Osteonecrosis of the femoral head remains one of the most feared complications after surgical treatment for developmental dysplasia of the hip. A meta-analysis published in 2026 in Frontiers in Pediatrics gathered 16 retrospective studies, totaling 1,631 children and 1,941 hips. AVN was diagnosed in 468 hips. [1]
The value of the work lies primarily in the multivariable analysis, which reduces the number of factors independently associated with risk.
Absence of the Ossification Centre
The absence of the ossification centre was associated with a higher risk of AVN, with an OR of 2.60 and a 95% confidence interval of 1.73–3.91. [1]
However, this data does not prove that it is beneficial to delay reduction until the nucleus appears. The studies are retrospective, and the nucleus can also represent a marker of biological age or different patient characteristics. Therefore, a timing decision cannot be directly derived from this association.
Severity of Dislocation
IHDI III–IV dislocations showed a higher risk of AVN compared to lower grades, with an OR of 2.43. [1]
This is plausible: more severely dislocated hips often require more complex maneuvers and may have greater vascular vulnerability from the outset. Initial severity should therefore also be considered in counseling with the family.
Secondary Procedures
The need for secondary procedures was associated with a higher risk, with an OR of 2.56. [1]
Here too, the causal relationship is not simple. An additional procedure can be a sign of a more difficult hip, a less stable reduction, or a more complex therapeutic pathway. It is not possible to conclude that the procedure itself causes osteonecrosis.
Less Robust Factors
Age, surgical approach, and abduction angle did not emerge with the same consistency in the multivariable analysis. [1]
This does not mean they are irrelevant in individual cases. It only means that, in the available aggregated literature, they do not behave as equally robust independent predictors.
How to Use This Data
In children with more severe dislocations or without an ossification centre, the risk of AVN should be discussed with particular attention. A treatment pathway requiring secondary procedures also identifies a more complex group.
The meta-analysis does not indicate a surgical technique capable of eliminating the risk. Rather, it helps to distinguish what appears to be linked to biology and initial severity from what, with the available data, remains more difficult to isolate.
Limitations
All included studies are retrospective. The diagnostic criteria for osteonecrosis are not uniform, and confounding by severity remains significant: more complex cases also receive more complex treatments. The confidence interval for secondary procedures is also wide. [1]
For now, these results are primarily useful for risk stratification and follow-up, rather than for transforming a single factor into a new therapeutic rule.
Disclaimer
This content is for informational purposes only and does not replace an individual clinical evaluation.
References
[1] Guo Z, Chen X, Dai G, Xue M. Risk factors for avascular necrosis of the femoral head after surgical treatment of developmental dysplasia of the hip in children: a systematic review and meta-analysis. Frontiers in Pediatrics. 2026;14:1811138. doi:10.3389/fped.2026.1811138.
PubMed: https://pubmed.ncbi.nlm.nih.gov/42051953/
Full text: https://pmc.ncbi.nlm.nih.gov/articles/PMC13111955/
