Research Article, J Spine Neurosurg Vol: 13 Issue: 1

Lumbar Interbody Spinal Fusions Using a Novel Cellular Bone Matrix Allograft

John David Dorchak¹, Miller Gantt², and J. Kenneth Burkus^1*

¹Department of Orthopedic Surgery, Jack Hughston Memorial University Hospital, Phenix City, Alabama, United State of America

²Department of Orthopedic Surgery, Mercer University School of Medicine, Avenue, Columbus, Georgia

*Corresponding Author: J. Kenneth Burkus,
Department of Orthopedic Surgery, Jack Hughston Memorial University Hospital, Phenix City, Alabama, United State of America
E-mail: jkb66@knology.net

Received date: 12 January, 2024, Manuscript No. JSNS-24-124991;

Editor assigned date: 15 January, 2024, PreQC No. JSNS-24-124991 (PQ);

Reviewed date: 29 January, 2024, QC No. JSNS-24-124991;

Revised date: 07 February, 2024, Manuscript No. JSNS-24-124991 (R);

Published date: 14 February, 2024, DOI: 10.4172/2325-9701.1000184

Citation: Dorchak JD, Gantt M, Burkus JK (2024) Lumbar Interbody Spinal Fusions Using a Novel Cellular Bone Matrix Allograft. J Spine Neurosurg 13:1.

Abstract

Keywords

Lumbar interbody fusion; Cellular bone matrix; Cellular allogeneic bone matrix; Cellular bone scaffold; Degenerative lumbar disc disease

Introduction

Spinal fusion surgery is a commonly used procedure for treating degenerative conditions of the lumbar spine [1,2]. Minimally invasive surgical techniques and spinal instrumentation have evolved to restore disc space height and sagittal alignment and provide segmental stabilization of the disc space to facilitate de novo bone growth across the interspace [3]. Successful interbody fusion requires the addition of grafting materials containing osteogenic cells or that provide osteoinductive signals to form bone across the intervertebral interspace. Autologous bone from the iliac crest has been widely used in bone graft procedures because of these osteogenic properties. While Iliac Crest Bone Grafts (ICBG) are effective, they have been associated with a number of complications, including pain and infection at the donor site [4-8]. Alternatives to ICBGs include local bone, allografts, synthetics, recombinant proteins, and bone marrow aspirate. These options are used individually or in combination [9-14].

Allogeneic bone grafts that contain living cells, including Mesenchymal Stem Cells (MSCs), have the potential to implant lineages capable of osteoblastic activity to the surgical fusion site [15-17]. These advanced allografts, known as Cellular Bone Matrices (CBMs), combine the inductivity of a Demineralized Bone Matrix (DBM) with a cellular component of cancellous bone containing MSCs. Through aseptic tissue, processing and advanced cryopreservation techniques, native cells, including MSCs and other osteoprogenitor cells, are retained [18]. This optimized CBM provides a minimum of 750,000 cells per cc within an osteoconductive matrix [13]. This viable tissue matrix provides the three components necessary for osteogenesis and may improve the rates of new bone formation and subsequent fusion in spinal surgeries. These data evaluate the clinical efficacy of an advanced CBM allograft in patients with degenerative lumbar disc disease undergoing Lumbar Interbody Fusion (LIF) surgery.

Materials and Methods

A single investigator reviewed fourteen patients who had been treated at a single site between January 2022 and May 2022. Consecutive patients diagnosed with degenerative lumbar disc disease between L1 and the sacrum were not randomized; all underwent instrumented interbody fusion and received the optimized CBM (VIA Form+, Vivex Biologics, Inc., Atlanta, Georgia) as a stand-alone bone graft replacement when used with an interbody device. This study received IRB approval (HIRB-2023-13).

Stand-alone bone graft substitute

In this clinical study, the optimized CBM was used without any autogenous grafts, including local bone or bone marrow aspirate. The CBM contains three key components that are considered essential for bone formation: An osteoconductive matrix from cancellous bone chips (100-300 μm), an osteoinductive potential achieved from demineralized cortical bone and an endogenous cellular content with potential for osteogenic differentiation [11-14,16]. Through aseptic processing, donor bone is separated into two components: Viable cellrich cancellous bone and cortical bone that is demineralized to accentuate growth factors. Cells attached to cancellous bone chips express markers linked with those identified as mesenchymal stem cells and osteoblasts [19]. These cell-rich grafts are frozen and protected using a proprietary non-DMSO cryoprotectant [18]. This novel processing results in a 92% viability of cells with expanded cells demonstrating osteogenic potential that was confirmed by in vitro assessment of alkaline phosphatase activity [20].

