Cervical facet oedema: prevalence, correlation to symptoms, and follow-up imaging.

AIM: To evaluate the prevalence of cervical facet oedema in patients referred for magnetic resonance imaging (MRI) to investigate neck pain and/or radiculopathy, and to investigate whether there is a correlation between the presence of oedema and patients' symptoms. MATERIALS AND METHODS: A retrospective report review of 1885 patients undergoing cervical spine MRI between July 2008 and June 2015 was performed. Exclusion criteria included acute trauma, surgery, neoplastic disease, or infection in the cervical spine. One hundred and seventy-three MRI studies with cervical facet oedema were evaluated by each of the two radiologists. In these patients, the grade of bone marrow oedema (BMO) and corresponding neuroforaminal narrowing at the cervical facets was assessed. Correlation with symptoms was performed based on pre-MRI questionnaire. RESULTS: The prevalence of cervical facet oedema was 9%; the most commonly affected levels were C3-4, C4-5, and C2-3. A total of 202 cervical facets were evaluated: mild BMO was seen in 35%, moderate in 41%, and severe in 24% of cases. Surrounding soft-tissue oedema was observed in 36%, 69%, and 92% of the BMO grades, respectively. The correlations between unilateral radiculopathy and ipsilateral facet BMO grades were 79%, 83%, and 73% (chi-square, p<0.001), respectively. Furthermore, neuroforaminal narrowing on the corresponding level was found in 35%, 38%, and 11% of cases, respectively. At follow-up imaging, facet oedema was most likely to remain unchanged or to decrease. CONCLUSION: The prevalence of cervical facet oedema is 9%. Cervical facet oedema is associated with ipsilateral radiculopathy. Neuroforaminal narrowing, however, is not associated with facet oedema.

Qualitative assessment of studies included in a meta-analysis: DES and the risk of pregnancy loss.

Meta-analysis, the qualitative and quantitative integration of available research information, is increasingly used in clinical research. This report examines the qualitative elements of meta-analysis through critical review of two published examples that assessed the effect of diethylstilboestrol (DES) on miscarriage and neonatal mortality, respectively. Our subjective review showed the internal validity of three of five trials aggregated in the former meta-analysis to be severely compromised. The remaining two trials (data from which were aggregated in the latter meta-analysis), while internally valid, studied different clinical populations. Therefore, pooling of their results may have been clinically inappropriate. In conclusion, meta-analysis involves substantial elements of subjective judgment. Qualitative assessment of studies is of pivotal importance, because the validity of any summary estimate of effect hinges on both the methodologic quality and the combinability of the aggregated studies.