Original Research

Pseudo-Pedicle Heterotopic Ossification From Use of Recombinant Human Bone Morphogenetic Protein 2 (rhBMP-2) in Transforaminal Lumbar Interbody Fusion Cages

Publish date: January 29, 2018

References

1. Urist MR. Bone: formation by autoinduction. Science. 1965;150(3698):893-899.

2. Burkus JK, Gornet MF, Schuler TC, Kleeman TJ, Zdeblick TA. Six-year outcomes of anterior lumbar interbody arthrodesis with use of interbody fusion cages and recombinant human bone morphogenetic protein-2. J Bone Joint Surg Am. 2009;91(5):1181-1189.

3. Boden SD, Kang J, Sandhu H, Heller JG. Use of recombinant human bone morphogenetic protein-2 to achieve posterolateral lumbar spine fusion in humans: a prospective, randomized clinical pilot trial: 2002 Volvo award in clinical studies. Spine. 2002;27(23):2662-2673.

4. Boden SD, Zdeblick TA, Sandhu HS, Heim SE. The use of rhBMP-2 in interbody fusion cages. Definitive evidence of osteoinduction in humans: a preliminary report. Spine. 2000;25(3):376-381.

5. Haid RW Jr, Branch CL Jr, Alexander JT, Burkus JK. Posterior lumbar interbody fusion using recombinant human bone morphogenetic protein type 2 with cylindrical interbody cages. Spine J. 2004;4(5):527-538.

6. Meisel HJ, Schnöring M, Hohaus C, et al. Posterior lumbar interbody fusion using rhBMP-2. Eur Spine J. 2008;17(12):1735-1744.

7. Mummaneni PV, Pan J, Haid RW, Rodts GE. Contribution of recombinant human bone morphogenetic protein-2 to the rapid creation of interbody fusion when used in transforaminal lumbar interbody fusion: a preliminary report. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004. J Neurosurg Spine. 2004;1(1):19-23.

8. Shimer AL, Oner FC, Vaccaro AR. Spinal reconstruction and bone morphogenetic proteins: open questions. Injury. 2009;40(suppl 3):S32-S38.

9. Slosar PJ, Josey R, Reynolds J. Accelerating lumbar fusions by combining rhBMP-2 with allograft bone: a prospective analysis of interbody fusion rates and clinical outcomes. Spine J. 2007;7(3):301-307.

10. Knox JB, Dai JM 3rd, Orchowski J. Osteolysis in transforaminal lumbar interbody fusion with bone morphogenetic protein-2. Spine. 2011;36(8):672-676.

11. Owens K, Glassman SD, Howard JM, Djurasovic M, Witten JL, Carreon LY. Perioperative complications with rhBMP-2 in transforaminal lumbar interbody fusion. Eur Spine J. 2011;20(4):612-617.

12. Mindea SA, Shih P, Song JK. Recombinant human bone morphogenetic protein-2-induced radiculitis in elective minimally invasive transforaminal lumbar interbody fusions: a series review. Spine. 2009;34(14):1480-1484.

13. Yoon ST, Park JS, Kim KS, et al. ISSLS prize winner: LMP-1 upregulates intervertebral disc cell production of proteoglycans and BMPs in vitro and in vivo. Spine. 2004;29(23):2603-2611.

14. Cahill KS, Chi JH, Day A, Claus EB. Prevalence, complications, and hospital charges associated with use of bone-morphogenetic proteins in spinal fusion procedures. JAMA. 2009;302(1):58-66.

15. Carragee EJ, Hurwitz EL, Weiner BK. A critical review of recombinant human bone morphogenetic protein-2 trials in spinal surgery: emerging safety concerns and lessons learned. Spine J. 2011;11(6):471-491.

16. Chen NF, Smith ZA, Stiner E, Armin S, Sheikh H, Khoo LT. Symptomatic ectopic bone formation after off-label use of recombinant human bone morphogenetic protein-2 in transforaminal lumbar interbody fusion. J Neurosurg Spine. 2010;12(1):40-46.

