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Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the mainstays of multimodal pain management. While effective for acute pain control, recent pre-clinical evidence has raised concerns regarding an association between NSAIDs and chronic pain and potential opioid use. Our objective was to explore the association between peri-operative use of prescription NSAIDs and the need for continued opioid prescriptions lasting 90-180 days in previously opioid-naïve patients undergoing total knee arthroplasty. A database of health claims in the USA was used to identify all opioid-naïve adult patients who underwent primary knee arthroplasty between January 2010 and October 2021. We evaluated the magnitude of association between peri-operative prescription NSAID claims and claims for opioids at 90 days postoperatively using multivariable logistic regression models. Secondary outcomes included: the magnitude of association between peri-operative NSAID prescription and claims for opioids at 180 days postoperatively; and identifying other potential factors associated with opioid claims at 90 days postoperatively. After risk adjustment using multivariable logistic regression models in the 789,736-patient cohort, the adjusted odds ratio (95%CI) for a continuous claim of opioids at 90 and 180 days postoperatively among patients with a peri-operative NSAID prescription within 30 days was 1.32 (1.30-1.35), p < 0.001; and 1.12 (1.10-1.15), p < 0.001, respectively. This estimate of effect remained robust at 90 days after accounting for known potential confounders, including pre-existing knee pain and acute postoperative pain severity. Similar analysis of other pain medications (e.g. paracetamol) did not detect such an association. This population-based cohort study suggests that peri-operative prescription NSAID use may be associated with continued opioid prescription claims at 90 and 180 days after knee arthroplasty, even after adjusting for other observed covariates for continuous opioid claims. These novel findings can inform clinical decision-making for post-surgical pain management, risk-benefit discussions with patients and future research., (© 2024 Association of Anaesthetists.)

Background: The analgesic effectiveness of contemporary motor-sparing nerve blocks used in combination for analgesia in total knee arthroplasty is unclear. This network meta-analysis was conducted to evaluate the analgesic effectiveness of adding single-injection or continuous adductor canal block (ACB) with or without infiltration of the interspace between the popliteal artery and the capsule of the posterior knee (iPACK) to intraoperative local infiltration analgesia (LIA), compared to LIA alone, after total knee arthroplasty., Methods: Randomized trials examining the addition of single-injection or continuous ACB with or without single-injection block at the iPACK to LIA for total knee arthroplasty were considered. The two primary outcomes were area-under-the-curve pain scores over 24 to 48 h and postoperative function at greater than 24 h. Secondary outcomes included rest pain scores at 0, 6, 12, and 24 h; opioid consumption (from 0 to 24 h and from 25 to 48 h); and incidence of nausea/vomiting. Network meta-analysis was conducted using a frequentist approach., Results: A total of 27 studies (2,317 patients) investigating the addition of (1) single-injection ACB, (2) continuous ACB, (3) single-injection ACB and single-injection block at the iPACK, and (4) continuous ACB and single-injection block at the iPACK to LIA, as compared to LIA alone, were included. For area-under-the-curve 24- to 48-h pain, the addition of continuous ACB with single-injection block at the iPACK displayed the highest P-score probability (89%) of being most effective for pain control. The addition of continuous ACB without single-injection block at the iPACK displayed the highest P-score probability (87%) of being most effective for postoperative function., Conclusions: The results suggest that continuous ACB, but not single-injection ACB and/or single-injection block at the iPACK, provides statistically superior analgesia when added to LIA for total knee arthroplasty compared to LIA alone. However, the magnitude of these additional analgesic benefits is clinically questionable., (Copyright © 2023 American Society of Anesthesiologists. All Rights Reserved.)

