Efficacy of Single-Shot Adductor Canal Block Combined With Posterior Capsular Infiltration on Postoperative Pain and Functional Outcome After Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study

The Effect of Postoperative Single-Injection Adductor Canal Block in Total Knee Arthroplasty Under Spinal Anesthesia With Intraoperative Dexmedetomidine Infusion

Background

Single-injection adductor canal block (SACB) is one of the multimodal pain managements in total knee arthroplasty. The effect of an intrathecal local anesthetic is prolonged with an intraoperative dexmedetomidine infusion. Currently, SACB's effect along with the prolonged spinal anesthesia effect by dexmedetomidine has not been studied elsewhere.

Methods

Seventy-eight patients were randomized to either the SACB group (n = 39) or the control group (n = 39). Spinal anesthesia and continuous infusion of dexmedetomidine were performed intraoperatively. The SACB was performed using 15 mL of either 0.5% ropivacaine or normal saline in postanesthesia care unit postoperatively. Primary endpoint examined the average numerical rating scale (NRS) pain scores at 2, 6, 12, and 24 hours after SACB while resting or moving. The secondary outcomes were the morphine equivalent, postoperative nausea and vomiting score, quadriceps strength, and overall satisfaction score.

Results

The SACB group showed a lower average NRS pain score until 24 hours than the control group (2.4 vs 3.3 resting, 3.4 vs 4.1 moving). Resting and moving NRS scores at 6 and 12 hours were significantly lower in the SACB group, whereas no difference was found at 2, 24, and 48 hours, regardless of movement. The satisfaction score was higher in the SACB group than in the control group (9 [7.3-10.0] vs 7 [5.3-8.8]), and morphine equivalent at 2 hours was lower in the SACB group (2 [1-3]) than in the control group (2.9 [1.6-4]).

Conclusions

SACB provided an additional analgesic effect in patients undergoing total knee arthroplasty under spinal anesthesia with continuous dexmedetomidine intravenous infusion.

Efficacy of adding infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) to adductor canal block and local infiltration analgesia in total knee arthroplasty: A retrospective cohort study

OBJECTIVE

Local infiltration analgesia (LIA), adductor canal block (ACB), and infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) are popular multimodal analgesia techniques used during total knee arthroplasty (TKA). This study aimed to explore the efficacy of adding the IPACK technique to ACB and LIA in patients undergoing TKA.

METHODS

In this retrospective cohort study, patients who underwent primary unilateral TKA were divided into two groups based on their date of admission. Sixty-three patients underwent IPACK, ACB and LIA (IPACK group) during surgery, while 60 patients underwent ACB and LIA (control group). The primary outcome was the postoperative administration of morphine hydrochloride as a rescue analgesic. Secondary outcomes included time to first rescue analgesia, postoperative pain assessed using the visual analog scale (VAS), functional recovery assessed by knee range of motion and ambulation distance, time until hospital discharge, and complication rates.

RESULTS

The two groups were similar in average postoperative 0-to-24-h morphine consumption (11.8 mg for the control group vs 12.7 mg for the IPACK group, p = .428) and average total morphine consumption (18.2 mg vs 18.0 mg, p = .983) during hospitalization. There were also no significant differences in the secondary outcomes.

CONCLUSIONS

The addition of IPACK to ACB and LIA did not provide any clinical analgesic benefits. Orthopedic surgeons and anesthesiologists are justified in using ACB and LIA without IPACK for TKA.

Analgesic Effectiveness of Motor-sparing Nerve Blocks for Total Knee Arthroplasty: A Network Meta-analysis

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.

