Comparison of Suprainguinal Fascia Iliaca Compartment Block and Adductor Canal Block for Pain Management in Total Knee Arthroplasty: A Randomized Clinical Trial

Comparison of Suprainguinal Fascia Iliaca Compartment Block and Adductor Canal Block for Pain Management in Total Knee Arthroplasty: A Randomized Clinical Trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparison of Suprainguinal Fascia Iliaca Compartment Block and Adductor Canal Block for Pain Management in Total Knee Arthroplasty: A Randomized Clinical Trial Ali Genç, Sezer Astan, Mehtap Gürler Balta, Vildan Kölükçü, Ahmet Tuğrul Şahin, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9286946/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Background: This study aimed to compare suprainguinal fascia iliaca compartment block (S-FICB) and adductor canal block (ACB) in terms of postoperative pain scores, opioid consumption, and clinical outcomes in total knee arthroplasty (TKA). Methods: In this prospective, randomized clinical trial conducted in Turkey, patients undergoing TKA under spinal anesthesia were randomized to receive either S-FICB or ACB. Postoperative pain at rest and with movement was evaluated using a numerical rating scale (NRS). Opioid consumption, duration of motor block, patient satisfaction, and adverse effects, such as nausea, vomiting, and pruritus, were also recorded. Results: Eighty-six patients were analyzed (S-FICB: n = 43; ACB: n = 43). Total 24-h opioid consumption was significantly lower in the S-FICB group (p = 0.001). Postoperative NRS scores at rest and with movement were reduced at various time points in the S-FICB group. Although motor block duration was longer, patient satisfaction scores were higher with S-FICB than with ACB (p < 0.001 and p = 0.006, respectively). Conclusion: S-FICB provides more effective early postoperative analgesia, reduces the need for opioids, and improves patient satisfaction compared with ACB following TKA. However, its longer duration of motor block should be considered in clinical decision-making. Clinical trial registration : The study was registered at ClinicalTrials.gov (NCT07040709) on June 10, 2025; retrospectively registered. Adductor canal block postoperative pain suprainguinal fascia iliaca block total knee arthroplasty opioid consumption Figures Figure 1 Introduction Total knee arthroplasty (TKA) is a commonly performed procedure for the treatment of advanced degenerative joint diseases, such as knee osteoarthritis, and is intended to relieve pain and restore function [1]. Although surgical techniques and perioperative care for TKA have substantially improved, postoperative pain remains a major clinical challenge. Inadequate analgesia may delay early mobilization, impair participation in rehabilitation, increase opioid requirements, and negatively affect overall patient satisfaction and recovery [2,3]. Therefore, multimodal analgesic strategies are essential for optimizing postoperative pain management [4]. Peripheral nerve blocks constitute a key component of multimodal analgesia in TKA. Among these, adductor canal block (ACB) has gained widespread acceptance due to its predominant sensory blockade of the saphenous nerve and preservation of quadriceps muscle strength [5]. Ultrasound-guided ACB has been shown to reduce postoperative pain scores and opioid consumption while facilitating early mobilization [6]. ACB, especially when combined with other regional techniques, has also been shown to reduce persistent postoperative pain and enhance overall analgesic outcomes [7]. An alternative to ACB is the suprainguinal fascia iliaca compartment block (S-FICB), which is intended to provide a more proximal blockade of the femoral, obturator, and lateral femoral cutaneous nerves, potentially resulting in broader sensory coverage. Fascia iliaca block techniques have been demonstrated to improve postoperative analgesia and reduce the need for opioids following TKA [8,9]. The suprainguinal approach, in particular, may allow more consistent proximal spread toward lumbar plexus branches, potentially resulting in more comprehensive analgesia. However, few studies have directly compared S-FICB and ACB in patients undergoing TKA, and the available evidence has yielded conflicting results. Therefore, the present study was designed to compare S-FICB and ACB in terms of analgesic efficacy, opioid consumption, duration of motor block, and patient satisfaction following TKA. Methods Ethical Approval This study was approved by the Erciyes University Ethics Committee (24-AKD-143) on May 29, 2025, and registered at ClinicalTrials.gov (NCT07040709) on June 10, 2025. The study was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent for inclusion in this stud was obtained from all participants prior to surgery. Patient recruitment and data collection were carried out from June 2025 to February 2026. Patient Selection This prospective randomized clinical trial was conducted at Tokat Gaziosmanpaşa University Hospital, a tertiary care center in Turkey. Patients aged 18–75 years with American Society of Anesthesiologists (ASA) physical status I–III who were scheduled for elective primary TKA were eligible for inclusion in this study. Exclusion criteria included refusal to undergo spinal anesthesia; contraindications to spinal anesthesia or peripheral nerve block (e.g., coagulopathy, infection at the injection site, severe spinal deformity); failed spinal anesthesia; chronic pain conditions; severe hepatic, cardiac, or renal insufficiency; active opioid use; revision knee surgery; and refusal to participate in the study. Randomization and Blinding Eligible patients were randomly assigned to either the S-FICB group or the ACB group using a computer-generated randomization sequence prepared by an independent investigator not involved in performing the anesthesia. Group allocation was revealed to the anesthesiologist with at least 5 years of experience performing the block immediately before the procedure. Owing to the nature of the intervention, the anesthesiologist performing the block was not blinded. However, all postoperative clinical assessments were conducted by a separate investigator, an anesthesiologist with more than 5 years of clinical experience, who was blinded to group allocation. Statistical analyses were also performed by a researcher blinded to group assignments. Patients were unaware of their group allocation. This study was conducted and reported in accordance with the CONSORT (Consolidated Standards of Reporting Trials) guidelines for randomized clinical trials. Anesthesia and Surgical Procedure All patients were monitored using standard intraoperative monitoring in the operating room. Spinal anesthesia was performed under aseptic conditions at the L3–L4 or L4–L5 interspace using a 25-gauge Quincke spinal needle. A total of 3 mL of 0.5% hyperbaric bupivacaine combined with 20 μg of fentanyl was injected intrathecally. Sensory blockade at the T10 dermatome level was considered adequate for surgery. Total knee arthroplasty was performed in a supine position under sterile conditions using a standard anteromedial parapatellar approach. Prosthetic components were fixed using polymethylmethacrylate bone cement. All patients received intravenous prophylactic antibiotics preoperatively. After achieving hemostasis, the joint capsule and skin were closed anatomically. A vacuum drain was placed and patients were transferred to the recovery unit. Suprainguinal Fascia Iliaca Compartment Block (S-FICB) The S-FICB was performed with the patient in a supine position under aseptic conditions using ultrasound guidance with a high-frequency linear probe (10–15 MHz). The probe was placed medial to the anterior superior iliac spine in a sagittal-oblique orientation to visualize the anterior inferior iliac spine, iliacus muscle, and fascia iliaca compartment. A block needle was advanced using the in-plane technique beneath the fascia iliaca. After negative aspiration, 30 mL of 0.25% bupivacaine was injected incrementally. Appropriate spread of the local anesthetic over the iliacus muscle, inferior to the deep circumflex iliac artery, and within the fascia iliaca compartment was confirmed sonographically. Adductor Canal Block (ACB) The ACB was performed in a supine position under aseptic conditions with ultrasound guidance using a high-frequency linear probe (10–15 MHz). The probe was positioned transversely at the mid-thigh level to identify the femoral artery, femoral vein, and saphenous nerve. The block needle was advanced into the adductor canal using the in-plane technique. Following negative aspiration, 20 mL of 0.25% bupivacaine was administered. Fifteen milliliters was injected within the adductor canal, and the remaining 5 mL was deposited above the sartorius muscle fascia to facilitate spread toward the genicular nerves. Adequate distribution of the local anesthetic within the canal and along the sartorius fascia was confirmed ultrasonographically. Postoperative Analgesia Protocol All patients received a standardized multimodal analgesic regimen. One gram of paracetamol was intravenously administered four times daily in a routine manner. In patients with resting NRS ≤3 who did not request additional analgesic, scheduled paracetamol doses were omitted. For postoperative analgesia, patients received intravenous