Open reduction and internal fixation of three- and four-part proximal humeral fractures by intra-focal distraction: observational study of twenty five cases.

Purpose: Reduction and fixation of proximal humerus fracture (PHF) by intra-focal distraction with a cemented device is seldom used. A cementless stem called JUST was developed to simplify and standardise reduction and fixation of three- or four-part fractures (3-/4-PFs). This study is designed to evaluate the performances of this device. In addition, we compared the results to those of a previous study based on cemented stems.

Method: Twenty-five patients underwent surgery between 2009 and 2011: ten 3-PFs and 15 4-PFs, with a median age of 65.5 and 71 years, respectively. The reduction and fixation device comprises a staple placed in the humeral head and a cementless stem impacted in the diaphysis that works like a jack. Median follow-up was 28 months.

Results: For the ten 3-PFs, the median raw and weighted Constant score were 66.5 and 86, respectively. Only one case presented with secondary displacement. All fractures healed and there was only one case of avascular necrosis. For the 15 4-PFs, the median raw and weighted Constant score were 64 and 76, respectively. Only one case of secondary cephalic displacement was observed and no cases of tuberosity displacement were observed. All fractures healed except for one case of pseudarthrosis of the lesser tuberosity. Five cases of avascular necrosis were observed.

Conclusions: This device resolves the mechanical difficulties relating to fixation of 3- and 4-PFs by providing stable fixation but does not prevent the risk of avascular necrosis. The cementless stem is more convenient but does not yield better results than the cemented stem.