Reversal of Delayed Union of Anterior Cervical Fusion Treated with Pulsed Electromagnetic Field Stimulation: Case Report

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

STUDY DESIGN

A prospective multicenter clinical trial (NCT03177473) 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/m 2 ; 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.

Effect of pulsed electromagnetic field on mandibular fracture healing: A randomized control trial, (RCT)

INTRODUCTION

Currently, the pulsed electromagnetic field (PEMF) method is utilized for the treatment of nonunion long bone fractures. Considering the established effect of the PEMF on the acceleration of the bone healing process, we conducted this study to evaluate the effect of PEMF on the healing process in mandibular bone fractures.

MATERIAL AND METHODS

This research was a randomized control trial (RCT) study. The sample consisted of patients with a mandibular fracture who were hospitalized in order to receive closed reduction treatment. The participants were randomly selected and then sequentially divided into two groups of 16 participants each (controls = 16, cases = 16). The patients in the control group received conventional therapy without any extra treatment, while the patients in the case group received PEMF therapy in addition to conventional therapy. For the PEMF therapy, patients in the case group received immediate post-surgery PEMF therapy for 6 h. Next, they received 3 h of exposure for the next 6 d, and finally, the same process was repeated for 1.5 h for post-surgery days 8-13. The maxillomandibular fixation (MMF) device was removed at post-surgery week 4. The patients in the control group, however, did not receive any extra treatment. The efficiency of the treatment modalities was evaluated clinically and radiographically. For the radiographical assessment, we employed a direct digital panoramic machine to calculate the computerized density of the bone, and those measurements were used for comparison of the results between the control group and the study patients.

RESULTS

There was no significant difference in the mean bone density values between the two groups (P > 0.05). However, the percentage of changes in bone density of the two groups revealed that the case group had insignificant decreases at post-surgery day 14 and a significant increase at post-surgery day 28 compared with the control group (P < 0.05). After releasing the MMF, a bimanual mobility test of the fractured segments showed the stability of the segments in all patients. In the case group, the mouth opening was significantly more stable than that of the control group (P < 0.05).

CONCLUSION

PEMF therapy postoperatively leads to increased bone density, faster recovery, increased formation of new bone, a further opening of the mouth, and decreased pain.

Pulsed electromagnetic fields enhance BMP-2 dependent osteoblastic differentiation of human mesenchymal stem cells

Mesenchymal stem cells (MSCs) express an osteoblastic phenotype when treated with BMP-2, and BMP-2 is used clinically to induce bone formation although high doses are required. Pulsed electromagnetic fields (PEMF) also promote osteogenesis in vivo, in part through direct action on osteoblasts. We tested the hypothesis that PEMF enhances osteogenesis of MSCs in the presence of an inductive stimulus like BMP-2. Confluent cultures of human MSCs were grown on calcium phosphate disks and were treated with osteogenic media (OM), OM containing 40 ng/mL rhBMP-2, OM + PEMF (8 h/day), or OM + BMP-2 + PEMF. MSCs demonstrated minor increases in alkaline phosphatase (ALP) during 24 days in culture and no change in osteocalcin. OM increased ALP and osteocalcin by day 6, but PEMF had no additional effect at any time. BMP-2 was stimulatory over OM, and PEMF + BMP-2 synergistically increased ALP and osteocalcin. PEMF also enhanced the effects of BMP-2 on PGE2, latent and active TGF-beta1, and osteoprotegerin. Effects of PEMF on BMP-2-treated cells were greatest at days 12 to 20. These results demonstrate that PEMF enhances osteogenic effects of BMP-2 on MSCs cultured on calcium phosphate substrates, suggesting that PEMF will improve MSC response to BMP-2 in vivo in a bone environment.