Local infiltration analgesia following total knee arthroplasty: effect on post-operative pain and opioid consumption--a meta-analysis

Less Induction Time and Postoperative Pain Using Spinal Anesthesia Versus General Anesthesia With or Without the Use of Peripheral Nerve Blocks in Total Knee Arthroplasty

BACKGROUND

Our aim was to analyze anesthetic induction time and postoperative pain using spinal anesthesia versus general anesthesia with or without the use of peripheral nerve blocks (PNBs) in total knee arthroplasty. The hypothesis was that spinal anesthesia would be beneficial with respect to induction time and postoperative pain and that PNBs would complement this effect.

METHODS

Patients were stratified according to demographics, American Society of Anesthesiologists physical status classification system (ASA), and opioid intake and divided into: (A) general anesthesia without PNB; (B) general anesthesia with PNB; (C) spinal anesthesia without PNB; and (D) spinal anesthesia with PNB. Endpoints were anesthetic induction time, opioid consumption, and pain. Of 559 patients, 348 (62.3%) received general anesthesia (consisting of group A with 46 and group B with 302 patients), and 211 (37.7%) spinal anesthesia (consisting of group C with 117 and group D with 94 patients).

RESULTS

We observed significantly lower total opioid intake 48 hours postoperative when applying spinal anesthesia by 2.08 mg (P < .05) of intravenous morphine-equivalent, and a reduction of 7.0 minutes (P < .05) until skin incision. The application of a PNB achieved a reduction of piritramide intake of 3.59 mg (P < .05) 48 hours postoperative and lengthened induction time by 8.5 minutes (P < .05).

CONCLUSIONS

Statistically shorter anesthetic induction times without clinical relevance, but lower postoperative opioid dosages with clinical relevance were observed for patients undergoing total knee arthroplasty with spinal anesthesia. The additional application of PNBs led to a lower need for opioids and lower pain levels in the early postoperative phase.

Local Periarticular Infiltration with Dexmedetomidine Results in Superior Patient Well-Being after Total Knee Arthroplasty Compared with Peripheral Nerve Blocks: A Randomized Controlled Clinical Trial with a Follow-Up of Two Years

BACKGROUND

This study aimed to compare local periarticular infiltration (LIA) with ultra-sound guided regional anesthesia (USRA) with ropivacaine and dexmedetomidine as an additive agent in primary total knee arthroplasty (TKA).

METHODS

Fifty patients were randomized into two groups in a 1:1 ratio. Patients in the LIA group received local periarticular infiltration into the knee joint. The USRA group received two single-shot USRA blocks. Functional outcomes and satisfaction (range of movement, Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Knee Score, and Forgotten Joint Score), including well-being, were analyzed preoperatively and at five days, six weeks, and one and two years postoperatively.

RESULTS

Functional outcomes did not significantly differ between the two groups at six weeks and one and two years after the implementation of TKA. A moderate correlation was observed in the LIA group regarding well-being and pain on day five. Six weeks postoperatively, the LIA group showed significantly superior well-being but worse pain scores. No differences between the groups in well-being and functional outcomes could be observed one and two years postoperatively.

CONCLUSION

Patients treated with LIA had superior postoperative well-being in the early postoperative phase of up to six weeks. Furthermore, LIA patients had similar functionality compared to patients treated with USRA but experienced significantly more pain six weeks postoperatively. LIA leads to improved short-term well-being, which is potentially beneficial for faster knee recovery. We believe that LIA benefits fast-track knee recovery with respect to improved short-term well-being, higher practicability, and faster application.

