[Postoperative outcome of 30 patients with navicular bone fractures-In connection with AOFAS-Score, SF-12 and fracture classifications].

Background: Fractures of the navicular bone are rare and the number of those treated surgically is even smaller. Moreover, scientific analyses on this topic are only sporadically present in the literature, therefore this retrospective and monocentric study was initiated.

Methods: A total of 30 patients with 30 fractures were included. With the exception of one primary fusion, all patients underwent open reduction with internal osteosynthesis. Clinical and radiological follow-up was performed at least 2 years postoperatively using AOFAS-Score, SF-12 and a radiological examination. The primary objectives were the clinical and radiologic outcomes as mid-term to long-term outcomes. The secondary objective was to compare these results with two existing computed tomography (CT) fracture classifications in terms of their association with the outcome.

Results: The median follow-up was 7.8 years (range 2-16.2 years) postoperatively. One patient suffered an infection, four patients required secondary arthrodesis and eight patients had to change their occupation. The mean AOFAS-Score was 80.8/100 and the mean physical and mental SF-12 component summary scores were 47.1 and 55.7 points, respectively. Male sex and arthrodesis were associated with worse outcomes in both scores but not patient age or ipsilateral concomitant injuries. Both CT fracture classifications showed low predictive value.

Conclusion: The severity of the injury in the preoperative CT showed no connection with the clinical outcome in the AOFAS-Score and SF-12 scores. Posttraumatic osteoarthritis and secondary arthrodesis are associated with a poor outcome. In the course of the observational period the reduction results improved, which was accompanied by a better clinical outcome.