Treating Pathological Metastatic Fractures of the Humerus by Compound Osteosynthesis: A Retrospective Cohort Study

Background:The number of malignant tumors is increasing as are bone metastases, such as those in the humerus. Arm function is important for an independent everyday life. In this study, compound osteosynthesis of metastatic fractures of the humerus is examined for its suitability in light of the competing risk of death. Methods:This retrospective monocentric study includes a cohort of tumor patients who underwent primary compound osteosynthesis for pathological humeral fractures. The main endpoint was the continued existence of compound osteosynthesis using competing risk analysis to contrast failure and death. Failure was defined as mechanical failure of the osteosynthesis construct like refracture or plate-and-screw dislocation or loosening, which provides an indication for reintervention. Other complications are also described. Results:We included 36 consecutive patients (64% male, mean age: 71.6 yr) from September 2007 to October 2020. In 58% of the cases, the left humerus was fractured. Lung carcinoma was the most common cause of bone metastases (27.8%). Compound osteosynthesis was performed with a median delay of 5 days after diagnosis of the pathologic fracture. Postoperative complications occurred in 7 of the 36 patients (19.4%): radial nerve palsy (n = 3), postoperative hematoma (n = 2), refracture (n = 2), and screw loosening (n = 1). Few mechanical failures (8.3%) occurred within the first year; only 1 patient needed revision of the osteosynthesis (2.8%). Median patient survival after compound osteosynthesis was 26.6 weeks. Competing risk analysis showed that for up to 2 years, the risk of death is clearly dominant over the risk of osteosynthesis failure from surgery. Conclusion:Our study shows that compound osteosynthesis of the humerus is a suitable option for patients with pathologic humerus fractures. Compound osteosynthesis of the humerus usually survives the duration of malignant tumor disease.