Adjunctive Use of Bone Growth Stimulation Increases Cervical Spine Fusion Rates in Patients at Risk for Pseudarthrosis

Abstract

Study Design: A prospective multicenter clinical trial (NCT 03177473) was conducted with a retrospective cohort used as a control arm. Objective: The purpose of this study was to evaluate cervical spine fusion rates in subjects with risk factors for pseudarthrosis who received pulsed electromagnetic field (PEMF) treatment. Summary of Background Data: Certain risk factors predispose patients to pseudarthrosis, which is associated with prolonged pain, reduced function, and decreased quality of life. Methods: Subjects in the PEMF group were treated with PEMF for 6 months postoperatively. The primary outcome measure was fusion status at the 12-month follow-up period. Fusion status was determined using anterior/posterior, lateral, and flexion/extension radiographs and computed tomography (without contrast). Results: A total of 213 patients were evaluated (PEMF, n=160; Control, n=53). At baseline, the PEMF group had a higher percentage of subjects who used nicotine (P=0.01), had osteoporosis (P<0.05), multi-level disease (P<0.0001), and were >65 years of age (P=0.01). The PEMF group showed over two-fold higher percentage of subjects that had ≥3 risk factors (n=92/160, 57.5%) compared with the control group (n=14/53, 26.4%). At the 12-month follow-up, the PEMF group demonstrated significantly higher fusion rates compared with the control (90.0% vs. 60.4%, P<0.05). A statistically significant improvement in fusion rate was observed in PEMF subjects with multi-level surgery (P<0.0001) and high BMI (>30 kg/m2; P=0.0021) when compared with the control group. No significant safety concerns were observed. Conclusions: Adjunctive use of PEMF stimulation provides significant improvements in cervical spine fusion rates in subjects having risk factors for pseudarthrosis. When compared with control subjects that did not use PEMF stimulation, treated subjects showed improved fusion outcomes despite being older, having more risk factors for pseudarthrosis, and undergoing more complex surgeries.