Background: Although total hip arthroplasty (THA) and total knee arthroplasty (TKA) offer significant cost savings to our health care system, the degree to which the burden of postoperative care has been transferred onto the informal caregiver is often overlooked. We performed a scoping review to identify the characteristics and factors that contribute to the burden of care experienced after outpatient THA and TKA., Methods: We systematically searched electronic literature databases according to scoping review guidelines from inception to June 2021 for articles reporting the experiences of informal caregivers providing care for patients having undergone outpatient THA or TKA. Our review included English-language studies that sought to elucidate the impact on caregivers in the acute postoperative period (up to 6 wk after surgery)., Results: Our search yielded 1423 unique articles, which were screened for inclusion. We removed 310 duplicate records and excluded another 1099 articles because they did not meet the inclusion criteria for full-text screening with relevancy. We thus assessed 14 articles for full-text review, and none were found to meet our inclusion criteria., Conclusion: We found no published data pertaining to the burden borne by informal caregivers who provide perioperative care to patients who have undergone ambulatory THA or TKA. Further research is needed to identify, quantify and determine the modifiability of the various characteristics and factors that contribute to caregiver burden in the outpatient setting., Competing Interests: Competing interests: Jesse Wolfstadt reports payments for advisory board work from MicroPort Orthopedics and for consultant work from DePuy Synthes. No other competing interests were declared., (© 2023 CMA Impact Inc. or its licensors.)

Background: Adductor canal block (ACB) can provide important analgesic benefits following total knee arthroplasty (TKA), however, the extent to which these benefits can be enhanced or prolonged by a continuous catheter-based infusion compared with a single-shot injection of local anesthetic is unclear., Objectives: This systematic review and meta-analysis (PROSPERO: CRD42021292738) review sought to compare the analgesic effectiveness of single shot to continuous ACB following TKA., Evidence Review: We sought randomized trials from the US National Library of Medicine database (MEDLINE), Excerpta Medica database (EMBASE), and Cochrane Database of Systematic Reviews from inception to November 1, 2021, that compared single-shot to continuous ACB in adult patients undergoing TKA. The primary outcomes were (1) area under the curve (AUC) pain severity at rest and (2) cumulative opioid (oral morphine equivalent) consumption during the first 48 hours postoperatively. Secondary outcomes included postoperative pain severity scores up to 48 hours, cumulative opioid consumption at 24 hours, functional recovery, opioid-related side effects, and block-related complications. Risk of bias of included studies was assessed using the Cochrane risk of bias tool. Statistical pooling was conducted using the Hartung-Knapp-Sidik-Jonkman method for random effects. No funding was obtained for this review., Findings: Eleven trials (1185 patients) were included. No differences were observed in rest pain severity (AUC) or cumulative opioid consumption up to 48 hours postoperatively. In addition, no differences were observed in individual postoperative rest pain scores in the recovery room and at 12 and 24 hours, or in cumulative opioid consumption at 24 hours, functional recovery, and opioid-related side effects. Finally, fewer block-related complications were observed with single-shot ACB, with an OR (95% CI) of 0.24 (0.14 to 0.41) (p=0.002)., Conclusions: Our results suggest that continuous catheter-based ACB does not enhance or prolong the analgesic benefits when compared with single-shot ACB for TKA over the first 48 hours postoperatively. Overall, the results of our meta-analysis do not support the routine use of continuous ACB for postoperative analgesia after TKA., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: When combined with adductor canal block (ACB), local anesthetic infiltration between popliteal artery and capsule of knee (iPACK) is purported to improve pain following total knee arthroplasty (TKA). However, the analgesic benefits of adding iPACK to ACB in the setting of surgeon-administered periarticular local infiltration analgesia (LIA) are unclear., Objectives: To evaluate the analgesic benefits of adding iPACK to ACB, compared with ACB alone, in the setting of LIA following TKA., Evidence Review: We conducted a meta-analysis of randomized trials comparing the effects of adding iPACK block to ACB versus ACB alone on pain severity at 6 hours postoperatively in adult patients undergoing TKA. We a priori planned to stratify analysis for use of LIA. Opioid consumption at 24 hours, functional recovery, and iPACK-related complications were secondary outcomes., Findings: Fourteen trials (1044 patients) were analyzed. For the primary outcome comparison in the presence of LIA (four trials, 273 patients), adding iPACK to ACB did not improve postoperative pain at 6 hours. However, in the absence of LIA (eight trials, 631 patients), adding iPACK to ACB reduced pain by a weighted mean difference (WMD) (95% CI) of -1.33 cm (-1.57 to -1.09) (p<0.00001). For the secondary outcome comparisons in the presence of LIA, adding iPACK to ACB did not improve postoperative pain at all other time points, opioid consumption