Does the Addition of iPACK Block to Adductor Canal Block Provide Improved Analgesic Effect in Total Knee Arthroplasty? A Systematic Review and Meta-Analysis

The interspace between popliteal artery and the capsule of posterior knee (iPACK) block was proposed in recent years to relieve posterior knee pain. Since adductor canal block (ACB) and iPACK involve different branches of the sensory nerves, it is theoretically feasible to combine iPACK block and ACB to relief pain after total knee arthroplasty (TKA). We aim to validate the efficacy of adding iPACK block to ACB in the setting of a multimodal pain management protocol following TKA. A comprehensive literature review on Web of Science, Embase, the Cochrane Library, and PubMed was performed. Eight studies (N = 1,056) that compared the efficacy of iPACK block + ACB with ACB alone were included. Primary outcomes consisted of Visual Analogue Scale (VAS) score at rest or during activity at various time points. Secondary outcomes include opioids consumption, walking distance, and length of hospital stay (LOS). Compared to ACB alone, VAS scores at rest (standardized mean difference [SMD]: -1.18; 95% confidence interval [CI]: -2.05 to -0.30) and during activity (SMD: -0.26; 95% CI: -0.49 to -0.03) on the day of surgery were lower in the iPACK block + ACB group. However, the difference did not reach the minimal clinically important difference. Opioids consumption at postoperative 24 hours was lower in the iPACK + ACB group (SMD: -0.295; 95% CI: -0.543 to -0.048). VAS score on postoperative day (POD) 1 and POD2, opioids consumption from 24 to 48 hours, walking distance, and LOS were not different. In conclusion, the addition of iPACK block to ACB in a multimodal pain management protocol can effectively reduce opioids consumption in the early postoperative period. This is a level III, meta-analysis study.

Opioid Free Anesthesia in Thoracic Surgery: A Systematic Review and Meta Analysis

Introduction: Recent studies showed that balanced opioid-free anesthesia is feasible and desirable in several surgical settings. However, in thoracic surgery, scientific evidence is still lacking. Thus, we conducted the first systematic review and meta-analysis of opioid-free anesthesia in this field. Methods: The primary outcome was the occurrence of any complication. Secondary outcomes were the length of hospital stay, recovery room length of stay, postoperative pain at 24 and 48 h, and morphine equivalent consumption at 48 h. Results: Out of 375 potentially relevant articles, 6 studies (1 randomized controlled trial and 5 observational cohort studies) counting a total of 904 patients were included. Opioid-free anesthesia compared to opioid-based anesthesia, was associated with a lower rate of any complication (74 of 175 [42%] vs. 200 of 294 [68%]; RR = 0.76; 95% CI, 0.65−0.89; p < 0.001; I2 = 0%), lower 48 h morphine equivalent consumption (MD −14.5 [−29.17/−0.22]; p = 0.05; I2 = 95%) and lower pain at 48 h (MD −1.95 [−3.6/0.3]; p = 0.02, I = 98%). Conclusions: Opioid-free anesthesia in thoracic surgery is associated with lower postoperative complications, and less opioid demand with better postoperative analgesia at 48 h compared to opioid-based anesthesia.

Comparison of the Effect of Intra-Articular, Periarticular, and Combined Injection of Analgesic on Pain Following Total Knee Arthroplasty: A Double-Blinded Randomized Clinical Trial

The aim of this study was to compare the efficacy of 3 methods of intraoperative analgesic cocktail injection during total knee arthroplasty (TKA)—intra-articular (IA), periarticular (PA), and combined intra-articular and periarticular (IA+PA)—on controlling early postoperative pain.

Effect of Steroid in Local Infiltration Analgesia in One-Stage Bilateral Total Knee Arthroplasty: A Paired-Randomized Controlled Study

Although local infiltration analgesia (LIA) is effective in relieving pain after total knee arthroplasty (TKA), its effect is short lasting and the optimal combination of drugs is unknown. Steroids being a potent and long-acting anti-inflammatory drug might extend LIA's effect. This study aims to evaluate the role of steroids in LIA. This is a paired-randomized controlled study involving one-stage bilateral TKA patients. LIA containing ropivacaine, ketorolac, and adrenaline with or without triamcinolone was given. One knee was randomized to receive LIA with steroids, while the other received LIA without steroids. The primary outcome was knee pain in terms of the visual analog scale (VAS). Secondary outcomes were rehabilitation progress, functional scores, and complications. Outcomes were compared between the knees of the same patient and documented up to 1 year. A total of 45 patients (90 TKAs) were included. LIA with steroid knees showed lower VAS score at rest and during activity from postoperation day 1 to 5 and at 6 weeks (p < 0.05). Passive and active range of movement was also greater in LIA with steroid group from day 1 to 7 and day 2 to 5, respectively (p < 0.05). Steroid-treated knees also achieved active straight leg raise earlier (1.2 vs. 2.0 days, p < 0.05). No differences in Knee Society Score and complication rates between both groups. Steroids in LIA offer additional and extended benefit in pain control and rehabilitation after TKA, while no adverse effects were found up to 1-year follow-up.