patient-controlled analgesia (PCA) containing 300 mg of tramadol. If pain intensity remained ≥4 on the NRS despite this regimen, 3 mg of morphine was administered intravenously as rescue analgesia when required. Data Collection and Clinical Assessments Postoperative pain intensity was evaluated using an 11-point (0–10) numerical rating scale (NRS) at rest (rNRS) and with movement (mNRS) at 1, 3, 6, 12, 18, and 24 h postoperatively. Total 24-h opioid consumption, including PCA and rescue doses, was recorded in morphine milligram equivalents (MME). Duration of motor block was defined as the time from block administration to the return of active motor function in the affected extremity. Patient satisfaction was also assessed 24 h postoperatively using an 11-point NRS [10]. Adverse effects such as nausea, vomiting, and pruritus were documented. Sample Size Calculation Sample size was calculated based on a previously published study reporting an effect size of 0.645 [11]. Assuming 80% statistical power and a 5% type I error rate (α = 0.05), a minimum of 78 patients were required [12]. To account for potential dropouts, the sample size was increased by 10%, resulting in a planned total of 86 patients. Statistical Analysis Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS), version 20.0 (SPSS Inc., Chicago, IL, USA). The data distribution of continuous variables was assessed using the Shapiro–Wilk test. Continuous variables are expressed as median (interquartile range, IQR), and categorical variables are presented as number (percentage). Comparisons of continuous variables between groups were performed using the Mann–Whitney U test, and categorical variables were compared using the chi-square test. A p value < 0.05 was considered statistically significant. Results A total of 114 patients were assessed for eligibility. After applying the inclusion and exclusion criteria, 86 patients were enrolled and randomized to the S-FICB group (n = 43) or the ACB group (n = 43). A diagram presenting the study flow is shown in Figure 1. The median (IQR) age of the study population was 65.5 (60.75–71.25) years, and 69 patients (80.2%) were female. Demographic characteristics are summarized in Table 1. There were no statistically significant differences between the groups in terms of age, sex, body mass index, ASA physical status classification, or comorbidities. Surgeries were performed by three orthopedic surgeons, and both surgeon distribution and operative duration were comparable between the groups (Table 1). Table 1. Demographic data of patients S-FICB ACB p Age (years) 68 (62 – 74) 65 (59 – 70) 0.37 a Gender (F – M) 34 (79.1) – 9 (20.9) 35 (81.4) – 8 (18.6) 0.79 b BMI (kg/m 2 ) 31.63 (28.93 – 34.38) 32.65 (28.93 – 35.96) 0.21 a ASA (I – II – III) 2( 4.7) – 20 (46.5) – 21 (48.8) 4(9.3) – 21 (48.8 ) – 18 (41.9) 0.63 b Hypertension 23 (53.5) 20 (46.5) 0.52 b Diabetes 12 (27.9) 16 (37.2) 0.67 b Ischemic heart disease 11 (25.6) 9 (20.9) 0.61 b Chronic lung Disease 9 (20.9) 7 (16.3) 0.58 b Thyroid disease 8 (18.6) 12 (27.9) 0.31 b Cerebral vascular disease 5 (11.6) 6 (14) 0.75 b Rheumatic disease 9 (20.9) 10 (23.3) 0.79 b Neoplasm 5 (11.6) 2 (4.7) 0.24 b Smoking 9 (20.9) 8 (18.6) 0.79 b Surgeon (A – B – E) 21 (48.8) – 13 (30.2) – 9 (21) 21 (48.8) – 10 (23.3) – 12 (27.9) 0.66 b Surgical duration (min) 120 (110 – 140) 120 (110 – 145) 0.19 a a Mann-Whitney U test; b Chi-Square test; Quantitative data are presented as median (IQR); Categorical variables were presented as n (%) (S-FICB: Supra-inguinal fascia iliaca compartment block; ACB: Adductor canal block; F: Female; M: Male; BMI: Body Mass Index; ASA: American Society of Anesthesiologists; Surgeon A, B, and E refer to the anonymized identifiers of the three orthopedic surgeons who performed the procedures) Primary outcomes At rest, NRS scores were significantly lower in the S-FICB group at postoperative hours 1, 12, and 18 than in the ACB group (all p < 0.05) (Table 2). No significant differences were observed at postoperative hours 3, 6, and 24. NRS scores with movement were significantly lower in the S-FICB group at postoperative hours 1, 3, 6, 12, 18, and 24 (all p < 0.05) (Table 2). The effect size (r) for significant NRS comparisons ranged between 0.22 and 0.34, indicating small-to-moderate magnitude differences between the groups (Table 2). Table 2. Comparison of postoperative pain scores at rest and movement between block groups S-FICB ACB p r U z rNRS postoperative 1st hour 1 (0 - 2) 1 (0 - 3) 0.013 a * 0.27 647.50 -2.48 mNRS postoperative 1st hour 2 (1 - 3) 3 (2 - 5) 0.004 a * 0.31 597.00 -2.89 rNRS postoperative 3rd hour 2 (1 - 3) 3 (1 - 4) 0.073 a mNRS postoperative 3rd hour 3 (2 - 5) 5 (2 - 6) 0.017 a * 0.26 653.50 -2.38 rNRS postoperative 6th hour 3 (2 - 3) 3 (1 - 4) 0.75 a mNRS postoperative 6th hour 3 (2 - 4) 5 (3 - 6) 0.006 a * 0.30 611.50 -2.74 rNRS postoperative 12th hour 2 (1 - 3) 3 (2 - 4) 0.038 a * 0.22 689.50 -2.08 mNRS postoperative 12th hour 3 (2 - 4) 4 (3 - 5) 0.014 a * 0.26 645.50 -2.45 rNRS postoperative 18th hour 2 (1 - 3) 3 (2 - 4) 0.012 a * 0.27 640.50 -2.51 mNRS postoperative 18th hour 3 (2 - 4) 4 (3 - 5) 0.004 a * 0.31 595.50 -2.89 rNRS postoperative 24th hour 2 (1 - 2) 2 (1 - 3) 0.13 a mNRS postoperative 24th hour 2 (2 - 3) 3 (2 - 4) 0.002 a * 0.34 581.00 -3.11 a Mann-Whitney U test; * p < 0.05 was considered statistically significant; r : standardized Z-based effect size (r = Z/√N); U = Mann–Whitney U statistic; z = standardized test statistic; data are presented as median (IQR) (S-FICB: Supra-inguinal fascia iliaca compartment block; ACB: Adductor canal block; rNRS: Numerical rating scale at rest; mNRS: Numerical rating scale with movement) Total opioid consumption within the first 24 h (MME) was significantly lower in the S-FICB group, with a median (IQR) of 16 (5–20) compared with 20 (16–23) in the ACB group (p = 0.001; r = 0.35) (Table 3). Table 3. Comparison of perioperative patient outcomes between block groups S-FICB ACB p r U z Total opioid consumed (MME) 16 (5 - 20) 20 (16 - 23) 0.001 a * 0.35 556.00 -3.21 Patient satisfaction score 8 (6 - 9) 7 (5 - 8) 0.006 a * 0.30 612.50 -2.75 Duration of motor block (hour) 3 (2 - 4) 1 (1 - 2) < 0.001 a * 0.44 459.50 -4.11 Nausea 18 (41.9) 12 (27.9) 0.18 b Vomiting 12 (27.9) 9 (20.9) 0.45 b Pruritus 4 (9.3) 3 (7) 0.69 b Total length of hospital stay (day) 2 (1 - 2) 2 (1 - 3) 0.76 a a Mann-Whitney U test; b Chi-Square test; * p < 0.05 was considered statistically significant; r : standardized Z-based effect size (r = Z/√N); U = Mann–Whitney U statistic; z = standardized test statistic; quantitative data are presented as median (IQR); categorical variables were presented as n (%) (S-FICB: Supra-inguinal fascia iliaca compartment block; ACB: Adductor canal block; MME = Morphine Secondary outcomes The comparisons of patient satisfaction, motor block duration, adverse effects, and hospital stay are presented in Table 3. Patient satisfaction scores were significantly higher in the S-FICB group, with a median (IQR) of 8 (6–9), compared with 7 (5–8) in the ACB group (p = 0.006; r = 0.30). The duration of motor block was significantly longer in the S-FICB group, with a median (IQR) of 3 (2–4) hours, compared with 1 (1–2) hours in the ACB group (p < 0.001; r = 0.44) . However, there were no statistically significant differences between the groups regarding adverse effects, including nausea, vomiting, and pruritus. Additionally, length of hospital stay was comparable between the two groups. No major block-related complications, including local anesthetic systemic toxicity, persistent motor deficit, nerve injury, infection, or falls, were observed in either group during the study period. Discussion In this prospective randomized study of postoperative analgesia in Turkish patients after TKA, the S-FICB group demonstrated significantly lower pain scores both at rest and with movement, reduced total opioid consumption, and higher patient satisfaction compared with the ACB group. However, the duration of motor block was significantly longer in patients receiving S-FICB. Peripheral nerve blocks have become a cornerstone of multimodal analgesia following TKA. The ACB is widely favored because it predominantly targets the saphenous nerve and sensory branches of the femoral nerve while largely preserving quadriceps strength [13]. Several studies have demonstrated that ACB is associated with effective postoperative pain control and decreased opioid consumption [13,14]. Moreover, when compared with femoral nerve block, ACB has been associated with improved preservation of quadriceps strength, potentially facilitating early mobilization and reducing fall risk [15-17]. Nevertheless, some investigations have reported no significant differences between ACB and femoral nerve block in terms of postoperative quadriceps strength or early functional recovery, highlighting the need for further investigation of this topic [18,19]. The suprainguinal fascia iliaca compartment block offers a more proximal approach, allowing spread of local anesthetic toward the femoral, obturator, and lateral femoral cutaneous nerves. The suprainguinal technique, compared with the infrainguinal approach, has been reported to provide more consistent obturator nerve blockade and broader sensory coverage [20-22]. This wider neural distribution may explain the superior