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Psoas Compartment Block

  • Author: Bassem Asaad, MD; Chief Editor: Meda Raghavendra (Raghu), MD  more...
Updated: Aug 07, 2014


Blockade of the lumbar plexus can be attained through an anterior approach described by Winnie[1] or through a posterior approach (psoas compartment block). The simplicity of completing the Winnie technique, well known as the 3-in-1 block, has made the technique much more popular than the posterior approach.

Controversy exists as to whether the anterior approach indeed covers the 3 target nerves: the femoral, obturator, and the lateral femoral. A meta-analysis found that more success is achieved with the obturator nerve block with the psoas compartment block when compared to the Winnie technique.[2] The obturator nerve provides innervation to the hip joint as well as the knee joint and, therefore, the degree of covering the nerve by the block results in better pain control and patient satisfaction.



Blockade of the lumbar plexus in combination with the sciatic nerve can provide anesthesia and high-quality analgesia for the whole lower extremity, with the advantage of more hemodynamic stability when compared to epidural analgesia.[3, 4, 5, 6] When a surgical block of the lower extremity is indicated, the psoas compartment block is favored over the Winnie technique. A surgical block may be considered for lower extremity amputation cases as well as orthopedic surgery cases in debilitated patients who may not tolerate the hemodynamic effects of general anesthesia.

The block may be done in conjunction with an IV opioid PCA instead of combining it with the sciatic nerve block for postoperative pain control. The use of the block is not only limited to the adult population but also extends to the pediatric population. Psoas compartment block was found to be a better technique for postoperative analgesia after hip and femoral surgery when compared to epidural block in children.[7, 8]

In a prospective single-blind study performed with 30 patients, Turker et al concluded that, when compared to epidural analgesia, lumbar plexus catheters are better tolerated for providing intraoperative and postoperative analgesia to hip fracture patients and for partial hip replacement surgery patients.[9] When combined with T12-L1 and sciatic nerve block, psoas compartment block can also be used in high-risk patients as the anesthetic technique for femoropopliteal bypass surgery.[10]



See the list below:

  • Patient’s refusal or lack of understanding of the benefits and adverse effects of the procedure
  • Anticoagulated and coagulopathy patients: Psoas compartment block is a paravertebral block. Although considered as an alternative for an epidural block in anticoagulated patients, this is no longer the case. The same American Society of Anesthesiology’s anticoagulation guidelines apply to paravertebral blocks. [11]
  • Localized and systemic infection


The lumbar plexus is formed within the substance of the psoas major muscle by the anterior rami of spinal nerves L1 through L4 and some fibers from T12. These nerve roots enter the psoas muscle within a confined compartment; they then divide into anterior divisions (forming the lumbar plexus) and posterior divisions.

The plexus is about 3 cm anterior to the plane of the lumbar transverse process. Under ultrasound guidance, it appears as a hyperechoic structure that lies within the hypoechoic psoas major muscle (see the image below). The plexus is responsible for the innervation of lower abdomen and anterior and medial portion of the lower extremities. The branches of the lumbar plexus include the iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous nerve, femoral nerve, and the obturator nerve.[12]

Ultrasound guided View of the Transverse process. Ultrasound guided View of the Transverse process. The probe is placed parallel to the spinous processes S. sacrum, TP. Transverse process, LP. Lumbar Plexus

The block is approached at the L4 level in a sagittal plane that corresponds to the lateral end of the lumbar L4 transverse process. Completing the block at this level decreases the probability of puncturing the ipsilateral kidney.

Contributor Information and Disclosures

Bassem Asaad, MD Assistant Professor of Clinical Anesthesiology, The School of Medicine at Stony Brook University Medical Center

Bassem Asaad, MD is a member of the following medical societies: International Spine Intervention Society

Disclosure: Nothing to disclose.


Arvind Chandrakantan, MBBS, MD Assistant Professor of Anesthesiology and Pediatrics, Stony Brook University Medical Center

Disclosure: Nothing to disclose.

Chief Editor

Meda Raghavendra (Raghu), MD Associate Professor, Interventional Pain Management, Department of Anesthesiology, Chicago Stritch School of Medicine, Loyola University Medical Center

Meda Raghavendra (Raghu), MD is a member of the following medical societies: American Society of Anesthesiologists, American Society of Regional Anesthesia and Pain Medicine, American Association of Physicians of Indian Origin

Disclosure: Nothing to disclose.

