[Advances in application of hydrogels for treatment of osteonecrosis of the femoral head].

Objective: To summarize recent research advances of hydrogels for the treatment of osteonecrosis of the femoral head (ONFH). Methods: The literature on hydrogels for treatment of ONFH at home and abroad in recent years was extensively reviewed, and the fundamental research and clinical application were summarized and analyzed. Results: In the field of fundamental research, functionalized hydrogels (including thermosensitive, oxygen-controlled release, and ion-doped types) demonstrate significant advantages in achieving targeted delivery, controlled release, and microenvironment regulation. Particularly, the development of novel material systems, such as composite scaffold systems, gene-activated hydrogels, and engineered exosomes, has further enhanced treatment precision and biological efficacy. In terms of clinical application, the materials like recombinant human fibroblast growth factor 2 (rhFGF-2) gelatin hydrogels have been validated in multiple trials, showing promising joint preservation rates and bone regeneration capabilities. This opens a promising new clinical pathway for hip-preserving treatment of ONFH. Among these, hydrogel-based multilevel composite scaffolds represent the most promising materials for clinical translation. Conclusion: Hydrogel systems, by synergistically regulating osteogenesis, angiogenesis, and immunomodulation, and leveraging the unique advantages of functionalized materials in precise drug control and microenvironment regulation, have evolved into advanced platforms for the comprehensive treatment of ONFH. Among them, rhFGF-2 gelatin hydrogels, with their remarkable clinical efficacy, offer a new strategy of significant translational value for hip-preserving therapy.