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 Table of Contents  
Year : 2017  |  Volume : 31  |  Issue : 3  |  Page : 146-151

The comparative study of two techniques of lumbar plexus block by anterior and posterior approach for lower limb surgery

1 Department of Anaesthesia, Karnataka Institute of Medical Sciences, Hubli, Karnataka, India
2 Department of Anaesthesia, Dr. V. M. Government Medical College, Solapur, Maharashtra, India

Date of Web Publication18-Jan-2018

Correspondence Address:
Milon Vasant Mitragotri
Department of Anaesthesia, Karnataka Institute of Medical Sciences, Hubli - 580 021, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0970-5333.223663

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Background: Lower extremity peripheral nerve blocks (PNBs) have been traditionally less employed compared to other forms of regional anesthesia. The advent of peripheral nerve stimulator and ultrasonography, complications associated with neuraxial anesthesia, and improved rehabilitation with PNBs has led to renewed interest in lower limb blocks. Lumbar plexus block can be given by anterior (Winnie's “3 in 1” block) and posterior (psoas compartment block) approaches. Subjects and Methods: In this randomized, observer-blinded study, we compared these techniques in two groups of patients (Group A [n = 30] and Group P [n = 30]) undergoing lower limb surgeries using nerve locator. They were supplemented with sciatic nerve block by Labat's approach. The primary objective was to compare the onset of sensory and motor blockade. Secondary objectives included the duration of sensory and motor blockade, sparing of nerves and complications if any. The onset of sensory analgesia was assessed by visual analog scale <3 and motor blockage by modified Bromage scale. For data analysis, t-test and Chi-square test were applied. Results: In Group A, onset of sensory block was 4.816 ± 0.932 min, and in Group P, 17.167 ± 2.364 min. In Group A, the onset of motor action was 7.833 ± 1.227 min, and in Group P, 22.8 ± 4.42 min. The duration of motor block was 5.6 ± 1.07 h in group A and 5.88 ± 0.90 h in Group P. The duration of sensory block was found to be 8.18 ± 1.32 h in Group A and 8.18 ± 0.88 h in Group P. Conclusion: Winnie's 3-in-1 block is associated with rapid onset of sensory and motor block but is associated with sparing of lateral femoral cutaneous nerve and obturator nerve causing inadequate analgesia and tourniquet pain needing additional block or sedation compared to psoas compartment block which provides denser block.

How to cite this article:
Mitragotri MV, Agrawal PI, Kulkarni VV, Adke NS, Ladhad DA. The comparative study of two techniques of lumbar plexus block by anterior and posterior approach for lower limb surgery. Indian J Pain 2017;31:146-51

How to cite this URL:
Mitragotri MV, Agrawal PI, Kulkarni VV, Adke NS, Ladhad DA. The comparative study of two techniques of lumbar plexus block by anterior and posterior approach for lower limb surgery. Indian J Pain [serial online] 2017 [cited 2021 Aug 3];31:146-51. Available from: https://www.indianjpain.org/text.asp?2017/31/3/146/223663

  Introduction Top

For lower limb surgery, neuraxial and general anesthesia are tried-and-true methods. They provide reliable, quick way to establish surgical anesthesia. Lower limb blocks have traditionally been less popular than their counterparts in the upper limb. This has been attributed to the onset of action, the density and reliability, the need of two injections in achieving anesthesia. The advent of peripheral nerve stimulator, ultrasonography, improved rehabilitation outcomes, reduced frequency of postoperative vomiting, and earlier discharge have led to renewed interest in lower limb blocks.[1],[2] We decided to revisit these blocks to assess and compare primarily the onset of analgesia, their efficacy and safety in providing anesthesia for lower limb surgeries.

Complete anesthesia of the lower limb requires lumbar and sacral plexus blockade by two separate injections. Lumbar plexus block can be given by anterior (“3-in-1” block by Winnie's approach) and posterior approach (psoas compartment block).

We hypothesize that both these approaches have equivocal onset of sensory and motor blockade. We compared both these techniques in lower limb surgeries using nerve locator with a primary objective to assess the onset of sensory and motor block. We also studied the duration of sensory and motor block, the sparing of nerves, need of rescue analgesia or additional nerve block and the complications associated. They were supplemented with Labat's sciatic nerve block.