  1. Winnie AP, Ramamurthy S, Durrani Z. The inguinal paravascular technic of lumbar plexus anesthesia: the "3-in-1 block". Anesth Analg. 1973 Nov-Dec. 52(6):989-96. [Medline].

  2. Touray ST, de Leeuw MA, Zuurmond WW, Perez RS. Psoas compartment block for lower extremity surgery: a meta-analysis. Br J Anaesth. 2008 Dec. 101(6):750-60. [Medline].

  3. de Leeuw MA, Slagt C, Hoeksema M, Zuurmond WW, Perez RS. Hemodynamic changes during a combined psoas compartment-sciatic nerve block for elective orthopedic surgery. Anesth Analg. 2011 Mar. 112(3):719-24. [Medline].

  4. Zhang X, Zhou Y, Chen L, Wang Q, Ni J, Liu L, et al. Anesthesia and postoperative analgesia during unilateral lower-extremity fracture surgeries using multiple injections through catheters beside the lumbar plexus or sciatic nerve. Ther Clin Risk Manag. 2013. 9:299-302. [Medline]. [Full Text].

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  6. Salviz EA, Gürkan Y, Tekin M, Buluç L. Ultrasound-guided psoas compartment block and general anesthesia for arthroscopic knee surgery: a case report. Agri. 2014 Jan. 26(1):34-8. [Medline].

  7. Omar AM, Mansour MA, Kamal AS. Psoas compartment block for acute postoperative pain management after hip surgery in pediatrics: a comparative study with caudal analgesia. Reg Anesth Pain Med. 2011 Mar-Apr. 36(2):121-4. [Medline].

  8. Dadure C, Bringuier S, Mathieu O, Raux O, Rochette A, Canaud N. [Continuous epidural block versus continuous psoas compartment block for postoperative analgesia after major hip or femoral surgery in children: a prospective comparative randomized study]. Ann Fr Anesth Reanim. 2010 Sep. 29(9):610-5. [Medline].

  9. Turker G, Uckunkaya N, Yavascaoglu B, Yilmazlar A, Ozcelik S. Comparison of the catheter-technique psoas compartment block and the epidural block for analgesia in partial hip replacement surgery. Acta Anaesthesiol Scand. 2003 Jan. 47(1):30-6. [Medline].

  10. Basagan-Mogol E, Turker G, Yilmaz M, Goren S. Combination of a psoas compartment, sciatic nerve, and T12-L1 paravertebral blocks for femoropopliteal bypass surgery in a high-risk patient. J Cardiothorac Vasc Anesth. 2008 Apr. 22(2):337-9. [Medline].

  11. Horlocker TT, Wedel DJ, Rowlingson JC, Enneking FK, Kopp SL, Benzon HT. Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition). Reg Anesth Pain Med. 2010 Jan-Feb. 35(1):64-101. [Medline].

  12. Van de Graaff, KM. Human Anatomy. 5thed. Boston: McGraw-Hill; 2000. 404-405.

  13. Danelli G, Ghisi D, Bellinghieri F, Borghi B, Fanelli G, Chelly J. The nerve stimulation technique versus the loss of resistance technique for the posterior approach to lumbar plexus block: a randomized, prospective, observer-blinded, pilot study. Minerva Anestesiol. 2011 Oct. 77(10):959-63. [Medline].

  14. Ilfeld BM, Loland VJ, Mariano ER. Prepuncture ultrasound imaging to predict transverse process and lumbar plexus depth for psoas compartment block and perineural catheter insertion: a prospective, observational study. Anesth Analg. 2010 Jun 1. 110(6):1725-8. [Medline].

  15. Li B, Xu XX, Du Y, Yang HF, Li Y, Zhang Q, et al. CT-Guided Chemonucleolysis Combined with Psoas Compartment Block in Lumbar Disc Herniation: A Randomized Controlled Study. Pain Med. 2014 Jul 8. [Medline].

Patient in a lateral decubitus position.
Ultrasound guided View of the Transverse process. The probe is placed parallel to the spinous processes S. sacrum, TP. Transverse process, LP. Lumbar Plexus
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