Anatomic locking plates for complex proximal humeral fractures: anatomic neck fractures versus surgical neck fractures.

Abstract

Continued debate exists on the management of displaced 3- or 4-part proximal humeral fractures. Only a few studies have compared the efficacy of proximal humeral locking plates (PHLPs) for treating anatomic neck fractures (ANFs) and surgical neck fractures (SNFs). The medical data of 31 consecutive patients with displaced 4-part proximal humeral fractures treated with PHLPs between May 2013 and April 2015 were reviewed retrospectively. We divided the patients into the ANF and SNF groups and assessed the neck-shaft angle (NSA), sum of the screw tip-articular surface distance, and other parameters postoperatively at 3 days and at 12 months using shoulder radiographs. The Constant-Murley scores were assessed at 3 days, 12 months, and last follow-up. The ANF group had a significantly lower mean age and significantly greater mean operative duration, estimated blood loss, and rate of bone grafting. Full or partial osteonecrosis of the humeral head developed in 7 patients and 1 patient in the ANF and SNF groups, respectively. Screw cutout and/or pullout complications occurred in 8 cases in the ANF group but not in the SNF group. In the ANF group, the values for NSA and the sum of the screw tip-articular surface distance changed significantly from 3 days to 12 months postoperatively. There were no significant correlations among the tested parameters. ANFs resulted in more complications at a younger age than SNFs. ANF treatment using PHLPs is more prone to a decreased NSA and humeral head osteonecrosis and has poorer clinical outcomes than SNF treatment using PHLPs.