Cervical myelopathy due to degenerative spondylolisthesis

Tomoaki Koakutsu,Junko Nakajo,Naoki Morozumi,Takeshi Hoshikawa,Shinji Ogawa,Yushin Ishii

doi:10.3109/03009734.2011.551932

Tomoaki Koakutsu, Junko Nakajo + Show 4 more

Open Access

https://doi.org/10.3109/03009734.2011.551932

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Abstract

Objective. To investigate clinical-radiological features of cervical myelopathy due to degenerative spondylolisthesis (DSL).Methods. A total of 448 patients were operated for cervical myelopathy at Nishitaga National Hospital between 2000 and 2003. Of these patients, DSL at the symptomatic disc level was observed in 22 (4.9%) patients. Clinical features were investigated by medical records, and radiological features were investigated by radiographs.Results. Disc levels of DSL were C3/4 in 6 cases and C4/5 in 16 cases. Distance of anterior slippage was 2 to 5 mm (average 2.9 mm) in flexion position. Space available for the spinal cord (SAC) was 11 to 15 mm (average 12.8 mm) in flexion position and 11 to 18 mm (average14.6 mm) in extension position; 11 cases were reducible and 11 cases were irreducible in extension position. Myelograms demonstrated compression of spinal cord by the ligamentum flavum in extension position. Compression of spinal cord was not demonstrated in flexion position. C5-7 lordosis angle was lower than control. C5-7 range of motion (ROM) was reduced compared to controls. These alterations were statistically significant.Conclusions. DSL occurs in the mid-cervical spine. Lower cervical spine demonstrated restricted ROM and lower lordosis angle. Pathogenesis of cervical myelopathy due to DSL is compression of spinal cord by the ligamentum flavum in extension position and not by reduced SAC in flexion position.

Highlights

Cervical myelopathy results from compression of the spinal cord by various degenerative processes of the spine
While it has long been suggested that degenerative spondylolisthesis (DSL) of the cervical spine may be a spinal factor [2], Kokubun et al [1] did not include DSL as a spinal factor
The purpose of this study is to investigate clinical-radiological features of cervical myelopathy due to DSL

Summary

Introduction

Cervical myelopathy results from compression of the spinal cord by various degenerative processes of the spine. Kokubun et al described the following seven spinal factors compressing the spinal cord: developmental stenosis, dynamic stenosis, disc herniation, segmental ossification of the posterior longitudinal ligament (OPLL), continuous OPLL, posterior spur, and calcification of ligamentum flavum. These factors were involved in 98% of cervical myelopathy cases [1]. The number of reports on cervical spondylotic myelopathy due to DSL has not been low [3,4,5,6,7], but no general consensus has been reached on the onset mechanism of spinal cord compression. The purpose of this study is to investigate clinical-radiological features of cervical myelopathy due to DSL

Methods

Results

Conclusion