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.