  Subjects and Methods Top

After institutional ethical clearance and informed valid consent, adult patients (18–60 years) and American Society of Anesthesiologists (ASA) I–III posted for elective or emergency lower limb surgeries below the gluteal fold such as above and below knee amputation, tibia nailing and plating, excision of tumors, major skin grafting, and knee surgeries were selected. Patients who had sensitivity to local anesthetic, infection at the site of block, bleeding disorder or refusal to be included in the study were excluded from this study. Other specific contraindications such as vertebral and meningeal infectious syndromes, lumbar vertebral trauma, scoliosis, sepsis, psychiatric illness, anxious or agitated patient, diabetic neuropathy, and difficult airway were also considered while selecting patients for the study.

Patients were randomly divided into two groups by an internet software-generated random numbers. Power analysis was done with two-sample t-test estimated a sample of 26 in each group to detect a difference of at least 8 min in onset of analgesia with an α error of 5% and power of 80% after considering standard deviation of 10 min for peripheral nerve block (PNB). Considering chances of failure and dropout of 3, a total of sixty patients were enlisted for the study. Group allocation was done by sequentially numbered sealed opaque envelope. The patients and anesthetist performing the procedure were not blinded to the procedure. The data collector and anesthetists monitoring the patient intraoperative were blinded to the group allocation and entered the induction room only after the block was given. The procedure was discussed with the patient as well as the surgeon. Facilities to give general anesthesia and for emergency resuscitation, equipment for PNB were kept ready [Figure 1].
Figure 1: Equipment for peripheral nerve block

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Group A received “3-in -1” block by Winnie's approach using nerve stimulator. Landmarks included mid-inguinal point and femoral artery [Figure 2]. End point for this block was patellar dance with a current <0.5 mA. Firm pressure was placed just distal to the needle during and a few minutes after injecting local anesthetic to allow cephalic spread.
Figure 2: Lumbar plexus block with Winnie's 3-in-1 block

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Group P received psoas compartment block. Landmarks included the point of intersection of a line joining the highest point of iliac crest and posterior superior iliac spine (PSIS) [Figure 3]. The stimulation of the femoral nerve produces the contraction of the quadriceps muscle and the movement of the patella, creating a spectacle known as “dancing patella.”[3] Traversing from posterior to anterior at the level of L4–L5, the following structures would be encountered: posterior lumbar fascia, paraspinous muscles, anterior lumbar fascia, quadratus lumborum, and the psoas muscle.[4] The common iliac artery and vein are situated anterior to the psoas muscle.[5] If the transverse process is contacted, the needle is walked off the bony structure, and the lumbar plexus is identified within the next 1.5–2.0 cm.
Figure 3: Lumbar plexus block by psoas compartment block

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Both the groups were supplemented with sciatic nerve block by Labat's approach. Landmarks marked were greater trochanter, PSIS, and sacral hiatus [Figure 4].
Figure 4: Sciatic nerve block

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Injection 0.25% bupivacaine 2 mg/kg was used with volume at each site being equal. Volume of the drug was fixed at 0.5 ml/kg with minimum volume of 15 ml and maximum volume of 35 ml.

Our observations included the onset and duration of sensory and motor block measured from the time of injecting the drug, the sparing of different branches of lumbar plexus after 30 min of injecting drug. The safety of both the approaches and hemodynamic stability was also assessed.

Sensory analgesia to pinprick was assessed up to 30 min in the distribution for each of the nerves of lumbar plexus,[5] that is, medial femoral nerve (L2–L4), lateral femoral cutaneous nerve (LFCN) (L2–L3), and obturator nerve (L2–L4) using visual analog scale (VAS), in which VAS <3 indicates onset of analgesia.[6] Muscular relaxation was assessed using modified “Bromage Scale (0–3).”[7]

Inadequate sensory and motor block were assessed and treated with sedation in the form injection pentazocine and injection ketamine or additional nerve block.

Failure was defined as follows and excluded from the study:

  1. If the VAS >5 in the distribution of the two or more nerves after 30 min of injecting drug
  2. Bromage scale <2 after 30 min of injecting drug or
  3. Block insufficient to perform surgery and needs general anesthesia.

