Single and Multilevel Lumbar Total Disc Replacement Adjacent to L5-S1 ALIF (Lumbar Hybrid): 6 Years of Follow-up.

Background: Single and multilevel lumbar arthroplasty has had excellent results, but the L5-S1 level frequently has pathology that precludes arthroplasty. This study evaluated clinical outcomes and sagittal range of motion (ROM) of operated levels and adjacent motion segments in single- and multiple-level ProDisc-L above a simultaneous L5-S1 fusion (hybrid) after a 2- to 6-year follow-up.

Methods: In this prospective cohort study, 46 patients underwent simultaneous lumbar total disc replacement (TDR) at one to three levels and anterior lumbar interbody fusion (ALIF) at L5-S1.

Multiple-Level Lumbar Total Disk Replacement: A Prospective Clinical and Radiographic Analysis of Motion Preservation at 24-72 Months.

Background: Recent studies demonstrate the efficacy of lumbar arthroplasty using the ProDisc-L. Patients frequently present with multilevel pathology and may be candidates for multilevel disk replacement.

Purpose: To evaluate clinical outcomes and sagittal range of motion of operated levels and adjacent lumbar motion segments in multiple-level ProDisc-L constructs after 2-6 years follow-up.

Radiographic Analysis of the Lumbosacral Juncture: Is There a Critical Sacral Angle for Total Disc Replacement?

Study Design: Retrospective review of a patient cohort through a prospective study.

Purpose: To determine whether there are correlations between radiographic measurements, including sacral slope (SS) and pelvic incidence (PI), and self-reported clinical outcomes among single-level L5/S1 ProDisc-L patients.

Overview Of Literature: The lumbosacral juncture presents unique biomechanical challenges with respect to artificial disc replacement (ADR) because of its orientation and consequential shear loading.

ProDisc-C Total Disc Replacement Versus Anterior Cervical Discectomy and Fusion for Single-Level Symptomatic Cervical Disc Disease: Seven-Year Follow-up of the Prospective Randomized U.S. Food and Drug Administration Investigational Device Exemption Study.

Background: In patients with single-level cervical degenerative disc disease, total disc arthroplasty can relieve radicular pain and preserve functional motion between two vertebrae. We compared the efficacy and safety of cervical total disc arthroplasty with that of anterior cervical discectomy and fusion (ACDF) for the treatment of single-level cervical degenerative disc disease between C3-C4 and C6-C7.

Methods: Two hundred and nine patients at thirteen sites were randomly treated with either total disc arthroplasty with ProDisc-C (n = 103) or with ACDF (n = 106).

The relationship between serum vitamin D levels and spinal fusion success: a quantitative analysis.

Study Design: An in vivo dosing study of vitamin D in a rat posterolateral spinal fusion model with autogenous bone grafting. Rats randomized to 4 levels of vitamin D-adjusted rat chow, longitudinal serum validation, surgeons/observers blinded to dietary conditions, and rats followed prospectively for fusion endpoint.

Objective: To assess the impact of dietary and serum levels of vitamin D on fusion success, consolidation of fusion mass, and biomechanical stiffness after posterolateral spinal fusion procedure.

Health state utility of patients with single-level cervical degenerative disc disease: comparison of anterior cervical discectomy and fusion with cervical disc arthroplasty.

Object: Cost-effectiveness analysis (CEA) of medical interventions has become increasingly relevant to the discussion of optimization of care. The use of utility scales in CEA permits a quantitative assessment of effectiveness of a given intervention. There are no published utility values for degenerative disc disease (DDD) of the cervical spine, anterior cervical discectomy and fusion (ACDF), or cervical disc replacement (CDR).

Bone marrow enhances the performance of rhBMP-2 in spinal fusion: a rodent model.

Background: Reliable and rapid bone formation is the goal of biologics and cell-based spinal fusion technologies. While no cell-based therapy alone has been successful, recombinant human bone morphogenetic protein-2 (rhBMP-2) has been successfully used in a wide spectrum of patients undergoing a variety of spinal fusion procedures since its approval by the United States Food and Drug Administration (FDA) in 2002. However, the question remains how to improve the biologic efficiency, or osteoinductivity, of rhBMP-2 for successful application in the most challenging patients undergoing spinal fusion or to reduce the doses currently required.

Does 360° lumbar spinal fusion improve long-term clinical outcomes after failure of conservative treatment in patients with functionally disabling single-level degenerative lumbar disc disease? Results of 5-year follow-up in 75 postoperative patients.

Background: Surgical treatment of patients with mechanical degenerative disc disease has been controversial, but improvements in clinical outcomes have been shown in properly selected patients with disease-specific diagnoses, with fusion arguably now becoming the "gold standard" for surgical management of these patients. No published study thus far has been designed for prospective enrollment of patients with specific inclusion/exclusion criteria in whom at least 6 months of conservative therapy has failed and who are then offered a standardized surgical procedure and are followed up for 5 years.

