Elsevier

The Spine Journal

Volume 14, Issue 12, 1 December 2014, Pages 2841-2846
The Spine Journal

Clinical Study
Comparison of revision surgeries for one- to two-level cervical TDR and ACDF from 2002 to 2011

https://doi.org/10.1016/j.spinee.2014.03.037Get rights and content

Abstract

Background context

Cervical total disc replacement (TDR) and anterior cervical discectomy and fusion (ACDF) provide comparable outcomes for degenerative cervical pathology. However, revisions of these procedures are not well characterized.

Purpose

The purpose of this study is to examine the rates, epidemiology, perioperative complications, and costs between the revision procedures and to compare these outcomes with those of primary cases.

Study design

This study is a retrospective database analysis.

Patient sample

A total of 3,792 revision and 183,430 primary cases from the Nationwide Inpatient Sample (NIS) database from 2002 to 2011 were included.

Outcome measures

Incidence of revision cases, patient demographics, length of stay (LOS), in-hospital costs, mortality, and perioperative complications.

Methods

Patients who underwent revision for either one- to two-level cervical TDR or ACDF were identified. SPSS v.20 was used for statistical analysis with χ2 test for categorical data and independent sample t test for continuous data. The relative risk for perioperative complications with revisions was calculated in comparison with primary cases using a 95% confidence interval. An alpha level of less than 0.05 denoted statistical significance.

Results

There were 3,536 revision one- to two-level ACDFs and 256 revision cervical TDRs recorded in the NIS database from 2002 to 2011. The revision cervical TDR cohort demonstrated a significantly greater LOS (3.18 vs. 2.25, p<.001), cost ($16,998 vs. $15,222, p=.03), and incidence of perioperative wound infections (13.6 vs. 5.3 per 1,000, p<.001) compared with the ACDF revision cohort (p<.001). There were no differences in mortality between the revision surgical cohorts. Compared with primary cases, both revision cohorts demonstrated a significantly greater LOS and cost. Furthermore, patients who underwent revision demonstrated a greater incidence and risk for perioperative wound infections, hematomas, dysphagia, and neurologic complications relative to the primary procedures.

Conclusions

This study demonstrated a significantly greater incidence of perioperative wound infection, LOS, and costs associated with a TDR revision compared with a revision ACDF. We propose that these differences are by virtue of the inherently more invasive nature of revising TDRs. In addition, compared with primary cases, revision procedures are associated with greater costs, LOS, and complications including wound infections, dysphagia, hematomas, and neurologic events. These additional risks must be considered before opting for a revision procedure.

Introduction

Evidence & Methods

Revision procedures for anterior cervical discectomy and fusion (ACDF) as well as disc replacement (TDR) are not well characterized. The authors sought to describe revision rates, complications and costs for revision procedures following primary ACDF or TDR using the Nationwide Inpatient Sample (NIS).

In this retrospective analysis, the authors evaluated 3,536 revision procedures following ACDF and 256 revisions for TDR. Revisions associated with TDR were found to have statistically increased hospital lengths of stay, risk of perioperative wound infection, and resultant health care costs. The authors maintain that their findings result from more invasive procedures necessary to revise cervical TDR.

The NIS is a representative sample drawn from hospitals across the country. While heavily utilized in a number of investigations associated with spine surgical research, the dataset was not specifically designed to support such efforts. As a result, certain procedures are particularly under-represented, such as the limited number of cases associated with revision TDR (n=256) identified here. This constrains the number of outcomes associated with the population under study and thus, some of the statistically significant associations presented by the authors may have occurred solely by chance. The NIS also cannot account for clustering of patients within surgeons and hospitals (eg, those that can treat patients who necessitate revision TDR) and, due to its methodology, complications are certainly under-reported. The advantage of the NIS lies in its capacity to capture a large number of procedures (often in the tens to hundreds of thousands) from centers across the US. When the types of surgery performed are particularly rare, or very limited in the NIS dataset, the database loses much of its power. Thus, the information presented here cannot be considered better than level IV evidence and a number of other study designs would likely provide more translatable data on this topic.

