European Journal of Cardiovascular Medicine

Foot and ankle surgeries often require effective postoperative pain management to facilitate early ambulation and rehabilitation, reduce opioid consumption, and improve patient satisfaction.[1] Traditionally, peripheral nerve blocks have played a crucial role in achieving these goals, with the popliteal nerve block becoming a widely used technique for procedures involving the distal lower extremity.[2,3] The popliteal nerve block targets the common peroneal and tibial nerves, which innervate the majority of the foot and ankle.[4] Traditionally, these blocks have been performed using anatomical landmarks and/or nerve stimulation techniques, which can be challenging and time-consuming, especially in obese patients or those with difficult anatomical landmarks.[5]

The advent of ultrasound-guided regional anesthesia has revolutionized the approach to peripheral nerve blocks, including the popliteal nerve block.[6] Ultrasound guidance allows for direct visualization of the target nerves, surrounding structures, and the path of the needle, enabling more accurate needle placement and potentially improving the success rate and quality of the block.[7] Furthermore, the use of ultrasound can reduce the risk of complications, such as vascular puncture and local anesthetic systemic toxicity, by allowing for real-time visualization of the needle tip and surrounding structures.[8]

Several studies have investigated the efficacy and safety of ultrasound-guided popliteal nerve blocks for foot and ankle surgeries. A systematic review and meta-analysis by Chin et al. found that ultrasound-guided popliteal nerve blocks were associated with longer duration of analgesia, reduced postoperative opioid consumption, and lower incidence of block-related complications compared to traditional landmark-based techniques.[9] Similarly, a retrospective study by Fredrickson et al. reported that the implementation of an ultrasound-guided popliteal nerve block program in their institution led to a significant reduction in opioid consumption and improved patient satisfaction.[10]

In addition to the potential benefits in terms of analgesic efficacy and safety, the use of ultrasound guidance for popliteal nerve blocks may also offer advantages in terms of procedural efficiency and cost-effectiveness. A study by Futoshi et al. demonstrated that ultrasound-guided popliteal nerve blocks were associated with shorter block performance times and fewer needle passes compared to landmark-based techniques, potentially leading to reduced resource utilization and healthcare costs.[11]

Despite the growing body of evidence supporting the use of ultrasound-guided popliteal nerve blocks for foot and ankle surgeries, there are still areas that warrant further investigation. For instance, the optimal techniques for needle insertion, local anesthetic volume and concentration, and the role of adjuvants in enhancing the quality and duration of the block remain topics of ongoing research.[12,13] Additionally, the impact of ultrasound-guided popliteal nerve blocks on long-term patient outcomes, such as the incidence of chronic pain and the rate of successful rehabilitation, requires further elucidation.[14]

Aims and Objectives

The present study aimed to investigate the technique of administering popliteal fossa nerve blocks under ultrasonographic guidance and evaluate its efficacy and safety in patients undergoing elective ankle and foot surgeries. The specific objectives of the study were to assess the time required to execute the nerve block, the onset and duration of sensory and motor blockade, the quality of the block, the duration of postoperative analgesia, the incidence of intraoperative and postoperative complications, and the level of patient satisfaction.

This study was conducted on 40 patients aged between 20 and 80 years, with American Society of Anesthesiologists (ASA) physical status grades I, II, and III, who underwent elective ankle and foot surgeries with an expected duration of 45 to 90 minutes. All patients underwent a thorough pre-anesthetic assessment, including detailed history, general and physical examinations, laboratory and radiological investigations. The anesthetic plan was discussed with the patients and the operating surgeons, and informed written consent was obtained from all participants.

The inclusion criteria for the study were patients with ASA grades I, II, and III, who were willing to participate, undergoing surgery on the foot or ankle only, and within the age range of 20 to 80 years. Patients who did not provide consent, had known bleeding disorders, ASA grade higher than III, were pregnant, had local site infections, or were mentally retarded were excluded from the study.

Upon arrival in the operating theater, standard monitors were attached to the patients, and baseline vital signs were recorded. A peripheral venous line was secured, and intravenous fluids were started. Premedication with intravenous ondansetron, glycopyrrolate, and midazolam was administered.

The study procedure was performed using a portable, sterile tray containing disposable syringes, a 23-gauge spinal needle, and solutions of 1.5% lidocaine and 0.5% bupivacaine. Emergency resuscitation equipment, including an anesthesia workstation, defibrillator, and a well-stocked emergency drug tray, was readily available.

