Proximal humeral fractures are a common limb fracture in the elderly, accounting for 4%-9% of total body fractures. Surgical treatment is the preferred treatment for proximal humeral fractures with apparent displacement. The proximal humeral internal fixation locking system for Neer III and IV fractures is relatively mature and practical, but screw cutting and internal fixation failure are still complications. For elderly patients with osteoporosis, although internal fixation materials and surgical techniques have become increasingly complete, there is still a lack of systematic and targeted postoperative rehabilitation programs. The theory of "cantilever-lever reconstruction-instability" indicates that premature postoperative exercise may lead to internal fixation failure, fracture nonunion, and other postoperative complications, so selecting an appropriate rehabilitation program is particularly important.

Based on the cantilever-lever reconstruction-instability theory, this study retrospectively analyzed the efficacy of different rehabilitation programs for elderly patients with proximal humerus fractures after surgery. It explored the most appropriate postoperative rehabilitation concepts and methods for elderly patients.

A retrospective case-control study was conducted on 31 patients who underwent PHILOS plate internal fixation for Neer type III and IV proximal humeral fractures in the Department of Orthopedics of Beijing Longfu Hospital from January 2019 to June 2021. PHFs patients over 60 who met the inclusion criteria were divided into the active group and the immobilization group. Postoperative shoulder function and quality of life were evaluated by Constant-murley scale, disabilities of the arm, shoulder and hand (DASH) , visual analogue scale (VAS) , and quality of life (SF-12) before, 3, and 12 months after surgery, respectively. The neck-shaft angle of the humerus was measured by X-ray 12 months after the operation and compared with the postoperative results to compare the advantages and disadvantages of the two rehabilitation methods.

Among the enrolled patients, 24 were aged (> 60 years) with osteoporosis. There were 15 cases in the active group and 16 in the immobilization group. There was a statistical difference in Constant score improvement between the active and braking groups at 3 and 12 months after surgery (P < 0.001) , and the progress was more evident in the braking group. The length of hospital stay was statistically significant (P =0.016) , and the length of hospital stay was longer in the immobilization group than in the activity group. There were no significant differences between the two groups in DASH, VAS, and SF-12 scores. At 12 months, the neck-shaft angle of the immobilization group (2.8°±0.9°) was less than that of the active group (3.9°±1.1°) .

For PHFs patients over 60 years old, a more conservative postoperative rehabilitation program should be selected, and shoulder range of motion exercise should not be carried out in the early postoperative period, which can not only ensure that the range of motion is not affected but also effectively improve the postoperative Constant score of patients.