or functional recovery. In contrast, in the absence of LIA, adding iPACK to ACB reduced pain at 12 hours, and 24 hours by a WMD (95% CI) of -0.98 (-1.79 to -0.17) (p = 0.02) and -0.69 (-1.18 to -0.20) (p=0.006), respectively, when compared with ACB alone, but did not reduce opioid consumption. Functional recovery was also improved by a log(odds ratio) (95% CI) of 1.28 (0.45 to 2.11) (p=0.003). No iPACK-related complications were reported., Conclusion: Adding iPACK to ACB in the setting of periarticular LIA does not improve analgesic outcomes following TKA. In the absence of LIA, adding iPACK to ACB reduces pain up to 24 hours and enhances functional recovery. Our findings do not support the addition of iPACK to ACB when LIA is routinely administered., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Periarticular local infiltration analgesia (LIA) is integral to multimodal analgesia following total knee arthroplasty (TKA); however, the duration of analgesia using traditional long-acting local anesthetics is often insufficient. LIA with slow-release liposomal bupivacaine may provide extended analgesia, but evidence of efficacy beyond the first 24 hours is conflicting. This meta-analysis compares the effects of periarticular liposomal and plain bupivacaine LIA on day 2 analgesic outcomes post-TKA. Trials comparing liposomal and plain bupivacaine LIA for TKA were sought. The two coprimary outcomes were (1) cumulative oral morphine equivalent consumption and (2) difference in area under the curve (AUC) of pooled rest pain scores on day 2 (24-48 hours) post-TKA. We also evaluated pain and analgesic consumption on day 3 (48-72 hours), functional recovery, length of hospital stay, patient satisfaction; and opioid-related side effects. Data were pooled using random-effects modeling. Seventeen trials (1836 patients) were analyzed. Comparing liposomal versus plain bupivacaine LIA for TKA failed to detect differences in morphine consumption and pain AUC on day 2 postoperatively, with mean differences of 0.54 mg (95% CI -5.09 to 6.18) and 0.08 cm/hour (95% CI -0.19 to 0.35), respectively (high-quality evidence). Secondary outcome analysis did not uncover any additional analgesic, functional or safety advantages to liposomal bupivacaine on postoperative day 2 or 3. Results indicate that liposomal and plain bupivacaine LIAs are not different for extended postoperative analgesic outcomes, including pain control, opioid consumption, as well as functional and safety outcomes on days 2 and 3 post-TKA. High-quality evidence does not support using liposomal bupivacaine LIA for TKA., Competing Interests: Competing interests: RB receives research time support from the Evelyn Bateman Cara Operations Endowed Chair in Ambulatory Anesthesia and Women’s Health, Women’s College Hospital, Toronto., (© American Society of Regional Anesthesia & Pain Medicine 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Adductor canal block (ACB) has emerged as an effective analgesic regional technique for major knee surgeries in the last decade. Its motor-sparing properties make it particularly attractive for ambulatory knee surgery, but evidence supporting its use in ambulatory arthroscopic knee surgery is conflicting. This systematic review and meta-analysis evaluates the analgesic effects of ACB for ambulatory arthroscopic knee surgeries., Methods: We conducted a comprehensive search of electronic databases for randomized controlled trials examining the analgesic effects of ACB compared to control or any other analgesic modality. Both minor arthroscopic and anterior cruciate ligament reconstruction (ACLR) surgeries were considered. Rest and dynamic pain scores, opioid consumption, opioid-related adverse effects, time to first analgesic request, patient satisfaction, quadriceps strength, and block-related complications were evaluated. Data were pooled using random-effects modeling., Results: Our search yielded 10 randomized controlled trials comparing ACB with placebo or femoral nerve block (FNB); these were subgrouped according to the type of knee surgery. For minor knee arthroscopic surgery, ACB provided reduced postoperative resting pain scores by a mean difference (95% confidence interval) of -1.46 cm (-2.03 to -0.90) (P < .00001), -0.51 cm (-0.92 to -0.10) (P = .02), and -0.48 cm (-0.93 to -0.04) (P = .03) at 0, 6, and 8 hours, respectively, compared to control. Dynamic pain scores were reduced by a mean difference (95% confidence interval) of -1.50 cm (-2.10 to -0.90) (P < .00001), -0.50 cm (-0.95 to -0.04) (P = .03), and -0.59 cm (-1.12 to -0.05) (P = .03) at 0, 6, and 8 hours, respectively, compared to control. ACB also reduced the cumulative 24-hour oral morphine equivalent consumption by -7.41 mg (-14.75 to -0.08) (P = .05) compared to control. For ACLR surgery, ACB did not provide any analgesic benefits and did not improve any of the examined outcomes, compared to control. ACB was also not different from FNB for these outcomes., Conclusions: After minor ambulatory arthroscopic knee surgery, ACB provides modest analgesic benefits, including improved relief for rest pain, and reduced opioid consumption for up to 8 and 24 hours, respectively. The analgesic benefits of ACB are not different from placebo or FNB after ambulatory ACLR, suggesting a limited role of both blocks in this procedure. Paucity of trials dictates cautious interpretation of these findings. Future studies are needed to determine the role of ACB in the setting of local anesthetic instillation and/or graft donor-site analgesia.

