Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P99. Laminoplasty and laminectomy hybrid decompression for the treatment of cervical spondylotic myelopathy with hypertrophic ligamentum flavum: a retrospective study

Abstract

BACKGROUND CONTEXT Laminoplasty is widely used in patients with cervical spondylotic myelopathy (CSM); however, for CSM patients with hypertrophic ligamentum flavum (HLF), traditional laminoplasty does not include resection of a pathological ligamentum flavum. PURPOSE To report the outcomes of a posterior hybrid decompression protocol for the treatment of CSM)associated withHLF. STUDY DESIGN/SETTING This study retrospectively reviewed 116 CSM patients with HLF who underwent hybrid decompression with a minimum of 12 months of follow-up. The procedure consisted of reconstruction of the C4 and C6 laminae using CENTERPIECE plates with spinous process autografts, and resection of the C3, C5, and C7 laminae. Surgical outcomes were assessed using Japanese Orthopedic Association (JOA) score, recovery rate, cervical lordotic angle, cervical range of motion, spinal canal sagittal diameter, bone healing rates on both the hinge and open sides, dural sac expansion at the level of maximum compression, drift-back distance of the spinal cord, and postoperative neck pain assessed by visual analog scale. PATIENT SAMPLE During a consecutive 3-year period from February 2009 through April 2012, 283 patients underwent hybrid posteriordecompression in our hospital. The current study retrospectively reviewed 116 CSM patients with HLF who underwent thisprocedure. The researchers selected patients with CSM caused only by HLF (dorsal compression of the spinal cord owing to HLF) and patients with CSM caused by the combination of anterior disease plus HLF (dorsal compression of the spinal cord owing to HLF and anterior disease such as ossification of the posterior longitudinal ligament [OPLL], degenerative disk disease [DDD], and congenital pathologies). The inclusion criteria were: (1) a clear diagnosis made by history, physical examination, plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI); (2) complete pre- and postoperative imaging and clinical data records; (3) a minimum of 12 months’ postoperative follow-up. Exclusion criteria were: (1) CSM patients with multilevel anterior compression only; e.g., consecutive OPLL or DDD, bu without HLF; and (2) patients lost to follow-up. Of the 116 patients (89 men, 27 women [mean age 61.9 years], 55 also had segmental or localized OPLL, 41 also had cervical degenerative disk herniation (DDH), 11 also had developmental spinal canal stenosis (DSCS), and 9 had ossification of ligament flavum (OLF). Thirteen of 116 patients had single-level spinal canal stenosis, 29 had twolevel stenosis, 48 had three-level stenosis, and the remaining 26 patients had four- or five-level stenosis. OUTCOME MEASURES Results were analyzed using PASW Statistics for Windows, Version 18.0 (SPSS Inc., Chicago, IL, USA). Descriptive statisticswere used for demographics, and Student's t-test was used for continuous variables. Significance was set at P METHODS Not applicable. RESULTS No hardware failure or restenosis was noted. Postoperative JOA score improved significantly, with a mean recovery rate of 65.3±15.5%. Mean cervical lordotic angle had decreased 4.9° by 1 year after surgery (P CONCLUSIONS Hybrid laminectomy and autograft laminoplasty decompression using Centerpiece plates may facilitate bone healing and produce a comparatively satisfactory prognosis for CSM patients with HLF.