Clinical Trial Registry Use in Orthopaedic Surgery Systematic Reviews

BACKGROUND

Results from systematic reviews and meta-analyses, which have the highest level of evidence (Level I), often drive clinical decision-making and health policy. Often, unpublished trial data are omitted from systematic reviews, raising concerns about the extent of the reliability and validity of results that have been drawn from systematic reviews. We aimed to determine the extent to which systematic review authors include searches of clinical trial registries for unpublished data when conducting systematic reviews in orthopaedic surgery.

METHODS

Systematic reviews and/or meta-analyses were gathered from the top 5 orthopaedic surgery journals based on the h5-index from Google Scholar Metrics. Systematic reviews that had been published in the Cochrane Database of Systematic Reviews, which requires the inclusion of a clinical trial registry search, served as controls. For the primary outcome, each systematic review from the top 5 orthopaedic journals was screened to determine whether the authors of each study searched for unpublished data in clinical trial registries. We then compared the rate of registry searches with those in the control group. For the secondary analysis, a search of ClinicalTrials.gov was performed for unpublished trial data for 100 randomized systematic reviews.

RESULTS

All 38 of the Cochrane systematic reviews (100%) included clinical trial registry searches, while the top 5 orthopaedic journals had only 31 of 480 studies (6.5%) that looked at clinical trial registries. The secondary analysis yielded 59 of 100 systematic review articles (59.0%) that could have included unpublished clinical trial data from ≥1 studies to their sample.

CONCLUSIONS

Systematic reviews that have been published in the top orthopaedic surgery journals seldom included a search for unpublished clinical trial data.

CLINICAL RELEVANCE

The exclusion of clinical trial registry searches potentially contributes to publication bias within the orthopaedic literature. Moving forward, systematic review authors should include clinical trial registry searches for unpublished clinical trial data to provide the most accurate representation of the available evidence for systematic reviews and meta-analyses.

[Pain concepts in fast-track endoprosthetics]

An effective and safe pain management is nowadays a pivotal component of fast-track endoprosthetics. The analgesic strategies should be opioid-sparing whenever possible because opioids induce side-effects that reduce the well-being of patients and are even associated with a risk of falling. This is not compatible with a fast mobilization. In order to achieve this goal, multimodal pain concepts have proven to be suitable. Decentralized analgesia with epidural and regional catheters as well as the use of local infiltration anesthesia (LIA) can be used; however, catheters are also associated with a muscular deficit and the danger of falling. Therefore, in the fast-track concepts LIA has become established. With respect to knee endoprosthetics many studies have shown that LIA achieves at least comparable results or even superiority in comparison with the use of catheters. It represents a safe and effective procedure with respect to postoperative analgesia and accelerated mobilization. A variety of protocols for the use of LIA can currently be found in the literature. In addition to analgesics the supportive administration of glucocorticoids is increasingly being used, which also reduce pain due to the anti-inflammatory effect; however, regarding this aspect relatively few prospective randomized studies in comparison to LIA are available in the literature.

Peri-articular infiltration analgesia for shoulder surgery: a systematic review and meta-analysis

