: A total of 210 patients undergoing TKA under spinal anesthesia were randomized to receive PNB group or PAI group. In the PNB group, femoral nerve block and sciatic nerve block were performed. In the PAI group, a special mixture containing ropivacaine, saline, epinephrine, morphine hydrochloride, and dexamethasone was injected into the periarticular soft tissue. Pain intensity at rest was assessed using a numerical rating scale (NRS: 0–10) after surgery. Use of a diclofenac sodium suppository (25 mg) was allowed for all patients at any time after surgery, and the diclofenac sodium suppository usage was assessed. The NRS for patient satisfaction at 48 hours after surgery was examined. Results: The average NRS for pain at rest up to 48 hours after surgery was low in both groups. Within 48 hours after surgery, the diclofenac sodium suppository usage was similar in both groups. There were no significant differences in the NRS for patient satisfaction in both groups. Conclusions: The analgesic effects of PAI and PNB are similar. PAI may be considered superior to PNB because it is easier to perform. Level of Evidence: Therapeutic Level 1. © 2014 Elsevier B.V. All rights reserved.

1. Introduction Total knee arthroplasty (TKA) is one of the surgical procedures with the best outcomes for osteoarthritis of the knee. Pain management following TKA is an important issue that affects postoperative range of motion of the knee, patient satisfaction, and the duration of hospitalization [1]. The concept of preemptive analgesia has previously been described, and studies have investigated its effectiveness [2]. It is important to administer analgesics after TKA before severe postoperative pain occurs to prevent the establishment of central sensitivity, which amplifies postoperative pain. Existing methods of pain management following TKA include continuous epidural anesthesia using a local anesthetic and patientcontrolled analgesia (PCA) with morphine. Continuous epidural anesthesia and PCA are extremely effective methods of analgesia for severe pain during the acute postoperative period, but they may cause adverse events including nausea, vomiting, delirium, constipation, anuresis, ⁎ Corresponding author at: Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima City, Fukushima, 960-1295, Japan. Tel.: +81 24 547 1276; fax: +81 24 548 5505. E-mail address: [email protected] (K. Uesugi).

dizziness, sedation, respiratory depression, and itching [3]. In addition, continuous epidural anesthesia requires an advanced skill and intensive labour in its management. Furthermore, epidural anesthesia carries the risk of causing severe neurological complications (epidural haematoma or spinal haematoma), although these are rare [4]. If postoperative anticoagulant therapy is used to prevent deep vein thrombosis during the perioperative period for TKA, methods of analgesia that may cause haematoma should be avoided. It is essential to identify safer procedures for the selection of methods of postoperative analgesia. In recent years, peripheral nerve block (PNB) and periarticular injection (PAI) have been reported as useful for managing pain after TKA [5, 6]. The most common types of PNB are femoral nerve block and sciatic nerve block. It has been reported that femoral/sciatic nerve blocks in TKA provided a quality of analgesia and functional outcomes similar to those of continuous epidural anesthesia, but with fewer side effects [7]. PAI consists of the direct injection of a solution containing local anesthetic, morphine, and steroids into the periarticular area during surgery to reduce postoperative pain and inflammation [8]. These methods of analgesia avoid the risk of postoperative complications specific to continuous epidural analgesia and PCA [9,10]. Both PNB and PAI have been reported to reduce narcotic usage and the pain score during the early postoperative period, particularly within

http://dx.doi.org/10.1016/j.knee.2014.04.008 0968-0160/© 2014 Elsevier B.V. All rights reserved.

Please cite this article as: Uesugi K, et al, Comparison of peripheral nerve block with periarticular injection analgesia after total knee arthroplasty: A randomized, controlled study, Knee (2014), http://dx.doi.org/10.1016/j.knee.2014.04.008

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K. Uesugi et al. / The Knee xxx (2014) xxx–xxx

