As we wind down 2016, it is a good time to reflect on what emerged in the spine literature over the past year. One area of intense focus was the role of fusion for degenerative spondylolisthesis (DS), with two RCTs comparing laminectomy alone to laminectomy plus fusion essentially reaching opposite conclusions. The American study demonstrated a lower reoperation rate and somewhat better patient reported outcomes for those who underwent fusion in addition to laminectomy, while the Swedish study demonstrated no advantage for fusion. 1,2 Spine readers responded to a quick poll on the topic after the publication of these papers, and a plurality (47%) noted that laminectomy and instrumented fusion was their preferred operation for single level DS without frank instability. Twenty-six percent favored laminectomy alone, 21% preferred laminectomy and interbody fusion, and 5% laminectomy and uninstrumented fusion. A recent meta-analysis on the topic noted no advantage to adding an interbody fusion when compared to laminectomy and fusion for DS.3 Another approach to DS that has gained popularity over the past decade is the MIS-TLIF, though there is not much literature major advantages to the technique. A prospective cohort study comparing MIS to open TLIF by Guan et al. published in Spine earlier this year reported lower blood loss in the MIS-TLIF group but similar patient reported outcomes.4 Contrary to conventional wisdom, the MIS-TLIF group had a longer length of stay than the conventional open procedure. Opinions on this topic were mixed among the Spine readership, with 58% of quick poll respondents feeling that MIS-TLIF offered advantages over open TLIF, while 42% did not.
The cost and value of spine surgery was also a hot topic in 2016. In one study, Kazberouk et al. showed 30-40% variation in costs for a variety of common spine procedures, with the greatest variation (80%) observed for lumbar fusion.5 When asked about the best way to reduce spine surgery costs, readers answered sticking to indications (71%), avoiding complications (14%), and decreasing length of stay (14%). Interestingly, no readers answered minimizing implant costs, while Kazberouk et al. reported that different implant choices was the main driver in cost variation. The use of BMP-2 remained a controversial topic due to its high cost and possible adverse effects. In a meta-analysis by Laurie et al., the authors analyzed subgroups that may have benefited from BMP-2 and reported that smokers had a significantly higher fusion rate when BMP-2 was used, though this was not reflected in better patient reported outcomes.6 When spine readers were queried about BMP-2 use, 40% of readers reported using it for pseudarthrosis, 20% for long fusions to the pelvis, 7% in smokers, and 33% for all of those indications. The association between BMP-2 and cancer continues to be debated. An August 2016 Spine article by Dettori et al. evaluated the link between BMP-2 use and cancer in a Washington state database and reported no connection.7 Despite most evidence showing no link between BMP-2 and cancer, 60% of quick poll respondents believed BMP-2 does cause cancer. One of the most controversial hypotheses in the spine world recently has been the concept that disk degeneration is caused by bacteria.8 A recent study by Coscia et al. showed a high rate of positive cultures of disk material removed for a variety of indications, with patients being treated for degenerative conditions having a significantly higher rate of positive cultures compared to trauma patients.9 Quick poll respondents were divided on the topic, with 50% believing bacteria play a role in disk degeneration, while the other half believed there was no link.
What do you believe will be the important topics in Spine in 2017? Let us know by leaving a comment on The Spine Blog. Happy New Year!
Adam Pearson, MD, MS
Associate Web Editor
1. Forsth P, Olafsson G, Carlsson T, et al. A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis. N Engl J Med 2016;374:1413-23.
2. Ghogawala Z, Dziura J, Butler WE, et al. Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis. N Engl J Med 2016;374:1424-34.
3. McAnany SJ, Baird EO, Qureshi SA, Hecht AC, Heller JG, Anderson PA. Posterolateral Fusion Versus Interbody Fusion for Degenerative Spondylolisthesis: A Systematic Review and Meta-Analysis. Spine (Phila Pa 1976) 2016;41:E1408-E14.
4. Guan J, Bisson EF, Dailey AT, Hood RS, Schmidt MH. Comparison of Clinical Outcomes in the National Neurosurgery Quality and Outcomes Database for Open Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion. Spine (Phila Pa 1976) 2016;41:E416-21.
5. Kazberouk A, Sagy I, Novack V, McGuire K. Understanding the Extent and Drivers of Interphysician Cost Variation for Spine Procedures. Spine (Phila Pa 1976) 2016;41:1111-7.
6. Laurie AL, Chen Y, Chou R, Fu R. Meta-analysis of the Impact of Patient Characteristics on Estimates of Effectiveness and Harms of Recombinant Human Bone Morphogenetic Protein-2 in Lumbar Spinal Fusion. Spine (Phila Pa 1976) 2016;41:E1115-23.
7. Dettori JR, Chapman JR, DeVine JG, McGuire RA, Norvell DC, Weiss NS. The Risk of Cancer With the Use of Recombinant Human Bone Morphogenetic Protein in Spine Fusion. Spine (Phila Pa 1976) 2016;41:1317-24.
8. Albert HB, Sorensen JS, Christensen BS, Manniche C. Antibiotic treatment in patients with chronic low back pain and vertebral bone edema (Modic type 1 changes): a double-blind randomized clinical controlled trial of efficacy. Eur Spine J 2013;22:697-707.
9. Coscia MF, Denys GA, Wack MF. Propionibacterium acnes, Coagulase-Negative Staphylococcus, and the "Biofilm-like" Intervertebral Disc. Spine (Phila Pa 1976) 2016;41:1860-5.