Obturator muscle strength was assessed with the patient supine by determining hip adductor strength using above scale.

Variables were presented as mean ± standard deviation for quantitative continuous data such as onset and duration of block and compared using unpaired t-test. Categorical data including sparing of nerves were compared using nonparametric Pearson's Chi-square test. The intragroup differences of the cardiovascular variables recorded over time were analyzed using the repeated-measures ANOVA and intergroup mean values with t-test. Statistical significance was defined as P < 0.05. Minitab ® Inc18.1, Coventry, United Kingdom was used for data tabulation and analysis.

  Results Top

The demographic characters (age, weight, and sex) were comparable in both the groups [Figure 5]. The number of female patients is less (11.67%) The surgeries performed in both the groups were similar as evident from [Table 1]. Most of the patients were nonrisk or ASA I patients with no systemic dysfunction (80%).
Figure 5: Demographics

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Table 1: Distribution of various surgeries in the two groups

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Onset of sensory action was found to be significantly faster in Group A (4.816 ± 0.932 min) than Group P (17.167 ± 2.364 min) (P = 0.000). Similarly, onset of motor action was significantly faster in Group A (7.833 ± 1.227 min) than Group P (22.8 ± 4.42 min) (P = 0.000).

In Group A, 11 (36.67%) patients had sparing of nerves, whereas in Group P, 10 (33.3%) patients had sparing, the difference being insignificant (P = 0.787). The difference in sparing of LFCN, obturator nerve, and medial femoral nerve between the two groups was also not significant (P = 0.157) as evident from [Figure 6] and [Table 2].
Figure 6: Sparing of nerves in the two groups

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Table 2: Percentage of blockage of different nerves in the two groups

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However, the difference in the need of supplementation between the two groups was found to be significant.(P = 0.035) Nine patients in Group A needed supplementation in form of sedation and analgesia or LFCN block compared to two patients in group P that needed supplementation.

The duration of motor block was 5.6 ± 1.07 h in Group A and 5.88 ± 0.90 h in Group P. The difference in duration of motor action was not found to be significant (P = 0.517). The duration of sensory block was found to be 8.18 ± 1.32 h in Group A and 8.18 ± 0.88 h in Group P which was not significantly different.(P = 0.5)

They were no untoward complications, and intraoperative hemodynamic characteristics were comparable in both the groups.

  Discussion Top

With the demographic characteristics being comparable in both the groups, the number of female patients was less because the most of the cases studied were traumatic and the incidence of road traffic accidents is more in young males than females.[8],[9] Although both the procedures being equally efficacious in providing surgical anesthesia, our study inferred that onset of analgesia and motor block was faster by 3-in-1 block compared to psoas compartment block. This could be attributed to the superficial nature of nerves in Winnie's approach compared to the deep-seated and less compact psoas compartment lumbar plexus.[10] Our study has been able to quantify this difference in onset of action between the two blocks. However, it is limited to the blocks performed with nerve locator. Ultrasonography based onset of action needs further study. The onset of sensory and motor block as noted by Kundu et al. by psoas compartment block using nerve stimulation was 18.07 ± 2.165 and 33.22 ± 4.569, respectively, which is comparable to our study.[11]

Psoas compartment block provided a more uniform blockade of LFCN, obturator nerve, and medial femoral nerve block than 3-in-1 block. Furthermore, the need of supplementation in the form of additional nerve block or sedation was more in 3-in-1 block. Sedation and analgesia were given in the form of injection pentazocine and titrated doses of injection ketamine. These findings were in harmony with Ganidagli et al. and Biboulet et al.[12],[13] We suggest it is accredited to the invariable distribution of local anesthetic in the posterior approach when compared to anterior. Proximal spread is essential in anterior approach to block obturator and lateral femoral cutaneous nerve block. Radiographic dye assistance with ultrasonography in the future studies can help better understand this variability in the spread of local anesthetic.

There were many other studies done by Pandin et al., Kaloul et al., Lang et al., Parkinson et al., and Biboulet et al. which compared the percentage of blockade.[13],[14],[15],[16],[17] However, due to lack of uniformity in methods of study, they were either contrary or had same results as our study. Contrary results were due to differing methodologies such as use of paresthesia and ultrasonography (USG), different posterior approaches to the lumbar plexus, method of assessment, and use of adjuvants.

