Mid-term results of a less-invasive locking plate fixation method for proximal humeral fractures: a prospective observational study

BACKGROUND The optimal treatment for proximal humeral fractures remains under debate. In this article, we report the mid-term results of patients who underwent the less-invasive implantation of a polyaxial locking plate for displaced proximal humeral fractures. METHODS This study included patients who were treated with a polyaxial locking plate via an anterolateral deltoid split approach from May 2008 to December 2011. We evaluated outcome parameters after a minimum follow-up period of 2.5 years (median 4.5 years, follow-up rate 62 %) including the age- and gender-dependent Constant score, the activities of daily living score, and the visual analog scale for both pain and subjective shoulder function. RESULTS Of the 140 patients who underwent surgery, 114 were included in the follow-up and 71 completed the questionnaire. Fifteen patients (21 %) exhibited 2-fragment fractures, and 56 patients (79 %) exhibited 3- and 4-part fractures. The Constant score improved significantly (4.5 years: 70 ± 21, p < 0.001) between the first two follow-ups (6 weeks: 35 ± 14, 6 months: 56 ± 18, p < 0.001), and also between 6 months and 4.5 years post-surgery. At the final follow-up, the activities of daily living score had not reached pre-fracture levels (before trauma: 27 ± 5, 4.5 years: 20 ± 8, p < 0.001). A multivariate analysis showed that age has a more significant influence on the final outcome than fracture morphology or gender. CONCLUSION Although the less-invasive surgical procedure is a feasible treatment option in proximal humeral fractures with acceptable complications and considerable improvement during the first six months, a lengthy recovery time is required. The majority of our patients did not become pain-free or reach pre-fracture activity levels.