Clinical features and diagnostic challenges in crowned dens syndrome: a systematic review and meta-analysis

Crowned Dens Syndrome (CDS) is an acute inflammatory neck pain linked to Calcium Pyrophosphate crystal deposition surrounding the odontoid process. This systematic review and meta-analysis aim to illuminate the Features and Diagnostic Challenges of CDS. PubMed, Web of Sciences, and Scopus databases were searched in July 2024 to include all studies on CDS without publication year or language restrictions. Demographic, clinical, laboratory, and radiological data, in addition to treatment regimens and outcomes, were extracted and analyzed. PROSPERO registration number is CRD42024575491. We analyzed 153 reports, including 196 CDS patients, with a mean age of 73.13 +/- 12.95 years and an almost equal female-to-male ratio. Neck pain was the most common symptom (96.8%). CRP and ESR were elevated in 91.4% and 80.7% of cases, respectively. CT scans had the highest detection rate for abnormalities (97.3%), compared to MRI (68.4%) and plain radiographs (79.4%). NSAIDs were the most frequently used treatment (62.5%), with improvement observed in 96.6% of cases. Meningitis was the most common misdiagnosis (21.4%), leading to a higher likelihood of plain radiographs and lumbar punctures. In contrast, patients with neck tenderness and restricted range of motion had a lower risk of misdiagnosis. Patients who were initially misdiagnosed were more likely to undergo LP (13.1% Vs. 34.8%; P-value < 0.001). CDS is an elderly disease that usually presents as acute neck pain with elevated inflammatory markers and is frequently misdiagnosed as meningitis. Recognizing key clinical features may improve diagnosis and management.