The medial cortical ratio as a risk factor for failure after surgical fixation of proximal humerus fractures in elderly patients

OBJECTIVES: This study aims to investigate whether the medial cortical ratio (MCR) is associated with fixation failure in patients undergoing plate-screw fixation due to proximal humeral fracture. PATIENTS AND METHODS: Between May 2011 and October 2020, a total of 93 patients (25 males, 68 females; mean age: 74.2±5.3 years; range, 65 to 92 years) who were operated for a proximal humeral fracture were retrospectively analyzed. The patients were divided into two groups during follow-up: patients with fixation failure (n=18) and patients with intact fixation (n=75). After radiological analysis, the MCR and fracture type were recorded. The effects of MCR and fracture type on the development of failure were evaluated. RESULTS: The mean follow-up was 41.3±4.7 (range, 18 to 66) months. There was no significant correlation between fixation failure and MCR in either group (p=0.535). However, the risk of fixation failure increased by seven-fold in patients with MCR greater than 0.09 compared to the other patients. In addition, the fracture type was significantly more severe in the failed fixation group than the intact fixation group (p<0.001). CONCLUSION: Surgical treatment of proximal humeral fractures in elderly patients still remains a challenge for surgeons due to the high failure rate. In elderly patients scheduled for surgery to treat a proximal humerus fracture, a reverse shoulder arthroplasty may be a reasonable choice to avoid reoperation due to fixation failure in elderly with three-part or more fragmented fractures and high MCR.