Allografts are not necessary for displaced proximal humeral fractures in patients less than 65 years old, a retrospective cohort study

Displaced proximal humeral fractures (PHF) are frequently treated with locking plates to achieve osteosynthesis. Bone grafts are used as augmentation techniques to improve stability in osteoporotic patients. However, there has been little research into whether bone grafts are necessary for patients younger than 65 years old. This study compared radiographic and clinical outcomes between PHFs augmented with bone grafts or not in a younger population.Between January 2016 and June 2020, 91 patients treated with a locking plate alone (LP), and 101 patients treated with locking plates augmented with bone grafts (BG) were analyzed. Potential confounding factors for outcomes were adjusted by propensity score-matching analyses. For the retrospective cohort study, 62 patients from each group were evaluated for radiographic outcomes and clinical outcomes and compared.Sixth-two patients in each group, both with a mean age of 52 years old, were with a mean follow-up time of 25 months in the LP group and 26 months in the BG group. There was no difference in demographic or surgical characteristics between the two groups after propensity score-matching. With regard to radiographic outcomes, the changes in neck-shaft angle (-5.1 ± 4.9 vs. -3.1 ± 5.3, p = 0.015) and humeral head height (-1.5 ± 2.5 vs. -0.4 ± 2.7, p = 0.002) were more obvious in the BG group. However, regarding functional outcomes, there were no significant differences between the two groups in DASH score, Constant-Murley score, or VAS score. Moreover, the complication rate was not significantly different between two groups.Allografts only provide minor improvements of stability in radiography for patients less than 65 years old after locking plate fixation of PHFs, but don't improve shoulder function, relieve pain or reduce complications. We concluded that allografts are unnecessary for younger patients with displaced PHFs.