Comparison between the spatial subchondral support plate and the proximal humeral locking plate in the treatment of unstable proximal humeral fractures.

PURPOSE: The aim of our study was to evaluate the effect of the S3 (spatial subchondral support) humeral plate and to compare the clinical outcomes and complications after ORIF (open reduction and internal fixation) of proximal humeral fractures using either a S3 plate or a PHLP (proximal humeral locking plate).

METHODS: A total of 144 patients with displaced unstable proximal humeral fractures were treated with either a S3 plate or a PHLP. Each patient had a follow-up at least for one year. We retrospectively collected the data and compared the shoulder functional outcome as well as complications of these two methods.

RESULTS: During the one-year follow-up, the average Constant scores gradually improved for both groups. Patients treated with use of an S3 plate had better functional results at three and six months (P < 0.05). The one-year Constant score for all fracture types (Neer classified) were not significantly different between the S3 and PHLP group (P > 0.05). The complication rate was comparable between the two groups (P > 0.05).

CONCLUSIONS: The treatment using an S3 plate for displaced unstable proximal humeral fractures resulted in a good union rate and functional outcome, which is comparable to the PHLP treatment. The S3 humerus plate can be considered as an effective implant for ORIF of displaced unstable proximal humeral fractures.