Clinical application of costal coaptation pins made of hydroxyapatite and poly-l-lactide composite for posterolateral thoracotomy

Background: Costal coaptation pins made of hydroxyapatite and poly-l-lactide (HA/PLLA) composite are used to prevent slippage of the connected ribs in posterolateral thoracotomy. The objective of this study was to evaluate rib fixation achieved by HA/PLLA costal coaptation pins. Methods: Between September 2005 and January 2006, HA/PLLA costal coaptation pins were used in 106 consecutive patients who underwent posterolateral thoracotomy at the National Cancer Center Hospital, Tokyo, Japan. Among these, 96 patients who were followed for one year were analyzed. Fixation was assessed on chest X-ray at one week, two months, and one year after surgery, and classified into four types: no displacement, vertical displacement, lateral displacement, and combined vertical with lateral displacement. Results: The incidence of displacement at one week, two months, and one year after surgery was 22%, 19%, and 31%, respectively. No severe adverse events leading to the removal of HA/PLLA pins occurred. At one year, the most frequent type of displacement was vertical displacement (15%), which reflected a delay in bone formation. The use of analgesics among patients with different types of displacement was not significantly different (p = 0.97). Conclusions: Based on the results of this study, the fixation of cut ribs with HA/PLLA costal coaptation pins may be less advantageous in posterolateral thoracotomy, as displacement and delay of bone formation appear to occur frequently.