Associations between Clinical Symptoms and Degree of Ossification in Patients with Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multi-Institutional Cross-Sectional Study

Takashi Hirai,Atsushi Okawa,Atsushi Kimura,Morio Matsumoto,Shiro Imagama,Kazuhiro Takeuchi,Satoshi Maki,Tetsuro Ohba,Kota Watanabe,Kanji Mori,Yukihiro Matsuyama,Satoshi Kato,Takeo Furuya,Hiroshi Ozawa,Soraya Nishimura,Yoshiharu Kawaguchi,Narihito Nagoshi,Shuta Ushio,Masaya Nakamura,Hiroyuki Katoh,Jun Hashimoto,Kenyu Ito,Kanichiro Wada,Keiichi Katsumi,Hiroyuki Inose,Takashi Kaito,Masashi Yamazaki,Katsuya Nagashima,Masato Yuasa,Yuji Matsuoka,Hirotaka Haro,Toshitaka Yoshii,Norihiro Nishida,Masao Koda,Kei Watanabe,Masahiko Watanabe,Katsushi Takeshita

doi:10.3390/jcm9124055

Abstract

This study aimed to clarify whether ossification predisposition influences clinical symptoms including pain, restriction of activities of daily living, and quality of life in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Cervical ossification predisposition potentially causes neurologic dysfunction, but the relationship between clinical symptoms and radiologic severity of OPLL has not yet been investigated. Data were prospectively collected from 16 institutions across Japan. We enrolled 239 patients with cervical OPLL. The primary outcomes were patient-reported outcomes, including visual analog scale (VAS) pain scores and other questionnaires. Whole-spine computed tomography images were obtained, and correlations were investigated between clinical symptoms and radiologic findings, including the distribution of OPLL, the sum of the levels where OPLL was present (OP-index), and the canal narrowing ratio (CNR) grade. The cervical OP-index was Grade 1 in 113 patients, Grade 2 in 90, and Grade 3 in 36. No significant correlations were found between radiologic outcomes and VAS pain scores. The cervical OP-index was associated with lower extremity function, social dysfunction, and locomotive function. The CNR grade was not correlated with clinical symptoms, but Grade 4 was associated with lower extremity dysfunction. Thickness and extension of ossified lesions may be associated with lower extremity dysfunction in cervical OPLL.

Highlights

Ossification of spinal ligaments is recognized as a musculoskeletal disorder that often leads to neurological dysfunction
Various studies have examined surgical techniques, [2] postoperative courses [6,7,21], perioperative complications [3], and types of ossification [22]; no study has investigated the association between radiologic severity of OPLL and clinical symptoms
We found that approximately half of the patients with a diagnosis of cervical OPLL had neck pain and/or low back pain (LBP), regardless of the number of ossified lesions

Summary

Introduction

Ossification of spinal ligaments is recognized as a musculoskeletal disorder that often leads to neurological dysfunction. Ossification of the posterior longitudinal ligament (OPLL) has been widely investigated worldwide because of its high prevalence This heterotopic ossification occurs in the cervical and thoracic spine, where the spinal cord lies inside the canal space, and can result in spinal disorders, even in asymptomatic cases following minor head trauma. OPLL has been shown to coexist with the ossification of other spinal ligaments, including the nuchal ligament [13], the anterior longitudinal ligament [14], the supra- and inter-spinous ligaments [15], the yellow ligament in the whole spine [16] Ossification of these ligaments, especially in the cervical spine, sometimes leads to neurologic symptoms, including numbness or loss of sensation in the extremities and difficulty walking.

Objectives

Methods

Results

Conclusion