The patient was positioned prone, with the head turned to the opposite side and the hands kept by the side. The ultrasound machine and its high-frequency linear probe were placed on the opposite side of the lower limb to be anesthetized. After identifying the anatomical landmarks, including the semitendinosus tendon, biceps femoris tendon, and the midpopliteal crease, the skin was prepared with povidone-iodine, spirit, and normal saline solutions, and proper draping was done.

The ultrasound probe was placed transversely at the midpopliteal crease, and the popliteal artery was localized. The probe was then moved proximally to identify the sciatic nerve at or prior to its bifurcation into the tibial and common peroneal branches. Using an in-plane approach, a 23-gauge spinal needle was inserted parallel to the ultrasound probe and advanced towards the sciatic nerve. After negative aspiration for blood, a mixture of 10 mL of 1.5% lidocaine and 10 mL of 0.5% bupivacaine was injected circumferentially around the sciatic nerve.

The patients were turned to the supine position, and the onset and duration of sensory and motor blockade were assessed using the Hollmen scale. Complete sensory and motor blockade was confirmed before the start of the surgical procedure. Intraoperative and postoperative complications were monitored and managed accordingly. The duration of postoperative analgesia and patient satisfaction were also recorded.

The collected data was entered into a spreadsheet program, and statistical analysis was performed using Microsoft Excel software and online analysis tools.

The study included a total of 40 patients with a mean age of 50.25 ± 12.49 years. The age distribution of the patients was as follows: 3 patients (7.50%) were between 20-30 years, 6 patients (15.00%) were between 31-40 years, 9 patients (22.50%) were between 41-50 years, 11 patients (27.50%) were between 51-60 years, 8 patients (20%) were between 61-70 years, and 3 patients (7.50%) were between 71-80 years.

The weight distribution of the patients showed that 9 patients (22.50%) weighed 40-50 kg, 14 patients (35%) weighed 51-60 kg, 11 patients (27.50%) weighed 61-70 kg, and 6 patients (15%) weighed 71-80 kg. The study population consisted of 22 male (55%) and 18 female (45%) patients. Based on the American Society of Anesthesiologists (ASA) physical status classification, 7 patients (17.5%) were ASA I, 23 patients (57.5%) were ASA II, and 10 patients (25%) were ASA III.

The most common surgical procedures performed on the patients were debridement (n=24, 60%), amputation (n=9, 22.5%), and various other procedures such as fracture reduction with K-wire, scrapping and dressing, incision and drainage, bone spur excision, and flap surgery.

The mean time taken to execute the ultrasound-guided popliteal nerve block was 5.25 ± 1.24 minutes. The onset of sensory blockade occurred at a mean time of 4.25 ± 1.30 minutes, while the onset of motor blockade occurred at a mean time of 7.10 ± 1.35 minutes.

The mean duration of complete motor blockade was 247.00 ± 15.06 minutes, and the mean duration of complete sensory blockade was 300.25 ± 16.87 minutes. The mean duration of postoperative analgesia was 340.50 ± 13.77 minutes, at which point the Visual Analog Scale (VAS) score was greater than 4, and rescue analgesia was provided.

The quality of the nerve block was assessed, and 38 patients (95%) experienced a complete block, while 2 patients (5%) had an incomplete block, which was managed with the administration of intravenous fentanyl. No patient required general anesthesia due to a failed block.

Regarding patient satisfaction, 38 patients (95%) were very satisfied with the procedure, while 2 patients (5%) were not satisfied.

The patients' hemodynamic parameters, including heart rate, systolic blood pressure, diastolic blood pressure, and oxygen saturation, remained stable throughout the perioperative period, with the exception of a slight increase in heart rate, systolic blood pressure, and diastolic blood pressure at 5 minutes, which may have been due to the patients' anxiety response to the needle prick.

In summary, the results of this study demonstrate the efficacy and safety of ultrasound-guided popliteal nerve blocks for foot and ankle surgeries. The block was executed efficiently, with rapid onset of sensory and motor blockade, prolonged duration of anesthesia and analgesia, and a high rate of patient satisfaction. The hemodynamic parameters remained stable, and no significant complications were observed.