Background: Total knee arthroplasty (TKA) is associated with moderate-to-severe postoperative pain despite the use of femoral nerve block (FNB). The analgesic benefits of adding sciatic nerve block (SNB) to FNB following TKA are unclear. The aim of this meta-analysis was to quantify the analgesic effects of adding SNB to FNB following TKA., Methods: We searched the US National Library of Medicine (MEDLINE), Excerpta Medica (Embase), and Cochrane Central Controlled Trials Register databases in March 2015 for randomized and quasi-randomized controlled trials (RCTs) that evaluated the analgesic advantages of adding SNB to FNB compared to FNB alone after TKA. The designated primary outcome was intravenous morphine consumption during the 24-hr postoperative interval. The severity of pain was evaluated at rest and with movement two, four, eight, 12, 24, 36, and 48 hr postoperatively. Morphine consumption during the postoperative 24-48 hr interval, time to first analgesic request, opioid-related side effects, block-related complications, patient satisfaction, functional recovery, and time to hospital discharge were also evaluated. Trials were stratified based on whether a single-shot SNB (SSNB) or continuous SNB (CSNB) was used. Data were combined using random effects modelling., Results: Eight RCTs, including 379 patients, were analyzed. Five trials examined SSNB, and three assessed CSNB. Together, SSNB and CSNB reduced the 0-24 hr weighted mean difference [95% confidence interval] of morphine consumption by 10.6 [-20.9 to -0.3] mg (P = 0.042; I(2) = 97%) and 20.5 [-28.6 to -12.4] mg (P < 0.001, I(2) = 86%), respectively. SSNB reduced pain at rest and during movement up to 8 hr postoperatively (P = 0.023 and P < 0.001, respectively), whereas CSNB reduced pain at rest up to 36 hr (P = 0.004) and pain with movement up to 48 hr (P = 0.031). CSNB also decreased the odds of postoperative nausea and vomiting by 91% (P = 0.011)., Conclusion: The available evidence supporting the analgesic benefits of adding SNB to FNB following TKA is marked by significant heterogeneity. With this challenge in mind, our meta-analysis suggests that SNB can significantly reduce postoperative opioid consumption and diminish knee pain following TKA compared to no SNB in the setting of FNB.

Many anesthesiologists may not be familiar with the rate of surgical neurological complications of the hip and knee procedures for which they are providing local anesthetic-based anesthesia and/or analgesia. Part 2 of this narrative review series on neurological complications of elective orthopedic surgery describes the mechanisms and likelihood of peripheral nerve injury associated with some of the most common hip and knee procedures, including arthroscopic hip and knee surgery and total hip and knee replacement., What's New: As the popularity of regional anesthesia continues to increase with the development of ultrasound guidance, anesthesiologists should have a thoughtful understanding of the nerves at risk of surgical injury during elective hip and knee procedures.