EDITOR’S PERSPECTIVE

Motor-Sparing Effect of Adductor Canal Block for Knee Analgesia: An Updated Review and a Subgroup Analysis of Randomized Controlled Trials Based on a Corrected Classification System

OBJECTIVE

Discrepancies in the definition of adductor canal block (ACB) lead to inconsistent results. To investigate the actual analgesic and motor-sparing effects of ACB by anatomically defining femoral triangle block (FTB), proximal ACB (p-ACB), and distal ACB (d-ACB), we re-classified the previously claimed ACB approaches according to the ultrasound findings or descriptions in the corresponding published articles. A meta-analysis with subsequent subgroup analyses based on these corrected results was performed to examine the true impact of ACB on its analgesic effect and motor function (quadriceps muscle strength or mobilization ability). An optimal ACB technique was also suggested based on an updated review of evidence and ultrasound anatomy.

MATERIALS AND METHODS

We systematically searched studies describing the use of ACB for knee surgery. Cochrane Library, PubMed, Web of Science, and Embase were searched with the exclusion of non-English articles from inception to 28 February 2022. The motor-sparing and analgesic aspects in true ACB were evaluated using meta-analyses with subsequent subgroup analyses according to the corrected classification system.

RESULTS

The meta-analysis includes 19 randomized controlled trials. Compared with the femoral nerve block group, the quadriceps muscle strength (standardized mean difference (SMD) = 0.33, 95%-CI [0.01; 0.65]) and mobilization ability (SMD = -22.44, 95%-CI [-35.37; -9.51]) are more preserved in the mixed ACB group at 24 h after knee surgery. Compared with the true ACB group, the FTB group (SMD = 5.59, 95%-CI [3.44; 8.46]) has a significantly decreased mobilization ability at 24 h after knee surgery.

CONCLUSION

By using the corrected classification system, we proved the motor-sparing effect of true ACB compared to FTB. According to the updated ultrasound anatomy, we suggested proximal ACB to be the analgesic technique of choice for knee surgery. Although a single-shot ACB is limited in duration, it remains the candidate of the analgesic standard for knee surgery on postoperative day 1 or 2 because it induces analgesia with less motor involvement in the era of multimodal analgesia. Furthermore, data from the corrected classification system may provide the basis for future research.

The Efficacy and Safety of Regional Nerve Blocks in Total Knee Arthroplasty: Systematic Review and Direct Meta-Analysis

BACKGROUND

Regional nerve blocks are widely used in primary total knee arthroplasty (TKA) to reduce postoperative pain and opioid consumption. The purpose of our study was to evaluate the efficacy and safety of regional nerve blocks after TKA in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management.

METHODS

We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published before March 24, 2020 on femoral nerve block, adductor canal block, and infiltration between Popliteal Artery and Capsule of Knee in primary TKA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of the regional nerve blocks compared to a control, local peri-articular anesthetic infiltration (PAI), or between regional nerve blocks.

RESULTS

Critical appraisal of 1,673 publications yielded 56 publications representing the best available evidence for analysis. Femoral nerve and adductor canal blocks are effective at reducing postoperative pain and opioid consumption, but femoral nerve blocks are associated with quadriceps weakness. Use of a continuous compared to single shot adductor canal block can improve postoperative analgesia. No difference was noted between an adductor canal block or PAI regarding postoperative pain and opioid consumption, but the combination of both may be more effective.

CONCLUSION

Single shot adductor canal block or PAI should be used to reduce postoperative pain and opioid consumption following TKA. Use of a continuous adductor canal block or a combination of single shot adductor canal block and PAI may improve postoperative analgesia in patients with concern of poor postoperative pain control.

iPACK block (local anesthetic infiltration of the interspace between the popliteal artery and the posterior knee capsule) added to the adductor canal blocks versus the adductor canal blocks in the pain management after total knee arthroplasty: a systematic review and meta-analysis

Background

Several studies have suggested that the addition of iPACK block (the popliteal artery and the posterior knee capsule have been given interspace local anesthetic infiltration) might get better analgesia than adductor canal block (ACB) only after total knee arthroplasty (TKA). This paper compiles all available evidence on the effect of two analgesia regimens (ACB and iPACK + ACB) involving all sides.