analgesic efficacy observed in the present study, particularly the consistently lower dynamic pain scores and reduced opioid consumption in the S-FICB group. Effective control of movement-evoked pain is particularly critical following TKA, as inadequate dynamic analgesia may hinder early rehabilitation and functional recovery. Previous studies have reported inconsistent findings regarding the relative analgesic effects of S-FICB and ACB. While some trials have demonstrated similar pain scores and opioid consumption between the two techniques, methodological differences such as the use of additional regional blocks, variations in local anesthetic volume and concentration, and differences in block timing may account for these discrepancies [23]. In contrast, the present study directly compared S-FICB and ACB as standalone techniques within a standardized multimodal analgesic protocol, thereby providing a clearer comparison of their analgesic effects. The significantly longer duration of motor block observed in the S-FICB group is consistent with the more proximal spread of local anesthetic and the potential involvement of motor fibers [15,24]. This aligns with the literature emphasizing the motor-sparing advantage of ACB [25,26]. Although prolonged motor blockade may theoretically delay mobilization, the higher patient satisfaction scores observed in the S-FICB group suggest that enhanced analgesia may outweigh transient motor impairment from the patient’s perspective, particularly in the early postoperative period. Regarding safety, no significant differences were observed between the groups in terms of adverse effects, including nausea, vomiting, and pruritus. These findings are consistent with previous reports demonstrating low complication rates associated with both techniques, supporting their overall safety [27]. The various limitations of this study should be acknowledged. First, this was a single-center study, which may limit the generalizability of the findings. Second, follow-up was limited to the early postoperative period; therefore, long-term functional recovery and rehabilitation outcomes were not evaluated. Additionally, technical factors such as the timing of block administration and local anesthetic volume and concentration may influence block characteristics and should be explored in future research. Larger multicenter trials incorporating functional outcome measures and longer follow-up periods would provide further insight into the optimal regional analgesic strategy following TKA. In conclusion, S-FICB provided more comprehensive early postoperative analgesia, reduced opioid requirements, and improved patient satisfaction compared with ACB after total knee arthroplasty. Although S-FICB was associated with prolonged motor block, its superior analgesic profile and opioid-sparing effect may justify its use in selected patients, provided that early mobilization strategies are carefully implemented. Declarations Ethics approval: This study was approved by the Erciyes University Committee (24-AKD-143). The study was conducted in accordance with the principles of the Declaration of Helsinki. Consent for publication: Not applicable. This manuscript does not contain any data that could be used to identify individuals. Data availability: The data used to support the findings of this study can be obtained from the corresponding author on request. Competing interests: The authors have no conflicts of interest to declare. All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. Funding: The authors did not receive support from any organization for the submitted work. Author contributions: All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by [Ali Genc], [Sezer Astan], [Mehtap Gürler Balta], [Vildan Kölükçü], [Ahmet Tuğrul Şahin], [Hakan Tapar] and [Tugba Karaman], [Serkan Karaman]. The first draft of the manuscript was written by [Ali Genc] and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Clinical trial registration : ClinicalTrials.gov (NCT07040709). Consent to participate : Written informed consent was obtained from all participants. References Brumat P, Kunšič O, Novak S, Slokar U, Pšenica J, Topolovec M, et al. The Surgical Treatment of Osteoarthritis. Life. 2022;12(7):982. Kolahdouzan K, Nazari B. Strategies for the prevention of postoperative chronic pain: Perioperative pain management after total joint replacement: a systematic review. Eurasian J Chem Med Pet Res. 2023;2(2):129–46. Grosu I, Lavand’homme P, Thienpont E. Pain after knee arthroplasty: an unresolved issue. Knee Surg Sports Traumatol Arthrosc. 2014;22(8):1744–58. Bai S, Hu A, Li W, Chen Y, Li X, Song X, et al. Comparing the analgesic effects of femoral triangle block and adductor canal block following total knee arthroplasty: a systematic review and meta-analysis. BMC Anesthesiol. 2025;25(1):202. Li D, Ma GG. Analgesic efficacy and quadriceps strength of adductor canal block versus femoral nerve block following total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2016;24(8):2614–9. Cakmak MF, Horoz L, Arslan FN, Demir OU, Basarir K. Comparison ultrasound-guided adductor canal block and surgeon-performed block for pain management after total knee arthroplasty: a prospective randomized controlled study. BMC Musculoskelet Disord. 2024;25(1):637. Et T, Korkusuz M, Menendi U. The Effect of the Application of Adductor and Infiltration of Local Anesthetic Between the Popliteal Artery and Capsule of the Knee (IPACK) Block to Patients on Postoperative Recovery and Sleep Quality Following Total Knee Arthroplasty: a Randomized, Controlled Study. Genel Tıp Derg. 2024;34(5):609–15. Gadalla RR, Daniel RFGSH, Ahmed NS. Ultrasound Guided Fascia Iliaca Block versus Femoral Nerve Block for Post Operative Analgesia for Patient Undergoing Total Knee Arthroplasty. QJM. 2023;116. (Supplement_1):hcad069.085. Bali C, Ozmete O, Eker HE, Hersekli MA, Aribogan A. Postoperative analgesic efficacy of fascia iliaca block versus periarticular injection for total knee arthroplasty. J Clin Anesth. 2016;35:404–10. Pronk Y, Peters MCWM, Brinkman JM. Is Patient Satisfaction After Total Knee Arthroplasty Predictable Using Patient Characteristics and Preoperative Patient-Reported Outcomes? J Arthroplasty. 2021;36(7):2458–65. Sinha C, Singh AK, Kumar A, Kumar A, Kumar S, Kumari P. Analgesic effect of continuous adductor canal block versus continuous femoral nerve block for knee arthroscopic surgery: a randomized trial. Braz J Anesthesiol. 2022;72(5):553–9. Faul F, Erdfelder E, Lang AG, Buchner A. G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39(2):175–91. Fillingham YA, Hannon CP, Kopp SL, Austin MS, Sershon RA, Stronach BM, et al. The Efficacy and Safety of Regional Nerve Blocks in Total Knee Arthroplasty: Systematic Review and Direct Meta-Analysis. J Arthroplasty. 2022;37(10):1906-1921.e2. Hussain N, Ferreri TG, Prusick PJ, Laura Banfield M, Bradley Long M, Vincent Roger Prusick MD, et al. Adductor canal block versus femoral canal block for total knee arthroplasty: a metaanalysis. Reg Anesth Pain Med. 2016;41:314–20. Hasabo EA, Assar A, Mahmoud MM, Abdalrahman HA, Ibrahim EA, Hasanin MA, et al. Adductor canal block versus femoral nerve block for pain control after total knee arthroplasty: A systematic review and Meta-analysis. Medicine. 2022;101(34):e30110. Borys M, Domagała M, Wencław K, Jarczyńska-Domagała J, Czuczwar M. Continuous femoral nerve block is more effective than continuous adductor canal block for treating pain after total knee arthroplasty: A randomized, double-blind, controlled trial. Medicine. 2019;98(39):e17358. Elkassabany NM, Antosh S, Ahmed M, Nelson C, Israelite C, Badiola I, et al. The Risk of Falls After Total Knee Arthroplasty with the Use of a Femoral Nerve Block Versus an Adductor Canal Block: A Double-Blinded Randomized Controlled Study. Anesth Analg. 2016;122(5):1696. Chuan A, Lansdown A, Brick KL, Bourgeois AJG, Pencheva LB, Hue B, et al. Adductor canal versus femoral triangle anatomical locations for continuous catheter analgesia after total knee arthroplasty: a multicentre randomised controlled study. Br J Anaesth. 2019;123(3):360–7. Lim YC, Quek HYK, Phoo WHJ, Mah CL, Tan S. A randomised controlled trial comparing adductor canal block and femoral nerve block for knee arthroplasty. Singapore Med J. 2019;60(3):145–9. Desmet M, Balocco AL, Van Belleghem V. Fascia iliaca compartment blocks: Different techniques and review of the literature. Best Pract Res Clin Anaesthesiol. 2019;33(1):57–66. Srivastava VK, Singh AK, Mishra NK, Prabha R, Raman R, Singh V, et al. Ultrasound-Guided Suprainguinal Versus Infrainguinal Fascia Iliaca Compartment Block for Postoperative Analgesia After Total Knee Replacement: A Prospective Randomized Trial. Cureus. 2025;17(5). Qian Y, Guo Z, Huang J, Zhang Q, An X, Hu H, et al. Electromyographic Comparison of the Efficacy of Ultrasound-guided Suprainguinal and Infrainguinal Fascia Iliaca Compartment Block for Blockade of the Obturator Nerve in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial. Clin J Pain. 2020;36(4):260. Canikli Adigüzel Ş, Genç C, Kayikçi E, Genç AS, Durusoy S, Yildiz A, et al. Comparison of analgesic efficacy, anti-inflammatory effect, and myotoxicity of ultrasound-guided suprainguinal fascia iliaca block and adductor canal with IPACK combination in patients undergoing total knee arthroplasty under spinal anesthesia: A prospective observational study. Medicine. 