Abstract: BACKGROUND: The incidence of proximal humerus osteoporotic fractures increases year by year. Fracture repair is difficult because of the greatly reduced resistance caused by osteoporosis.  
OBJECTIVE: To investigate the clinical effect of proximal humerus locking plate combined with allogeneic bone transplantation (an effective method of augmentation fixation) in the treatment of proximal humerus osteoporotic fracture.
METHODS:  A total of 50 elderly patients with proximal humerus osteoporotic fracture from December 2013 to November 2018 in the Second Affiliated Hospital of Hebei North University were divided into group A (n=30) and group B (n=20) according to different surgical methods. In group A, proximal humerus locking plate supplemented by allogeneic bone transplantation was used for strengthening fixation, while in group B, proximal humerus locking plate was used alone. The changes of post-operative neck shaft angle, the loss of humeral head height, the time of fracture healing, and the shoulder joint function before and after operation were compared between the two groups, and the complications between the two groups were recorded.  
RESULTS AND CONCLUSION: (1) Compared with group B, group A had no significant reduction in postoperative humeral neck shaft angle compared with normal group (t=5.226, P < 0.001), the loss of humeral head height was significantly reduced (t=2.609, P=0.012), and the healing time of proximal humerus fracture was significantly shortened (t=2.036, P=0.047). (2) Three months after surgery, the scores of pain, function, movement limitation and anatomic reduction in the two groups were all significantly increased compared with those before surgery (t=4.731, 6.707, 4.370, 6.196, P < 0.01), and the scores in the group A were significantly better than those in the group B. The excellent and good rate was 90% (27/30) in group A, significantly higher than 60% (12/20) in group B (χ2=6.294, P=0.012). (3) After a follow-up of three months after surgery, there were no cases of infection due to allogeneic bone transplantation in group A, and two patients experienced transient fever. There were two cases of shoulder joint stiffness, and the complication rate of surgery was 7%. In group B, internal fixation failure occurred in one case, screw penetration occurred in one case, steel plate fracture occurred in one case, and shoulder joint stiffness occurred in three cases. The complication rate was 30%. The incidence of complications in group A was significantly lower than that in group B (χ2=4.861, P=0.027). (4) It is indicated that the method of allogeneic bone transplantation combined with proximal humerus locking plate strengthening fixation can significantly promote the healing of proximal humerus osteoporotic fractures and improve the motor function of shoulder joint, with less complications. The clinical effect is obviously superior to that of using proximal humerus locking plate alone.

Key words: proximal humeral fracture, osteoporosis, allogeneic bone graft, proximal humerus locking plate, collodiaphyseal angle