High bone union rate using a locking plate for proximal humeral fractures in patients older than 70 years: importance of the medial column.

PURPOSE: This study aimed to evaluate the results of surgical treatment for proximal humeral fractures using a locking plate in patients aged > 70 years.

METHODS

Between September 2010 and March 2018, we retrospectively analyzed the clinical and radiological outcomes of 56 patients aged > 70 years who underwent locking plate fixation for proximal humeral fractures. We analyzed bone union, neck-shaft angle, University of California Los Angeles (UCLA) score, range of motion (compared to that of the opposite side), and complications. Further, clinical and radiological results of unstable medial column fractures were investigated.

RESULTS

Fifty-four patients (96.2%) achieved bone union. The mean time to bone union was 14.7 ± 1.2 weeks, and the mean neck-shaft angle was 126.4° ± 14.2°. The mean UCLA shoulder score was 22.4 ± 6.5. The mean forward flexion, abduction, and external rotation angles were 129.2° ± 19.4°, 112.3° ± 14.8°, and 44.2° ± 18.5°, respectively, with internal rotation to L2/3 (S-T11). The range of motion was significantly different from that in the opposite shoulder motion. Unstable medial column fractures led to a significant loss in the neck-shaft angle compared with fractures with an intact medial cortex.

CONCLUSION

For the surgical treatment of proximal humeral fractures in patients aged > 70 years, using a locking plate helped achieve a high bone union rate with relatively satisfactory results. However, the prevalence of unstable medial column fracture was high. Clinical and radiological outcomes were poor in these patients. Therefore, it is necessary to accurately understand the fracture pattern prior to surgery, and various surgical methods, including conservative treatment, should be considered.