2025;104(32):e43719. Jæger P, Nielsen ZJK, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor Canal Block Versus Femoral Nerve Block and Quadriceps Strength: A Randomized, Double-blind, Placebo-Controlled, Crossover Study in Healthy Volunteers. Survey of Anesthesiology. 2013;57(4):199. Kwofie MK, Shastri UD, Gadsden JC, Sinha SK, Abrams JH, Xu D, et al. The Effects of Ultrasound-Guided Adductor Canal Block Versus Femoral Nerve Block on Quadriceps Strength and Fall Risk: A Blinded, Randomized Trial of Volunteers. Reg Anesth Pain Med. 2013;38(4):321–5. Lund J, Jenstrup MT, Jaeger P, Sørensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2011;55(1):14–9. Turgut MC, Oral Ahiskalioglu E, Karapinar YE, Koksal EM, Engin C, Celik EC, et al. Comparison of periarticular injection and low-concentration high-volume suprainguinal fascia Iliaca plane block in total knee arthroplasty: a randomized prospective study. Arch Orthop Trauma Surg. 2025;145(1):349. Additional Declarations No competing interests reported. Supplementary Files CONSORTchecklist.pdf Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 12 May, 2026 Reviewers agreed at journal 21 Apr, 2026 Reviewers invited by journal 13 Apr, 2026 Editor assigned by journal 10 Apr, 2026 Editor invited by journal 07 Apr, 2026 Submission checks completed at journal 07 Apr, 2026 First submitted to journal 07 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9286946","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":622119402,"identity":"93a5fdcf-60ca-4580-9346-b902f025cd0c","order_by":0,"name":"Ali Genç","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9klEQVRIiWNgGAWjYDACdsYGEMXDz97Y+ADIkGFgYCOghRmiRU6y5/BhAwYGAx4itEAoY4MbbmkSRGnhb2ZufvFxh13izBk8ZhUf2/4AXdiWwPCjYhtOLRKHGdssZ55JTuyX7jG7ObPNgEey59gBxp4zt3FbA9RizNt2IHHmnDNmt3mBWgxupDcwM7bh1iIP0vIXqGXDjRyzYqK0GBxmbH7M2HYA6P20NGaIlrQDeLUYAm1h7G1LBgey5IxzxiC/JBzE5xe54+2PP/xsswNH5YcPZXJywBAzfPCjAo/3gdEggSF0AJ96IGD+QEDBKBgFo2AUjHQAAIzhWW/Ph3+VAAAAAElFTkSuQmCC","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":true,"prefix":"","firstName":"Ali","middleName":"","lastName":"Genç","suffix":""},{"id":622119403,"identity":"c85d3740-65b0-47ec-935f-056b125ddb8b","order_by":1,"name":"Sezer Astan","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Sezer","middleName":"","lastName":"Astan","suffix":""},{"id":622119404,"identity":"aafa2d28-0e0a-499b-a331-54d11eab410b","order_by":2,"name":"Mehtap Gürler Balta","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Mehtap","middleName":"Gürler","lastName":"Balta","suffix":""},{"id":622119405,"identity":"0f6cfcbe-ba18-4827-9b2d-fba6e0c9bcb8","order_by":3,"name":"Vildan Kölükçü","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Vildan","middleName":"","lastName":"Kölükçü","suffix":""},{"id":622119406,"identity":"088f8d14-98f2-49cc-8c48-c8181e76d517","order_by":4,"name":"Ahmet Tuğrul Şahin","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Ahmet","middleName":"Tuğrul","lastName":"Şahin","suffix":""},{"id":622119407,"identity":"f375bf97-b1ca-4b90-93c5-1e8dd097443e","order_by":5,"name":"Hakan Tapar","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Hakan","middleName":"","lastName":"Tapar","suffix":""},{"id":622119408,"identity":"f04b6ece-25da-4c4c-b83d-3666ddbd016a","order_by":6,"name":"Tuğba Karaman","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Tuğba","middleName":"","lastName":"Karaman","suffix":""},{"id":622119409,"identity":"73996387-67b5-4010-bdd3-68174841754c","order_by":7,"name":"Serkan Karaman","email":"","orcid":"","institution":"Tokat Gaziosmanpaşa University","correspondingAuthor":false,"prefix":"","firstName":"Serkan","middleName":"","lastName":"Karaman","suffix":""}],"badges":[],"createdAt":"2026-04-01 05:38:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9286946/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9286946/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107486471,"identity":"e434edac-8919-4544-ac09-694e0536572a","added_by":"auto","created_at":"2026-04-22 02:38:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":50444,"visible":true,"origin":"","legend":"\u003cp\u003eFlow diagram of the study\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9286946/v1/1fcc8244bee8a7eeeb0f8482.png"},{"id":107488495,"identity":"eed27ef2-c2e1-47a5-bab3-7eee0b05b364","added_by":"auto","created_at":"2026-04-22 02:44:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":522650,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9286946/v1/a8e1b7dc-3bff-446a-ad01-0e51726e7a36.pdf"},{"id":107319875,"identity":"19facb83-cba2-4ea6-96a5-56aa84a97f31","added_by":"auto","created_at":"2026-04-20 10:22:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":447865,"visible":true,"origin":"","legend":"","description":"","filename":"CONSORTchecklist.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9286946/v1/fa4736dc473fd018063b6cc2.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of Suprainguinal Fascia Iliaca Compartment Block and Adductor Canal Block for Pain Management in Total Knee Arthroplasty: A Randomized Clinical Trial","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTotal knee arthroplasty (TKA) is a commonly performed procedure for the treatment of advanced degenerative joint diseases, such as knee osteoarthritis, and is intended to relieve pain and restore function [1]. Although surgical techniques and perioperative care for TKA have substantially improved, postoperative pain remains a major clinical challenge. Inadequate analgesia may delay early mobilization, impair participation in rehabilitation, increase opioid requirements, and negatively affect overall patient satisfaction and recovery [2,3]. Therefore, multimodal analgesic strategies are essential for optimizing postoperative pain management [4].\u003c/p\u003e\n\u003cp\u003ePeripheral nerve blocks constitute a key component of multimodal analgesia in TKA. Among these, adductor canal block (ACB) has gained widespread acceptance due to its predominant sensory blockade of the saphenous nerve and preservation of quadriceps muscle strength [5]. Ultrasound-guided ACB has been shown to reduce postoperative pain scores and opioid consumption while facilitating early mobilization [6]. ACB, especially when combined with other regional techniques, has also been shown to reduce persistent postoperative pain and enhance overall analgesic outcomes [7].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAn alternative to ACB is the suprainguinal fascia iliaca compartment block (S-FICB), which is intended to provide a more proximal blockade of the femoral, obturator, and lateral femoral cutaneous nerves, potentially resulting in broader sensory coverage. Fascia iliaca block techniques have been demonstrated to improve postoperative analgesia and reduce the need for opioids following TKA [8,9]. The suprainguinal approach, in particular, may allow more consistent proximal spread toward lumbar plexus branches, potentially resulting in more comprehensive analgesia.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHowever, few studies have directly compared S-FICB and ACB in patients undergoing TKA, and the available evidence has yielded conflicting results. Therefore, the present study was designed to compare S-FICB and ACB in terms of analgesic efficacy, opioid consumption, duration of motor block, and patient satisfaction following TKA.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Erciyes University Ethics Committee (24-AKD-143) on May 29, 2025, and registered at ClinicalTrials.gov (NCT07040709) on June 10, 2025. The study was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent\u0026nbsp;for inclusion in this stud was obtained from all participants prior to surgery. Patient recruitment and data collection were carried out from June 2025 to February 2026.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatient Selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis prospective randomized clinical trial was conducted at Tokat Gaziosmanpaşa University Hospital, a tertiary care center in Turkey. Patients aged 18–75 years with American Society of Anesthesiologists (ASA) physical status I–III who were scheduled for elective primary TKA were eligible for inclusion in this study. Exclusion criteria included refusal to undergo spinal anesthesia; contraindications to spinal anesthesia or peripheral nerve block (e.g., coagulopathy, infection at the injection site, severe spinal deformity); failed spinal anesthesia; chronic pain conditions; severe hepatic, cardiac, or renal insufficiency; active opioid use; revision knee surgery; and refusal to participate in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRandomization and Blinding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEligible patients were randomly assigned to either the S-FICB group or the ACB group using a computer-generated randomization sequence prepared by an independent investigator not involved in performing the anesthesia. Group allocation was revealed to the anesthesiologist with at least 5 years of experience performing the block immediately before the procedure.