Usefulness of osteosynthesis device made of hydroxyapatite-poly-L-lactide composites in port-access cardiac surgery

Port-access minimally invasive cardiac surgery has been developed with the aim of reducing surgical invasion. We conduct port-access cardiac surgery, generally through an intercostal space. To ensure sufficient visual field, either the upper or lower rib may be divided. In the process of restoration of divided ribs, we have developed a bone fixation technique using a new osteosynthesis device by way of prevention of pseudoarthrosis.

Forty-five consecutive patients underwent right-sided anterior intercostal thoracotomy under the port-access method between July 2006 and July 2007. We used a totally resorbable osteosynthesis device (Super Fixsorb; Takiron Co., Ltd., Osaka, Japan) consisting of a mix of poly-L-lactide (PLLA) and particulate resorbable uncalcined hydroxyapatite (u-HA).

Fixation of the rib-costal cartilage was sufficiently achieved in this manner. No clinical symptoms suggestive of inflammation or infection were identified in the areas corresponding to the site of bone junction, and no patients have suffered pseudoarthrosis perioperatively and up to one year after surgery. Computed tomographic (CT) scanning clearly visualized these devices, and their attachment to the rib surfaces was confirmed in the patient who underwent CT scanning after the longest tested interval of 133 days after surgery.

In this study, the possibility was suggested that the advantages of u-HA/PLLA composite, such as early osteoconductive property and bioactive property, might beneficially affect bone fusion. We conclude that this osteosynthesis device can be applied in various fields, including cardiovascular surgery, and that its use will contribute to improvement of patients' postoperative quality of life.