Inclusion criteria

All patients had clinical complaints of low back pain and radiating leg pain that was unresponsive to a minimum of eight weeks of nonoperative treatment that included immobilization, traction, modalities, medications, and physical therapy. In addition to recurrent or persistent complaints of pain, all patients had an objective neurologic deficit that included one or more of the following: An asymmetric deep tendon reflex, a sensory deficit in a dermatomal pattern, or motor weakness. All patients had a correlative neuroradiographic study. Smoking status and the presence of diabetes, osteoporosis, and obesity were recorded for all patients. Patients were not treated surgically if they had a chronic medical condition that required medication, such as steroids or nonsteroidal antiinflammatory medications that could interfere with fusion.

Patients included in this study required plain radiographic findings documenting single or two-level degenerative lumbar disc disease, and they had undergone an additional confirmatory MRI scan. Patients with up to a Grade one spondylolisthesis were also included.

Surgical technique

The CBM was used exclusively as a bone graft replacement. The CBM was placed in the disc space and in the intradiscal implant. Pedicle screws were inserted through a minimally invasive percutaneous technique. Following surgery, all patients were encouraged to ambulate immediately after surgery, and physical activities were advanced at the discretion of the attending surgeon. An external lumbar orthosis was used at the discretion of the attending surgeon.

Patient demographics

Patients with single or two-level degenerative disc disease of the lumbar spine and associated radiculopathy were treated by a Posterior Lumbar Interbody Fusion (PLIF) (fourteen levels) or Extreme Lateral Interbody Fusion (XLIF) (three levels) using a titanium interbody implant, pedicle screw fixation and the advanced CBM allograft bone graft substitute. Patient age, sex, smoking status, and comorbidities were assessed.

Clinical and radiographic follow-up

All patients were examined at three, six, and twelve months; four patients were followed for eighteen months. All clinical outcomes were assessed by the attending physician; however, clinical outcomes were not assessed through patient-derived questionnaires. Neurological physical examination was conducted at each follow-up clinical visit. Neurological success was defined as maintenance or improvement in three objective clinical findings: Sensory, motor, and reflex testing.

Neutral anteroposterior and lateral radiographs were obtained at each visit. Dynamic flexion-extension lateral radiographs were taken at six, twelve, and eighteen months. Sagittal plane angulation was measured on neutral lateral radiographs and determined by Cobb’s criteria. Intradiscal distraction and subsidence were measured by assessing the vertical distance between the midpoints of the adjacent vertebral endplates. Intradiscal motion and implant migration were assessed on dynamic radiographs. All radiographs were reviewed by an independent physician. Successful fusion was defined by three criteria. The first was uninterrupted bridging bone across the instrumented disc space through either the interbody implants or around the implants. At the host bone implant interface, there were no radiolucent lines around more than 50% of either implant. In addition, on dynamic flexion extension radiographs, there was less than 5° of angular motion and less than 3 mm of translation.

Adverse events

All patients were monitored for the presence of adverse events during the surgical procedure and during routine or unanticipated office visits. All complications were documented, including additional surgical procedures, spinal injections, and hospital readmissions.

Results

All patients in the study had a minimum follow-up of 12 months; no patients were lost to follow-up. The fourteen-patient cohort included six females and eight males with an average age of 60 years ranging from 40 to 78 (Table 1). Four patients (4/14; 28%) smoked or used tobacco products; three (3/14; 21%) were obese with a BMI of greater than 30; three (3/14; 21%) were diabetic. The choice of implant was not correlated with comorbidities or the number of levels treated. There were eleven single-level and three 2-level fusions between L1 and L5 (Tables 2 and 3).

Patient Demographics	Male	Female
No. of Patient	8/14 (57%)	6/14 (43%)
Age	40-78 (Average 60)
Smokers	4/14 (28%)
Diabetes	3/14 (21%)
Obesity (BMI>30)	3/14 (21%)
Osteoporosis (T-Score>2.5)	None