Assessing Microbiome in Primary Anterior Cervical Fusion Patients

With the introduction of instrumentation, free-flowing bacteria can potentially collect in the biofilm formation. In this context, "free-flowing bacteria" refers to bacteria that are not contained within tissue or biofilm and can circulate in the fluids surrounding surgical implants. These bacteria can potentially colonize the implant and contribute to biofilm formation. As for the culture methodologies, the investigators will be using traditional microbiology cultures, including aerobic and anaerobic cultures, to grow and identify bacteria that are free-flowing and potentially could form biofilms on the implant surfaces. The cultures would be assessed by two different methodologies with the ultimate goal of understanding if the current microbiology methodology fully elucidates the bacterial flora compared to advanced metagenomic methodology. Ultimately, the investigators hope to improve primary surgical outcomes.

• Primary Anterior Cervical Discectomy Procedures (Procedure): Clinical swabs will be taken during the anterior cervical surgery to assess bacterial presence at the surgical site.

Primary outcomes

• Metagenomic sequencing to assess bacterial presence [perioperative]: Metagenomic sequencing will be compared to microbiological cultures

Secondary outcomes

• Visual Analog Scale (VAS) for Neck and Arm Pain [Up to 1 year postoperatively]: Neck pain and arm pain (left and right arms rated separately) will be assessed using a 100 mm Visual Analog Scale (VAS). Scores range from 0 mm (no pain) to 100 mm (worst possible pain). Higher scores indicate more severe pain (a worse outcome).
• Neck Disability Index (NDI) Score [Up to 1 year postoperatively]: The Neck Disability Index (NDI) is a 10-item questionnaire that measures how neck pain affects daily activities. Each item is scored from 0 to 5, and the total score (0 to 50) is expressed as a percentage ranging from 0% (no disability) to 100% (complete disability). Higher scores indicate greater disability (a worse outcome).
• Number of Participants With Radiographic Fusion [Up to 1 year postoperatively]: Fusion status at the operative level(s) will be assessed using standard-of-care postoperative plain radiographs (X-ray) and computed tomography (CT) scans.
• Number of Participants With Radiographic Evidence of Screw Lucency or Loosening [Up to 1 year postoperatively]: Radiographic evidence of lucency (radiolucency) around screws or implant loosening at the operative level(s) will be assessed using standard-of-care postoperative plain radiographs (X-ray) and computed tomography (CT) scans.
• Adverse events [Up to 1 year postoperatively]: To categorize any surgery-related adverse events

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

1. Age between 18 and 80 years.
2. Indicated for primary anterior cervical discectomy and fusion involving one to three contiguous cervical levels.
3. Physically and mentally able and willing to comply with the Protocol, including the ability to read and complete the required forms and willing and able to adhere to the scheduled follow-up visits and requirements of the Protocol.
4. Medically cleared for surgery.
5. Able to understand the study requirements and provide written informed consent.

Exclusion Criteria:

1. Have an active systemic infection or evidence of infection at the operative site.
2. Have a history of or anticipated treatment for active systemic infection, including HIV or hepatitis C.
3. Have congenital bony or spinal cord abnormalities that affect cervical spine stability, including but not limited to congenital fusion anomalies.
4. Have prior trauma to the cervical spine (C3-C7) resulting in significant bony, ligamentous, or spinal cord injury.
5. Have had any prior cervical spine surgery at the operative level.
6. Have had a prior cervical fusion procedure at any level.
7. Have a significantly increased risk of osteoporosis. Screening may include clinical assessment or prior bone mineral density testing. Subjects with a documented dual-energy X-ray absorptiometry (DEXA) T-score ≤ -1.5 within 24 months prior to surgery may be excluded at the discretion of the investigator.
8. Have active malignancy or a history of invasive malignancy, except for non-melanoma skin cancer.
9. Have known allergies to cobalt, chromium, molybdenum, nickel, or polyethylene.
10. Are pregnant or breastfeeding at the time of enrollment, or plan to become pregnant within three years following surgery.
11. Have rheumatoid arthritis, lupus, or other autoimmune diseases affecting the musculoskeletal system.
12. Have a Body Mass Index (BMI) greater than 40 kg/m².
13. Have medical or neurologic conditions that would preclude accurate clinical evaluation or compliance with follow-up (e.g., neuromuscular disorders).
14. Require chronic daily high-dose oral or inhaled corticosteroids or other immunosuppressive therapies.
15. Have a current or recent history (within one year prior to screening) of substance abuse, including alcoholism or narcotic addiction, requiring intervention.
16. Have used another investigational drug or medical device within 30 days prior to surgery.
17. Are taking medications known to interfere with bone or soft-tissue healing, including high-dose corticosteroids, immunosuppressive agents, or chemotherapeutic drugs.
18. Have pending personal litigation related to spinal injury (workers' compensation is not an exclusion).
19. Anticipate relocation greater than 50 miles that may interfere with completion of required follow-up visits.
20. Have mental illness or belong to a vulnerable population (e.g., prisoner or developmentally disabled) that would compromise the ability to provide informed consent or comply with study requirements.
21. Have an uncontrolled seizure disorder.
22. Have a history or evidence of psychosocial disorders that could interfere with accurate completion of self-reported outcome measures or adherence to the protocol.
23. Insulin-dependent diabetes mellitus or other medical conditions that significantly increase surgical risk or impair healing.

• Callanan TC, Abjornson C, DiCarlo E, Henry M, Sama AA, Girardi FP, Schroeder J, Kiely P, Lebl DR, Cammisa FP Jr. Prevalence of Occult Infections in Posterior Instrumented Spinal Fusion. Clin Spine Surg. 2021 Feb 1;34(1):25-31. doi: 10.1097/BSD.0000000000001014. PMID 32453165

• Study Protocol (PDF, 2026-08-15)
• Informed Consent Form (PDF, 2025-10-09)

• Frank P Cammisa, MD, Principal investigator, Hospital for Special Surgery, New York