Methods

We searched in eight major databases for all clinical trials discussing the effect of two analgesia regimens after TKA. Statistical analyses were conducted by Stata and RevMan Software. In addition, we performed GOSH analysis, subgroup analysis, meta-regression analysis to study the source of heterogeneity. Publication bias was checked using Egger’s test. Trim-and-fill analysis was applied in terms of sensitivity analysis of the results.

Results

There are fourteen eligible studies for our meta-analysis. There are significant differences between the two groups in VAS score at rest and with activity, and the VAS scores were lower in the ACB + iPACK Group (VAS scores at rest: 95%CI [− 0.96, − 0.53], P < 0.00001. VAS scores with activity: 95%CI [− 0.79, − 0.43], P < 0.00001). A differential was discovered to support the ACB + iPACK Group when comparing the two groups on postoperative cumulative morphine consumption (95%CI: [− 0.52, − 0.14], P: 0.0007). The patients in the group of ACB + iPACK performed better in the postoperative range of knee movement (95%CI: [5.18, 10.21], P < 0.00001) and walking distance (95%CI: [0.15, 0.41], P < 0.00001). There were significant differences between the patients in the ACB + iPACK Group and ACB Group on the TUG test of POD1 and POD2. We found that patients' hospital stays in the ACB + iPACK Group were significantly shorter than in the ACB Group (95%CI: [− 0.78, − 0.16], P: 0.003). No difference was found between the patients in the ACB + iPACK Group and ACB Group on postoperative quadriceps muscle strength and the incidence of PONV.

Conclusion

The addition of iPACK lowers postoperative VAS scores, cumulative morphine consumption, and hospital stays. Meanwhile, the addition of iPACK improves postoperative patients’ activity performance without extra side effects. iPACK combined with ACB proves to be a suitable pain management technique after TKA.

Ultrasound-Guided Adductor Canal Block Versus Intraoperative Transarticular Saphenous Nerve Block: A Retrospective Analysis

BACKGROUND

The ultrasound-guided adductor canal block (High-ACB) is an effective option for pain control in total knee arthroplasty (TKA), but its use can add substantial cost and preparatory time to a TKA procedure. An intraoperative adductor canal block (Low-ACB) performed by the operative surgeon has been described as an alternative. The hypothesis of this study is that the Low-ACB would achieve noninferior pain control and opioid utilization postoperatively when compared to the High-ACB.

METHODS

This is a retrospective study of a prospectively maintained database comparing the High-ACB vs the Low-ACB. The primary outcome measure was morphine milligram equivalents consumed. Secondary outcome measures included Visual Analog Scale pain scores, postoperative outcomes (Patient-Reported Outcome Measurement Information System, Knee Injury and Osteoarthritis Outcome Score, knee range of motion), length of stay, postoperative speed of mobilization, and complications related to the type of block.

RESULTS

There were 139 patients in the study. There was lower opioid use in the first 24 hours in the Low-ACB compared to the High-ACB group respectively (26.3 vs 30, P = .29) but this did not reach statistical significance. There was a statistically significant difference in Visual Analog Scale score on postoperative day 1 in the Low-ACB vs High-ACB groups respectively (4.6 vs 3.7, P = .02) but this did not reach the level of clinical significance. There was no statistical difference in the Patient-Reported Outcome Measurement Information System, Knee Injury and Osteoarthritis Outcome Score, or postoperative range of motion. There were no block-related complications in either group.

CONCLUSION

The Low-ACB is a safe, effective, and cost-saving alternative to the traditional High-ACB for pain control in TKA.

Combined application of adductor canal block and local infiltration anesthesia in primary total knee arthroplasty: an updated meta-analysis of randomized controlled trials

BACKGROUND

Perioperative pain after total knee arthroplasty (TKA) may seriously affect the rapid recovery of patients. The purpose of this study was to assess whether the combined use of adductor canal block (ACB) and local infiltration anesthesia (LIA) can further reduce postoperative pain and improve early functional recovery.

