Pulsed Electromagnetic Field Stimulation Increases Multilevel Cervical Fusion Rates

Kevin T Foley,MD
Alfred C. Shen,MD (5an Bernardino, CA)
Michelle Murphy, LPN (Memphis, TN)

Introduction:

The purpose of this study was to assess the efficacy of pulsed electromagnetic fields (PEMF) as an adjunct to multilevel cervical fusion.

Methods:

The charts and radiographs of 45 patients who underwent multilevel cervical fusion were reviewed. There were 24 anterior fusions, 9 posterior fusions, and 12 combined procedures. Nineteen procedures were two–level, 13 were three–level, 9 were four–level, and 4 were five– level. Allograft was used for anterior procedures and autograft for posterior surgeries. All cases were instrumented. Postoperatively, all patients received PEMF stimulation using an external device for four hours/day for three months. Follow–up radiographs were obtained monthly for the first three months and evaluated for the presence of fusion and hardware failure. Subsequent radiographs were obtained at six months and one year. Fusion was defined as 1) evidence of bony bridging at all levels and 2) no motion on flexion–extension views.

Results:

Radiographic fusion was present at all levels in 43 of the 45 patients (95.6%) with a minimum follow–up period of 12 months. Fusion rates were 91.7% for multilevel ACDF (n=l 2), 66.7% for occipital–cervical fusion (n=3), I 00% for multilevel corpectomy with strut–grafting (n=l 2), 1 00% for combined anterior and posterior fusion (n=l I), and I 00% for multilevel lateral mass plating (n=5).

Conclusions:

We observed a fusion rate of 95.6% in a heterogeneous patient population undergoing multilevel cervical fusion with adjunctive PEMF. Reported fusion rates for similar procedures range as low as 59– 80%. PEMF appears to be a safe and effective adjunct for improving the rate of multilevel cervical fusion. A randomized, prospective clinical trial to definitively assess the efficacy of this treatment modality is currently underway.