Diagnostic features of osteitis condensans ilii by MRI-a systematic literature review.

Objective: To describe and  evaluate the current knowledge of MRI characteristics of osteitis condensans ilii (OCI) in the diagnostics and differentiation of OCI from other conditions.

Materials and methods: The databases PubMed, EMBASE, Scopus, and Web of Science were searched from their inception to March 2024 using the search terms "Magnetic Resonance Imaging" (MESH term in PubMed) and "osteitis condensans ilii" and limited to English language. Two reviewers independently screened titles, abstracts, and full-text eligibility and assessed the risk of bias according to Quality Assessment of Diagnostic Accuracy Studies, QUADAS-2.

Results: The search identified 53 records. Case reports, letters/notes, and conference abstracts were excluded, resulting in 24 reports assessed by full-text, 9 research articles, 14 reviews, and a book chapter. Five retrospective research studies were found eligible for the review. Detailed MRI features of OCI were only described in two studies of patients with pain where they encompassed manifest subchondral iliac sclerosis often accompanied by bone marrow edema (BME) located peripheral to the sclerosis and displaying a continuous distribution and frequently accompanied by sacral BME. Erosions were rare and ankylosis did not occur. Fat deposition in the bone marrow was frequent and similar to BME often located to anterior strain-related joint areas. The QUADAS-2 assessments revealed risks of bias in all studies analyzed, especially regarding general applicability of the MRI features.

Conclusion: There is a lack of valid data describing characteristic MRI features in general groups of OCI patients with and without pain.