\u003c/p\u003e\n\u003cp\u003eOwing to the nature of the intervention, the anesthesiologist performing the block was not blinded. However, all postoperative clinical assessments were conducted by a separate investigator, an anesthesiologist with more than 5 years of clinical experience, who was blinded to group allocation. Statistical analyses were also performed by a researcher blinded to group assignments. Patients were unaware of their group allocation.\u003c/p\u003e\n\u003cp\u003eThis study was conducted and reported in accordance with the CONSORT (Consolidated Standards of Reporting Trials) guidelines for randomized clinical trials.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAnesthesia and Surgical Procedure\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll patients were monitored using standard intraoperative monitoring in the operating room. Spinal anesthesia was performed under aseptic conditions at the L3–L4 or L4–L5 interspace using a 25-gauge Quincke spinal needle. A total of 3 mL of 0.5% hyperbaric bupivacaine combined with 20 μg of fentanyl was injected intrathecally. Sensory blockade at the T10 dermatome level was considered adequate for surgery.\u003c/p\u003e\n\u003cp\u003eTotal knee arthroplasty was performed in a supine position under sterile conditions using a standard anteromedial parapatellar approach. Prosthetic components were fixed using polymethylmethacrylate bone cement. All patients received intravenous prophylactic antibiotics preoperatively. After achieving hemostasis, the joint capsule and skin were closed anatomically. A vacuum drain was placed and patients were transferred to the recovery unit.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSuprainguinal Fascia Iliaca Compartment Block (S-FICB)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe S-FICB was performed with the patient in a supine position under aseptic conditions using ultrasound guidance with a high-frequency linear probe (10–15 MHz). The probe was placed medial to the anterior superior iliac spine in a sagittal-oblique orientation to visualize the anterior inferior iliac spine, iliacus muscle, and fascia iliaca compartment.\u003c/p\u003e\n\u003cp\u003eA block needle was advanced using the in-plane technique beneath the fascia iliaca. After negative aspiration, 30 mL of 0.25% bupivacaine was injected incrementally. Appropriate spread of the local anesthetic over the iliacus muscle, inferior to the deep circumflex iliac artery, and within the fascia iliaca compartment was confirmed sonographically.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdductor Canal Block (ACB)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe ACB was performed in a supine position under aseptic conditions with ultrasound guidance using a high-frequency linear probe (10–15 MHz). The probe was positioned transversely at the mid-thigh level to identify the femoral artery, femoral vein, and saphenous nerve.\u003c/p\u003e\n\u003cp\u003eThe block needle was advanced into the adductor canal using the in-plane technique. Following negative aspiration, 20 mL of 0.25% bupivacaine was administered. Fifteen milliliters was injected within the adductor canal, and the remaining 5 mL was deposited above the sartorius muscle fascia to facilitate spread toward the genicular nerves. Adequate distribution of the local anesthetic within the canal and along the sartorius fascia was confirmed ultrasonographically.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePostoperative Analgesia Protocol\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll patients received a standardized multimodal analgesic regimen. One gram of paracetamol was intravenously administered four times daily in a routine manner. In patients with resting NRS ≤3 who did not request additional analgesic, scheduled paracetamol doses were omitted.\u003c/p\u003e\n\u003cp\u003eFor postoperative analgesia, patients received intravenous patient-controlled analgesia (PCA) containing 300 mg of tramadol. If pain intensity remained ≥4 on the NRS despite this regimen, 3 mg of morphine was administered intravenously as rescue analgesia when required.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Collection and Clinical Assessments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePostoperative pain intensity was evaluated using\u0026nbsp;an 11-point (0–10) numerical rating scale (NRS) at rest (rNRS) and with movement (mNRS) at 1, 3, 6, 12, 18, and 24 h postoperatively. Total 24-h opioid consumption, including PCA and rescue doses, was recorded in morphine milligram equivalents (MME).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDuration of motor block was defined as the time from block administration to the return of active motor function in the affected extremity. Patient satisfaction was also assessed 24 h postoperatively using an 11-point NRS [10]. Adverse effects such as nausea, vomiting, and pruritus were documented.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample Size Calculation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSample size was calculated based on a previously published study reporting an effect size of 0.645 [11]. Assuming 80% statistical power and a 5% type I error rate (α = 0.05), a minimum of 78 patients were required [12]. To account for potential dropouts, the sample size was increased by 10%, resulting in a planned total of 86 patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analyses were performed using the Statistical Package for the Social Sciences (SPSS), version 20.0 (SPSS Inc., Chicago, IL, USA). The data distribution of continuous variables was assessed using the Shapiro–Wilk test. Continuous variables are expressed as median (interquartile range, IQR), and categorical variables are presented as number (percentage). Comparisons of continuous variables between groups were performed using the Mann–Whitney U test, and categorical variables were compared using the chi-square test. A p value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 114 patients were assessed for eligibility. After applying the inclusion and exclusion criteria, 86 patients were enrolled and randomized to the S-FICB group (n = 43) or the ACB group (n = 43). A diagram presenting the study flow is shown in Figure 1. The median (IQR) age of the study population was 65.5 (60.75\u0026ndash;71.25) years, and 69 patients (80.2%) were female.\u003c/p\u003e\n\u003cp\u003eDemographic characteristics are summarized in Table 1. There were no statistically significant differences between the groups in terms of age, sex, body mass index, ASA physical status classification, or comorbidities. Surgeries were performed by three orthopedic surgeons, and both surgeon distribution and operative duration were comparable between the groups (Table 1).\u003c/p\u003e\n\u003cp\u003eTable 1.\u0026nbsp;Demographic data of patients\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eS-FICB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eACB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e68 (62 \u0026ndash; 74)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e65 (59\u0026nbsp;\u0026ndash; 70)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.37\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eGender (F \u0026ndash; M)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e34 (79.1) \u0026ndash; 9 (20.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e35 (81.4) \u0026ndash; 8 (18.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.79\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e31.63 (28.93 \u0026nbsp;\u0026ndash; 34.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32.65 (28.93 \u0026nbsp;\u0026ndash; 35.96)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.21\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eASA (I \u0026ndash; II \u0026ndash; III)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2( 4.7) \u0026ndash; 20 (46.5) \u0026ndash; 21 (48.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4(9.3) \u0026ndash; 21 (48.8 ) \u0026ndash; 18 (41.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.63\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eHypertension\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e23 (53.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20 (46.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.52\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDiabetes\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (27.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16 (37.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.67\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIschemic heart disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e11 (25.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (20.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.61\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eChronic lung Disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (20.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7 (16.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.58\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eThyroid disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (18.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (27.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.31\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCerebral vascular disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (11.