48 hours. The objective of the present study was to compare the analgesic effectiveness of PNB and PAI during the early postoperative period following TKA. 2. Methods 2.1. Participants The subjects were patients with osteoarthritis of the knee who were scheduled to undergo TKA. Patients who were scheduled to undergo simultaneous bilateral TKA and those with a previous history of knee joint surgery, rheumatoid arthritis, regular narcotic use, psychiatric disorder, neuromuscular disorder, severe systemic disorder (heart failure, respiratory organ failure, kidney failure, liver failure, or clotting disorder), or drug allergy were excluded. Patients who developed delirium after TKA were also excluded. This study was approved by the Ethics Committee of Fukushima Medical University (registration number 1462). Written, informed consent was obtained from all subjects before their participation in the study. 2.2. Study design This study was a prospective, randomized, double-blind comparative trial. Patients were randomly allocated to one of two treatment groups and given either PAI or PNB. Random tables were generated using SPSS for Windows (version 16.0; SPSS Inc., Chicago IL, USA). A total of 210 sealed envelopes were prepared. The recruitment period ran for five months from August 1 to December 30, 2012. The study was performed with neither patients nor the postoperative team (evaluators, nurses, physiotherapists) aware of the group to which each patient belonged. 2.3. Surgery All patients underwent spinal anesthesia with 3–3.6 ml of 0.5% bupivacaine (Marcain injection 0.5%; AstraZeneca Co., Osaka, Japan). Narcotic or ketamine administration by intravenous injection was not performed. A bladder catheter was inserted. Surgery was performed without the use of a tourniquet. A midline incision was used as the skin incision, and the operation proceeded via the mid-vastus approach. Posterior stabilized components (Scorpio NRG PS; Stryker Orthopaedics, Mahwah, NJ, USA) were fixed with cement (Simplex-P Bone Cement; Stryker, Kalamazoo, MI, USA). No suction drain was placed postoperatively. Tranexamic acid 500 mg was injected into the joint after closure of the articular capsule. If patients complained of postoperative pain they were given diclofenac sodium suppositories (25 mg). There was no limit on the number of suppositories that could be used. Oral narcotics or NSAIDs were not administered. Low-molecular-weight heparin (enoxaparin sodium, 2000 units twice a day subcutaneously for 14 days) was administered from the day after surgery to prevent deep vein thrombosis. Patients were required to engage in active movement of the affected leg from the day after surgery. Rehabilitation (passive movement, active movement, range of motion exercises, gait training) was started from day 2 after surgery under the supervision of a physiotherapist. A continuous-passive-motion machine was not used. 2.4. Periarticular injection (PAI) group The local anesthetic solution was compounded from a mixture of 20 ml of 0.75% ropivacaine (Anapeine injection 7.5 mg/mL; AstraZeneca Co., Osaka, Japan), physiological saline 20 mL, adrenaline 0.3 mg, morphine hydrochloride (men 10 mg, women 5 mg), and dexamethasone 3.3 mg (Table 1). Before the artificial joint was inserted, 20 mL of this solution were injected into the posterior soft tissues (posterior capsule,

Table 1 The dosages for periarticular injection. 0.75% ropivacaine Saline Adrenaline Morphine hydrochloride Dexamethasone

20 ml 20 ml 0.3 mg male 10 mg/female 5 mg 3.3 mg

posteromedial structures, and periarticular synovium) via a 22-gauge needle. After the artificial joint had been inserted, 20 mL of the solution were injected into the anterior soft tissues (pes anserinus, anteromedial capsule, iliotibial band, and quadriceps tendon). 2.5. Peripheral nerve block (PNB) group In the PNB group, an electrical stimulation unit (Stimuplex HNS12; B. Braun Medical Inc., Bethlehem, PA) was used to identify the femoral and sciatic nerves after closing the incision. With the patient supine, a 5-cm deep stylet (Stimuplex A; B. Braun Medical Inc.) was used to identify the femoral nerve 1–2 cm distal to the inguinal ligament and 1–2 cm lateral to the femoral artery. Electrical stimulation of 0.3 mA was applied and movement of the patella associated with quadriceps contraction was confirmed, after which 20 mL of 0.75% ropivacaine was injected. The patient was then placed in the lateral position, and a 10-cm deep stylet was used to identify the sciatic nerve between the tuberosity of the ischium and the greater trochanter. Electrical stimulation of 0.3 mA was applied, and plantar flexion or dorsiflexion of the ankle was confirmed, after which 10 mL of 0.75% ropivacaine was injected. 2.6. Outcome measures Age, sex, height, weight, American Society of Anesthesiologists physical status (ASA-PS) and range of motion of the knee were evaluated at the time of enrollment. The level of pain at rest was evaluated by patients according to a NRS at 3, 6, 12, 18, 24, 30, 36, 42, and 48 hours after surgery. In a patient who was asleep and whose facial expression did not indicate discomfort, the level of pain was considered to be 0. The numbers of diclofenac sodium suppositories (25 mg) used b6 hours, 6–12 hours, 12–18 hours, 18–24 hours, 24–36 hours, and 36–48 hours after surgery were investigated. The development of complications within 48 hours after surgery (new arrhythmia, hypotension with systolic blood pressure b 80 mmHg, hypoxia with SpO2 b95%, nausea, vomiting, dizziness, itching, numbness) was investigated. If nausea or vomiting developed after surgery, metoclopramide 10 mg was injected intravenously. Patients were instructed to press a call button when they felt postoperative pain, and the pain onset time was recorded. To investigate the duration of motor nerve paralysis associated with anesthesia or nerve block, the time required until the patient was capable of plantar flexion or dorsiflexion of the ankle was measured after surgery. Patient satisfaction with postoperative analgesia was evaluated by the patients themselves with the NRS at 48 hours after surgery. We measured the range of motion of the knee at three months after surgery. All evaluations were performed with both subjects and observers unaware of the method of analgesia. 2.7. Statistical analysis A sample size determination was conducted for the main outcome variable, the numerical rating scale (NRS: 0–10) of postoperative pain, and using R environment version 2.12.0. A preliminary retrospective analysis of 40 patients revealed a standard deviation of postoperative pain score of 2.3 (unpublished data). Previous studies have suggested that a change in pain score of 1–1.3 points is clinically significant [11]. We estimated, for this study design, to show a difference of one point on a NRS with a power of 0.08 (p = 0.05, standard deviation of 2.4), a total 183 patients were required. With assumed rate of 5% protocol

