Sonoanatomy and injection technique of the iliolumbar ligament.

Background: The iliolumbar ligament plays an important biomechanic role in anchoring the spine to the pelvic ring and stabilizing the sacroiliac joint. Iliolumbar syndrome is a back pain condition caused by pathology of the iliolumbar ligament. History and physical examination are important in the assessment of back pain, but they lack sufficient specificity. Injection of small volumes of local anesthetic into the structure considered to be the source of the pain (i.e. the iliolumbar ligament) increases the specificity of the diagnostic workup.

Objective: To describe an ultrasound - guided technique for injecting the iliolumbar ligament.

Study Design: Case report based on knowledge of topographic anatomy and sonoanatomy.

Setting: Outpatient clinic.

Methods: A patient with a clinical picture suggestive of iliolumbar syndrome was selected. An ultrasound-guided injection of the iliolumbar ligament with local anesthetic was performed. We recorded the patient's subjective assessment of pain and the change in range of movement and pain scores during provocative tests.

Results: Following the injection, the patient's pain score decreased, provocation tests became negative, and the range of movement increased.

Limitations: Case report. Target specificity and dispersion of local anesthetic spread not confirmed with an independent technique (i.e. magnetic resonance imaging).

Conclusions: Ultrasound guidance allows the selective deposition of small volumes of local anesthetic into structures believed to cause soft tissue back pain and thus to confirm or exclude the working diagnosis. Further studies are needed to confirm our conclusions and to prove the clinical feasibility of this technique.