Background: The analgesic efficacy of sciatic nerve block (SNB) after total knee arthroplasty (TKA) is unclear. Proximal and distal SNB are each reported to provide posterior knee analgesia, whereas others suggest that posterior knee pain is not important after TKA. This prospective, randomized, double-blind, parallel-arm, placebo-controlled trial examined whether proximal or distal SNB provides superior analgesia in the posterior knee compared with no SNB after TKA., Methods: Sixty patients undergoing TKA were randomized to single-shot SNB using either the infragluteal (Proximal group) or popliteal (Distal group) technique, or no SNB (Placebo group). All patients received spinal anesthesia and continuous-femoral nerve blockade. A blinded observer assessed posterior and anterior knee pain at 2, 4, 6, 8, 12, and 24 h postoperatively. The primary outcome was moderate-to-severe posterior knee pain at 4 h postoperatively; secondary outcomes included SNB procedural time, needle passes, and discomfort., Results: Fifty-three patients were analyzed. The proportion of patients (Proximal:Distal:Placebo) who experienced moderate-to-severe posterior knee pain was 18%:22%:89% (P<0.00001) at 2 h, 24%:28%:72% (P<0.01) at 4 h, and 12%:17%:78% (P=0.00003) at 6 h postoperatively. For the anterior knee, the proportion of patients reporting moderate-to-severe pain was 6%:11%:44% (P=0.02) at 2 h, 6%:6%:39% (P=0.012) at 4 h, and 12%:6%:44% (P=0.017) at 6 h postoperatively. Moderate-to-severe pain did not differ between groups beyond 6 h. Both proximal and distal SNB reduced rest pain in the posterior and anterior knee up to 8 h postoperatively compared with no SNB. The popliteal technique required shorter procedural time, fewer needle passes, and produced less discomfort., Conclusion: Proximal and distal SNB each reduce posterior and anterior knee pain after TKA compared with no SNB.

Background: The ideal local anesthetic regime for femoral nerve block that balances analgesia with mobility after total knee arthroplasty (TKA) remains undefined., Questions/purposes: We compared two volumes and concentrations of a fixed dose of ropivacaine for continuous femoral nerve block after TKA to a single injection femoral nerve block with ropivacaine to determine (1) time to discharge readiness; (2) early pain scores and analgesic consumption; and (3) functional outcomes, including range of motion and WOMAC scores at the time of recovery., Methods: Ninety-nine patients were allocated to one of three continuous femoral nerve block groups for this randomized, placebo-controlled, double-blind trial: a high concentration group (ropivacaine 0.2% infusion), a low concentration group (ropivacaine 0.1% infusion), or a placebo infusion group (saline 0.9% infusion). Infusions were discontinued on postoperative Day (POD) 2. The primary outcome was time to discharge readiness. Secondary outcomes included opioid consumption, pain, and functional outcomes. Ninety-three patients completed the study protocol; the study was halted early because of unanticipated changes to pain protocols at the host institution, by which time only 61% of the required number of patients had been enrolled., Results: With the numbers available, the mean time to discharge readiness was not different between groups (high concentration group, 62 hours [95% confidence interval [CI], 51-72 hours]; low concentration group, 73 hours [95% CI, 63-83 hours]; placebo infusion group 65 hours [95% CI, 56-75 hours]; p = 0.27). Patients in the low concentration group consumed significantly less morphine during the period of infusion (POD 1, high concentration group, 56 mg [95% CI, 42-70 mg]; low concentration group, 35 mg [95% CI, 27-43 mg]; placebo infusion group, 48 mg [95% CI, 38-59 mg], p = 0.02; POD 2, high concentration group, 50 mg [95% CI, 41-60 mg]; low concentration group, 33 mg [95% CI, 24-42 mg]; placebo infusion group, 39 mg [95% CI, 30-48 mg], p = 0.04); however, there were no important differences in pain scores or opioid-related side effects with the numbers available. Likewise, there were no important differences in functional outcomes between groups., Conclusions: Based on this study, which was terminated prematurely before the desired sample size could be achieved, we were unable to demonstrate that varying the concentration and volume of a fixed-dose ropivacaine infusion for continuous femoral nerve block influences time to discharge readiness when compared with a conventional single-injection femoral nerve block after TKA. A low concentration of ropivacaine infusion can reduce postoperative opioid consumption but without any important differences in pain scores, side effects, or functional outcomes. These pilot data may be used to inform the statistical power of future randomized trials., Level of Evidence: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Background