Effective analgesic alternatives to interscalene brachial plexus block are sought for shoulder surgery. Peri-articular infiltration analgesia is a novel, less invasive technique, but evidence surrounding its use is unclear. This systematic review and meta-analysis aims to evaluate the utility of peri-articular infiltration analgesia in shoulder surgery. We searched literature for trials comparing peri-articular infiltration analgesia with control or with interscalene brachial plexus block. Control groups received no intervention, placebo or systemic opioids. The primary outcome was cumulative oral morphine equivalent consumption during the first 24 h postoperatively. Secondary outcomes included: rest pain scores up to 48 h; risk of side-effects; and durations of post-anaesthetic care unit and hospital stay. Data were pooled with random-effects modelling. Seven trials (383 patients) were included. Compared with control, peri-articular infiltration analgesia reduced 24-h oral morphine consumption by a mean difference (95%CI) of -38.0 mg (-65.5 to -10.5; p = 0.007). It also improved pain scores up to 6 h, 36 h and 48 h, with the greatest improvement observed at 0 h (-2.4 (-2.7 to -1.6); p < 0.001). Peri-articular infiltration analgesia decreased postoperative nausea and vomiting by an odds ratio (95%CI) of 0.3 (0.1-0.7; p = 0.006). In contrast, peri-articular infiltration analgesia was not different from interscalene brachial plexus block for analgesic consumption, pain scores or side-effects. This review provides moderate evidence supporting peri-articular infiltration for postoperative analgesia following shoulder surgery. The absence of difference between peri-articular infiltration analgesia and interscalene brachial plexus block for analgesic outcomes suggests that these interventions are comparable, but further trials are needed to support this conclusion and identify the optimal peri-articular infiltration technique.

Additional benefit of local infiltration of analgesia to femoral nerve block in total knee arthroplasty: double-blind randomized control study

PURPOSE

Multimodal analgesia has become an important concept in current pain management following total knee arthroplasty (TKA). However, controversy remains over what is the most accepted combination. In this study, the additional benefits of local infiltration of analgesia to femoral nerve block were evaluated.

METHODS

Forty patients were randomly allocated into a combined local infiltration of analgesia and femoral nerve block or femoral nerve block alone group. In the former, analgesic drugs consisting of ropivacaine and dexamethasone were injected into the peri-articular tissues, while the same amount of saline was injected into the femoral nerve block group. The primary outcome measure was the total amount of fentanyl consumption by the patient-controlled analgesia pump during the 48-h post-operative period.

RESULTS

A combination of local infiltration of analgesia and femoral nerve block had less total fentanyl consumption and a larger knee ROM at post-operative day 2 than femoral nerve block alone (p < 0.05). C-reactive protein levels in the combined treatment group were significantly lower than the femoral nerve block group at post-operative day 3 (p < 0.01). There was no difference between the two groups, post-operatively, on the visual analogue scale for pain at rest or while walking, quadriceps strength, timed up and go test, circumference of thigh, Knee Society Score, and Western Ontario and McMaster Universities Osteoarthritis Index.

CONCLUSION

The addition of local infiltration of analgesia to femoral nerve block promoted post-operative pain relief and the recovery of knee ROM in the early post-operative period. This combination is an effective method for post-operative pain management after TKA.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

Ultrasound-guided adductor canal block using levobupivacaine versus periarticular levobupivacaine infiltration after totalknee arthroplasty: a randomized clinical trial

BACKGROUND

Both postoperative pain control and range of motion are important in total knee arthroplasty (TKA). However, in the literature, there is little comparison of peripheral nerve blocks and periarticular infiltration techniques using levobupivacaine. The aim of our study was to measure pain with visual analogue scale (VAS) and knee range of motion (ROM) between in patients undergoing adductor canal block (ACB) for TKA using levobupivacaine compared to periarticular levobupivacaine infiltration (PAI-L).

DESIGN AND SETTING

Prospective randomized clinical trial in a university hospital.

METHODS

Patients aged 40-85 years who underwent unilateral TKA were included; 39 were treated withperiarticular infiltration using 40 ml (0.125 mg) of levobupivacaine (PAI-L group); and 40 were treated with ACB using 20 ml of 0.25% levobupivacaine (ACB-L group). Postoperative pain scores at rest and during active physical therapy were assessed using a VAS, along with knee ROM in flexion and extension. In addition, 100-foot walking time results, total morphine consumption and time of first analgesia requirement were recorded postoperatively.

RESULTS

VAS scores at rest and during active physical therapy and the total amount of morphine consumed were lower in the ACB-L group than in the PAI-L group (P < 0.05). In contrast, knee ROM in flexion and extension and 100-foot walking times were greater in the PAI-L group than in the ACB-L group (P < 0.05).