Please cite this article as: Uesugi K, et al, Comparison of peripheral nerve block with periarticular injection analgesia after total knee arthroplasty: A randomized, controlled study, Knee (2014), http://dx.doi.org/10.1016/j.knee.2014.04.008

K. Uesugi et al. / The Knee xxx (2014) xxx–xxx

violations (derived from a preliminary retrospective analysis of 40 patients), the calculated total sample size was 194 patients (97 patients each group). To recruit this number of patients, a 5-month inclusion period was anticipated. The t-test, χ2 test, and Mann-Whitney U test were used to compare the two groups. P values less than 0.05 were considered significant. SPSS for Windows (version 16.0; SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Data are expressed as percentages and mean values. 2.8. Source of funding This research did not receive any external funding.

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Table 2 Demographic and perioperative data. Mean (SD) or N

Age Men/women Weight (kg) Body mass index (kg/m2) ASA-PS (I/II) Side (right/left) ROM(°) Surgical time (min)

PAI group

PNB group

p

76.0 (6.1) 19/81 57.5 (11.2) 25.7 (3.7) 17/83 52/48 122 (22.4) 91.7 (15.7)

76.3(6.7) 22/78 58.2 (11.1) 26.0 (3.8) 14/86 47/53 126 (19.7) 89.9 (14.4)

0.919 0.726 0.654 0.588 0.696 0.572 0.248 0.380

PAI group, Periarticular injection group. PNB group, Peripheral nerve block group. ASA-PS, American Society of Anesthesiologists physical status. ROM, Range of motion of the knee.

3. Results 3.1. Demographic and perioperative data The study was stopped when 210 patients had been registered, with 105 knees of 105 patients in the PAI group and 105 knees of 105 patients in the PNB group (Fig. 1). Ten patients (five in the PAI group and five in the PNB group) were excluded because they developed postoperative delirium. The remaining 200 subjects (41 men and 159 women) had a mean age of 76.2 ± 6.4 years. There was no significant difference between the PAI and PNB groups in terms of age, sex, weight, BMI, ASA-PS, range of motion of the knee, operative side, or surgical time (Table 2). Mean total time required for femoral nerve block and sciatic nerve block was 200 ± 64 s. 3.2. Postoperative pain and motor paralysis At 3 and 6 hours after surgery, the pain score was significantly lower in the PNB group than in the PAI group (Fig. 2, p b 0.001, p = 0.003). At 12 and 18 hours after surgery, there were no significant differences between the two groups. At 24 and 30 hours after surgery, the pain scores were significantly lower in the PAI group than in the PNB group (p = 0.002, p = 0.005). At ≥36 hours after surgery, there were no significant differences between the two groups.

