Background The purpose of otomicrosurgery in modern times is to achieve complete removal of disease, which is the basis for hearing rehabilitation. Artificial ossicles are important for hearing rehabilitation. One of the materials is hydroxyapatite that acts as ossicular replacement prosthesis (HA prosthesis, PORP & TORP) and is commonly used as substitute bone in clinics. Although HA prostheses feature good biocompatibility, stability and certain resistance to infection, the structure of the material can be decomposed and absorbed. Based upon animal experiments and clinical application, this article explores the infectivity of HA prostheses and influencing factors. Materials and Methods HA prostheses were implanted in the bulla in guinea pigs. Infected HA prostheses were examined under a scanning electron microscope. Ninety patients implanted with HA prostheses were followed for more than 3 months. Five cases that had undergone revision operations were reported. Results Scanning electronic microscopy showed that the normal compact structures had disappeared and become loose in infected HA prostheses, with their micropores infiltrated with effusion, fibrous tissue and inflammatory cells. As a result, the normal ceramic structure was decomposed and the micropores structure disappeared. The infected mesotympanum in the reported cases also led to HA infection. The shape and structure of bone were destroyed, which was visible by visual examination and light microscopy. The process of cholesteatoma recurrence was always associated with infection, although the HA prosthesis was sometimes spared. Conclusion While HA prosthesis is anti-infective to some extent, long-term infection and cholesteatoma recurrence can lead to destruction and decomposition of HA prostheses. Long-term infected middle ear cavity, dysfunctional Eustachian tube, residual and recurrent cholesteatoma and other factors can cause decomposition of HA prosthesis and result in hearing loss. Background The purpose of otomicrosurgery in modern times is to achieve complete removal of disease, which is the basis for hearing rehabilitation. Artificial ossicles are important for hearing rehabilitation. One of the materials is hydroxyapatite that acts as ossicular replacement prosthesis (HA prosthesis, PORP & TORP) and is commonly used as substitute bone in clinics. Although HA prostheses feature good biocompatibility, stability and certain resistance to infection, the structure of the material can be decomposed and absorbed. Based upon animal experiments and clinical application, this article explores the infectivity of HA prostheses and influencing factors. Materials and Methods HA prostheses were implanted in the bulla in guinea pigs. Infected HA prostheses were examined under a scanning electron microscope. Nine cases patients implanted with HA prostheses were followed for more than 3 months. Five cases that had undergone revision operations were reported. Results Scanning elect ronic microscopy showed that the normal compact structures had disappeared and become loose in infected HA prostheses, with their micropores infiltrated with effusion, fibrous tissue and inflammatory cells. As a result, the normal ceramic structure was decomposed and the micropores structure disappeared. The infected mesotympanum in the reported cases also led to HA infection. The shape and structure of bone were destroyed, which was visible by visual examination and light microscopy. The process of cholesteatoma recurrence was always associated with infection, although the HA prosthesis was sometimes spared. Conclusion While HA prosthesis is anti-infective to some extent, long-term infection and cholesteatoma recurrence can lead to destruction and decomposition of HA prostheses. Long-term infected middle ear cavity, dysfunctional Eustachian tube, residual and recurrent cholesteatoma and other factors can cause decomposition of HA prosthesis and result in hearing loss.