Interspinous implants (X Stop®, Wallis®, Diam®) for the treatment of LSS: is there a correlation between radiological parameters and clinical outcome?
- 446 Downloads
Neurogenic intermittent claudication, caused by lumbar spinal stenosis (LSS), usually occurs after the age of 50 and is one of the most common degenerative spinal diseases in the elderly. Among patients over the age of 65 with LSS, open decompression is the most frequently performed spinal operation. The recently introduced interspinous spacers are a new alternative under discussion. In this retrospective study, we reviewed medical records and radiographs of patients with LSS and NIC treated from June 2003 to June 2007. All included patients (n = 129) were treated with interspinous implants (X Stop® Wallis®, or Diam®). Evaluations of pain, using a visual analog scale (VAS), and radiographic signs, using two-plane X-rays of the lumbar spine, were performed preoperatively (preop), postoperatively (postop) and after discharge (FU 2–3). Gender ratio (m:w) was 1.1:1. Mean age of the patients was 60.8 ± 16.3 years. Foraminal height, foraminal width, foraminal cross-sectional area, intervertebral angle, as well as anterior and posterior disc height changed significantly (P < 0.0001) after implantation of the interspinous device. Postoperatively, symptom relief (VAS) was significant (P < 0.0001). The X Stop implant improved (in some cases significantly) the radiographic parameters of foraminal height, width, and cross-sectional area, more than the Diam and Wallis implants; however, there was no significant difference among the three regarding symptom relief. FU 1 was on average 202.3 ± 231.9 and FU 2 527.2 ± 377.0 days postoperatively. During FU, the radiological improvements seemed to revert toward initial values. Pain (VAS) did not increase despite this “loss of correction.” There was no correlation between age and symptom improvement. There was only very weak correlation between the magnitude of radiographic improvement and the extent of pain relief (VAS). The interspinous implant did not worsen low-grade spondylolisthesis. Provided there is a strict indication and fusion is not required, implantation of an interspinous spacer is a good alternative to treat LSS. The interspinous implant offers significant, longlasting symptom control, even if initially significant radiological changes seem to revert toward the initial values (“loss of correction”).
KeywordsInterspinous spacer Interspinous process device Interspinous process decompression Lumbar spinal stenosis Neurogenic intermittent claudication
- 2.Anderson PA, Tribus CB, Kitchel SH (2006) Treatment of neurogenic claudication by interspinous decompression: application of the X Stop device in patients with lumbar degenerative spondylolisthesis. J Neurosurg 4:463–471Google Scholar
- 9.Costa F, Sassi M, Cardia A, Ortolina A, De Santis A, Luccarell G, Fornari M (2007) Degenerative lumbar spinal stenosis: analysis of results in a series of 374 patients treated with unilateral laminotomy for bilateral microdecompression. J Neurosurg 7:579–586Google Scholar
- 17.Hsu KY, Zucherman JF, Hartjen CA, Mehalic TF, Implicito DA, Martin MJ, Johnson DR 2nd, Skidmore GA, Vessa PP, Dwyer JW, Cauthen JC, Ozuna RM (2006) Quality of life of lumbar stenosis-treated patients in whom the X Stop interspinous device was implanted. J Neurosurg 5:500–507Google Scholar
- 23.Kosaka H, Sairyo K, Biyani A, Leaman D, Yeasting R, Higashino K, Sakai T, Katoh S, Sano T, Goel VK, Yasui N (2007) Pathomechanism of loss of elasticity and hypertrophy of lumbar ligamentum flavum in elderly patients with lumbar spinal canal stenosis. Spine 32:2805–2811. doi:10.1097/BRS.0b013e31815b650f PubMedCrossRefGoogle Scholar
- 26.Malmivaara A, Slatis P, Heliovaara M, Sainio P, Kinnunen H, Kankare J, Dalin-Hirvonen N, Seitsalo S, Herno A, Kortekangas P, Niinimaki T, Ronty H, Tallroth K, Turunen V, Knekt P, Harkanen T, Hurri H (2007) Surgical or non-operative treatment for lumbar spinal stenosis? A randomized controlled trial. Spine 32:1–8. doi:10.1097/01.brs.0000251014.81875.6d PubMedCrossRefGoogle Scholar
- 33.Schulte TL, Hurschler C, Haversath M, Liljenqvist U, Bullmann V, Filler TJ, Osada N, Fallenberg EM, Hackenberg L (2008) The effect of dynamic, semi-rigid implants on the range of motion of lumbar motion segments after decompression. Eur Spine J 17:1057–1065. doi:10.1007/s00586-008-0667-0 PubMedCrossRefGoogle Scholar
- 41.Weinstein JN, Tosteson TD, Lurie JD, Tosteson AN, Blood E, Hanscom B, Herkowitz H, Cammisa F, Albert T, Boden SD, Hilibrand A, Goldberg H, Berven S, An H (2008) Surgical versus non-surgical therapy for lumbar spinal stenosis. N Engl J Med 358:794–810. doi:10.1056/NEJMoa0707136 PubMedCrossRefGoogle Scholar
- 43.Zucherman JF, Hsu KY, Hartjen CA, Mehalic TF, Implicito DA, Martin MJ, Johnson DR 2nd, Skidmore GA, Vessa PP, Dwyer JW, Puccio ST, Cauthen JC, Ozuna RM (2005) 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 30:1351–1358. doi:10.1097/01.brs.0000166618.42749.d1 PubMedCrossRefGoogle Scholar