The fate of a macroporous hydroxyapatite cranioplasty four years after implantation: Macroscopical and microscopical findings in a case of recurrent atypical meningioma

Reconstruction of calvarial bone defects can be achieved using autologous bone or a wide range of prosthetic materials [1]. Macroporous hydroxyapatite (MH) has histologically proven its potential osteointegration in animal models [2], [3] and [4]. Recent radiological and clinical data in human subjects are in favour of good osteointegration of MH cranioplasty [5] and [6]. However, the MH implant has weak mechanic stability and is prone to fractures [7]. Furthermore, it is not known how fast and to which extent the implant is ossified in vivo. We report a case with limited ossification of a MH prosthesis four years after implantation