200 Section - Iliac Crest Pseudoarticulation with the Lumbar Transverse Process: Two Cases, Imaging Considerations, and a Review of Clinical Response to Steroid Injection

Wednesday, May 20, 2026

6:00 PM - 7:30 PM PT

Presenting Author/Autor expositor(s)

KS

Kara Sidhu, MD

Resident Doctor
University of Calgary
Calgary, Alberta, Canada

Corresponding Author/Autor a quien dirigir la corr(s)

GD

George Deng, MD

Physician, Physical Medicine and Rehabilitation
University of Calgary
Calgary, Alberta, Canada

Co-Author/Coautor(s)

RE

Ryan Endersby, MD

Physician, Anesthesiology
University of Calgary
Calgary, Alberta, Canada
AA

Ammar Al Khudairy, MD

Physician
University of Calgary
Calgary, Alberta, Canada

Case Diagnosis: Isolated pseudoarticulation between lumbar transverse processes and iliac crest (without involvement of the sacrum), resulting in low back pain.

Case Description: Patient A, 74-year-old male, presented with chronic diffuse low back pain aggravated with activity. He was minimally responsive to conservative measures. Physical examination localized his pain diffusely across his lower back. Imaging demonstrated an isolated pseudoarticulation between L4 and iliac crest. A fluoroscopically guided steroid injection into the pseudoarticulation produced substantial and durable pain relief.

Patient B, 59-year-old female, presented with chronic right sided axial low back pain, worse with prolonged standing. Previous p</span>hysiotherapy and steroid injection in the right sacroiliac joint provided limited relief. Physical examination revealed localized tenderness over the right iliac crest with provocative pain with rotation and extension on the right. Imaging demonstrated a L5–iliac crest pseudoarticulation. Following an identical injection protocol, Patient B experienced a significant but transient pain relief response.

Discussions: In this case study, we present isolated pseudoarticulations between lumbar transverse process and iliac crest. Isolated pseudoarticulation between lumbar transverse processes and iliac crest is sparsely described and may represent a distinct entity from the well-known Bertolotti's syndrome.

Targeted injections with local anesthetic can serve as a diagnostic tool and assess potential for therapeutic injections. Our first case demonstrated a pseudoarticulation that can be responsive to targeted steroid injection. The second case, however, illustrates the heterogeneity of clinical outcomes, with significant initial pain relief but minimal durable long term pain relief with steroid injection. The variable response suggests heterogeneity in clinical presentation and multifactorial nature of low back pain.

Conclusions: Pseudoarticulation of the lumbar transverse process with the iliac crest is an under-recognized anatomical variant distinct from Bertolotti’s syndrome. These cases expand the spectrum of anomalous pseudoarticulations that contribute to chronic low back pain and highlight both their clinical relevance and variable treatment responses.