and Objectives: Despite ultrasound (US) guidance, sciatic nerve block (SNB) remains among the least performed peripheral blocks. By targeting the tissue plane between the gluteus maximus and quadratus femoris muscles, the US-guided subgluteal space technique may facilitate the performance of US-guided SNB. We aimed to evaluate whether the subgluteal space technique shortens SNB performance time in overweight and obese patients compared with the conventional infragluteal technique., Methods: Overweight and obese patients (body mass index, > 25 kg m ) undergoing US-guided SNB for knee arthroplasty received 30 mL admixture (1:2 lidocaine 2%; bupivacaine 0.5% with 1:200,000 epinephrine) in the tissue plane between the gluteus maximus and quadratus femoris (subgluteal space group) or around the sciatic nerve at the infragluteal level (infragluteal group). All patients received spinal anesthesia, continuous femoral nerve block, and postoperative multimodal analgesia. The primary outcome was SNB performance time defined as the time interval between placement of the US transducer on skin, and needle withdrawal after injection. Number of needle passes, procedural pain, SNB-related complications, SNB success, postoperative pain, and opioid consumption were also assessed., Results: Twenty-seven patients were assessed (subgluteal space, 14; infragluteal, 13). Mean SNB performance time was 4.4 minutes (95% confidence interval, 3.7-5.0) for the subgluteal space group and 9.0 minutes (95% confidence interval, 7.7-10.3) for the infragluteal group (P < 0.0001). Number of needle passes and procedural pain scores were lower in the subgluteal space group. There were no differences in SNB success or analgesic outcomes., Conclusions: The subgluteal space technique may be performed 50% faster, with no detectable differences in block success and analgesic efficacy, compared with the infragluteal technique for US-guided SNB in overweight and obese patients receiving multimodal analgesia. Injection of local anesthetics along tissue planes may produce similar block characteristics to perineural injection for US-guided SNB.

We asked whether femoral nerve blockade (FNB) was an independent risk factor for inpatient post-operative falls after total knee arthroplasty (TKA). Data on 2197 primary TKAs were collected from our institution between 2003 and 2010. Patient demographics, type and duration of blocks were considered predictors of falls in a logistic regression model. Among 60 (2.7%) falls, the odds ratio was 1.04 (1.0-1.07; p=0.008) for each 1 year of increased age above the mean (66 years), 2.4 (1.3-4.5; p=0.005) for BMI >30 kg/m(2) and 4.4 (1.04-18.2; p=0.04) for continuous FNB. Single-shot FNB did not increase risk. No fall resulted in operative morbidity. The use of continuous FNB should be cautioned, especially in patients with other risk factors such as obesity and advanced age., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Introduction: Total knee arthroplasty is associated with moderate to severe pain, and effective analgesia is essential to facilitate postoperative recovery. This retrospective cohort study examined the analgesic and rehabilitation outcomes associated with 48-hour continuous femoral nerve block, local infiltration analgesia, or local infiltration analgesia plus adductor canal nerve block., Methods: Patients undergoing total knee arthroplasty under spinal anesthesia, during an 8-month period, were retrospectively assessed with a targeted review of 100 patients per group. Records of eligible patients were reviewed to identify the analgesic technique used and the primary outcome of distance walked on postoperative day 1. Secondary outcomes included ambulation on days 2 and 3, numeric rating scale pain scores, opioid consumption, and adverse effects and discharge disposition., Results: Two hundred ninety-eight eligible patients were reviewed. Local infiltration analgesia and local infiltration plus adductor canal block were associated with longer distances walked on postoperative day 1 than continuous femoral nerve block (median values of 20, 30, and 0 m, respectively; P < 0.0001). The addition of adductor canal block was associated with further improvement in early ambulation benchmarks and a higher rate of home discharge compared with only local infiltration (88.2% vs 73.2%, P = 0.018). Local infiltration with or without adductor canal block was associated with lower pain scores at rest and during movement for the first 24 hours and lower opioid consumption than continuous femoral nerve infusion., Conclusions: Local infiltration analgesia was associated with improved early analgesia and ambulation. The addition of adductor canal nerve block was associated with further improvements in early ambulation and a higher incidence of home discharge.