—The Editors

Radiographic evidence demonstrates at least one degenerative finding in the cervical spine on X-rays by age 65 in nearly 95% of men and 70% of women [1], [2], [3]. Cervical total disc replacement (TDR) and anterior cervical discectomy and fusion (ACDF) are both indicated as surgical interventions for this degenerative condition.

Currently, five artificial disc devices are approved by the US Food and Drug Administration (FDA) for TDR involving single-level anterior cervical procedures [4]. These devices include the Bryan Disc (Medtronic Sofamor Danek, Memphis, TN, USA), the Prestige Disc (Medtronic Sofamor Danek), the ProDisc-C (Synthes Spine, West Chester, PA, USA), the Secure C Disc (Globus Medical, Inc., Audubon, PA, USA), and the PCM Disc (NuVasive, Inc., San Diego, CA, USA) [4]. Several studies have consistently established the noninferiority of TDR with these approved products with regard to the rates of revision compared with ACDF [5], [6], [7].

Although several studies and meta-analyses both within and outside the FDA Investigational Device Exemption (IDE) trials have assessed the revision rates of these procedures, no studies to our knowledge have characterized the patient demographics, length of stay (LOS), hospital costs, mortality, and perioperative complications associated with revising these devices. The purpose of this study is to examine the rates, epidemiology, perioperative complications, and costs between revision procedures and to compare these outcomes with those of primary cases.

Section snippets

Materials and methods

The Nationwide Inpatient Sample (NIS) database is part of the Healthcare Cost and Utilization Project (HCUP) and is governed by the Agency for Healthcare Research and Quality. [8] The NIS represents the largest all-payer health-care database in the United States approximating a 20% stratified sample of all hospital discharges. Each entry contains data from a single hospital admission. The NIS issues admission diagnosis, in-hospital complications, and procedural data using the International

Results

There were 3,536 revision one- to two-level ACDFs and 256 revision cervical TDRs recorded from 2002 to 2011. Of the 256 revision cervical TDRs, 106 cases had concurrent ACDF codes. The number of revision cases in both cohorts increased during this period (Figure). There were no significant differences among the mean age (50.9 vs. 50.3 years), comorbidity burden (CCI 2.06 vs. 2.03), race, or teaching status (50.2% vs. 46.8%) between the revision ACDF and cervical TDR cohorts, respectively (

Discussion

Proponents of cervical disc replacement have clearly demonstrated the noninferiority of cervical arthroplasty compared with ACDF [13], [14], [15], [16], [17], [18]. The prospective, randomized controlled FDA IDE trials have reported no significant differences in the LOS, costs, or the intraoperative course [5], [6], [7], [19]. No studies, to our knowledge, have assessed these outcome parameters with regard to revision cases. In addition, this is the first study to compare perioperative outcomes

Conclusions

In this analysis of the NIS database, the revision cervical TDR cohort demonstrated a greater hospitalization, costs, and incidence of perioperative infection than the revision ACDF cohort. We propose that these differences are by virtue of the inherently more invasive nature of revising TDRs. In addition, compared with primary cases, revision procedures are associated with greater costs, LOS, and incidence and risk for complications including wound infections, dysphagia, hematomas, and

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  • Cited by (0)

    FDA device/drug status: Approved: Bryan Disc (Medtronic Sofamor Danek, Memphis, TN, USA), the Prestige Disc (Medtronic Sofamor Danek, Memphis, TN, USA), the ProDisc-C (Synthes Spine, West Chester, PA, USA), the Secure C Disc (Globus Medical, Inc., Audubon, PA, USA), and the PCM Disc (NuVasive, Inc., San Diego, CA, USA).

    Author disclosures: SVN: Nothing to disclose. AM-L: Nothing to disclose. SJF: Nothing to disclose. KS: Royalties: Pioneer (C), Stryker (C), Thieme (B); Consulting: Depuy (B), Globus (B), Stryker (B); Board of Director: Vital 5, LLC (no financial relationship).

    Disclosure: No funds were received in support of this work. No benefits in any form have been or will be received from any commercial party related directly or indirectly to the subject of the article.

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