Comparison of variable and fixed angle proximal humeral locking plates for the treatment of displaced proximal humerus fractures.

Abstract

Controversy surrounds the optimal surgical management of proximal humerus fractures (PHFs). The aim of this study was to evaluate and compare the anatomic and clinical outcomes of open reduction internal fixation (ORIF) of PHFs using FA or VA locking plates. This was a retrospective study of 85 patients (19 male, mean age 60.5 ± 14 years) with displaced surgical neck PHFs treated with VA (44 patients) or FA (41 patients) locking plates. Inclusion criteria were a minimum of 1 year postoperative follow up (mean 3.1 years) or earlier revision surgery. Outcome measures included active range of motion, American Shoulder and Elbow Surgeons (ASES) score, Oxford Shoulder Score (OSS), Single Assessment Numeric Evaluation (SANE), EuroQol-5D (EQ-5D), Visual Analog Scale Pain score (VAS pain) and radiographic assessments of reduction quality, screw position, avascular necrosis (AVN) and failure of fixation. The initial reduction was anatomic in 47 (55 %), acceptable in 29 (34 %), and malreduced in 9 (11 %). 69 (81 %) met inclusion criteria with no differences in reduction quality between the VA and FA plates (p=.16). VA plating was associated with significantly greater plate height compared to FA plating (B = 4.94; p<.001). Additionally, VA plating was associated with better calcar screw placement in terms of both shorter calcar distance (difference in means =1.8 mm, p=.009) and head distance (difference in means=2.4 mm, p=.007). Reoperation was required in 15 (22 %) patients while AVN occurred in 13 (19 %) patients. Neither reoperation nor AVN differed by plate type (p=.75 and p=.99, respectively). Finally, there were no significant differences in PROMs or ROM at final follow up between groups (difference in mean ASES: 1.1, p=.69; OSS: 1.4, p=.76; SANE: 6.5, p=.07; VAS Pain: 0.1, p=.35; EQ-5D: 0.02, p=.68; Active Forward Flexion: 2.3 degrees, p=.77; Active External Rotation: 6.7 degrees; Active Internal Rotation: 0.8, p=.55). ORIF of PHFs with VA locking plates yields comparable outcomes to FA plates while facilitating plate positioning and calcar screw placement. Optimizing fracture reduction and fixation when performing ORIF of displaced PHFs is crucial to reducing the incidence of AVN and reoperation. Level III, Comparative Cohort Series, Treatment Study.