Long-term outcomes of metacarpal fractures surgically treated using bioabsorbable plates: a retrospective study

BACKGROUND: Implants made from bioabsorbable unsintered hydroxyapatite and poly-L-lactate composites (u-HA/PLLA) are widely used in the oral, maxillofacial, and orthopedic fields. This study assess the long-term (> 5 years) outcomes of patients with metacarpal fractures who were surgically treated using bioabsorbable plates and screws (Super-Fixsorb MX40 mesh; Teijin Medical Technology, Osaka, Japan). METHODS: A retrospective analysis of six patients with eight metacarpal fractures treated with bioabsorbable plates was done. All patients were followed for more than 5 years post-surgery. The clinical outcomes were evaluated using Q-DASH scores and the grip strength (GS): opposite side ratio. The resorption status of implants was assessed on plain computed tomography (CT) scans at final follow-up appointments. RESULTS: The mean age of the patients at the time of surgery was 29.5 years (16–54), and the median follow-up period was 81.8 months (68–101). All fractures united without displacement after an average of 3.5 months, and there were no implant specific complications associated with the use of absorbable plates. The mean grip strength ratio was 85.1% (56.8–104.5). The mean Q-DASH scores of 11.36 points (0–34.09) was good in all but two patients. We also observed that it took more than 8 years for the plates to be absorbed completely. CONCLUSIONS: This study demonstrates that the process of bioabsorption in metacarpal fractures might be completed in about 8 years, and the absorption speeds were different inside and outside of the bone. The bioabsorbable plates are more cost-effective than metallic implants. The potential for bioabsorbable plates to be used in various clinical procedures is promising. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-020-03841-x.