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.75 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRheumatic disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (20.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10 (23.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.79\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNeoplasm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (11.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (4.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.24\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSmoking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (20.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (18.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.79\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSurgeon (A \u0026ndash; B \u0026ndash; \u0026nbsp;E)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e21 (48.8)\u0026nbsp;\u0026ndash;\u0026nbsp;13 (30.2)\u0026nbsp;\u0026ndash;\u0026nbsp;9\u0026nbsp;(21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e21 (48.8) \u0026ndash; 10 (23.3) \u0026ndash; 12 (27.9)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.66\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSurgical duration (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e120 (110 \u0026ndash; 140)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e120 (110 \u0026nbsp;\u0026ndash; 145)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.19\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Mann-Whitney U test; \u003csup\u003eb\u003c/sup\u003e Chi-Square test; Quantitative data are presented as median (IQR); Categorical variables were presented as n (%)\u003c/p\u003e\n\u003cp\u003e(S-FICB: Supra-inguinal fascia iliaca compartment block; ACB: Adductor canal block; F: Female; M: Male;\u0026nbsp;BMI: Body Mass Index; ASA: American Society of Anesthesiologists; Surgeon A, B, and E refer to the anonymized identifiers of the three orthopedic surgeons who performed the procedures)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrimary outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAt rest, NRS scores were significantly lower in the S-FICB group at postoperative hours 1, 12, and 18 than in the ACB group (all p \u0026lt; 0.05) (Table 2). No significant differences were observed at postoperative hours 3, 6, and 24.\u003c/p\u003e\n\u003cp\u003eNRS scores with movement were significantly lower in the S-FICB group at postoperative hours 1, 3, 6, 12, 18, and 24 (all p \u0026lt; 0.05) (Table 2). The effect size (r) for significant NRS comparisons ranged between 0.22 and 0.34, indicating small-to-moderate magnitude differences between the groups (Table 2).\u003c/p\u003e\n\u003cp\u003eTable 2.\u0026nbsp;Comparison of postoperative pain scores at rest and movement between block groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eS-FICB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eACB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003er\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eU\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ez\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003erNRS postoperative 1st hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (0 - 2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (0 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.013\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e647.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emNRS postoperative 1st hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.004\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e597.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.89\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003erNRS postoperative 3rd hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (1 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.073\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emNRS postoperative 3rd hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (2 - 6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.017\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e653.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.38\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003erNRS postoperative 6th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (1 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.75\u003csup\u003e\u0026nbsp;a\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emNRS postoperative 6th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (3 - 6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.006\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e611.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.74\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003erNRS postoperative 12th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.038\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e689.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.08\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emNRS postoperative 12th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (3 - 5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.014\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e645.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.45\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003erNRS postoperative 18th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.012\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e640.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.51\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emNRS postoperative 18th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (3 - 5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.004\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e595.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.89\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003erNRS postoperative 24th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.13\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emNRS postoperative 24th hour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (2 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.002\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e581.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-3.11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u0026nbsp;\u003c/sup\u003eMann-Whitney U test; * p \u0026lt; 0.05 was considered statistically significant; \u003cem\u003er\u003c/em\u003e: standardized Z-based effect size (r = Z/\u0026radic;N); U = Mann\u0026ndash;Whitney U statistic; z = standardized test statistic; data are presented as median (IQR)\u003c/p\u003e\n\u003cp\u003e(S-FICB: Supra-inguinal fascia iliaca compartment block; ACB: Adductor canal block;\u0026nbsp;rNRS: Numerical rating scale at rest; mNRS: Numerical rating scale with movement)\u003c/p\u003e\n\u003cp\u003eTotal opioid consumption within the first 24 h (MME) was significantly lower in the S-FICB group, with a median (IQR) of 16 (5\u0026ndash;20) compared with 20 (16\u0026ndash;23) in the ACB group (p = 0.001; r = 0.35) (Table 3).\u003c/p\u003e\n\u003cp\u003eTable 3.\u0026nbsp;Comparison of perioperative patient outcomes between block groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eS-FICB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eACB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003er\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eU\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ez\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTotal opioid consumed (MME)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16 (5 - 20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20 (16 - 23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.001\u003csup\u003e\u0026nbsp;a\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e556.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-3.21\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePatient satisfaction score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (6 - 9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7 (5 - 8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.006\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e612.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-2.75\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDuration of motor block (hour)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (2 - 4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;1 (1 - 2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003csup\u003ea\u003c/sup\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e459.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-4.11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNausea\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e18 (41.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (27.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.18\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eVomiting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (27.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (20.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.45\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePruritus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (9.