Methods: The study group was composed of the patients in the prospective, randomized Food and Drug Administration Investigational Device Exemption trial comparing ProDisc-L (Synthes Spine, West Chester, Pennsylvania) with 360° fusion for the treatment of single-level symptomatic disc degeneration.

Five-year reoperation rates, cervical total disc replacement versus fusion, results of a prospective randomized clinical trial.

Study Design: Prospective randomized clinical trial.

Objective: Determine the reasons for, and rates of, secondary surgical intervention up to 5 years at both the index and adjacent levels in patients treated with cervical total disc replacement (TDR) or anterior cervical discectomy and fusion (ACDF). Patients undergoing TDR received ProDisc-C.

Five-year adjacent-level degenerative changes in patients with single-level disease treated using lumbar total disc replacement with ProDisc-L versus circumferential fusion.

Object: The authors report the 5-year results for radiographically demonstrated adjacent-level degenerative changes from a prospective multicenter study in which patients were randomized to either total disc replacement (TDR) or circumferential fusion for single-level lumbar degenerative disc disease (DDD).

Methods: Two hundred thirty-six patients with single-level lumbar DDD were enrolled and randomly assigned to 2 treatment groups: 161 patients in the TDR group were treated using the ProDisc-L (Synthes Spine, Inc.), and 75 patients were treated with circumferential fusion.

Five-year results of the prospective, randomized, multicenter, Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential arthrodesis for the treatment of single-level degenerative disc disease.

Object: The purpose of this study was to evaluate the long-term safety and effectiveness of the ProDisc-L total disc replacement (TDR) as part of an FDA-mandated postmarket approval study. This report summarizes the clinical findings after 5 years of follow-up.

Methods: Two hundred thirty-six patients were treated and followed up for 5 years; 161 TDRs and 75 fusions had been performed in these patients.

ProDisc-C and anterior cervical discectomy and fusion as surgical treatment for single-level cervical symptomatic degenerative disc disease: five-year results of a Food and Drug Administration study.

Study Design: Randomized controlled trial.

Objective: Analyze the clinical outcomes at 5 years comparing cervical total disc replacement (TDR) with ProDisc-C (Synthes Spine USA Products; LLC, West Chester, PA) with anterior cervical discectomy and fusion (ACDF).

Summary Of Background Data: Previous reports of 2- and 4-year results have shown that ProDisc-C, a TDR for surgical treatment of patients experiencing single-level symptomatic cervical disc disease between C3 and C7, is safe and effective.

Lumbar plexus anatomy within the psoas muscle: implications for the transpsoas lateral approach to the L4-L5 disc.

Background: The transpsoas lateral surgical approach has been advocated as an alternative to direct anterior approaches for less invasive or minimally invasive access to the spine. Postoperative thigh pain, paresthesia, and/or weakness have been described after the use of this surgical approach. The purpose of this cadaveric anatomic study is to provide a description of the lumbar plexus as it relates to the transpsoas lateral surgical approach.

Prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement compared with circumferential arthrodesis for the treatment of two-level lumbar degenerative disc disease: results at twenty-four months.

Background: Disc replacement arthroplasty previously has been shown to be an effective alternative to spine fusion for the treatment of single-level lumbar degenerative disc disease. The purpose of the present study was to determine the twenty-four-month results of a clinical trial of the ProDisc-L total disc replacement as compared with spinal fusion for the treatment of degenerative disc disease at two contiguous vertebral levels from L3 to S1.

Methods: A total of 237 patients were treated in a randomized controlled trial designed as a non-inferiority study for regulatory application purposes.

Spinal fusion in the United States: analysis of trends from 1998 to 2008.

Study Design: Epidemiological study using national administrative data.

Objective: To provide a complete analysis of national trends in spinal fusion from 1998 to 2008 and compare with trends in laminectomy, hip replacement, knee arthroplasty, percutaneous transluminal coronary angioplasty, and coronary artery bypass graft.

Summary Of Background Data: Previous studies have reported a rapid increase in volume of spinal fusions in the United States prior to 2001, but limited reports exist beyond this point, analyzing all spinal fusion procedures collectively.

Variability across ten production lots of a single demineralized bone matrix product.

Background: Demineralized bone matrix is an osteoinductive allograft derived from processed bone that is commonly mixed with autogenous bone in fusion procedures to treat diseases of the spine. An increasing number of demineralized bone matrix-based products are commercially available for spinal fusion procedures, but osteoinductive variability has been found not only across different products but also among production lots from the same demineralized bone matrix formulation. The purpose of this study was to assess the lot-to-lot variability across a single demineralized bone matrix-based product in terms of both extracted bone morphogenetic protein (BMP) concentrations (in vitro) and fusion performance in rats (in vivo).

