This study examines the effect of adjunctive use of the SpinalStim bone growth stimulator on lumbar fusion rate in high risk subjects who have had lumbar fusion surgery. All participants will wear the bone growth stimulator for a minimum of 2 hours/day for 6 months.

The purpose of this post market prospective study is to examine the effect of the adjunctive use of the Orthofix SpinalStim™ device on lumbar fusion rate in high risk subjects who have undergone lumbar fusion surgery. High risk subjects are those who are currently using nicotine, who are having a multi-level fusion, who have had a prior failed fusion at any lumbar level, who are diabetic or who are osteoporotic. Because this is a post market prospective study, subjects who are enrolled in this study will be identified by the Investigator as needing lumbar fusion surgery and asked if they would like to participate in a study looking at the efficacy of lumbar fusion with adjunctive use of the SpinalStim bone growth simulator. The type of lumbar fusion surgery performed (lateral lumbar interbody fusion [XLIF], posterior lumbar interbody fusion [PLIF], anterior lumbar interbody fusion [ALIF], posterolateral fusion) is up to the Investigator; the subjects in the study must be agreeable to using the bone growth stimulator daily for 6 months post surgery.

Inclusion Criteria:

1. Male or female, ≥ 18 years of age at the time of Informed Consent

2. Requires a lumbar fusion surgery within 30 days of signing Informed Consent.

   a. Surgical approach is according to physician's discretion.

3. Subject has one or more risk factors:

   • Is currently using nicotine
   • multi-level lumbar fusion surgery planned
   • Prior failed fusion at any lumbar level
   • Subject reported diabetes
   • Subject reported osteoporosis

4. Body mass index ≤ 45 kg/m2 at the time of consent.

5. Must have reliable access to an iPhone or an iPad with Wi-Fi access for downloading the free device-specific app (iPhone 5S or higher, iPad, iPad Pro, iPad mini or iTouch using iOS v9.3 or later). When the android version of the mobile app for the SpinalStim becomes available (estimated to be Dec. 2017), subjects who have reliable access to devices using android operating systems will be eligible for study inclusion.

6. Able and willing to complete electronic questionnaires and able to read and understand study instructions in English

7. Able and willing to comply with the study plan and able to understand and sign the study-specific ICF.

Exclusion Criteria:

1. Scoliosis greater than 30 degrees
2. Current alcoholism or drug abuse, and/or any known current addiction to pain medications or medical marijuana
3. Any active malignancy or prior history of malignancy within last 5 years prior to fusion (except basal cell carcinoma of the skin).
4. Any clinically significant finding that places the subject at health risk, impacts the study, or affects completion of the study, in the opinion of the Investigator
5. Any psychiatric illness that prevents subject from completing the assessments accurately, in the opinion of the Investigator
6. Prisoners.

subjects from all over the United States are eligible for enrollment as long as they meet the inclusion/exclusion criteria.

if we decide to share, we will only share deidentified summary data