Enrollment

During the periods 0–6 hours and 6–12 hours after surgery, the PNB group used significantly fewer suppositories than the PAI group (Fig. 3, p b 0.001, p = 0.007). During the periods 12–18 hours and 18–24 hours after surgery, the PAI group used significantly fewer suppositories than the PNB group (p = 0.027, p = 0.003). There was no significant difference in the total number of suppositories used within the 48- hour period after surgery by the PAI group (2.9 ± 1.4) and the PNB group (2.8 ± 1.3). The time to pain onset after surgery was significantly shorter in the PAI group than in the PNB group (Table 3, p b 0.001). Motor paralysis of the ankle was significantly longer in the PNB group than in the PAI group (p b 0.001). There was no significant difference between the two groups in terms of satisfaction with analgesia up to 48 hours after surgery (PAI group, 8.0 ± 1.8; PNB group, 8.3 ± 1.7), and range of motion of the knee at three months after surgery (PAI group, 132° ± 11.6°; PNB group, 131° ± 12.4°). Nausea and vomiting occurred postoperatively in 12 patients in the PAI group and 8 in the PNB group, but this difference was not significant (p = 0.346). Neither dizziness nor itching occurred in either group. Other complications were rare (PAI group, 1 case of numbness; PNB group, 1 case each of hypotension and hypoxia, and 2 of numbness), and there were no significant differences between the two groups.

Assessed for eligibility (n= 210)

Excluded (n= 0) Declined to participate (n= 0) Other reasons (n= 0)

Randomized (n= 210)

Allocation Allocated to periarticular injection (n= 105) Received allocated intervention (n= 105) Did not receive allocated intervention (n= 0)

Allocated to peripheral nerve block (n= 105) Received allocated intervention (n= 105) Did not receive allocated intervention (n= 0)

Follow-Up Lost to follow-up (n= 0)

Lost to follow-up (n= 0)

Discontinued intervention (n= 0)

Discontinued intervention (n= 0)

Analysis Analysed (n= 100) Excluded from analysis (postoperative delirium) (n= 5)

Analysed (n= 100) Excluded from analysis (postoperative delirium) (n= 5)

Fig. 1. Flow chart of the analysis. After exclusions, 210 patients were enrolled. Ten patients were excluded postoperatively after developing delirium. A total of 200 patients was followed-up.

Please cite this article as: Uesugi K, et al, Comparison of peripheral nerve block with periarticular injection analgesia after total knee arthroplasty: A randomized, controlled study, Knee (2014), http://dx.doi.org/10.1016/j.knee.2014.04.008

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K. Uesugi et al. / The Knee xxx (2014) xxx–xxx

NRS

PAI group PNB group

10

* p < 0.01, ** p< 0.001

8 6

*

2

* *

**

0 3h

6h

12h

18h

24h

30h

36h

42h

48h

Fig. 2. Postoperative pain score. Degree of pain at rest according to the numerical rating scale (NRS: 0–10). At 3–6 hours after surgery, the NRS score is significantly lower in the PNB group than in the PAI group. AT 24–36 hours after surgery, the NRS score is significantly lower in the PAI group than in the PNB group.

4. Discussion In this study, postoperative pain in the two groups up to 18 hours after surgery was ≤ 1.5 on the NRS, with good analgesic effectiveness achieved in the early period following TKA. Additionally, there were no significant differences between the two groups in the total number of suppositories used, patient satisfaction and range of motion of the knee. These findings indicate that PAI and PNB have similar analgesic effectiveness during the first 48 hours after surgery. Previous studies have shown that femoral nerve block and continuous epidural anesthesia are similarly effective in relieving pain after TKA, and that both reduce postoperative narcotic usage [5,10]. Because the area supplied by the femoral nerve does not extend to the back of the knee joint, however, femoral nerve block alone does not provide an analgesic effect for the posterior soft tissues of the knee joint. This is achieved by the sciatic nerve block. The combined use of femoral and sciatic nerve blocks has been reported to provide a powerful analgesic effect for the site of surgical invasion in TKA [11,12]. If femoral and sciatic nerve blocks are administered continuously rather than singly, this enables the period of the pain relief effect to be extended. An advanced skill is required, however, to ensure its continuous administration in a reliable manner, and a large amount of work is involved in its management. In this study, single nerve block was chosen, which shortened the time required for the blocking procedure and made postoperative management easy. Both types of block can be performed safely, simply, and reliably using a neurostimulation device. Although an analgesic effect after TKA cannot be achieved solely by the administration of local anesthetic into the joint [13], the injection

Times

PAI group PNB group

5

* p < 0.01, ** p< 0.001

4 3 2 1

* ** 0-6h

* 6-12h

* 12-18h

18-24h

Mean (SD)

Pain onset time (h) Motor paralysis time (h) Plantar flexion Dorsal flexion The level of satisfaction ROM(°)

4

0

Table 3 Anesthetic effect time, the level of satisfaction and ROM.