MATERIALS AND METHODS

PubMed, Web of Science, EMBASE, and Cochrane Central Register of Controlled Trials were systematically searched for randomized controlled trials (RCTs) comparing ACB + LIA and LIA alone in primary TKA. The primary outcomes were visual analog scale (VAS) scores at rest and walking, morphine consumption, range of motion (ROM) at 24 and 48 h postoperatively and distance walked. The secondary outcomes were the length of stay, the incidence of nausea and vomiting, and the total complications. Subgroup analyses were performed on the VAS at rest and walking, morphine consumption, and distance walked at 24, 48, and 72 h postoperatively.

RESULTS

A total of 10 RCTs involving 797 patients were enrolled in this meta-analysis. The results demonstrated that the combined application of ACB + LIA had a lower resting VAS at 24 h postoperatively (p = 0.02) and the walking score at 24 (p = 0.0002) and 48 h (p = 0.02) postoperatively compared with LIA alone. Similarly, the combined ACB + LIA group also had less morphine consumption at 48 h postoperatively (p = 0.0005) and had a higher ROM score at 24 h (p = 0.01) postoperatively compared to the LIA group. There were no statistical differences in length of stay, distance walked, and incidence of nausea and vomiting.

CONCLUSION

The current meta-analysis showed that ACB + LIA significantly reduced postoperative walking pain and morphine consumption and promoted rapid recovery in the early postoperative period. There is no statistical difference in the length of stay and ROM after 72 h in the two groups.

Efficacy of Two Unique Combinations of Nerve Blocks on Postoperative Pain and Functional Outcome After Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study

BACKGROUND

This study aimed to explore the efficacy of two unique combinations of nerve blocks on postoperative pain and functional outcome after total knee arthroplasty (TKA).

METHODS

Patients scheduled for TKA were randomized to receive a combination of adductor canal block (ACB) + infiltration between the popliteal artery and capsule of the posterior knee block (IPACK) + sham obturator nerve block (ONB) + sham lateral femoral cutaneous nerve block (LFCNB) (control group), or a combination of ACB + IPACK + ONB + sham LFCNB (triple nerve block group), or a combination of ACB + IPACK + ONB + LFCNB (quadruple nerve block group). All patients received local infiltration analgesia. Primary outcome was postoperative morphine consumption. Secondary outcomes were the time until first rescue analgesia, postoperative pain assessed on the visual analog scale (VAS), QoR-15 score, functional recovery of knee, and postoperative complications.

RESULTS

Compared with the control group, the triple and quadruple nerve block groups showed significantly lower postoperative morphine consumption (17.2 ± 9.7 mg vs. 11.2 ± 7.0 mg vs. 11.4 ± 6.4 mg, P = .001). These two groups also showed significantly longer time until first rescue analgesia (P = .007 and .010, respectively, analyzed with Kaplan-Meier method), significantly lower VAS scores on postoperative day 1 (P < .01), significantly better QoR-15 scores on postoperative days 1 and 2 (P < .001), and significantly better functional recovery of knee including range of motion (P = .002 and .001 on postoperative days 1 and 2), and daily ambulation distance (P < .001 and P = .004 on postoperative days 1 and 2). However, the absolute change in morphine consumption, VAS scores, and QoR-15 scores did not exceed the reported minimal clinically important differences (MCIDs) (morphine consumption: 10 mg; VAS scores: 1.5 at rest and 1.8 during movement; QoR-15 scores: 8.0). The MCIDs of other outcomes have not been reported in literature. The triple and quadruple nerve block groups showed no significant differences in these outcomes between each other. The three groups did not show a significant difference in complication rates.

CONCLUSION

Adding ONB or ONB + LFCNB to ACB + IPACK can statistically reduce morphine consumption, improve early pain relief, and functional recovery. However, the absolute change in morphine consumption, VAS scores, and QoR-15 scores did not exceed the MCIDs. Based on our findings and considering the sample size of this study, there is not enough clinical evidence to support the triple or quadruple nerve block use within a multimodal analgesic pathway after TKA.

