Elsevier

The Spine Journal

Volume 8, Issue 3, May–June 2008, Pages 443-448
The Spine Journal

Clinical Study
The perioperative cost of Infuse bone graft in posterolateral lumbar spine fusion

https://doi.org/10.1016/j.spinee.2007.03.004Get rights and content

Abstract

Background context

There is mounting evidence supporting the efficacy of bone morphogenetic protein (BMP) for both anterior interbody and posterolateral lumbar fusion. However, the relative cost of BMP remains an important concern for physicians, hospitals, and payers.

Purpose

The purpose of this study is to report on the perioperative costs for patients treated with rhBMP-2 as compared with an iliac crest bone graft (ICBG) supplemented with graft extenders.

Study design/setting

A prospective randomized controlled trial of rhBMP-2/ACS (Infuse Bone Graft; Medtronic Sofamor Danek, Memphis, TN) versus ICBG±graft extender for lumbar spine fusion in patients over 60 years old.

Patient sample

One hundred two patients over 60 years old who required a posterolateral lumbar spine fusion randomized between receiving rhBMP-2/ACS or ICBG.

Outcome measures

All health-care costs over the first 3 months after surgery.

Methods

As part of a prospective randomized trial of rhBMP-2/ACS versus ICBG±graft extender for lumbar spine fusion, all costs over the first 3 months after surgery were directly recorded by a dedicated coder funded by Norton Healthcare, Louisville, KY. A dedicated research nurse also followed all patients throughout their hospital stay and posthospitalization recovery to identify any adverse events or additional outpatient medical care.

Results

Fifty patients received rhBMP-2/ACS and 52 underwent ICBG harvest. The mean hospital cost for the index admission was $24,736 for the rhBMP-2/ACS group and $21,138 for the ICBG group. Mean inpatient physician costs were $5,082 in the rhBMP-2/ACS group and $5,316 in the ICBG group. Costs associated with posthospital rehabilitation averaged $4,906 in the rhBMP-2/ACS group versus $6,820 in the ICBG group. Total payer expenditure for the 3-month perioperative period averaged $33,860 in the rhBMP-2/ACS group and $37,227 in the ICBG group.

Conclusions

The hospital carries the cost burden associated with the utilization of rhBMP-2/ACS. In contrast, the payer in a Diagnosis-Related Group (DRG) model achieves a net savings, based primarily on the decreased payment for inpatient rehabilitation, but also on decreased hospital reimbursement, physician costs, and other outpatient services.

Introduction

RhBMP-2/ACS (Infuse Bone Graft; Medtronic Sofamor Danek, Memphis, TN) is now widely used as an iliac crest bone graft (ICBG) substitute for lumbar spine fusion. There is extensive level I clinical data supporting the efficacy of rhBMP-2/ACS for anterior interbody fusion [1], [2], [3]. There is also mounting evidence that rhBMP-2/ACS is a viable ICBG replacement for posterolateral lumbar spine fusion [4], [5], [6]. Despite these encouraging reports and the almost uniform desire of patients to avoid ICBG harvest, the relative cost of rhBMP-2/ACS remains an important concern for physicians, hospitals, and payers.

It is evident that ICBG is associated with some incremental cost based on the greater extent of surgery required [7]. ICBG harvest involves additional surgical time and blood loss and generates a resultant surgical fee. The morbidity of ICBG is well documented, with complications ranging from wound infection to vascular injury [8], [9], [10], [11]. Even barring complications, up to 49% of patients complain of ICBG-related pain, which is often persistent several years after graft harvest [12], [13], [14], [15].

Efforts to model the costs related to ICBG [7] and to compare them with the cost of rhBMP-2/ACS for single-level anterior interbody fusion [16], [17] have been undertaken. Polly et al.'s analysis of relative costs [17], which was performed based on an amalgamation of available clinical data and expert opinion, considers potential cost offsets as compared with the known expense of rhBMP-2/ACS. As an example, the model assumes that use of rhBMP-2/ACS should significantly decrease the need for bone graft extenders. Using this model, the authors conclude that over a 2-year period after surgery the cost of rhBMP-2/ACS is “likely to be offset to a significant extent by reductions in the use of other medical resources” [17]. Obviously, a number of the assumptions contained in their model are hypothetical.

The purpose of this study is to report on the directly measured perioperative and early postoperative costs for patients treated with rhBMP-2/ACS as compared with ICBG. An economic analysis was undertaken as part of a prospective randomized controlled trial of rhBMP-2/ACS versus ICBG±graft extender for posterolateral spine fusion in patients over 60 years old. We sought to evaluate comparative costs for the initial 3-month Medicare global billing period. The economic burden associated with rhBMP-2/ACS in this initial timeframe is important because utilization of rhBMP-2/ACS is limited in many instances by concern regarding prohibitive hospital costs. Although this is certainly a legitimate consideration, no available data support or refute this assumption.

Section snippets

Methods

One hundred six patients were enrolled in a prospective randomized trial of rhBMP-2/ACS versus ICBG±graft extender for lumbar spine fusion in patients over 60 years old. The study protocol was institutional review board approved and funded by Norton Healthcare, Louisville, KY. Single or multilevel decompression and instrumented fusion procedures were performed by an orthopedic/neurosurgical team. Other than the requirement for rhBMP-2/ACS, prepared according to the package labeling

Demographic data

Of the 102 patients in the study, 50 received rhBMP-2/ACS and 52 underwent ICBG harvest±graft extender. The rhBMP-2/ACS group included 15 men and 35 women, with a mean age of 69.2±5.5 years. The ICBG group was comprised of 17 men and 35 women, with a mean age of 69.9±5.8 years. There were 11 smokers in the rhBMP-2/ACS group and 9 smokers in the ICBG group. Mean body mass index was 29.4±5.7 in the rhBMP-2/ACS group and 28.1±6.1 in the ICBG group. There were no substantial differences in reported

Discussion

This study is the first, to our knowledge, that prospectively tracks and records the specific costs associated with bone grafting and lumbar spine fusion. The economic analysis was performed as part of a randomized controlled trial comparing ICBG±graft extender versus rhBMP-2/ACS for posterolateral instrumented lumbar fusion. The study population, patients over 60 years of age, was selected in order to simplify the economic model by assuming Medicare to be the primary payer. Although the index

Acknowledgments

The authors would like to thank Cathy Summers, RN, for her significant dedication to this project.

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  • Cited by (0)

    FDA device/drug status: not approved for this indication (Infuse bone graft).

    This study was supported by Norton Healthcare, Louisville, KY SDG, MJC, JRJ, RMP, MD, JRD receive royalties, research grant support, and consulting fees from Medtronic Sofamor Danek, Memphis, TN.

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