A less-invasive cervical laminoplasty for spondylotic myelopathy that preserves the semispinalis cervicis muscles and nuchal ligament

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Modified cervical laminoplasty techniques have been developed to reduce postoperative axial neck pain and preserve function in patients with cervical spondylotic myelopathy (CSM). However, the previous studies demonstrating satisfactory surgical outcomes had a retrospective design. Here, the authors aimed to prospectively evaluate the 2-year outcomes of a modified cervical laminoplasty technique for CSM that preserves the paravertebral muscles.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Outcomes were analyzed for 40 patients (22 men and 18 women; mean age, 66.6 years; age range 44–92 years) with CSM who underwent C4–6 laminoplasty with C-3 and C-7 partial laminectomies or C-3 total and C-7 partial laminectomies and received hydroxyapatite spacers. Neurological, pain severity, and spinal radiographic evaluations were performed preoperatively and at 3, 6, 12, 18, and 24 months postoperatively. Plain radiography and MRI of the cervical spine were performed to evaluate the range of motion (ROM), sagittal alignment, and cross-sectional areas of the deep extensor muscles. The extent of bone–spacer bonding and bony union at the gutter was assessed by CT.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>The mean preoperative Japanese Orthopaedic Association CSM score was 10.2, but it increased to 14.4 by 24 months after surgery. Eleven patients had axial neck pain preoperatively, but only 3 reported mild pain at 24 months, and in all 3 cases the pain was mild. The mean angle of lordosis was 11.7° preoperatively and 12.0° 2 years postoperatively. Although the ROM at the C2–7 levels was significantly reduced 3 months postoperatively, an increasing trend was observed up to 12 months, and 86% of the preoperative ROM was achieved by 2 years postoperatively. The mean paravertebral muscle cross-sectional areas were 833 ± 215 mm<jats:sup>2</jats:sup> preoperatively and 763 ± 197 mm<jats:sup>2</jats:sup> 24 months postoperatively, but the difference was not statistically significant. The rates of bone–spacer bonding and bony union at the gutter were low during the early stages but increased to 90% and 93%, respectively, by 2 years after surgery.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The modified laminoplasty technique used in this study ensured very good neurological status and ROM after 2 years and was associated with low incidences of axial neck pain and serious complications. This simple and easy operative method could benefit future laminoplasty protocols.</jats:p></jats:sec>

The Change of Range of Motion at Anterior Compression of the Cervical Cord after Laminoplasty in Patients with Cervical Spondylotic Myelopathy

“…A number of laminoplasty procedures have been developed for the treatment of CSM. Many studies have shown that the surgical outcome of laminoplasty are satisfactory131115182225). However, postoperative complications may arise, including decreased cervical ROM and loss of cervical lordotic alignment, all of which may significantly impair the quality of life4510).…”

“…However, there have been several reports describing a reduction in ROM and cervical malalignment after cervical laminoplasty such as kyphosis and spondylolisthesis, and these problems remain under discussion241324). In many researches, ROM reduction is reported to range from 30% to 70% of the preoperative ROM1722).…”

“…Some authors have reported a relationship between cervical ROM and cervical posterior muscle condition, especially that of the deep muscles, after laminoplasty3). Another hypothesized cause of the reduction is spontaneous laminar fusion, for which several preventative methods have been considered22). Early mobilization after surgery has been recommended10).…”

Differences in radiological and functional outcomes between cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament after multi-level laminoplasty

“…Some previous reports have described a reduction in ROM as well as a progression of sagittal imbalance after laminoplasty, but the etiology of these problems remain debatable [10,11]. The damage and atrophy of the posterior deep muscles including the semispinalis cervicis muscle, injury of the nuchal ligament, and bony fusion of facet joints after laminoplasty are considered the main reasons for these postoperative changes [12][13][14]. The reduction in ROM following laminoplasty is reported to range from 30-70% of the preoperative ROM [15][16][17].…”

Cervical laminoplasty developments and trends, 2003–2013: a systematic review

“…9,15,41,42,45,46,81,87,97 Emphasis was placed on the semispinalis cervicis, which they tried to preserve 97 or repair. 5,74,110 Furthermore, they also tried to preserve muscles that attach to the spinous processes of C-7.…”