Clinical StudyThe perioperative cost of Infuse bone graft in posterolateral lumbar spine fusion
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.