Preliminary Results of Bioactive Amniotic Suspension with Allograft for Achieving One and Two-Level Lumbar Interbody Fusion

Abstract

Background: Bone graft material for lumbar fusion was historically autologous bone graft (ABG). In recent years alternatives such as allograft, demineralized bone matrix (DBM), ceramics, and bone morphogenetic protein (BMP) have gained favor, although the complications of these are not fully understood. Bioactive amniotic suspension (BAS) with allograft is a new class of material derived from human amniotic tissue.

Methods: Eligible patients receiving a one or two level lumbar interbody fusion with Nucel, a BAS with allograft, were contacted and scheduled for a mininmim 12 month follow-up visit. Patients were evaluated for fusion using CT's and plain radiographs. Clincal outcomes, including ODI, VAS back and leg were collected, as well as comorbidities including BMI, smoking status, diabetes and previous lumbar surgery.

Results: One-level patients (N=38) were 71.1% female with mean age of 58.4 ± 12.7 and mean BMI of 30.6 ± 6.08. Two-level patients (N=34) were 58.8% female with mean age of 49.3 ±10.9 and mean BMI of 30.1 ± 5.82. Kinematic fusion was achieved in 97.4% of one-level patients and 100% of two-level patients. Baseline comorbidities were present in 89.5% of one-level patients and 88.2% of two-level patients. No adverse events related to BAS were reported in this study.

Conclusion: Fusion status is evaluated with many different biologics and varying methods in the literature. BAS with allograft in this study demonstrated high fusion rates with no complications within a largely comorbid population. Although a small population, BAS with allograft results were encouraging for one and two-level lumbar interbody fusion in this study. Further prospective studies should be conducted to investigate safety and efficacy in a larger population.

Keywords: Bone graft; Nucel; allograft; bioactive amniotic suspension; bone graft alternative; lumbar fusion.

Fig. 1

CT Classification of Spinal Fusion. 0 – No bony ingrowth; 1 – Cranial downgrowth or caudal upgrowth; 2 – Cranial downgrowth and caudal upgrowth but NOT bridging; 3 – Complete bridging trabecular bone fusion; A – No evidence of supplemental fixation failure/no halo seen; B – Evidence of supplemental fixation failure/halo seen.

Fig. 2

Representative example of 2A fusion status

Fig. 3

Representative example of 3A fusion status.

Fig. 4

One-level fusion status.

Fig. 5

Two-level fusion status by patient.

Fig. 6

Two-level fusion status by level.

Fig. 7

One-Level Clinical Outcomes preoperative and postoperative. Error Bars show standard deviation from the mean.

Fig. 8

Two-Level Clinical Outcomes preoperative and postoperative. Error Bars show standard deviation from the mean.