Enhanced bioactivity of a poly(propylene fumarate) bone graft substitute by augmentation with nano-hydroxyapatite.

The bioactivity of a nano-hydroxyapatite-augmented, bioresorbable bone graft substitute made from the unsaturated polyester, poly(propylene fumarate), was analyzed by evaluating biocompatibility and osteointegration of implants placed into a rat tibial defect. Three groups of eight animals each were evaluated by grouting bone graft substitutes into 3-mm holes that were made into the anteromedial tibial metaphysis of rats. Thus, a total of 24 animals was included in this study.

Composite resorbable polymer/hydroxylapatite composite screws for fixation of osteochondral osteotomies.

The aim of this study was to evaluate biomechanically the healing of an osteochondral fragment created in the distal sheep femur in response to fixation with a resorbable composite screw made of polylactide and hydroxylapatite. Pure poly(L-lactide) screws were used for comparison. At follow-up times of 4 or 8 weeks, specimens were examined with standard radiography, biomechanics, and histology.

Porous poly(propylene fumarate) foam coating of orthotopic cortical bone grafts for improved osteoconduction.

A porous biodegradable scaffold coating for perforated and demineralized cortical bone allografts could maintain immediate structural recovery and subsequently allow normal healing and remodeling by promoting bony ingrowth and avoiding accelerated graft resorption. This new type of osteoconductive surface modification should improve allograft incorporation by promoting new bone growth throughout the biodegradable scaffold, hence encasing the graft with the recipient's own bone. We investigated the feasibility of augmenting orthotopically transplanted cortical bone grafts with osteoconductive biodegradable polymeric scaffold coatings.

Composite poly(lactide)/hydroxylapatite screws for fixation of osteochondral osteotomies. A morphometric, histologic and radiographic study in sheep.

The aim of this study was to evaluate the healing of an osteochondral fragment created in the distal sheep femur in response to fixation with a biodegradable polylactide/hydroxylapatite composite screw. Poly(L-lactide) screws were used for comparison. At follow-up times of 4 and 8 weeks, the specimens were examined with standard radiography and computed tomography, as well as with macro- and micro-histomorphometry.

Healing of osteochondral osteotomies after fixation with a hydroxyapatite-buffered polylactide. A histomorphometric and radiographic study in rabbits.

The tissue response of subchondral bone to a biodegradable fixation device manufactured in the shape of a screw and made of polylactide with a hydroxyapatite buffer were implanted through the articular surface of the intercondylar portion of the distal rabbit femur. One screw was implanted per animal. The screws had a core diameter of 3.