Renal osteodystrophy in pediatric patients. A systematic review and meta-analysis.

Chronic kidney disease (CKD) in children is associated with significant comorbidities, including mineral and bone disorder (CKD-MBD). A key manifestation of CKD-MBD is renal osteodystrophy (ROD), diagnosed by bone biopsy followed by histomorphometric analysis. In pediatric patients, ROD can lead to bone deformities and impaired growth. However, the limited use of bone biopsy in this population hampers the understanding of ROD patterns and severity. This systematic review and meta-analysis aimed to evaluate histomorphometric findings in children with CKD. We screened 5082 abstracts published up to 2024 and included 28 eligible studies, encompassing 980 bone biopsies from children in different stages of CKD. Significant heterogeneity in nomenclature, abbreviations, and reference units of histomorphometric parameters was observed, despite the ASBMR recommendations. Osteitis fibrosa was the most prevalent type of ROD. Notably, 36% of the studies did not report dynamic parameters. Meta-analyses revealed substantial variability in both histomorphometric and biochemical measures. Meta-regression identified study design, age, sex, and CKD treatment modality as key contributors to heterogeneity in bone structure, formation, and resorption parameters. In conclusion, most children with CKD exhibit some form of ROD. Standardized biopsy protocols and normative histomorphometric references stratified by age and sex are needed to enhance result interpretation and comparability across future studies.