CONCLUSION

ACB-L was superior to PAI-L regarding pain treatment after TKA; however, PAI-L was superior to ACB-L regarding postoperative ROM and walking ability.

CLINICAL TRIAL REGISTRY

ACTRN-12618000438257.

Opioid-Free Total Knee Arthroplasty? Local Infiltration Analgesia Plus Multimodal Blood-Loss Prevention Make it Possible

Opioids have been widely used in the USA for pain control after total knee arthroplasty (TKA). However, adverse effects, especially the possibility of addiction, have increased interest in opioid-free pain management after surgery. We therefore sought to review current pain management protocols after TKA, focusing especially on opioid-free alternatives. We reviewed the literature on pain management after TKA using Medline (PubMed), through June 30, 2018, using the keywords "TKA" and "analgesia." We found 388 articles but chose to analyze the 34 that presented high-quality (levels I and II) evidence. Local infiltration analgesia (LIA) is a good option for reducing the use of post-operative opioids; many reports have compared LIA against a nerve block or studied the synergies between two protocols of loco-regional anesthesia. Multimodal blood-loss prevention is sometimes recommended in combination with opioid-free analgesia. In most studies, however, no differences are reported or contradictory results exist. Post-operative pain management protocols vary so much that it is difficult to strongly favor a determined pathway.

Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in total knee arthroplasty

BACKGROUND

Postoperative pain control and enhanced mobilization, muscle strength and range of motion following total knee arthroplasty (TKA) are pivotal requisites to optimize rehabilitation and early recovery. The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary total knee arthroplasty.

METHODS

Between January 2016 until August 2016, 280 patients underwent primary TKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 81) or epidural catheter (group SP&EPI, n = 51) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 86) or spinal anesthesia (group SP&LIA, n = 61). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed.

RESULTS

Pain relief was similar in all groups, while the use of opioid medication was significantly lower (up to 58%) in combination with spinal anesthesia, especially in SP&EPI. The LIA groups, in contrast, revealed significant higher mobilization (up to 26%) and muscle strength (up to 20%) in the early postoperative period. No analgesic technique-related or surgery-related complications occurred within the first 7 days. Due to insufficient pain relief, 8.4% of the patients in the catheter-based groups and 12.2% in the LIA groups resulted in a change of the anesthetics pain management.

CONCLUSIONS

The LIA technique offers a safe and effective treatment option concerning early functional recovery and pain control in TKA. Significant advantages were shown for mobilization and muscle strength in the early postoperative period while pain relief was comparable within the groups.

Single Local Infiltration Analgesia (LIA) Aids Early Pain Management After Total Knee Replacement (TKR): An Evidence-Based Review and Commentary

BACKGROUND

There is controversy in the literature regarding the role of single local infiltration analgesia (LIA) after total knee replacement (TKR).

QUESTIONS/PURPOSES

Is single LIA really efficient in controlling pain after TKR?

METHODS

A Cochrane Library and PubMed (MEDLINE) search related to the justification LIA after TKR was analyzed. The main criteria for selection were that the articles were focused in the aforementioned question.

RESULTS

Two hundred ninety-nine articles were found until February 9, 2017, but only 27 were selected and reviewed because they were focused on clinical experience with LIA following TKR. Fifteen of them were considered level of evidence (I-II) while 12 had a lower level of evidence (III-IV). LIA reduced the amount of perioperative opioid administration and enabled adequate pain management in conjunction with oral medication without adverse effects. No clinically marked effects on the functional outcome after TKR were detected.

CONCLUSION

Single dose LIA provides effective analgesia in the initial postoperative period after TKR in most randomized clinical trials, systematic reviews, and meta-analyses.

Fast-track total knee arthroplasty improved clinical and functional outcome in the first 7 days after surgery: a randomized controlled pilot study with 5-year follow-up

INTRODUCTION

Fast-track protocols (FP) are used more and more to optimize results after total knee arthroplasty (TKA). Many studies evaluating FP in TKA concentrate on clinical outcome and medium to long-term results. Since discharge from hospital after TKA is achieved increasingly quicker worldwide using FP in an increasingly younger and active patient population, the effects of FP on functional outcome in the first days after TKA become more important. The purpose of the current study was to compare FP with a regular joint care protocol (RP), with an emphasis on the first 7 days after surgery.