Peripheral nerve block anesthesia/analgesia for patients undergoing primary hip and knee arthroplasty: recommendations from the International Consensus on Anesthesia-Related Outcomes after Surgery (ICAROS) group based on a systematic review and meta-analysis of current literature

BACKGROUND

Evidence-based international expert consensus regarding the impact of peripheral nerve block (PNB) use in total hip/knee arthroplasty surgery.

METHODS

A systematic review and meta-analysis: randomized controlled and observational studies investigating the impact of PNB utilization on major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, thromboembolic, neurologic, infectious, and bleeding complications.Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, were queried from 1946 to August 4, 2020.The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess evidence quality and for the development of recommendations.

RESULTS

Analysis of 122 studies revealed that PNB use (compared with no use) was associated with lower ORs for (OR with 95% CIs) for numerous complications (total hip and knee arthroplasties (THA/TKA), respectively): cognitive dysfunction (OR 0.30, 95% CI 0.17 to 0.53/OR 0.52, 95% CI 0.34 to 0.80), respiratory failure (OR 0.36, 95% CI 0.17 to 0.74/OR 0.37, 95% CI 0.18 to 0.75), cardiac complications (OR 0.84, 95% CI 0.76 to 0.93/OR 0.83, 95% CI 0.79 to 0.86), surgical site infections (OR 0.55 95% CI 0.47 to 0.64/OR 0.86 95% CI 0.80 to 0.91), thromboembolism (OR 0.74, 95% CI 0.58 to 0.96/OR 0.90, 95% CI 0.84 to 0.96) and blood transfusion (OR 0.84, 95% CI 0.83 to 0.86/OR 0.91, 95% CI 0.90 to 0.92).

CONCLUSIONS

Based on the current body of evidence, the consensus group recommends PNB use in THA/TKA for improved outcomes.

RECOMMENDATION

PNB use is recommended for patients undergoing THA and TKA except when contraindications preclude their use. Furthermore, the alignment of provider skills and practice location resources needs to be ensured. Evidence level: moderate; recommendation: strong.

A comparison of analgesic techniques for total knee arthroplasty: A network meta-analysis

STUDY OBJECTIVE

There is no established analgesic method for postoperative total knee arthroplasty. We comprehensively compared the analgesic methods for postoperative total knee arthroplasty.

DESIGN

A network meta-analysis of randomised controlled trials was used to compare 18 interventions, which were ranked by six outcome indices, to select the best modality.

SETTING

Postoperative recovery room and inpatient ward.

PATIENTS

98 randomised controlled trials involving 7452 patients (ASA I-III) were included in the final analysis.

INTERVENTIONS

Studies that included the use of at least one of the following 12 nerve block(fascia iliaca compartment block (FIB), FNB, cFNB, single femoral nerve block (sFNB), adductor canal block (ACB), sciatic nerve block (SNB), obturator nerve block (ONB), continuous posterior lumbar plexus block (PSOAS), FNB + SNB, ACB + LIA, FNB + LIA, PCA + FNB).

MEASUREMENTS

Pain intensity was compared using Visual Analogue Scale (VAS). Also, postoperative complications, function score, hospital length of stay, morphine consumption and patient satisfaction were measured.

MAIN RESULTS

For visual analogue scale scores, continuous femoral nerve block (FNB) and FNB + sciatic nerve block (SNB) were the the most effective interventions. For reducing postoperative complications, fascia iliaca compartment block, FNB, SNB, and obturator nerve block showed the best results. For reducing postoperative morphine consumption, adductor canal block (ACB) + local infiltration analgesia (LIA) and FNB + SNB were preferred. For function scores (range of motion, Timed-Up-and-Go test), ACB and LIA were optimal choices. For reducing hospital length of stay and patient satisfaction, ACB + LIA and FNB + LIA were best, respectively.