17. Joseph V, Rampersaud YR. Heterotopic bone formation with the use of rhBMP2 in posterior minimal access interbody fusion: a CT analysis. Spine. 2007;32(25):2885-2890.

18. McClellan JW, Mulconrey DS, Forbes RJ, Fullmer N. Vertebral bone resorption after transforaminal lumbar interbody fusion with bone morphogenetic protein (rhBMP-2). J Spinal Disord Tech. 2006;19(7):483-486.

19. Mroz TE, Wang JC, Hashimoto R, Norvell DC. Complications related to osteobiologics use in spine surgery: a systematic review. Spine. 2010;35(9 suppl):S86-S104.

20. Muchow RD, Hsu WK, Anderson PA. Histopathologic inflammatory response induced by recombinant bone morphogenetic protein-2 causing radiculopathy after transforaminal lumbar interbody fusion. Spine J. 2010;10(9):e1-e6.

21. Ong KL, Villarraga ML, Lau E, Carreon LY, Kurtz SM, Glassman SD. Off-label use of bone morphogenetic proteins in the United States using administrative data. Spine. 2010;35(19):1794-1800.

22. Rihn JA, Patel R, Makda J, et al. Complications associated with single-level transforaminal lumbar interbody fusion. Spine J. 2009;9(8):623-629.

23. Vaidya R, Sethi A, Bartol S, Jacobson M, Coe C, Craig JG. Complications in the use of rhBMP-2 in PEEK cages for interbody spinal fusions. J Spinal Disord Tech. 2008;21(8):557-562.

24. Wong DA, Kumar A, Jatana S, Ghiselli G, Wong K. Neurologic impairment from ectopic bone in the lumbar canal: a potential complication of off-label PLIF/TLIF use of bone morphogenetic protein-2 (BMP-2). Spine J. 2008;8(6):1011-1018.

25. Delawi D, Dhert WJ, Rillardon L, et al. A prospective, randomized, controlled, multicenter study of osteogenic protein-1 in instrumented posterolateral fusions: report on safety and feasibility. Spine. 2010;35(12):1185-1191.

26. Vaccaro AR, Patel T, Fischgrund J, et al. A pilot study evaluating the safety and efficacy of OP-1 putty (rhBMP-7) as a replacement for iliac crest autograft in posterolateral lumbar arthrodesis for degenerative spondylolisthesis. Spine. 2004;29(17):1885-1892.

27. Vaidya R, Weir R, Sethi A, Meisterling S, Hakeos W, Wybo CD. Interbody fusion with allograft and rhBMP-2 leads to consistent fusion but early subsidence. J Bone Joint Surg Br. 2007;89(3):342-345.

28. Glassman SD, Howard J, Dimar J, Sweet A, Wilson G, Carreon L. Complications with recombinant human bone morphogenic protein-2 in posterolateral spine fusion: a consecutive series of 1037 cases. Spine. 2011;36(22):1849-1854.

29. Helgeson MD, Lehman RA Jr, Patzkowski JC, Dmitriev AE, Rosner MK, Mack AW. Adjacent vertebral body osteolysis with bone morphogenetic protein use in transforaminal lumbar interbody fusion. Spine J. 2011;11(6):507-510.

30. Hoffmann MF, Jones CB, Sietsema DL. Adjuncts in posterior lumbar spine fusion: comparison of complications and efficacy. Arch Orthop Trauma Surg. 2012;132(8):1105-1110.

31. Villavicencio AT, Burneikiene S, Nelson EL, Bulsara KR, Favors M, Thramann J. Safety of transforaminal lumbar interbody fusion and intervertebral recombinant human bone morphogenetic protein-2. J Neurosurg Spine. 2005;3(6):436-443.

