{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T23:05:06Z","timestamp":1765667106468},"reference-count":18,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["SPI"],"published-print":{"date-parts":[[2015,5]]},"abstract":"<jats:sec>\n<jats:title>OBJECT<\/jats:title>\n<jats:p>The cervical interfacet spacer (CIS) is a relatively new technology that can increase foraminal height and area by facet distraction. These offer the potential to provide indirect neuroforaminal decompression while simultaneously enhancing fusion potential due to the relatively large osteoconductive surface area and compressive forces exerted on the grafts. These potential benefits, along with the relative ease of implantation during posterior cervical fusion procedures, make the CIS an attractive adjuvant in the management of cervical pathology. One concern with the use of interfacet spacers is the theoretical risk of inducing iatrogenic kyphosis. This work tests the hypothesis that interfacet spacers are associated with loss of cervical lordosis.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>METHODS<\/jats:title>\n<jats:p>Records from patients undergoing posterior cervical fusion at Rush University Medical Center between March 2011 and December 2012 were reviewed. The FacetLift CISs were used in all patients. Preoperative and postoperative radiographic data were reviewed and the Ishihara indices and cervical lordotic angles were measured and recorded. Statistical analyses were performed using STATA software.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>RESULTS<\/jats:title>\n<jats:p>A total of 64 patients were identified in whom 154 cervical levels were implanted with machined allograft interfacet spacers. Of these, 15 patients underwent anterior-posterior fusions, 4 underwent anterior-posterior-anterior fusions, and the remaining 45 patients underwent posterior-only fusions. In the 45 patients with posterior-only fusions, a total of 110 levels were treated with spacers. There were 14 patients (31%) with a single level treated, 16 patients (36%) with two levels treated, 5 patients (11%) with three levels treated, 5 patients (11%) with four levels treated, 1 patient (2%) with five levels treated, and 4 patients (9%) with six levels treated. Complete radiographic data were available in 38 of 45 patients (84%). On average, radiographic follow-up was obtained at 256.9 days (range 48\u2013524 days). There was no significant difference in the Ishihara index (5.76 preoperatively and 6.17 postoperatively, p = 0.8037). The analysis had 80% power to detect a change of 4.25 in the Ishihara index at p = 0.05. There was no significant difference in the preand postoperative cervical lordotic angles (35.6\u00b0 preoperatively and 33.6\u00b0 postoperatively, p = 0.2678). The analysis had 80% power to detect a 7\u00b0 change in the cervical lordotic angle at p = 0.05. The ANOVA of the Ishihara index and cervical lordotic angle did not show a statistically significant difference in degree of change in cervical lordosis among patients with a different number of levels of CIS insertion (p = 0.25 and p = 0.96, respectively).<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>CONCLUSIONS<\/jats:title>\n<jats:p>In the authors' experience of placing CISs in more than 100 levels, they found no evidence of significant loss of cervical lordosis. The long-term impacts of these implants on fusion rates and clinical outcomes (particularly radiculopathy and postoperative C-5 palsies) remain active areas of interest and fertile ground for further studies.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2014.10.spine14192","type":"journal-article","created":{"date-parts":[[2015,2,13]],"date-time":"2015-02-13T15:03:17Z","timestamp":1423839797000},"page":"466-469","source":"Crossref","is-referenced-by-count":33,"title":["Cervical interfacet spacers and maintenance of cervical lordosis"],"prefix":"10.3171","volume":"22","author":[{"given":"Lee A.","family":"Tan","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David C.","family":"Straus","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vincent C.","family":"Traynelis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1754","reference":[{"key":"b1-spine14192","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"962","DOI":"10.1097\/00007632-200004150-00011","article-title":"Complications of pedicle screw fixation in reconstructive surgery of the cervical spine","volume":"25","author":"Abumi","year":"2000"},{"key":"b2-spine14192","series-title":"Arch Orthop Trauma Surg","doi-asserted-by":"publisher","first-page":"471","DOI":"10.1007\/s004020050296","article-title":"Multiple regression analysis of the factors influencing the results of expansive open-door laminoplasty for cervical myelopathy due to ossification of the posterior longitudinal ligament","volume":"117","author":"Fujimura","year":"1998"},{"key":"b3-spine14192","series-title":"J Neurosurg Spine","doi-asserted-by":"publisher","first-page":"689","DOI":"10.3171\/2011.2.SPINE10601","article-title":"Facetal distraction as treatment for singleand multilevel cervical spondylotic radiculopathy and myelopathy: a preliminary report","volume":"14","author":"Goel","year":"2011"},{"key":"b4-spine14192","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"521","DOI":"10.1097\/00007632-198607000-00003","article-title":"Roentgenographic findings of the cervical spine in asymptomatic people","volume":"11","author":"Gore","year":"1986"},{"key":"b5-spine14192","series-title":"Eur Spine J","doi-asserted-by":"publisher","first-page":"523","DOI":"10.1007\/s00586-010-1602-8","article-title":"Surgical treatment of cervical kyphosis","volume":"20","author":"Han","year":"2011"},{"key":"b6-spine14192","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"1472","DOI":"10.1097\/00007632-199707010-00009","article-title":"Radiographic standing cervical segmental alignment in adult volunteers without neck symptoms","volume":"22","author":"Hardacker","year":"1997"},{"key":"b7-spine14192","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"2442","DOI":"10.1097\/00007632-199511001-00013","article-title":"Complications of posterior cervical plating","volume":"20","author":"Heller","year":"1995"},{"key":"b8-spine14192","series-title":"Eur Spine J","doi-asserted-by":"publisher","first-page":"890","DOI":"10.1007\/s00586-010-1590-8","article-title":"A late neurological complication following posterior correction surgery of severe cervical kyphosis","volume":"20","author":"Hojo","year":"2011"},{"key":"b9-spine14192","series-title":"Nippon Seikeigeka Gakkai Zasshi","first-page":"1033","article-title":"[Roentgenographic studies on the normal pattern of the cervical curvature]","volume":"42","author":"Ishihara","year":"1968"},{"key":"b10-spine14192","series-title":"Anat Clin","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1007\/BF01654627","article-title":"Spinal stability as defined by the three-column spine concept","volume":"7","author":"Louis","year":"1985"},{"key":"b11-spine14192","series-title":"J Neurosurg Spine","doi-asserted-by":"publisher","first-page":"103","DOI":"10.3171\/2012.4.SPINE11255","article-title":"Multivariate analysis of C-5 palsy incidence after cervical posterior fusion with instrumentation","volume":"17","author":"Nakashima","year":"2012"},{"key":"b12-spine14192","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"447","DOI":"10.1097\/00007632-198805000-00001","article-title":"The vertical stability of the cervical spine","volume":"13","author":"Pal","year":"1988"},{"key":"b13-spine14192","series-title":"J Neurosurg Spine","doi-asserted-by":"publisher","first-page":"141","DOI":"10.3171\/2013.4.SPINE12838","article-title":"Cervical spine alignment, sagittal deformity, and clinical implications. 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