Device-Related Complications of the Coflex Interspinous Process Implant for the Lumbar Spine
Authors: Zang L. 
Published: May 2014

Introduction

Coflex, a type of interspinous process implant, can provide intervertebral dynamic stability for surgical segments and relieve lumbocrural pain effectively. However, few studies have described the avoidance and therapeutic strategies of Coflex implant complications.

Materials and Methods

Coflex implant complications included intraoperative or postoperative spinous process fracture, aggravated postoperative lumbocrural pain, dislodgment, and malposition in this study. The complications were analyzed, and therapeutic strategies were applied according to the specific complication. The Visual Analogue Scale and Oswestry Disability Index scores were evaluated by using the paired-samples test of SPSS 12.0

Results

Conservative treatment was provided to seven patients who experienced aggravated lumbocrural pain even though their devices remained in the correct position, and pedicle screw treatment was used as an alternative in four cases. The Visual Analogue Scale and Oswestry Disability Index scores showed evident improvement in these patients. The Visual Analogue Scale and Oswestry Disability Index scores of two patients who underwent revision also improved.

Conclusion

Coflex implants should be avoided in patients with osteoporosis, a narrow interspinous space and intervertebral coronal spondylolysis, or sagittal instability; furthermore, the device choice, depth of implantation, and clamping intensity should be appropriate. Conservative treatment can be provided to patients with symptoms if the device remains in the correct position; however, revisions and salvages should be undertaken with internal fixation of pedicle screws for patients with device malposition, intraoperative implantation failure, or device intolerance. Disclosure of Interest None declared References Richards JC, Majumdar S, Lindsey DP, Beaupré GS, Yerby SA. The treatment mechanism of an interspinous process implant for lumbar neurogenic intermittent claudication. Spine 2005;30(7):744–749 Siddiqui M, Nicol M, Karadimas E, Smith F, Wardlaw D. The positional magnetic resonance imaging changes in the lumbar spine following insertion of a novel interspinous process distraction device. Spine 2005;30(23):2677–2682 Lee J, Hida K, Seki T, Iwasaki Y, Minoru A. An interspinous process distractor (X STOP) for lumbar spinal stenosis in elderly patients: preliminary experiences in 10 consecutive cases. J Spinal Disord Tech 2004;17(1):72-77, discussion 78 Kong DS, Kim ES, Eoh W. One-year outcome evaluation after interspinous implantation for degenerative spinal stenosis with segmental instability. J Korean Med Sci 2007;22(2):330–335 Errico TJ, Kamerlink JR, Quimo M, et al. Survivorship of coflex interlaminar-interspinous implant. SAS J 2009;3(2):59–67 Park SC, Yoon SH, Hong YP, Kim KJ, Chung SK, Kim HJ. Minimum 2-year follow-up result of degenerative spinal stenosis treated with interspinous u (coflex). J Korean Neurosurg Soc 2009;46(4):292–299 Bono CM, Vaccaro AR. Interspinous process devices in the lumbar spine. J Spinal Disord Tech 2007;20(3):255–261 Trautwein FT, Lowery GL, Wharton ND, Hipp JA, Chomiak RJ. Determination of the in vivo posterior loading environment of the Coflex interlaminar-interspinous implant. Spine J 2010;10(3):244–251 Tsai KJ, Murakami H, Lowery GL, Hutton WC. A biomechanical evaluation of an interspinous device (Coflex) used to stabilize the lumbar spine. J Surg Orthop Adv 2006;15(3):167–172 Christie SD, Song JK, Fessler RG. Dynamic interspinous process technology. Spine 2005; 30 (16, Suppl)S73-S78 Lindsey DP, Swanson KE, Fuchs P, Hsu KY, Zucherman JF, Yerby SA. The effects of an interspinous implant on the kinematics of the instrumented and adjacent levels in the lumbar spine. Spine 2003;28(19):2192–2197 Swanson KE, Lindsey DP, Hsu KY, Zucherman JF, Yerby SA. The effects of an interspinous implant on intervertebral disc pressures. Spine 2003;28(1):26–32 Bowers C, Amini A, Dailey AT, Schmidt MH. Dynamic interspinous process stabilization: review of complications associated with the X-Stop device. Neurosurg Focus 2010;28(6):E8 Chao S, Malloy JP, Bono CM. Complications specific to motion-sparing devices in the lumbar spine. Semin Spine Surg 2011;23(2):123–134 Kim DH, Tantorski M, Shaw J, et al. Occult spinous process fractures associated with interspinous process spacers. Spine 2011;36(16):E1080-E1085 Barbagallo GM, Olindo G, Corbino L, Albanese V. Analysis of complications in patients treated with the X-Stop Interspinous Process Decompression System: proposal for a novel anatomic scoring system for patient selection and review of the literature. Neurosurgery 2009;65(1):111-119, discussion 119–120 Barbagallo GM, Corbino LA, Olindo G, Foti P, Albanese V, Signorelli F. The “sandwich phenomenon”: a rare complication in adjacent, double-level X-stop surgery: report of three cases and review of the literature. Spine 2010;35(3):E96-E100 Anderson PA, Tribus CB, Kitchel SH. Treatment of neurogenic claudication by interspinous decompression: application of the X STOP device in patients with lumbar degenerative spondylolisthesis. J Neurosurg Spine 2006;4(6):463–471 Zucherman JF, Hsu KY, Hartjen CA, et al. A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results. Spine 2005;30(12):1351–1358 Siddiqui M, Smith FW, Wardlaw D. One-year results of X Stop interspinous implant for the treatment of lumbar spinal stenosis. Spine 2007;32(12):1345–1348