Results at 24 months from the prospective, randomized, multicenter Investigational Device Exemption trial of ProDisc-C versus anterior cervical discectomy and fusion with 4-year follow-up and continued access patients.

Background: Cervical total disk replacement (TDR) is intended to address pain and preserve motion between vertebral bodies in patients with symptomatic cervical disk disease. Two-year follow-up for the ProDisc-C (Synthes USA Products, LLC, West Chester, Pennsylvania) TDR clinical trial showed non-inferiority versus anterior cervical discectomy and fusion (ACDF), showing superiority in many clinical outcomes. We present the 4-year interim follow-up results.

Cost comparison of patients with 3-level artificial total lumbar disc replacements versus 360° fusion at 3 contiguous lumbar vertebral levels: an analysis of compassionate use at 1 site of the US investigational device exemption clinical trial.

Background: We sought to evaluate the difference between hospital service costs of 2 treatment options for patients diagnosed with 3-level degenerative disc disease (DDD) in the lumbar spine. In this retrospective analysis, itemized billing records of hospital stay for patients with 3-level DDD treated with artificial disc replacement (ADR) were compared with those treated with circumferential fusion (standard of care).

Methods: Sequential 3-level DDD patients treated with either ADR (ProDisc-L; Synthes, West Chester, Pennsylvania) or circumferential fusion during the period from January 2004 to October 2005 were included.

Results of the prospective, randomized, controlled multicenter Food and Drug Administration investigational device exemption study of the ProDisc-C total disc replacement versus anterior discectomy and fusion for the treatment of 1-level symptomatic cervical disc disease.

Background Context: Cervical total disc replacement (TDR) is intended to address radicular pain and preserve functional motion between two vertebral bodies in patients with symptomatic cervical disc disease (SCDD).

Purpose: The purpose of this trial is to compare the safety and efficacy of cervical TDR, ProDisc-C (Synthes Spine Company, L.P.

Access strategies for revision in anterior lumbar surgery.

Study Design: Sixty-two consecutive patients undergoing anterior lumbar revision surgery from February 2000 to September 2007 were evaluated for approach strategies and complications.

Objective: To determine the incidence of complications in these patients and to make recommendations on future revisions based on the results obtained.

Summary Of Background Data: Only 2 articles exist in the literature that address this situation and they have widely varying results in a small number of patients.

Clinical outcomes of the Dynesys dynamic neutralization system: 1-year preliminary results.

Object: In this study the authors present the preliminary clinical outcomes of dynamic stabilization with the Dynesys spinal system as part of a multicenter randomized prospective Food and Drug Administration (FDA) investigational device exemption (IDE) clinical trial.

Methods: This study included 101 patients from six IDE sites (no participants were omitted from the analysis) who underwent dynamic stabilization of the lumbar spine with the Dynesys construct. Patient participation was based on the presence of degenerative spondylolisthesis or retrolisthesis (Grade I), lateral or central spinal stenosis, and their physician's determination that the patient required decompression and instrumented fusion for one or two contiguous spinal levels between L-1 and S-1.

Results of the prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential fusion for the treatment of 1-level degenerative disc disease.

Study Design: A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial.

Objective: To evaluate the safety and effectiveness of the ProDisc-L (Synthes Spine, West Chester, PA) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1.

Summary Of Background Data: As part of the Investigational Device Exemption clinical trial, favorable single center results of lumbar total disc replacement with the ProDisc-L have been reported previously.

An in vitro and in vivo analysis of fibrin glue use to control bone morphogenetic protein diffusion and bone morphogenetic protein-stimulated bone growth.

Background Context: Recombinant human bone morphogenetic protein-2 (rh-BMP2) has become popular for augmenting spine fusion in the lumbar and cervical spine. Concerns exist, however, over bone morphogenetic protein (BMP)-stimulated soft-tissue swelling and bone growth stimulation in areas where bone is not desired, especially as the material "leaks" into such spaces. The most detrimental effects of such leakage might be airway compromise, while heterotopic bone formation into the spinal canal has been reported in animal and human studies.

Intervariability and intravariability of bone morphogenetic proteins in commercially available demineralized bone matrix products.

Study Design: Enzyme-linked immunosorbent assay was used to detect bone morphogenetic proteins (BMPs) 2, 4, and 7 in 9 commercially available ("off the shelf") demineralized bone matrix (DBM) product formulations using 3 different manufacturer's production lots of each DBM formulation.

Objectives: To evaluate and compare the quantity of BMPs among several different DBM formulations (inter-product variability), as well as examine the variability of these proteins in different production lots within the same DBM formulation (intra-product variability).

Summary Of Background Data: DBMs are commonly used to augment available bone graft in spinal fusion procedures.