The incidence and risk factors for femoral head necrosis after femoral neck fracture in pediatric patients: a systematic review and meta-analysis

BACKGROUND: The incidence of avascular necrosis (AVN) after pediatric femoral neck fracture (PFNF) in the literature varies widely, and the risk factors associated with AVN after PFNF are controversial. Therefore, this study aimed to accurately investigate the incidence of AVN after PFNF and systematically evaluate and meta-classify their risk factors. METHODS: A comprehensive search was performed of PubMed, Web of Science, and Embase. The pooled rate and 95% confidence interval (CI) were used to assess the incidence of AVN after PFNF, and pooled odds ratio (OR) were calculated to measure the effect sizes. In addition, we performed subgroup, stratified, and publication bias analyses. RESULTS: A total of 30 articles were included in our meta-analysis, with 303 AVN cases among 1185 patients. The pooled incidence of AVN after PFNF was 22% (95% CI 18%, 27%). Subgroup analyses indicated Delbet type I–IV fracture incidences with AVN of 45%, 32%, 17%, and 12%, respectively. The incidence of AVN after PFNF in Asia was 19%, lower than in Africa at 36%, Europe at 26%, and North America at 23%. In addition, the larger sample size group and the earlier published literature group showed a higher incidence of necrosis. Stratified analyses showed that patient age and Delbet fracture classification were both important factors affecting AVN after PFNF (OR = 1.61, p = 0.02 and OR = 3.02, p < 0.001, respectively), while the time to treatment was not (OR = 0.9, p = 0.71). CONCLUSION: The pooled incidence of AVN after PFNF was ~ 22%; furthermore, the available evidence demonstrates that patient age and Delbet type of fracture were important influencing factors of AVN after PFNF. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13018-023-03502-4.