Although the need of rescue analgesic was high in anterior group, the surgical level of anesthesia was adequately achieved. Ganidagli et al. found that rescue analgesia was found to less in psoas compartment block compared to Winnie's 3-in-1 block but time to the first analgesic request was not found to be significant.[12]

There were no failures in our study, probably due to the stringent selection of patients who were cooperative and the same anesthesiologist performing all the procedures. There was a patient in Group A who needed injection Propofol for sedation, as surgery was prolonged beyond 2 h and patient complained of tourniquet pain. Yet, general anesthesia was not instituted in this patient and patient recovered uneventfully.

Earlier literature states that failure rates were higher in posterior approach. Parkinson et al. had no failures reported in the anterior group but reported 10 patients of failed psoas compartment block.[17] Similarly, Biboulet et al. noted 5 failure cases in psoas compartment block.[13] de Visme et al., n = 29, judged inadequate anesthesia in 4/15 (27%) patients in the psoas compartment group.[18] Kundu et al. (n = 3) noted three failures in psoas compartment block.[11] The higher rates of failure with this approach could be due to disparity of depth at which stimulus is elicited.

The use of ultrasonographic imaging for psoas compartment block in adults, unfortunately, has failed to reproduce the excellent images obtained for other peripheral blocks such as brachial plexus or femoral nerve blocks. The main reason is the depth of the plexus at 5–8 cm necessitating the use of lower frequency ultrasound probes (5–8 MHz), resulting in reduced image resolution. Nevertheless, the use of ultrasonographic imaging in conjunction with peripheral nerve stimulation enhances block performance by providing an indication of psoas muscle depth, position of the kidney, and spread of solution.[19],[20] We propose the future studies using various imaging modalities such as magnetic resonance imaging, USG, and nerve stimulator to average the skin-plexus distance to avoid these disparities and complication rates.

The difference in duration of motor and sensory block in both the groups was not found to be significant. However, our objectives did not include need of postoperative analgesia. Future research demands comparing the need of postop analgesia between the two approaches.

In the present study, we did not find any significant complications during the surgery and postoperatively. However, due to juxtaposition to vital structures in the back, the psoas compartment block is prone to associated with complications. Earlier studies found that the deep placement of needle increases the risk of possible renal hematoma, retroperitoneal hematoma, pneumocele, and unintended intraabdominal and intravertebral disk catheter placement. Seizures were also reported.[21] Epidural block of local anesthetic is another side effect of psoas compartment block occurring in 9% to 16% patients.[1]

There are case reports of total spinal anesthesia occurring during lumbar plexus blockade and vigilance must be maintained during the management of this block.[1] A major French study of complications after regional anesthesia found five serious complications after 394 psoas compartment blocks, but none after 10,309 femoral nerve blocks.[22] The complications related to psoas compartment block were all either secondary to the occurrence of bilateral anesthesia (intrathecal/epidural) or vascular administration of local anesthetic.

