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.

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.

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.

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.

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.

Controlling bone morphogenetic protein diffusion and bone morphogenetic protein-stimulated bone growth using fibrin glue.

Study Design: An in vitro and in vivo study.

Objective: To evaluate the ability of fibrin glue to limit diffusion of recombinant human bone morphogenetic protein (rhBMP)-2 and its ability to protect spinal nerves from rhBMP-2 stimulated bone growth.

Summary Of Background Data: Studies have shown bone morphogenetic protein (rhBMP-2) stimulated bone growth can encroach on the spinal canal and nerves, causing neural compression.

Graft resorption with the use of bone morphogenetic protein: lessons from anterior lumbar interbody fusion using femoral ring allografts and recombinant human bone morphogenetic protein-2.

Study Design: This is a prospective cohort study examining the results and radiographic characteristics of anterior lumbar interbody fusion (ALIF) using femoral ring allografts (FRAs) and recombinant human bone morphogenetic protein-2 (rhBMP-2). This was compared to a historical control ALIF using FRAs with autologous iliac crest bone graft (ICBG).

Objective: To determine whether the use of rhBMP-2 can enhance fusion ALIF with stand-alone FRAs.

Computed tomography assessment of the accuracy of in vivo placement of artificial discs in the lumbar spine including radiographic and clinical consequences.

Study Design: Prospective cohort study of 52 patients who had undergone artificial lumbar disc replacement.

Objectives: To evaluate the implantation accuracy of prosthesis positioning, subsequent facet joint changes and prosthesis migration, and the clinical consequences of implant position.

Summary Of Background Data: Accuracy of spinal prosthesis implantation has not been evaluated rigorously, especially with a mini-incision approach.

Kyphoplasty reduction of osteoporotic vertebral compression fractures: correction of local kyphosis versus overall sagittal alignment.

Study Design: A retrospective study of patients who underwent 1-3-level kyphoplasty procedures at a single institute.

Objective: To examine and compare the effects of single and multilevel kyphoplasty procedures on local versus overall sagittal alignment of the spine.

Summary Of Background Data: Cement augmentation has been a safe and effective method in the treatment of symptomatic vertebral compression fractures (VCFs).

An outcomes analysis of the treatment of cervical pseudarthrosis with posterior fusion.

Study Design: A retrospective review of 33 consecutive patients treated with posterior fusion and selective nerve root decompression for the treatment of pseudarthrosis following anterior cervical discectomy and fusion.

Objectives: Use standardized outcome measures to evaluate the results of posterior fusion with selective nerve root decompression as a treatment option for symptomatic pseudarthrosis of the cervical spine.

Summary Of Background Data: Pseudarthrosis after anterior cervical discectomy and fusion has been recognized as a cause of continued cervical pain and unsatisfactory outcomes.

Clinical results of ProDisc-II lumbar total disc replacement: report from the United States clinical trial.

The much-awaited clinical use of lumbar artificial discs has begun in the United States. The United States Investigational Device Exemption (US IDE) clinical trial of the ProDisc-II prosthetic disc (Synthes, Paoli, PA) was recently completed, with all indications that it meets or surpasses the test of equivalence against fusion controls. This is a review of the clinical performance of the ProDisc-II artificial disc and includes an interim report from the US IDE trial at one site.

Vascular injury during anterior lumbar surgery.

Background Context: With the number of anterior lumbar procedures expected to increase significantly over the next few years, it is important for spine surgeons to have a good understanding about the incidence of vascular complications during these operations.

Purpose: To determine the incidence of vascular injury in 1,315 consecutive cases undergoing anterior lumbar surgery at various levels from L2 to S1.

Study Design/setting: Patients undergoing anterior lumbar surgery were studied.

The IDET procedure for chronic discogenic low back pain.

Study Design: Retrospective study with independent evaluation of patient outcomes approximately 1 year post-intradiscal electrothermal therapy (IDET). OBJECTIVE.: To assess functional status, symptoms, and subsequent treatments of patients treated with IDET.