MATERIALS AND METHODS

A non-blinded randomized controlled clinical pilot study was performed with 25 patients assigned to a FP group and 25 patients assigned to a RP group. Primary outcome was functional outcome, clinical outcome, pain, and complications for each day in the first week after surgery. Patients were followed up to 5 years after surgery.

RESULTS

Significantly lower VAS scores for knee pain, faster Timed-Up and Go test times and more mobility on functional tests were seen on several days in the first week in the FP group compared to the RP group. Few other significant differences were found at 2, 6 weeks, and no significant differences were found at 12 weeks and 1, 2 and 5 years after surgery.

CONCLUSIONS

Fast-track protocol for primary TKA showed significantly lower knee pain scores and improved functional outcome in the first 7 days after TKA compared to a regular protocol.

The role of elastomeric pumps in postoperative analgesia in orthopaedics and factors affecting their flow rate

Elastomeric pumps are mechanical devices composed of an elastomeric balloon reservoir into which the drug to be infused is stored, a protective casing (used by some manufacturers), a flow controller and a wound catheter. In orthopaedics they are used to provide continuous local infiltration analgesia. In this way patients rely less on other routes of analgesia and thus avoid their systemic side effects. Studies have shown good response to analgesia with these pumps for the first 24 hours but their benefit is not as clear at 48 and 72 hours. There are numerous factors that affect the flow rate of elastomeric pumps. Some are inherent to all elastomeric pumps such as: the pressure exerted by the elastomeric balloon, catheter size, the vertical height of the pump in relation to the wound, viscosity and partial filling. There are also other factors which vary according to the manufacturer such as: the optimal temperature to obtain the desired flow rate as this directly affects viscosity, the dialysate that the analgesic drug is mixed with (ie normal saline or 5% dextrose), and the storage conditions of the fluid to be infused. It is thus essential to follow the clinical guidelines provided by the manufacturer in order to obtain the desired flow rate.

Local infiltration analgesia in knee and hip arthroplasty efficacy and safety

Background

This is a secondary publication of a PhD thesis. Local infiltration analgesia (LIA) is a new multimodal wound infiltration method for treating postoperative pain after knee and hip arthroplasty. This method is based on systematic infiltration of a mixture of ropivacaine, a long acting local anaesthetic, ketorolac, a cyclooxygenase inhibitor (NSAID), and adrenalin around all structures subject to surgical trauma in knee and hip arthroplasty.

Aims

Paper I: to assess whether pain relief after LIA in total knee arthroplasty (TKA) is as effective as femoral block. Paper II: to assess whether the plasma concentration of ropivacaine and ketorolac after LIA in TKA reaches levels linked to toxicity. Paper III: to assess whether the plasma concentration of unbound ropivacaine after LIA in THA reaches levels linked to toxicity and if it is higher in THA as compared to TKA. Paper IV: to assess whether the plasma concentration of ketorolac after LIA in THA reaches levels linked to toxicity, and whether administration of ketorolac in LIA is safer as compared to the intramuscular route.

Methods

Two patient cohorts of 40 patients scheduled for elective total knee arthroplasty (TKA) and 15 patients scheduled for total hip arthroplasty (THA) contributed to this work. In a randomized trial the efficacy of LIA in TKA with regard to pain at rest and upon movement was compared to femoral block.

Results

Both methods result in a high quality pain relief and similar morphine consumption during the 24 h monitoring period. In the same patient cohort the maximal total plasma concentration of ropivacaine was below the established toxic threshold for most patients. All patients in the THA cohort were subjected to the routine LIA protocol. In these patients both the total and unbound plasma concentration of ropivacaine was determined. The concentration was below the established toxic threshold. As ropivacaine binds to α–1 acid glycoprotein (AAG) we assessed the possibility that increased AAG may decrease the unbound concentration of ropivacaine. A 40% increase in AAG was detected during the first 24 h after surgery, however the fraction of unbound ropivacaine remained the same. There was a trend towards increased C max of ropivacaine with increasing age and decreasing creatinine clearance but the statistical power was too low to draw any conclusion. Administration of 30 mg ketorolac according to the LIA protocol both in TKA and THA resulted in a similar C max as previously reported after 10 mg intramuscular ketorolac. Neither age, nor body weight or BMI, nor creatinine clearance, correlates to maximal ketorolac plasma concentration or total exposure to ketorolac (AUC).