  Conclusion Top

From the above study, we conclude that Winnie's 3-in-1 block is associated with rapid onset of sensory and motor block compared to psoas compartment block using a nerve stimulator. Psoas compartment block performs better considering the uniformity, density of block and need of supplementation. Both techniques provide safe surgical anesthesia with equivocal duration of action and patients remain hemodynamically stable intraoperatively although reviewed literature states the risk of epidural spread and other complications with psoas compartment block.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Michael JC, Phillip OB, Daniel BC, Terese TH. Neural blockade. In: Clinical Anaesthesia and Pain Medicine. 4th revised ed. Philadelphia: Lippincott Williams and Wilkins; 2009. p. 1-22, 354-55, 348.  Back to cited text no. 1
Jacques EC. Atlas of Regional Anaesthesia. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2004. p. xxiii.  Back to cited text no. 2
Harold E, Stanley F, William HG. Anatomy for Anaesthetists. 8th ed. Denmark: Blackwell; 2003. p. 185.  Back to cited text no. 3
Michael JC, Phillip OB, Daniel BC, Terese TH. Neural blockade. In: Clinical Anaesthesia and Pain Medicine. 4th revised ed. Philadelphia: Lippincott Williams & Wilkins; 2009. p. 348.  Back to cited text no. 4
Phillip OB. The lower extremity somatic nerve blockade. Neural Blockade in Clinical Anaesthesia and Management of Pain. 2nd ed. Philadelphia: Lippincott Raven; 1988. p. 417-431.  Back to cited text no. 5
Muralidhar J. Textbook on Pain Management. 3rd ed. Hyderabad: Paras Medical Publishers; 2014. p. 70.  Back to cited text no. 6
Pramila B. Clinical Anaesthesia. 2nd ed. Hyderabad: Paras Medical Publisher; 2001.  Back to cited text no. 7
Park K. Textbook of Preventive and Social Medicine. 21st ed.. India, Jabalpur: Bhanot; 2011. p. 375.  Back to cited text no. 8
Sharma SM. Road traffic accidents in India. Int J Adv Integr Med Sci 2016;1:57-64.  Back to cited text no. 9
Boezaart AP. Anaesthesia and Orthopaedic Surgery. 1st ed. Europe: McGraw-Hill Education; 2006. p. 362-3, 365.  Back to cited text no. 10
Kundu S, Mukherjee M, Bhattacharya D. A comparative study of spinal bupivacaine and fentanyl versus combined lumbar plexus and sciatic nerve block in lower limb orthopedic procedures. Indian J Pain 2016;30:189-93.  Back to cited text no. 11
  [Full text]  
Ganidagli S, Cengiz M, Baysal Z, Baktiroglu L, Sarban S. The comparison of two lower extremity block techniques combined with sciatic block: 3-in-1 femoral block vs. Psoas compartment block. Int J Clin Pract 2005;59:771-6.  Back to cited text no. 12
Biboulet P, Morau D, Aubas P, Bringuier-Branchereau S, Capdevila X. Postoperative analgesia after total-hip arthroplasty: Comparison of intravenous patient-controlled analgesia with morphine and single injection of femoral nerve or psoas compartment block. A prospective, randomized, double-blind study. Reg Anesth Pain Med 2004;29:102-9.  Back to cited text no. 13
Pandin PC, Vandesteene A, d'Hollander AA. Lumbar plexus posterior approach: A catheter placement description using electrical nerve stimulation. Anesth Analg 2002;95:1428-31.  Back to cited text no. 14
Kaloul I, Guay J, Côté C, Fallaha M. The posterior lumbar plexus (psoas compartment) block and the three-in-one femoral nerve block provide similar postoperative analgesia after total knee replacement. Can J Anaesth 2004;51:45-51.  Back to cited text no. 15
Lang SA, Yip RW, Chang PC, Gerard MA. The femoral 3-in-1 block revisited. J Clin Anesth 1993;8:376-8.  Back to cited text no. 16
Parkinson SK, Mueller JB, Little WL, Bailey SL. Extent of blockade with various approaches to the lumbar plexus. Anesth Analg 1989;68:243-8.  Back to cited text no. 17
de Visme V, Picart F, Le Jouan R, Legrand A, Savry C, Morin V, et al. Combined lumbar and sacral plexus block compared with plain bupivacaine spinal anesthesia for hip fractures in the elderly. Reg Anesth Pain Med 2000;25:158-62.  Back to cited text no. 18
Kirchmair L, Entner T, Kapral S, Mitterschiffthaler G. Ultrasound guidance for the psoas compartment block: An imaging study. Anesth Analg 2002;94:706-10.  Back to cited text no. 19
Mannion S, O'Callaghan S, Walsh M, Murphy DB, Shorten GD. In with the new, out with the old? Comparison of two approaches for psoas compartment block. Anesth Analg 2005;101:259-64.  Back to cited text no. 20
Chayen D, Nathan H, Chayen M. The psoas compartment block. Anesthesiology 1976;45:95-9.  Back to cited text no. 21
Auroy Y, Benhamou D, Bargues L, Ecoffey C, Falissard B, Mercier FJ, et al. Major complications of regional anesthesia in France: The SOS Regional Anesthesia Hotline Service. Anesthesiology 2002;97:1274-80.  Back to cited text no. 22


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]

  [Table 1], [Table 2]


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