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.69\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTotal length of hospital stay (day)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1 - 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.76\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Mann-Whitney U test; \u003csup\u003eb\u003c/sup\u003e Chi-Square test; * p \u0026lt; 0.05 was considered statistically significant; \u003cem\u003er\u003c/em\u003e: standardized Z-based effect size (r = Z/\u0026radic;N); U = Mann\u0026ndash;Whitney U statistic; z = standardized test statistic; quantitative data are presented as median (IQR); categorical variables were presented as n (%)\u003c/p\u003e\n\u003cp\u003e(S-FICB: Supra-inguinal fascia iliaca compartment block; ACB: Adductor canal block; MME = Morphine\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSecondary outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe comparisons of patient satisfaction, motor block duration, adverse effects, and hospital stay are presented in Table 3. Patient satisfaction scores were significantly higher in the S-FICB group, with a median (IQR) of 8 (6\u0026ndash;9), compared with 7 (5\u0026ndash;8) in the ACB group (p = 0.006; r = 0.30). The duration of motor block was significantly longer in the S-FICB group, with a median (IQR) of 3 (2\u0026ndash;4) hours, compared with 1 (1\u0026ndash;2) hours in the ACB group (p \u0026lt; 0.001; r = 0.44) . However, there were no statistically significant differences between the groups regarding adverse effects, including nausea, vomiting, and pruritus. Additionally, length of hospital stay was comparable between the two groups. No major block-related complications, including local anesthetic systemic toxicity, persistent motor deficit, nerve injury, infection, or falls, were observed in either group during the study period.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this prospective randomized study of postoperative analgesia in Turkish patients after TKA, the S-FICB group demonstrated significantly lower pain scores both at rest and with movement, reduced total opioid consumption, and higher patient satisfaction compared with the ACB group. However, the duration of motor block was significantly longer in patients receiving S-FICB.\u003c/p\u003e\n\u003cp\u003ePeripheral nerve blocks have become a cornerstone of multimodal analgesia following TKA. The ACB is widely favored because it predominantly targets the saphenous nerve and sensory branches of the femoral nerve while largely preserving quadriceps strength [13]. Several studies have demonstrated that ACB is associated with effective postoperative pain control and decreased opioid consumption [13,14]. Moreover, when compared with femoral nerve block, ACB has been associated with improved preservation of quadriceps strength, potentially facilitating early mobilization and reducing fall risk [15-17]. Nevertheless, some investigations have reported no significant differences between ACB and femoral nerve block in terms of postoperative quadriceps strength or early functional recovery, highlighting the need for further investigation of this topic [18,19].\u003c/p\u003e\n\u003cp\u003eThe suprainguinal fascia iliaca compartment block offers a more proximal approach, allowing spread of local anesthetic toward the femoral, obturator, and lateral femoral cutaneous nerves. The suprainguinal technique, compared with the infrainguinal approach, has been reported to provide more consistent obturator nerve blockade and broader sensory coverage [20-22]. This wider neural distribution may explain the superior analgesic efficacy observed in the present study, particularly the consistently lower dynamic pain scores and reduced opioid consumption in the S-FICB group. Effective control of movement-evoked pain is particularly critical following TKA, as inadequate dynamic analgesia may hinder early rehabilitation and functional recovery.\u003c/p\u003e\n\u003cp\u003ePrevious studies have reported inconsistent findings regarding the relative analgesic effects of S-FICB and ACB. While some trials have demonstrated similar pain scores and opioid consumption between the two techniques, methodological differences such as the use of additional regional blocks, variations in local anesthetic volume and concentration, and differences in block timing may account for these discrepancies [23]. In contrast, the present study directly compared S-FICB and ACB as standalone techniques within a standardized multimodal analgesic protocol, thereby providing a clearer comparison of their analgesic effects.\u003c/p\u003e\n\u003cp\u003eThe significantly longer duration of motor block observed in the S-FICB group is consistent with the more proximal spread of local anesthetic and the potential involvement of motor fibers [15,24]. This aligns with the literature emphasizing the motor-sparing advantage of ACB [25,26]. Although prolonged motor blockade may theoretically delay mobilization, the higher patient satisfaction scores observed in the S-FICB group suggest that enhanced analgesia may outweigh transient motor impairment from the patient’s perspective, particularly in the early postoperative period.\u003c/p\u003e\n\u003cp\u003eRegarding safety, no significant differences were observed between the groups in terms of adverse effects, including nausea, vomiting, and pruritus. These findings are consistent with previous reports demonstrating low complication rates associated with both techniques, supporting their overall safety [27].\u003c/p\u003e\n\u003cp\u003eThe various limitations of this study should be acknowledged. First, this was a single-center study, which may limit the generalizability of the findings. Second, follow-up was limited to the early postoperative period; therefore, long-term functional recovery and rehabilitation outcomes were not evaluated. Additionally, technical factors such as the timing of block administration and local anesthetic volume and concentration may influence block characteristics and should be explored in future research. Larger multicenter trials incorporating functional outcome measures and longer follow-up periods would provide further insight into the optimal regional analgesic strategy following TKA.\u003c/p\u003e\n\u003cp\u003eIn conclusion, S-FICB provided more comprehensive early postoperative analgesia, reduced opioid requirements, and improved patient satisfaction compared with ACB after total knee arthroplasty. Although S-FICB was associated with prolonged motor block, its superior analgesic profile and opioid-sparing effect may justify its use in selected patients, provided that early mobilization strategies are carefully implemented.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval:\u003c/strong\u003e This study was approved by the Erciyes University Committee (24-AKD-143). The study was conducted in accordance with the principles of the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Not applicable. This manuscript does not contain any data that could be used to identify individuals.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u003c/strong\u003e The data used to support the findings of this study can be obtained from the corresponding author on request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e The authors have no conflicts of interest to declare. All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e The authors did not receive support from any organization for the submitted work.\u003c/p\u003e\n\u003cp\u003eAuthor contributions: All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by [Ali Genc], [Sezer Astan], [Mehtap Gürler Balta], [Vildan Kölükçü], [Ahmet Tuğrul Şahin], [Hakan Tapar] and [Tugba Karaman], [Serkan Karaman]. The first draft of the manuscript was written by [Ali Genc] and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial registration\u003c/strong\u003e: ClinicalTrials.gov (NCT07040709).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate\u003c/strong\u003e: Written informed consent was obtained from all participants.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBrumat P, Kun\u0026scaron;ič O, Novak S, Slokar U, P\u0026scaron;enica J, Topolovec M, et al. The Surgical Treatment of Osteoarthritis. Life. 2022;12(7):982.\u003c/li\u003e\n\u003cli\u003eKolahdouzan K, Nazari B. Strategies for the prevention of postoperative chronic pain: Perioperative pain management after total joint replacement: a systematic review. Eurasian J Chem Med Pet Res. 2023;2(2):129\u0026ndash;46.\u003c/li\u003e\n\u003cli\u003eGrosu I, Lavand\u0026rsquo;homme P, Thienpont E. Pain after knee arthroplasty: an unresolved issue. Knee Surg Sports Traumatol Arthrosc. 2014;22(8):1744\u0026ndash;58.\u003c/li\u003e\n\u003cli\u003eBai S, Hu A, Li W, Chen Y, Li X, Song X, et al. Comparing the analgesic effects of femoral triangle block and adductor canal block following total knee arthroplasty: a systematic review and meta-analysis. BMC Anesthesiol. 2025;25(1):202.\u003c/li\u003e\n\u003cli\u003eLi D, Ma GG. Analgesic efficacy and quadriceps strength of adductor canal block versus femoral nerve block following total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2016;24(8):2614\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eCakmak MF, Horoz L, Arslan FN, Demir OU, Basarir K. Comparison ultrasound-guided adductor canal block and surgeon-performed block for pain management after total knee arthroplasty: a prospective randomized controlled study. BMC Musculoskelet Disord. 