Proximal humerus fracture combined with humeral shaft fracture is a particular type of fracture in middle-aged and older adults. It has an extensive fracture range, great surgical difficulty, and perioperative complications, which is a great challenge to postoperative rehabilitation and the functional prognosis of patients. The long PHILOS plate and the MultiLoc intramedullary nail are the surgical methods for treating proximal humeral fracture with the humeral shaft in recent years. They have different advantages and characteristics. The former is reliable, less invasive, and does not hurt the rotator cuff. At the same time, the latter is a micro-motion internal fixation, which is conducive to early functional exercise after surgery. There is limited experience in treating proximal humeral fracture with the humeral shaft, and there is a lack of systematic comparison of different internal fixation methods. It is unclear that the best internal fixation method for middle-aged and elderly patients with the proximal humeral fracture combined with the humeral shaft is still unclear.

To compare the safety, efficacy, and functional outcome of long PHILOS plate and long MultiLoc intramedullary nail in middle-aged and elderly patients with proximal humerus fractures combined with humeral shaft fractures.

This is a prospective cohort study. Middle-aged and elderly patients with proximal humeral fracture combined with humeral shaft fracture admitted into our department from June 2017 to August 2019 were enrolled in the study. According to the inclusive criteria, they were divided into the plate group (long PHILOS plate) and the intramedullary nail group (long MultiLoc intramedullary nail) . The perioperative indicators, complications, fracture healing time, humeral neck-shaft angle, and VAS score were compared between the two groups. The Constant-Murley score, Mayo elbow performance score (MEPS) , range of motion (ROM) , and positive rate of rotator cuff resistance test were analyzed. The endpoint of follow-up was one year after surgery.

The mean follow-up was (12.4±2.5) months in the plate group (n=16) and (12.7±1.9) months in the intramedullary nail group (n=14) . The length of hospital stay (P=0.045) , intraoperative blood loss (P=0.002) , and operation time (P=0.036) in the intramedullary nail group were lower than those in the plate group. There were no significant differences in fracture healing time, VAS score, humeral neck-shaft angle, Constant shoulder score, MEPS elbow score, and rotator cuff resistance test positive rate at one-year follow-up between the two groups (P>0.05) . The shoulder abduction angle in the intramedullary nail group was significantly higher than in the plate group (P=0.033) .

For middle-aged and elderly patients, the two types of internal fixation have the same effect on fracture healing after proximal humeral fracture. However, the intramedullary nail has higher perioperative safety, faster early postoperative recovery, and a more comprehensive prognosis range of shoulder ROM, which is more suitable for elderly patients.