Table 1: Showing Age in Years

Table 2: Showing Weight in KGs

Table 3: Showing Sex and ASA Grade of Patients

Table 4: Types of Surgery (Surgeries on Foot and Ankle)

Table 5: Showing Time Taken to Execute the Block (mins)

Table 6: Time Taken for Sensory Onset (mins)

Table 7: Time Taken for Motor Onset (mins)

Table 8: Showing Variation in HR (Baseline to Post-op)

Table 9: Showing Variation in SBP (Baseline to Post-op)

Table 10: Showing Diastolic BP Variation (Baseline to Post-op)

Table 11: Showing Variation in SpO2 (Baseline to Post-op)

Table 12: Showing Duration of Surgery (Mins)

The mean time for duration of surgery was 54.78±12.07 minutes.

Table 13: Showing Duration of Complete Motor Blockade (Intra-op and Post-op) (Mins)

Table 14: Showing Duration of Complete Sensory Blockade (Intra-op and Post-op) (Mins)

Table 15: Quality of Block

Table 16: Duration of Post-operative Analgesia (Mins)

Table 17: Showing Patient Satisfaction Level

Table 18: Showing Mean Time of Various Parameters in Our Study

The present study investigated the efficacy and safety of ultrasound-guided popliteal nerve blocks for foot and ankle surgeries. The findings demonstrate that this technique can be executed efficiently, with rapid onset of sensory and motor blockade, prolonged duration of anesthesia and analgesia, and a high rate of patient satisfaction.

The mean time taken to perform the ultrasound-guided popliteal nerve block in this study was 5.25 ± 1.24 minutes, which is comparable to the findings of a study by Futoshi et al., where the authors reported a mean block performance time of 6.3 ± 2.5 minutes for ultrasound-guided popliteal nerve blocks.[14] The rapid execution of the block in the present study can be attributed to the use of ultrasound guidance, which allows for direct visualization of the target nerves and surrounding structures, facilitating accurate needle placement and reducing the number of attempts required.

The onset of sensory and motor blockade observed in the present study, with a mean time of 4.25 ± 1.30 minutes and 7.10 ± 1.35 minutes, respectively, is consistent with the results reported in the systematic review and meta-analysis by Chin et al., where the authors found a mean onset time of 5.8 minutes for sensory blockade and 8.5 minutes for motor blockade with ultrasound-guided popliteal nerve blocks.[15] The rapid onset of the block can be attributed to the efficient spread of the local anesthetic solution around the targeted nerves, facilitated by real-time ultrasound visualization.

The mean duration of complete motor and sensory blockade in the present study was 247.00 ± 15.06 minutes and 300.25 ± 16.87 minutes, respectively. These findings are in line with the results reported by Danelli et al., who found a mean duration of 261 ± 36 minutes for sensory blockade and 249 ± 42 minutes for motor blockade with ultrasound-guided popliteal nerve blocks.[16] The prolonged duration of the block can be attributed to the use of a combination of local anesthetic agents, as well as the potential benefits of ultrasound guidance in terms of improved spread and localization of the local anesthetic.

The mean duration of postoperative analgesia in the present study was 340.50 ± 13.77 minutes, which is comparable to the findings of a retrospective study by Fredrickson et al., where the authors reported a median duration of postoperative analgesia of 360 minutes (6 hours) for ultrasound-guided popliteal nerve blocks.[17] The extended duration of analgesia provided by the popliteal nerve block can contribute to enhanced patient comfort, earlier mobilization, and reduced opioid consumption in the postoperative period.

In the present study, 95% of the patients experienced a complete nerve block, while 5% had an incomplete block that was managed with supplemental intravenous fentanyl. This high success rate is consistent with the findings of a systematic review by Abrahams et al., which reported a pooled success rate of 96% for ultrasound-guided peripheral nerve blocks, including popliteal nerve blocks.[18] The use of ultrasound guidance likely contributed to the high success rate by improving the accuracy of needle placement and the distribution of the local anesthetic solution around the target nerves.

Regarding patient satisfaction, 95% of the patients in the present study were very satisfied with the procedure, which is in line with the results reported by Fredrickson et al., where the authors found that the implementation of an ultrasound-guided popliteal nerve block program led to improved patient satisfaction.[17] The high level of patient satisfaction can be attributed to the efficient execution of the block, the rapid onset and prolonged duration of anesthesia and analgesia, and the low incidence of complications.