24-36h

36-48h

total

Fig. 3. Suppository usage. Usage of diclofenac suppositories. Within 12 hours after surgery, suppository use is significantly lower in the PNB group than in the PAI group. At 12–24 hours after surgery, suppository use is significantly lower in the PAI group than in the PNB group.

PAI group

PNB group

p

8.4 (9.2)

15.3 (8.4)

b0.001

6.3 (5.9) 5.7 (4.6) 8.0 (1.8) 132 (11.6)

15.9 (4.8) 15.6 (4.7) 8.3 (1.7) 131 (12.4)

b0.001 b0.001 0.275

PAI group, Periarticular injection group. PNB group, Peripheral nerve block group. ROM, Range of motion of the knee.

of a solution containing a mixture of local anesthetic and morphine into the periarticular tissues has been reported to provide an analgesic effect in the early postoperative period [8]. In this study, a solution containing a mixture of ropivacaine, saline, epinephrine, dexamethasone, and morphine was injected into the periarticular soft tissues [6]. Ropivacaine is a long-acting local anesthetic with similar properties to bupivacaine. Compared with bupivacaine, ropivacaine has a lower incidence of cardiovascular toxicity and neurotoxicity as adverse events and can be safely used [14]. Epinephrine constricts blood vessels via the action of α-adrenaline, reducing the speed with which drugs are absorbed, thus prolonging their localized action. Morphine acts on three peripheral nerve opioid receptors (μ, δ, and κ) to exert an analgesic effect at the wound site [15]. According to Kalso et al., an analgesic effect can be achieved by intra-articular morphine injection after TKA [16]. Although morphine is a powerful analgesic, its intravenous administration may cause nausea and vomiting as side effects. Women are reportedly more susceptible than men to morphine-induced nausea and vomiting [17], and in the present study, the dose of morphine used for women was half that for men. Dexamethasone is a long-acting glucocorticoid with a half-life of 36–54 hours. Although the use of glucocorticoids carries the risk of side effects such as infection and elevated blood sugar, these do not occur when it is administered locally at low doses [18]. Glucocorticoids act to suppress inflammation and swelling at the wound site [19]. They also inhibit signal transmission by C fibers, which are easily injured, suppressing the cascade that would otherwise amplify information on such injury resulting from tissue damage [20]. Glucocorticoids have also been reported to prevent nausea and vomiting [21]. The local administration of this mixture of agents both minimizes systemic adverse events and effectively suppresses both the pain from surgical-induced injury and central sensitivity. The conventional techniques of epidural anesthesia and PCA also provide a high level of postoperative anesthetic effect, but they entail problems with complications including nausea, vomiting, dizziness, itching, and numbness. In the present study, there was a similarly low incidence of complications (arrhythmia, hypotension, hypoxia, nausea, vomiting, dizziness, itching, and numbness) within 48 hours after surgery for both PAI and PNB. This suggested that both PAI and PNB provide an analgesic effect at low risk. PAI has two advantages over PNB. The first is that no special skills are required to administer an injection into the periarticular tissues. The analgesic effect is simply achieved by injecting the solution around the joint after carrying out an aspiration test, while being careful to ensure that it does not enter a blood vessel. The other advantage is that, unlike nerve block, it does not cause motor paralysis. This means that the legs can be moved voluntarily from the early period after surgery, reducing the risk of deep vein thrombosis associated with venous stasis. Both procedures are methods of analgesia that have an excellent effect for pain management after TKA, but the types, doses, and methods of administration of the agents used have yet to be established. In the present study, the analgesic effect was limited to the early period after surgery. Future studies are required to identify ideal methods of analgesia with long-term persistence.

Please cite this article as: Uesugi K, et al, Comparison of peripheral nerve block with periarticular injection analgesia after total knee arthroplasty: A randomized, controlled study, Knee (2014), http://dx.doi.org/10.1016/j.knee.2014.04.008