CONCLUSIONS

Peripheral nerve block, especially FNB and ACB, is a better option than other analgesic methods, and its combination with other methods can be beneficial. Peripheral nerve block is a safe and effective postoperative analgesia method. However, our findings can only provide objective evidence. Clinicians should choose the treatment course based on the individual patient's condition and clinical situation.

Efficacy of Adductor Canal Block Combined With Additional Analgesic Methods for Postoperative Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study

BACKGROUND

The aim of this study is to evaluate the efficacy of adductor canal block (ACB) combined with additional analgesic methods in total knee arthroplasty (TKA) and investigate whether blocking the sensory nerves that are distributed in the posterior and lateral aspect of knee could improve postoperative pain control.

METHODS

Two hundred scheduled patients for TKA were randomly allocated into 4 groups: Group A received ACB combined with iPACK (interspace between the popliteal artery and capsule of the knee) block and lateral femoral cutaneous nerve block (LFCNB); Group B received ACB combined with iPACK block; Group C received ACB combined with LFCNB; and Group D received ACB only. Postoperative pain score was the main primary outcome. Secondary outcomes included the morphine consumption and analgesic duration. Other outcomes included knee range of motion, quadriceps strength, ambulation, Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index physical function, timed up and go (TUG) test, and complications.

RESULTS

Groups A, B, and C had lower postoperative pain scores within 12 hours at rest and 8 hours with activity than Group D (P < .05). In addition, Group A had lower morphine consumption than both Group C (P < .05) and Group D (P < .01). Group A had the longest analgesic duration (19.21 ± 3.22 hours) among all groups. There were no significant differences among the groups in terms of mobility and complication after surgery.

CONCLUSION

Combining ACB with both iPACK and LFCNB is an effective method for decreasing early postoperative pain in TKA without increasing the complications or affecting the early rehabilitation.

Assessing Preoperative Pain Sensitivity Predicts the Postoperative Analgesic Requirement and Recovery after Total Knee Arthroplasty: A Prospective Study of 178 Patients

BACKGROUND

The aim of this article is to study the correlation between preoperative pain sensitivity and postoperative pain and analgesic requirements for patients undergoing primary total knee arthroplasty.

METHODS

Between December 2018 and April 2019, the pain sensitivity of 178 consecutive patients undergoing primary total knee arthroplasty was assessed preoperatively with a digital algometer. The patients reported the VAS (visual analog scale) score at 3 instances of needle prick (phlebotomy, glucometer blood sugar, intradermal antibiotic test dose), during the range of movements and completed the Depression Anxiety Stress Scale score. Postoperative VAS score, analgesic requirement, and physiotherapy milestones were recorded in all these patients on day 0 to day 4.

RESULTS

The average age of the patients was 64.13 years and 69.1% were females. Females had lower mean algometry values (56.12 ± 12.77 [standard deviation]) compared to males (71.09 ± 18.78 [standard deviation]) (P < .001). Higher Depression Anxiety Stress Scale correlated with lower algometry values (P < .001). The postoperative VAS score was 2.54 ± 0.59 on the day of surgery which increased to 3.27 ± 0.69 on day 1 after mobilization (P < .001) and reduced to 1.67 ± 0.62 on day 4. Low algometer score correlated with higher postoperative VAS score (P < .05), increased analgesic requirement, and opioid utilization (P < .001), delay in achieving an optimum range of movements (P < .001) and independent ambulation (P < .001).

CONCLUSION

Preoperative assessment of pain sensitivity predicts postoperative analgesic requirements and recovery. Patients with a lower pain threshold should be counseled preoperatively and also receive a better titration of analgesics perioperatively and prolonged physiotherapy.

Ultrasound-guided adductor canal block combined with lateral femoral cutaneous nerve block for post-operative analgesia following total knee arthroplasty: a prospective, double-blind, randomized controlled study

PURPOSE

The purpose of this study was to investigate whether adductor canal block (ACB) combined with lateral femoral cutaneous nerve block (LFCNB) could improve the efficacy of post-operative analgesia in a comparison with a standard peri-articular infiltration analgesia (PIA) after a total knee arthroplasty (TKA).