32. Patel VV, Zhao L, Wong P, et al. Controlling bone morphogenetic protein diffusion and bone morphogenetic protein-stimulated bone growth using fibrin glue. Spine. 2006;31(11):1201-1206.

33. Zhang H, Sucato DJ, Welch RD. Recombinant human bone morphogenic protein-2-enhanced anterior spine fusion without bone encroachment into the spinal canal: a histomorphometric study in a thoracoscopically instrumented porcine model. Spine. 2005;30(5):512-518.

Bone morphogenetic proteins (BMPs), first isolated by Urist in 1964¹, are a family of growth factors that stimulate the cascade of bone formation. Recombinant human BMP (rhBMP), specifically rhBMP-2 and rhBMP-7 (also known as osteogenic protein 1 [OP-1]), was developed in the 1990s after the advent of gene splicing. Then, in 2002, the US Food and Drug Administration (FDA) approved use of rhBMP to stimulate fusion in the human spine. Specifically, rhBMP-2 (Medtronic) was approved for use in combination with a specific brand of interbody cage in 1-level anterior lumbar interbody fusion.² Over the past decade, off-label use of rhBMP-2 to achieve osseous union has increased dramatically, particularly in spinal surgery: transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion, and posterolateral lumbar fusion.^3-9 However, this widespread off-label use for posterior spinal fusion began despite FDA data indicating that specific complications were underreported in the peer-reviewed literature.^10,11 Although rhBMP-2 is very effective in increasing osteoblast formation and improving osteogenesis and subsequent bone healing in spinal surgery,^12,13 its use in TLIF resulted in significant adverse side effects, including radiculopathy with and without neuroforaminal heterotopic ossification (HO);^14-24 complications in the FDA studies;^14,22,25-27 and osteolysis causing intervertebral cage subsidence, inflammatory radiculitis, genitourinary complications, infections, possible systemic effects, and significant HO complications.^10,28-30 Of these, HO complications involved rhBMP leakage through the annulotomy to the disk space that led to HO. Specifically, rhBMP leaked directly out of the disk space and formed a pillar of bone that encased the nerve roots and dura, which led to occlusion of the foramen and symptoms of radiculopathy.^10,28-30

Despite this frequent finding of HO in the intervertebral space outside the target fusion area, use of rhBMP-2 with intervertebral cages increased so rapidly that rhBMP-2 was used more often than autologous bone.^5,11,17,31 In this study, we reviewed the common characteristics of patients who developed HO and subsequent radiculopathy from TLIF with rhBMP.

METHODS

After this study received Institutional Review Board approval, we retrospectively reviewed cases of radiculopathy symptoms that developed after TLIF with rhBMP between January 2002 and January 2015. During this period, 38 patients (26 males, 12 females) with a mean (SD) age of 50.8 (7.5) years and radiculopathy symptoms arising from TLIF with rhBMP-2 were identified to determine commonalities and defining characteristics that will help facilitate diagnosis.

Inclusion criteria were computed tomography (CT)–documented HO arising from the TLIF annulotomy site in continuity with bone in the disk space or ectopic bone forming a distinctive shell with contouring around the thecal sac or nerve roots, as well as recurrence or initial occurrence of radiculopathy with signs and symptoms corresponding to the CT site of aberrant bone growth in terms of laterality and particular nerve root(s) involved. Exclusion criteria were malplacement of interbody cage or pedicle screws, disk herniation, systemic neuropathic disease, and new or unresolved radiculopathy immediately after index surgery.

To improve recognition of this complication, we also documented the amount of BMP used, common patterns of radiculopathy symptom development, and radiologic findings. Type and timing of radiculopathy symptom onset and consistency with side of TLIF placement were documented as well. Radiculopathy symptoms included shooting pain in the legs, incontinence, sexual dysfunction, and severe paralysis. Radiologic findings were specific to bone formation from the disk space (detected with CT).

Continue to: RESULTS