6.23 Finger

In this chapter, we describe our renewed attempts at phalangeal regeneration by applying an osteoinductive biodegradable three-dimensional (3D) copolymer of P(LA-CL) with hydroxyapatite particles, shaped into a human phalanx. By combining a high-performance biodegradable copolymer with periosteum, we sought to achieve a better induction of phalangeal regeneration. Maintenance of joint cartilage after cartilage formation is functionally important. Periosteum has been suggested to play an important role in the regulation of joint cartilage, although the mechanism is not precisely known. An analytical study of the interaction between the periosteum and the joint cartilage in our model was undertaken. Periosteum was attached circumferentially around one half of a phalanx-molded biodegradable copolymer and the regenerative ability of bone between the periosteal and nonperiosteal sides was compared with respect to tissue-forming properties and 3D-maintained shape. Thus, our study was designed from both functional (human phalanx shape) and analytical viewpoints. A basic knowledge and understanding of the developmental processes that occur in phalangeal regeneration are clearly necessary for future clinical applications.