METHODS

One hundred and sixty patients of scheduled unilateral primary TKA were randomly allocated into two groups for post-operative analgesia. Eighty cases were treated with ACB combined with LFCNB and the other eighty treated with PIA. The primary outcomes were pain visual analogue scale (VAS) and rescue pain killer consumption, and the secondary outcomes were knee active range of motion (ROM), quadriceps strength, patients' ambulation ability, Knee Society Score (KSS), length of hospital stay, and adverse events.

RESULTS

We found that ACB combined with LFCNB was better on decreasing the post-operative pain score within 12 hours at rest and 8 h with activity (p < 0.05) and provided longer duration of analgesia (19.91 ± 5.09 VS 12.06 ± 3.67 h, p < 0.01) and less rescue morphine consumption (13.63 ± 9.84 vs 18.00 ± 11.52 mg, p = 0.011) than the PIA. There was no significant difference between the two groups (p > 0.05) in terms of knee ROM, quadriceps strength, daily mobilization distance, KSS, and complication occurrence.

CONCLUSIONS

ACB combined with LFCNB provides a significantly better pain control, less opioid consumption, and longer duration of analgesia than peri-articular infiltration while preserving muscle function without affecting knee functional recovery nor the length of stay or side effects occurrence.

Which is the best analgesia treatment for total knee arthroplasty: Adductor canal block, periarticular infiltration, or liposomal bupivacaine? A network meta-analysis

STUDY OBJECTIVE

To review all randomized controlled trials (RCTs) comparing the analgesic efficacy of adductor canal block (ACB), periarticular infiltration (PAI), and any other mode of these treatments in analgesia, such as PAI with liposomal bupivacaine (LB), continuous adductor canal block (cACB) or ACB + PAI, after total knee arthroplasty (TKA).

DESIGN

Systematic review and network meta-analysis of RCTs.

PATIENTS

We searched PubMed, Embase, and the Cochrane database to detect all relevant RCTs on investigating the analgesic effects of ACB, PAI and LB for TKA published until April 2020.

INTERVENTIONS

Use of different analgesic methods of ACB, PAI, cACB, ACB + PAI and LB.

MEASUREMENTS

The primary endpoint was visual analog scale (VAS) score at rest and movement. The secondary endpoints were opioids consumption, length of hospitalization and knee range of motion (ROM). We used Cochrane risk of bias to assess the quality of evidence for outcomes.

RESULTS

Forty-two studies involving 3785 patients with 5 different methods containing ACB, PAI, ACB + PAI, continuous ACB (cACB), LB, were evaluated. According to surface under the cumulative ranking curve value, 24 h resting VAS score was the lowest the ACB + PAI (88.4%), followed by cACB (73.4%); Resting VAS score at 48 h and movement VAS score at 24 h and 48 h was the lowest in the cACB (99.9%, 92% and 100%). Total opioids consumption was the least in LB (81.4%) before cACB (60.8%). ROM was the largest in the ACB + PAI (84.1%) before cACB (78.8%).

CONCLUSION

Although all analgesic methods available were not evaluated, and further studies are needed to establish our results, the 24 h resting VAS score was lowest in ACB + PAI and 48 h resting and movement VAS score was lowest in cACB.

CLINICAL TRIAL REGISTRATION

PROSPERO (CRD 42020168102).

Motor-sparing nerve blocks for total knee replacement: A scoping review

STUDY OBJECTIVE

This scoping review investigates the optimal combination of motor-sparing analgesic interventions for patients undergoing total knee replacement (TKR).

DESIGN

Scoping review.

INTERVENTION

MEDLINE, EMBASE and CINAHL databases were searched (inception-last week of May 2020). Only trials including motor-sparing interventions were included. Randomized controlled trials lacking prospective registration and blinded assessment were excluded.

