Neurosurgeon Institute of Neuro Innovation Sherman Oaks, California, United States
Introduction: A multicenter postmarket prospective study conducted to examine the effectiveness of the adjunctive use of a pulsed electromagnetic field (PEMF) device on lumbar spine fusion rates in subjects with risk factors for nonunion.
Methods: Patients undergoing lumbar spine fusion with one or more risk factors for nonunion were enrolled from 10 investigator sites. Risk factors for nonunion included multilevel (2 or more levels) fusion, prior lumbar spine fusion, diabetes, osteoporosis, or smoking. Subjects were required to wear the device for 2 hours/day for 6 months. Compliance was measured based on usage data downloaded from the device. The primary outcome measure was fusion status at the 12 month follow-up period using A/P, lateral, and flexion/extension radiographs and CT. ODI, EQ-5D, and VAS Pain (back and leg) were collected as secondary outcome measures.
Results: Out of 142 subjects, 125 (88.0%) were graded as fused (all levels) at the 12 month visit. Subjects with 2+ risk factors for nonunion had an 87.5% fusion rate (n=56/64). In addition to the named risk factors, the majority of subjects were over age 65 (53.5%) and obese (55.6%), and 90.8% had 3 or more levels fused. Subjects’ ODI score improved from a mean of 48.5 at baseline to 26.2 at 12 months (p < 0.0001). Similarly, subjects experienced improved EQ-5D scores from a mean of 0.59 at baseline to 0.76 at 12 months (p < 0.0001). Mean pain scores also improved significantly from baseline to 12 months – from 50.1 to 22.9 (p < 0.0001) and from 25.3 to 16.7 (p < 0.0001) for low back and leg pain, respectively.
Conclusion : The PEMF bone growth stimulator device is a valuable tool to aid in fusion healing, especially in challenging populations. Subjects in this study experienced favorable fusion rates of 88% and significant improvement in patient reported outcomes despite having risk factors and/or complex surgeries.