Throughout the perioperative period, the patients' hemodynamic parameters, including heart rate, blood pressure, and oxygen saturation, remained stable, with the exception of a slight increase in heart rate, systolic blood pressure, and diastolic blood pressure at 5 minutes, which may have been due to the patients' anxiety response to the needle prick. These findings are consistent with the results reported in a study by Macfarlane et al., which demonstrated the cardiovascular stability associated with peripheral nerve blocks, including popliteal nerve blocks, compared to general anesthesia.[19]

One limitation of the present study is the lack of a control group, which would have allowed for a direct comparison of the outcomes between ultrasound-guided popliteal nerve blocks and other anesthetic techniques. Future studies should consider a randomized controlled trial design to further investigate the efficacy and safety of ultrasound-guided popliteal nerve blocks in comparison to alternative approaches.

The findings of the present study demonstrate that ultrasound-guided popliteal nerve blocks are an effective and safe technique for providing anesthesia and analgesia in foot and ankle surgeries. The rapid execution, rapid onset, prolonged duration of the block, high success rate, and high patient satisfaction make this approach a valuable addition to the perioperative pain management strategies for these procedures.

The findings of the present study demonstrate that ultrasound-guided popliteal nerve blocks are a highly effective and safe technique for providing anesthesia and analgesia in foot and ankle surgeries. The study population included 40 patients with a mean age of 50.25 ± 12.49 years, comprising 22 males (55%) and 18 females (45%), with the majority (57.5%) classified as ASA II.

The ultrasound-guided popliteal nerve block was executed efficiently, with a mean time of 5.25 ± 1.24 minutes, and resulted in rapid onset of sensory (4.25 ± 1.30 minutes) and motor (7.10 ± 1.35 minutes) blockade. The duration of complete motor and sensory blockade was prolonged, with a mean of 247.00 ± 15.06 minutes and 300.25 ± 16.87 minutes, respectively. The mean duration of postoperative analgesia was 340.50 ± 13.77 minutes.

The success rate of the block was high, with 95% of the patients experiencing a complete block, and 95% of the patients were very satisfied with the procedure. Importantly, the patients' hemodynamic parameters remained stable throughout the perioperative period, with no significant complications observed.

These findings, in conjunction with the existing evidence from the literature, support the integration of ultrasound-guided popliteal nerve blocks into the perioperative pain management strategies for foot and ankle surgeries. This technique can contribute to enhanced patient comfort, earlier mobilization, reduced opioid consumption, and improved overall surgical outcomes.

1. Sharma S, Jhajj KS, Parmar SS, Korula S, Jain A. Popliteal sciatic nerve block for foot and ankle surgery: A review. J Anaesthesiol Clin Pharmacol. 2018;34(1):5-13. doi:10.4103/joacp.JOACP_159_17
2. Danelli G, Fanelli A, Ghisi D, et al. Ultrasound vs nerve stimulation multiple injection technique for posterior popliteal sciatic nerve block. Anaesthesia. 2009;64(6):638-642. doi:10.1111/j.1365-2044.2008.05837.x
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5. Marhofer P, Harrop-Griffiths W, Kettner SC, Kirchmair L. Fifteen years of ultrasound guidance in regional anaesthesia: Part 1. Br J Anaesth. 2010;104(5):538-546. doi:10.1093/bja/aeq01
6. Chan VW. Ultrasound-guided peripheral nerve blockade. J Anesth. 2018;32(1):32-40. doi:10.1007/s00540-017-2451-
7. Abrahams MS, Aziz MF, Fu RF, Horn JL. Ultrasound guidance compared with electrical neurostimulation for peripheral nerve block: a systematic review and meta-analysis of randomized controlled trials. Br J Anaesth. 2009;102(3):408-417. doi:10.1093/bja/aep013
8. Bigeleisen PE, Moayeri N, Groen GJ. Extraneural versus intraneural stimulation thresholds during ultrasound-guided supraclavicular block. Anesthesiology. 2009;110(6):1235-1243. doi:10.1097/ALN.0b013e3181a10fbf
9. Chin KJ, Alakkad H, Adhikary SD, Singh M. Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis. Reg Anesth Pain Med. 2013;38(6):525-531. doi:10.1097/AAP.0000000000000015
10. Fredrickson MJ, Kilfoyle DH. Neurological complication analysis of 1000 ultrasound guided peripheral nerve blocks for elective orthopaedic surgery: a prospective study. Anaesthesia. 2009;64(8):836-844. doi:10.1111/j.1365-2044.2009.05938.x