MAIN RESULTS

The cumulative evidence suggests that femoral triangle blocks outperform placebo and periarticular infiltration. When combined with the latter, femoral triangle blocks are associated with improved pain control, higher patient satisfaction and decreased opioid consumption. Continuous femoral triangle blocks provide superior postoperative analgesia compared with their single-injection counterparts. However, these benefits seem less pronounced when perineural adjuvants are used. Combined femoral triangle-obturator blocks result in improved analgesia and swifter discharge compared with femoral triangle blocks alone.

CONCLUSIONS

The optimal analgesic strategy for TKR may include a combination of different analgesic modalities (periarticular infiltration, femoral triangle blocks, obturator nerve block). Future trials are required to investigate the incremental benefits provided by local anesthetic infiltration between the popliteal artery and the capsule of the knee (IPACK), popliteal plexus block and genicular nerve block.

Intraoperative Surgeon Administered Adductor Canal Blockade Is Not Inferior to Anesthesiologist Administered Adductor Canal Blockade: A Prospective Randomized Trial

BACKGROUND

Controlling postoperative pain and reducing opioid requirements after total knee arthroplasty remain a challenge, particularly in an era stressing rapid recovery protocols and early discharge. A single-shot adductor canal blockade (ACB) has been shown to be effective in decreasing postoperative pain. The purpose of the present study is to compare the efficacy of an anesthesiologist administered ACB and a surgeon administered intraoperative ACB.

METHODS

Patients undergoing primary total knee arthroplasty were prospectively randomized to receive either an anesthesiologist administered (group 1) or surgeon administered (group 2) ACB using 15 mL of ropivacaine 0.5%. Primary outcomes were pain visual analog scale, range of motion, and opioid consumption.

RESULTS

Thirty-four patients were randomized to group 1 and 29 to group 2. Opioid equivalents consumed were equal on postoperative day (POD) 0, 1, and 2. Patients in group 1 had statistically less pain on POD 0, but this did not reach clinical significance and there was no difference in pain on POD 1 or 2. Patients in group 1 had significantly increased active flexion POD 1, but there was no difference in active flexion on POD 0 or 6 weeks postop. There was no difference in patient satisfaction with pain control or short-term functional outcomes.

CONCLUSION

Surgeon administered ACB is not inferior to anesthesiologist administered ACB with respect to pain, opioid consumption, range of motion, patient satisfaction, or short-term functional outcomes. Surgeon administered ACB is an effective alternative to anesthesiologist administered ACB.

Slightly better pain relief but more frequently motor blockade with combined nerve block analgesia compared to continuous intraarticular analgesia after total knee arthroplasty

PURPOSE

Pain management after total knee arthroplasty (TKA) is still under debate. Continuous peripheral nerve blocks (PNB) can provide long pain relief but impair muscle function. Continuous intraarticular analgesia could result in longer pain relief than local infiltration analgesia without negative effects on muscle function. This study investigated the efficacy of pain control between PNB's and continuous intraarticular analgesia after TKA.

METHODS

A prospective randomized study on 140 patients undergoing TKA was performed. Patients received either a combination of continuous femoral nerve block, continuous sciatic nerve block and single-shot obturator nerve block (group R) or a local infiltration analgesia and a continuous intraarticular catheter with ropivacaine (group L). Primary outcome was pain measured on a numerical rating scale. Knee function, patient-reported outcome (PRO) and adverse events were assessed until 1 year after surgery.

RESULTS

Pain at rest was lower in group R on the day of surgery (mean NRS 3.0 vs. 4.2) and the morning of postoperative day 1 (mean NRS 3.4 vs. 4.4). Motor blockade longer than postoperative day 3 occurred more often in group R compared to group L (15.3% vs. 1.5%). Pain levels, PRO and satisfaction 3-month and 1-year after surgery were similar.

CONCLUSION

Continuous PNB's were slightly more effective in the first 24 h after surgery but were associated more often with motor blockade which should be avoided. It must be balanced if the small amount of better pain relief immediately after surgery justifies the risks associated with motor blockade following PNB's.

LEVEL OF EVIDENCE

I.