Conclusion

LIA provides good postoperative analgesia which is similar to femoral block after total knee arthroplasty. The plasma concentration of ropivacaine seems to be below toxic levels in most TKA patients. The unbound plasma concentration of ropivacaine in THA seems to be below the toxic level.

Implication

The use of ketorolac in LIA may not be safer than other routes of administration, and similar restrictions should be applied in patients at risk of developing side effects.

Local infiltration analgesia adds no clinical benefit in pain control to peripheral nerve blocks after total knee arthroplasty

PURPOSE

To evaluate the effect of the local infiltration of analgesics for pain after total knee arthroplasty in patients treated with femoral and sciatic peripheral nerve blocks. The secondary objective was to detect differences in analgesic consumption as well as blood loss after local infiltration of analgesics.

METHODS

Prospective randomized double-blinded study in patients who underwent a TKA for knee osteoarthritis under spinal anesthesia and treated with femoral and sciatic nerve blocks. This study compared 50 patients treated with local infiltration with ropivacaine, epinephrine, ketorolac and clonidine and 50 patients treated with a placebo with the same technique. The visual analogic score was registered postoperatively at 2, 6, 12, 24, 36, 48 and 72 h after surgery. Analgesic consumption was also registered. Both groups of patients were treated with the same surgical and rehabilitation protocols.

RESULTS

A significant difference of one point was found in the visual analogic pain scores 12 h after surgery (0.6 ± 1.5 vs. 1.7 ± 2.3). There were no significant differences in the visual analogic pain scores evaluated at any other time between 2 and 72 h after surgery. No significant differences were found in the required doses of tramadol or morphine in the postoperative period. Postoperative hemoglobin and blood loss were also similar in both groups.

CONCLUSION

Adding local infiltration of analgesics to peripheral nerve blocks after TKA surgery only provides minimal benefit for pain control. This benefit may be considered as non-clinically relevant. Moreover, the need for additional analgesics was the same in both groups. Therefore, the use of local infiltration of analgesics treatment in TKA surgery cannot be recommended if peripheral nerve blocks are used.

LEVEL OF EVIDENCE

I.

Interventions for the prediction and management of chronic postsurgical pain after total knee replacement: systematic review of randomised controlled trials

OBJECTIVES

Total knee replacement can be a successful operation for pain relief. However, 10-34% of patients experience chronic postsurgical pain. Our aim was to synthesise evidence on the effectiveness of applying predictive models to guide preventive treatment, and for interventions in the management of chronic pain after total knee replacement.

SETTING

We conducted a systematic review of randomised controlled trials using appropriate search strategies in the Cochrane Library, MEDLINE and EMBASE from inception to October 2014. No language restrictions were applied.

PARTICIPANTS

Adult patients receiving total knee replacement.

INTERVENTIONS

Predictive models to guide treatment for prevention of chronic pain. Interventions for management of chronic pain.

PRIMARY AND SECONDARY OUTCOME MEASURES

Reporting of specific outcomes was not an eligibility criterion but we sought outcomes relating to pain severity.

RESULTS

No studies evaluated the effectiveness of predictive models in guiding treatment and improving outcomes after total knee replacement. One study evaluated an intervention for the management of chronic pain. The trial evaluated the use of a botulinum toxin A injection with antinociceptive and anticholinergic activity in 49 patients with chronic postsurgical pain after knee replacement. A single injection provided meaningful pain relief for about 40 days and the authors acknowledged the need for a large trial with repeated injections. No trials of multidisciplinary interventions or individualised treatments were identified.

CONCLUSIONS

Our systematic review highlights a lack of evidence about the effectiveness of prediction and management strategies for chronic postsurgical pain after total knee replacement. As a large number of people are affected by chronic pain after total knee replacement, development of an evidence base about care for these patients should be a research priority.