Sciatic nerve block (SNB) is commonly performed in combination with femoral nerve block (FNB) for postoperative analgesia following total knee arthroplasty (TKA). This systematic review examines the effects of adding SNB to FNB for TKA compared with FNB alone on acute pain and related outcomes. Four intermediate-quality randomized and 3 observational trials, including a total of 391 patients, were identified. Three of 4 trials investigating the addition of single-shot SNB and 2 of 3 trials investigating continuous SNB reported improved early analgesia at rest and reduced early opioid consumption. Only 2 trials specifically assessed posterior knee pain. We were unable to uncover any clinically important analgesic advantages for SNB beyond 24 hours postoperatively. At present, there is inconclusive evidence in the literature to define the effect of adding SNB to FNB on acute pain and related outcomes compared with FNB alone for TKA.

We describe a case of ultrasound (US)-facilitated spinal anesthesia in a patient with a prior lumbar laminectomy and spinal fusion who presented for total knee arthroplasty. Traditional, landmark-guided spinal anesthesia had previously failed. Although pre-procedural US identified a soft-tissue window at L3/4, a 25G pencilpoint needle encountered resistance. Reassured from US imaging that this was not bone, we used a 22G cutting tip needle successfully. We believe spinal anesthesia would not have been possible in this patient without US, adding to the evidence that US-facilitated neuraxial anesthesia is useful, particularly in technically difficult, if not 'impossible,' cases.

Total knee arthroplasty (TKA) is amenable to various regional anesthesia techniques that may improve patient outcome. We sought to answer whether regional anesthesia decreased mortality, cardiovascular morbidity, deep venous thrombosis and pulmonary embolism, blood loss, duration of surgery, pain, opioid-related adverse effects, cognitive defects, and length of stay. We also questioned whether regional anesthesia improved rehabilitation. To do so, we performed a systematic review of the contemporary literature comparing general anesthesia and/or systemic analgesia with regional anesthesia and/or regional analgesia for TKA. To reflect contemporary surgical and anesthetic practice, only randomized, controlled trials from 1990 onward were included. We identified 28 studies involving 1538 patients. There was insufficient evidence from randomized, controlled trials alone to conclude if anesthetic technique influenced mortality, cardiovascular morbidity other than postoperative hypotension, or the incidence of deep venous thrombosis and pulmonary embolism when using thromboprophylaxis. Our review suggests there was no difference in perioperative blood loss or duration of surgery in patients who received general anesthesia versus regional anesthesia. Compared with general anesthesia and/or systemic analgesia, regional anesthesia and/or analgesia reduced postoperative pain, morphine consumption, and opioid-related adverse effects. Length of stay may be reduced and rehabilitation facilitated for patients undergoing regional anesthesia and analgesia for TKA.

Purpose: Spinal anesthesia can be challenging in patients undergoing total joint arthroplasty because of poorly palpable surface landmarks and age-related changes in the lumbar spine. We hypothesized that pre-procedural ultrasound imaging would be effective in identifying the lumbar intervertebral spaces and would provide an accurate measure of the depth to the intrathecal space., Methods: Fifty patients undergoing elective total joint arthroplasty were recruited in this prospective descriptive study. Using a curved-array 2-5 MHz transducer, the lumbar spine was imaged in two views, i.e., longitudinal parasagittal (LP) and transverse midline (TM). The intervertebral levels were identified by counting upwards from the sacrum. The locations of the interlaminar spaces were identified by visualizing the ligamentum flavum-dura mater complex and the posterior aspect of the vertebral body. The needle insertion point for a midline approach was determined from the ultrasound examination and was marked on the skin of the patient's back., Results: The mean patient age was 67 +/- 10 yr, and 46% of the patients had a body mass index >30 kg . m(-2). Surface landmarks were difficult or impossible to palpate in 38% of the patients. The scan quality on the LP and TM views was adequate or better in 100 and 98% of the patients, respectively. Dural puncture was achieved with one needle insertion attempt and within two needle insertion attempts in 84% and 98% of the patients, respectively. The ultrasound-measured depth to the intrathecal space correlated well with the actual needle insertion depth (concordance correlation coefficient = 0.82, accuracy 0.95, precision 0.86), with a tendency to overestimate the depth by just 2.1 +/- 5.4 mm., Conclusions: Ultrasound imaging of the lumbar spine provides clinically useful information that can facilitate spinal anesthesia in the older orthopedic patient population.