The Impact of Reduction on Survivorship and Outcomes Following Locked Plate Fixation of Proximal Humerus Fractures.

Objectives: To evaluate outcomes of proximal humerus fractures (PHFs) treated with locked plating constructs and assess association between fracture reduction and outcome.

Design: Retrospective cohort study.

Setting: Academic tertiary care hospital and affiliated Level 1 Trauma Center.

Patient selection criteria: All patients treated with proximal humerus locked plating (PHLP) for PHFs (OTA/AO 11A/B/C) by three fellowship-trained orthopaedic traumatologists from 2008-2020 were screened. Patients were excluded for <12-month follow-up, lack of preoperative radiographic imaging, segmental fracture, isolated tuberosity fracture, humeral nailing, and revision surgery as initial procedure at the study institution.

Outcome measurements and comparisons: Fracture pattern, reduction, fixation characteristics, and failure were radiographically evaluated. Functional outcomes were assessed using range of motion, ASES score, QuickDASH, Constant score, and SF-12. Survivorship was calculated using the Kaplan-Meier method. Association of variables with failure was assessed.

Methods: Among 153 patients treated for PHFs with PHLP, there were 23 OTA/AO A-type, 40 B-type, and 90 C-type fractures. Mean follow-up was 66 months and mean age 59±15 years (68% female). Mean postoperative coronal alignment was 135°, 91% were fixed within 120-150°, and 53% within 130-140°. Sagittal reduction was neutral in 94%. Medial column restoration was achieved in 80%. Survivorship free from revision surgery was 89% at 5-years. Reduction with coronal alignment outside all neutral reduction ranges (120-150°, 125-145°, 130-140°) and sagittal alignment outside neutral were associated with both radiographic failure and revision surgery (p<.05). Preoperative factors associated with failure included female-sex, number of fragments, head-split, fracture-dislocation, valgus coronal alignment, and medial calcar displacement (p<.05). Functional outcomes included overall mean ASES of 81±21, QuickDASH 16±19, Constant 80±18, SF-12 Physical 50±9, SF-12 Mental 53±8, active forward flexion 145±33°, active abduction 140±35°, active external rotation 73±24°.

Conclusions: Proximal humerus locked plating demonstrated a survivorship free from revision surgery of 89% free at 5-years and favorable functional outcomes including mean Constant scores of 80. Fracture reduction was associated with outcome. Reduction with coronal and sagittal alignment outside of neutral were associated with radiographic failure and revision surgery. These findings highlight that favorable functional outcomes can be achieved with restoration of the proximal humerus anatomy.

Level of evidence: Level IV case series.