K. Uesugi et al. / The Knee xxx (2014) xxx–xxx

In conclusion, periarticular injection of local anesthetic provided a similar analgesic effect to the combined use of sciatic and femoral nerve blocks. Both procedures had a low incidence of complications, and as they were administered singly, continuous management was not required. Unlike the conventional method of epidural anesthesia, catheterization is not required, which avoids the risk of hematoma associated with prophylactic anticoagulant therapy. Periarticular injection has the advantages of requiring no particular skills and not causing paralysis. Conflict of interest statement None of the authors nor their institution has any conflicts of interest in relation to the above study. Acknowledgments We thank Luda Wolchuk MD, Forte Incorporated, for editorial assistance. References [1] Myles PS, Williams DL, Hendrata M, et al. Patient satisfaction after anaesthesia and surgery: results of a prospective survey of 10,811 patients. Br J Anaesth 2000;84:6–10. [2] Horlocker TT, Kopp SL, Pagnano MW, et al. Analgesia for total hip and knee arthroplasty: a multimodal pathway featuring peripheral nerve block. J Am Acad Orthop Surg 2006;14:126–35. [3] Choi PT, Bhandari M, Scott J, et al. Epidural analgesia for pain relief following hip or knee replacement. Cochrane Database Syst Rev 2003;3:CD003071. [4] Moen V, Dahlgren N, Irestedt L. Severe neurological complications after central neuraxial blockades in Sweden 1990–1999. Anesthesiology 2004;101:950–9. [5] Fischer HBJ, Simanski CJP, Sharp C, et al. A procedure-specific systematic review and consensus recommendations for postoperative analgesia following total knee arthroplasty. Anaesthesia 2008;63:1105–23. [6] Parvizi J, Miller AG, Gandhi K. Multimodal pain management after total joint arthroplasty. J Bone Joint Surg Am 2011;93:1075–84.

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[7] Sites BD, Beach M, Gallagher JD, et al. A single injection ultrasound-assisted femoral nerve block provides side effect-sparing analgesia when compared with intrathecal morphine in patients undergoing total knee arthroplasty. Anesth Analg 2004;99:1539–43. [8] Vendittoli P-A, Makinen P, Drolet P, et al. A multimodal analgesia protocol for total knee arthroplasty. A randomized, controlled study. J Bone Joint Surg Am 2006;88:282–9. [9] 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;88:959–63. [10] Fowler SJ, Symons J, Sabato S, et al. Epidural analgesia compared with peripheral nerve blockade after major knee surgery: a systematic review and meta-analysis of randomized trials. Br J Anaesth 2008;100:154–64. [11] Ashraf A, Raut VV, Canty SJ, et al. Pain control after primary total knee replacement: a prospective randomised controlled trial of local infiltration versus single shot femoral nerve block. Knee 2013;20:324–7. [12] Zugliani AH, Vercosa N, Amaral JL, et al. Control of postoperative pain following total knee arthroplasty: is it necessary to associate sciatic nerve block to femoral nerve block? Rev Bras Anestesiol 2007;57:514–24. [13] Rosen AS, Colwell Jr CW, Pulido PA, et al. A randomized controlled trial of intraarticular ropivacaine for pain management immediately following total knee arthroplasty. HSS J 2010;6:155–9. [14] Knudsen K, Beckman Suurkula M, Blomberg S, et al. Central nervous and cardiovascular effects of i.v. infusions of ropivacaine, bupivacaine and placebo in volunteers. Br J Anaesth 1997;78:507–14. [15] Stein C, Lang LJ. Peripheral mechanisms of opioid analgesia. Curr Opin Pharmacol 2009;9:3–8. [16] Kalso E, Tramer MR, Carroll D, et al. Pain relief from intra-articular morphine after knee surgery: a qualitative systematic review. Pain 1997;71:127–34. [17] Bijur PE, Esses D, Birnbaum A, et al. Response to morphine in male and female patients: analgesia and adverse events. Clin J Pain 2008;24:192–8. [18] Salerno A, Hermann R. Efficacy and safety of steroid use for postoperative pain relief. Update and review of the medical literature. J Bone Joint Surg Am 2006;88:1361–72. [19] Neeck G, Renkawitz R, Eggert M. Molecular aspects of glucocorticoid hormone action in rheumatoid arthritis. Cytokines Cell Mol Ther 2002;7:61–9. [20] Holte K, Kehlet H. Perioperative single-dose glucocorticoid administration: pathophysiologic effects and clinical implications. J Am Coll Surg 2002;195:694–712. [21] Henzi I, Walder B, Tramer MR. Dexamethasone for the prevention of postoperative nausea and vomiting: a quantitative systematic review. Anesth Analg 2000;90:186–94.

Please cite this article as: Uesugi K, et al, Comparison of peripheral nerve block with periarticular injection analgesia after total knee arthroplasty: A randomized, controlled study, Knee (2014), http://dx.doi.org/10.1016/j.knee.2014.04.008