2024;25(1):637.\u003c/li\u003e\n\u003cli\u003eEt T, Korkusuz M, Menendi U. The Effect of the Application of Adductor and Infiltration of Local Anesthetic Between the Popliteal Artery and Capsule of the Knee (IPACK) Block to Patients on Postoperative Recovery and Sleep Quality Following Total Knee Arthroplasty: a Randomized, Controlled Study. Genel Tıp Derg. 2024;34(5):609\u0026ndash;15.\u003c/li\u003e\n\u003cli\u003eGadalla RR, Daniel RFGSH, Ahmed NS. Ultrasound Guided Fascia Iliaca Block versus Femoral Nerve Block for Post Operative Analgesia for Patient Undergoing Total Knee Arthroplasty. QJM. 2023;116. (Supplement_1):hcad069.085.\u003c/li\u003e\n\u003cli\u003eBali C, Ozmete O, Eker HE, Hersekli MA, Aribogan A. Postoperative analgesic efficacy of fascia iliaca block versus periarticular injection for total knee arthroplasty. J Clin Anesth. 2016;35:404\u0026ndash;10.\u003c/li\u003e\n\u003cli\u003ePronk Y, Peters MCWM, Brinkman JM. Is Patient Satisfaction After Total Knee Arthroplasty Predictable Using Patient Characteristics and Preoperative Patient-Reported Outcomes? J Arthroplasty. 2021;36(7):2458\u0026ndash;65.\u003c/li\u003e\n\u003cli\u003eSinha C, Singh AK, Kumar A, Kumar A, Kumar S, Kumari P. Analgesic effect of continuous adductor canal block versus continuous femoral nerve block for knee arthroscopic surgery: a randomized trial. Braz J Anesthesiol. 2022;72(5):553\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eFaul F, Erdfelder E, Lang AG, Buchner A. G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39(2):175\u0026ndash;91.\u003c/li\u003e\n\u003cli\u003eFillingham YA, Hannon CP, Kopp SL, Austin MS, Sershon RA, Stronach BM, et al. The Efficacy and Safety of Regional Nerve Blocks in Total Knee Arthroplasty: Systematic Review and Direct Meta-Analysis. J Arthroplasty. 2022;37(10):1906-1921.e2.\u003c/li\u003e\n\u003cli\u003eHussain N, Ferreri TG, Prusick PJ, Laura Banfield M, Bradley Long M, Vincent Roger Prusick MD, et al. Adductor canal block versus femoral canal block for total knee arthroplasty: a metaanalysis. Reg Anesth Pain Med. 2016;41:314\u0026ndash;20.\u003c/li\u003e\n\u003cli\u003eHasabo EA, Assar A, Mahmoud MM, Abdalrahman HA, Ibrahim EA, Hasanin MA, et al. Adductor canal block versus femoral nerve block for pain control after total knee arthroplasty: A systematic review and Meta-analysis. Medicine. 2022;101(34):e30110.\u003c/li\u003e\n\u003cli\u003eBorys M, Domagała M, Wencław K, Jarczyńska-Domagała J, Czuczwar M. Continuous femoral nerve block is more effective than continuous adductor canal block for treating pain after total knee arthroplasty: A randomized, double-blind, controlled trial. Medicine. 2019;98(39):e17358.\u003c/li\u003e\n\u003cli\u003eElkassabany NM, Antosh S, Ahmed M, Nelson C, Israelite C, Badiola I, et al. The Risk of Falls After Total Knee Arthroplasty with the Use of a Femoral Nerve Block Versus an Adductor Canal Block: A Double-Blinded Randomized Controlled Study. Anesth Analg. 2016;122(5):1696.\u003c/li\u003e\n\u003cli\u003eChuan A, Lansdown A, Brick KL, Bourgeois AJG, Pencheva LB, Hue B, et al. Adductor canal versus femoral triangle anatomical locations for continuous catheter analgesia after total knee arthroplasty: a multicentre randomised controlled study. Br J Anaesth. 2019;123(3):360\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eLim YC, Quek HYK, Phoo WHJ, Mah CL, Tan S. A randomised controlled trial comparing adductor canal block and femoral nerve block for knee arthroplasty. Singapore Med J. 2019;60(3):145\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eDesmet M, Balocco AL, Van Belleghem V. Fascia iliaca compartment blocks: Different techniques and review of the literature. Best Pract Res Clin Anaesthesiol. 2019;33(1):57\u0026ndash;66.\u003c/li\u003e\n\u003cli\u003eSrivastava VK, Singh AK, Mishra NK, Prabha R, Raman R, Singh V, et al. Ultrasound-Guided Suprainguinal Versus Infrainguinal Fascia Iliaca Compartment Block for Postoperative Analgesia After Total Knee Replacement: A Prospective Randomized Trial. Cureus. 2025;17(5).\u003c/li\u003e\n\u003cli\u003eQian Y, Guo Z, Huang J, Zhang Q, An X, Hu H, et al. Electromyographic Comparison of the Efficacy of Ultrasound-guided Suprainguinal and Infrainguinal Fascia Iliaca Compartment Block for Blockade of the Obturator Nerve in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial. Clin J Pain. 2020;36(4):260.\u003c/li\u003e\n\u003cli\u003eCanikli Adig\u0026uuml;zel Ş, Gen\u0026ccedil; C, Kayik\u0026ccedil;i E, Gen\u0026ccedil; AS, Durusoy S, Yildiz A, et al. Comparison of analgesic efficacy, anti-inflammatory effect, and myotoxicity of ultrasound-guided suprainguinal fascia iliaca block and adductor canal with IPACK combination in patients undergoing total knee arthroplasty under spinal anesthesia: A prospective observational study. Medicine. 2025;104(32):e43719.\u003c/li\u003e\n\u003cli\u003eJ\u0026aelig;ger P, Nielsen ZJK, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor Canal Block Versus Femoral Nerve Block and Quadriceps Strength: A Randomized, Double-blind, Placebo-Controlled, Crossover Study in Healthy Volunteers. Survey of Anesthesiology. 2013;57(4):199.\u003c/li\u003e\n\u003cli\u003eKwofie MK, Shastri UD, Gadsden JC, Sinha SK, Abrams JH, Xu D, et al. The Effects of Ultrasound-Guided Adductor Canal Block Versus Femoral Nerve Block on Quadriceps Strength and Fall Risk: A Blinded, Randomized Trial of Volunteers. Reg Anesth Pain Med. 2013;38(4):321\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003eLund J, Jenstrup MT, Jaeger P, S\u0026oslash;rensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2011;55(1):14\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eTurgut MC, Oral Ahiskalioglu E, Karapinar YE, Koksal EM, Engin C, Celik EC, et al. Comparison of periarticular injection and low-concentration high-volume suprainguinal fascia Iliaca plane block in total knee arthroplasty: a randomized prospective study. Arch Orthop Trauma Surg. 2025;145(1):349.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Adductor canal block, postoperative pain, suprainguinal fascia iliaca block, total knee arthroplasty, opioid consumption","lastPublishedDoi":"10.21203/rs.3.rs-9286946/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9286946/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003eThis study aimed to compare suprainguinal fascia iliaca compartment block (S-FICB) and adductor canal block (ACB) in terms of postoperative pain scores, opioid consumption, and clinical outcomes in total knee arthroplasty (TKA).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eIn this prospective, randomized clinical trial conducted in Turkey, patients undergoing TKA under spinal anesthesia were randomized to receive either S-FICB or ACB. Postoperative pain at rest and with movement was evaluated using a numerical rating scale (NRS). Opioid consumption, duration of motor block, patient satisfaction, and adverse effects, such as nausea, vomiting, and pruritus, were also recorded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eEighty-six patients were analyzed (S-FICB: n = 43; ACB: n = 43). Total 24-h opioid consumption was significantly lower in the S-FICB group (p = 0.001). Postoperative NRS scores at rest and with movement were reduced at various time points in the S-FICB group. Although motor block duration was longer, patient satisfaction scores were higher with S-FICB than with ACB (p \u0026lt; 0.001 and p = 0.006, respectively).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eS-FICB provides more effective early postoperative analgesia, reduces the need for opioids, and improves patient satisfaction compared with ACB following TKA. However, its longer duration of motor block should be considered in clinical decision-making.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial registration\u003c/strong\u003e: The study was registered at ClinicalTrials.gov (NCT07040709) on June 10, 2025; retrospectively registered.\u003c/p\u003e","manuscriptTitle":"Comparison of Suprainguinal Fascia Iliaca Compartment Block and Adductor Canal Block for Pain Management in Total Knee Arthroplasty: A Randomized Clinical Trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-20 10:21:43","doi":"10.21203/rs.3.rs-9286946/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-12T17:28:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"194164330933235929749403338408055059530","date":"2026-04-21T19:14:26+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-13T08:03:19+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-10T11:19:40+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-07T06:18:27+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-07T05:41:42+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Anesthesiology","date":"2026-04-07T05:35:19+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a9bb842e-4df1-47e9-a2bd-7c0748189702","owner":[],"postedDate":"April 20th, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-12T17:28:45+00:00","index":41,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T10:21:43+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-20 10:21:43","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9286946","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9286946","identity":"rs-9286946","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}