97 - Electrical Stimulation Used as an Adjunct to Cervical Spine Fusion in Patients at Risk for Pseudarthrosis

Introduction: Prior studies show that pulsed electromagnetic field (PEMF) stimulation promotes bone healing and can be a valuable tool to help overcome biological deficiencies in patients at risk. The current study further evaluates the adjunct effect of PEMF in subjects undergoing cervical spinal surgery presenting with risk factors for pseudarthrosis.
Aims/

Objectives: The present study examined the efficacy and safety of PEMF when used as an adjunct to cervical arthrodesis out to 12-months follow-up.

Methods: A prospective multicenter clinical trial (NCT 03177473) was conducted at eleven clinical sites across the USA. Subjects undergoing cervical spinal fusion surgery with one or more risk factors for pseudarthrosis were identified for enrollment. Risk factors for pseudarthrosis included multilevel (2 or more levels) fusion, prior failed cervical spine fusion, diabetes, osteoporosis, or smoking. Subjects undergoing cervical spinal fusion were required to wear the PEMF device for 4 hours/day for 6 months post-op. The primary outcome measure was fusion status at the 12-month follow-up period. Fusion status was determined at the 12-month visit using anterior/posterior, lateral, and flexion/extension radiographs and computed tomography (without contrast). Patient reported outcomes including Neck Disability Index (NDI), quality of life (EQ5D), well-being (SF-36) and visual analog scale for pain (VAS pain for neck and arm) were collected as secondary outcome measures.

Results: Out of 160 subjects, 144 (90.0%) were graded as fused (all levels) at the 12-month visit. Over half of the subjects (55.6%) had 2 or more risk factors for pseudarthrosis. Fusion success was 91.7% (n=55/60) for subjects with a single risk factor, 89.0% (n=89/100) for subjects with 2 or more risk factors and 90.9% (n=20/22) for subjects with 3 or more risk factors. Significant improvements in NDI, VAS-arm and VAS-neck were observed compared to baseline scores (p < 0.001) along with improvements in SF-36 and EQ-5D (p < 0.001). A compliance rate of 85.0% (SD 24.1) was observed at 3-months and 78.3% (SD 26.2) at 6-months in subjects who had successful cervical fusion. A total of 715 AEs were reported with the majority of AEs considered mild (n=451, 63.1%) and unexpected (n=568, 79.4%). A total of 69 AEs (9.7%) were serious (S), and two SAEs, considered unrelated to the device, led to study discontinuation.

Conclusions: 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 90% and significant improvement in patient reported outcomes despite having elevated comorbidity and/or complex surgeries.