7 - Twenty-Four-Month Interim Results from a Prospective Clinical Trial Evaluating the Performance and Safety of Cellular Bone Allograft in Patients Undergoing Lumbar Spinal Fusion

Introduction: Autologous bone grafts are the gold standard for spinal fusion, however harvesting autologous bone can result in donor site infection, hematomas, increased operative time, and prolonged pain. Cellular bone allografts (CBAs) are a viable alternative that avoids the need for bone harvesting and may increase fusion success alone or when used as an adjunct material.

Aims/

Objectives: The present study examined the efficacy and safety of CBA when used as an adjunct to lumbar arthrodesis out to 24-months follow-up.

Methods: A prospective multicenter clinical trial (NCT 02969616) was conducted at nine clinical sites across the USA. Subjects undergoing lumbar spinal fusion with CBA (Trinity Elite®) were enrolled that met inclusion/exclusion criteria. Adult subjects (≥18 years) that had failed at least 6 months of conservative care who planned to undergo posterolateral fusion (1–4 levels) or interbody fusion (1–2 levels) and met the predefined inclusion/exclusion criteria were enrolled. Subjects who had had prior lumbar spine fusion surgery at a level currently scheduled for surgery, were undergoing treatment for malignancy or had undergone treatment for malignancy within the last 5 years (benign skin cancer permitted), an active local or systemic infection, or were undergoing adjunctive treatment for local or systemic infection were excluded. Dynamic X-rays (flexion/extension) for QMA were obtained at 3 months, 6 months, and 12 months postoperatively, while CT scans were obtained at 12 months. Clinical outcomes were assessed with the Oswestry Disability Index (ODI), and visual analog scales (VAS) score for back and leg pain. Clinical outcomes were obtained at baseline, 6 weeks, 3 months, 6 months, 12 months and 24 months postoperatively. Adverse events were assessed through the 24-month follow-up. Adverse events were recorded from surgery through 24 months postoperatively for each subject, including the event’s relatedness, severity, and outcome. The presented data represents an analysis of available patients (N = 86) at 24 months.

Results: A total of 86 subjects were analyzed at 24-months. Eighty-six patients completed 24-months post-operative radiographic and clinical evaluations. The mean age was 59.2 ± 11.9 (range 28-82) years and included a higher number of females (n=57, 66.3%) to males (n=29, 33.7%) with a mean body mass index (BMI) of 30.1 ± 6.3 kg/m2 (range 18.9 – 44.6). Successful fusion was achieved in 95.3% of patients undergoing lumbar spinal surgery. Clinical outcomes showed statistically significant improvements from baseline in ODI, VAS-Back pain score, and VAS-Leg pain score outcome measures (p < 0.01). No patient characteristics or surgical factors were associated with pseudoarthrosis. A limited number of adverse events were noted with only three determined to be related to the graft.

Conclusions: The use of CBA as an adjunct graft material results in high rates of successful lumbar arthrodesis. Clinical outcomes demonstrated significant improvements in pain and disability and a positive safety profile was observed.