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.
Key words: Technique, visualization, real-time, ultrasound, iliolumbar ligament,iliolumbar
syndrome, diagnostic injection, low back pain, groin pain.
Sonoanatomy and Injection Technique of the
Iliolumbar Ligament