Bioabsorbable screws in the healing of experimentally induced fractures of the proximal sesamoid bone in horses

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">This study evaluated the efficacy of bioabsorbable polylactic acid implants in internal fixation of induced fractures of the proximal sesamoid bone in horses. Eight horses underwent osteosynthesis; four received bioabsorbable implants (group GI) and other four received metallic implants (group GII). Fractures were experimentally induced by means of osteotomy on the midportion of the lateral proximal sesamoid bone. Subsequently, the fragments were fixed with screws and the horses were x-rayed and a fiberglass cast was placed (D0). The cast was removed for radiographic examination on the 30th postoperative day (D30), with radiographic follow up on the 60th (D60), 90th (D90) and 120th (D120) days. Radiographs taken on D30 showed radiodense filling of the fracture site; however, horses from group GII had a less dense fracture line; clinical and radiographic analysis showed a better fracture filling in group GI when compared to Group GII. On D120 radiographic examination revealed radiodense filling of the fracture site in both groups, indicating almost complete fracture healing. However, sclerotic spots were observed around the bioabsorbable implant in GI; on physical examination, horses from group GI were not lame, while horses from group GII had reduced flexion of the metacarpo-phalangeal joint and grade I lameness.