Abstract
Introduction
To analyze how K-line is related to change in sagittal cervical curvature and laminoplasty outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL).
Materials and methods
The study retrospectively analyzed 81 patients with OPLL who had undergone posterior cervical single-door laminoplasty and arch plate fixation between June 2011 and June 2017. Fifty-five were K-line positive (K[+]) and 26 were K-line negative (K[−]). Clinical and radiological results were compared between the groups. Patients were followed up for at least 2 years.
Results
Before the operation, Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS) score, neck disability index (NDI), and short-form-36 (SF-36) quality of life score did not differ significantly between the groups. Neurological function was improved in both groups after the procedure. At last follow-up, JOA score, VAS score, NDI, SF-36 score, and JOA score improvement rate differed significantly between the groups. Before the operation, at the 3-month and final follow-ups, C2–7 Cobb angle, T1 slope, and C2–7 SVA differed significantly between the groups. The changes were more marked in the K(−) group than in the K(+) group. The incidence of cervical kyphosis differed significantly between the groups (P < 0.05), as well as between patients with lordosis < 7° and those with lordosis ≥ 7°.
Conclusions
K-line negativity and lordosis < 7° may predict kyphosis after laminoplasty in patients with OPLL. The cervical curvature in patients with OPLL tends towards kyphosis and anteversion after laminoplasty, which contributes to the reduced clinical effect of the procedure.
Similar content being viewed by others
References
Tsuyama N (1984) Ossification of the posterior longitudinal ligament of the spine. Clin Orthop Relat Res 184:71–84
Fargen KM, Cox JB, Hoh DJ (2012) Does ossification of the posterior longitudinal ligament progress afterlaminoplasty? Radiographic and clinical evidence of ossification of the posterior longitudinal ligament lesion growth and the risk factors for lateneurologic deterioration. J Neurosurg Spine 17(6):512–524
Matsunaga S, Nakamura K, Seichi A et al (2008) Radiographic predictors forthe development of myelopathy in patients with ossification of the posterior longitudinal ligament: a multicenter cohort study. Spine (Phila Pa 1976) 33(24):2648–2650
Ikeda Y, Nakajima A, Aiba A et al (2011) Association between serum leptin and bone metabolic markers, and the development of heterotopic ossification of the spinal ligament in femalepatients with ossification of the posterior longitudinal ligament. Eur Spine J 20(9):1450–1458
Matsunaga S, Sakou T (2012) Ossification of the posterior longitudinal ligament of the cervical spine: etiology and natural history. Spine (Phila Pa 1976) 37(5):E309-314
Kobashi G, Washio M, Okamoto K et al (2004) High body mass index after age 20 and diabetes mellitus are independent risk factors for ossification of the posterior longitudinal ligament of the spine in Japanese subjects: a case–control study in multiple hospitals. Spine (Phila Pa 1976) 29(9):1006–1010
Fujimori T, Watabe T, Iwamoto Y et al (2016) Prevalence, concomitance, and distribution of ossification of the spinalligaments: results of whole spine CT scans in 1500 Japanese patients. Spine (Phila Pa 1976) 41(21):1668–1676
Nouri A, Martin AR, Tetreault L et al (2017) MRI analysis of the combined prospectively collected AOSpine North America and International Data: the prevalence and spectrum of pathologies in a global cohort of patients with degenerative cervical myelopathy. Spine (Phila Pa 1976) 42(14):1058–1067
Nakashima H, Tetreault L, Nagoshi N et al (2016) Comparison of outcomes of surgical treatment for ossification of the posterior longitudinal ligament versus other forms of degenerative cervical myelopathy: results from the prospective, multicenter AOSpine CSM-international study of 479 patients. J Bone Jt Surg Am 98(5):370–378
Fujiyoshi T, Yamazaki M, Kawabe J et al (2008) A new concept for making decisions regarding the surgical approach for cervical ossification of the posterior longitudinal ligament: the K-line. Spine (Phila Pa 1976) 33(26):E990-993
Maruo K, Moriyama T, Tachibana T et al (2014) The impact of dynamic factors on surgical outcomes after double-doorlaminoplasty for ossification of the posterior longitudinal ligament of the cervical spine. J Neurosurg Spine 21(6):938–943
Vedantam A, Jonathan A, Rajshekhar V (2011) Association of magnetic resonance imaging signal changes and outcome prediction after surgery for cervical spondylotic myelopathy. J Neurosurg Spine 15(6):660–666
Kim B, Yoon DH, Ha Y et al (2016) Relationship between T1 slope and loss of lordosis after laminoplasty in patients with cervical ossification of the posterior longitudinal ligament. Spine J 16(2):219–225
Matsuoka T, Yamaura I, Kurosa Y et al (2001) Long-term results of the anterior floating method for cervical myelopathy caused by ossification of the posterior longitudinal ligament. Spine (Phila Pa 1976) 26(3):241–248
Kim TH, Lee SY, Kim YC et al (2013) T1 slope as a predictor of kyphotic alignment change after laminoplasty in patients with cervical myelopathy. Spine (Phila Pa 1976) 38(16):E992-997
Ames CP, Blondel B, Scheer JK et al (2013) Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy. Spine (Phila Pa 1976) 38:S149-160
Bronson WH, Moses MJ, Protopsaltis TS (2018) Correction of dropped head deformity through combined anterior and posterior osteotomies to restore horizontal gaze and improve sagittal alignment. Eur Spine J 27(8):1992–1999
Patwardhan AG, Khayatzadeh S, Havey RM et al (2018) Cervical sagittal balance: a biomechanical perspective can help clinicalpractice. Eur Spine J 27(Suppl 1):25–38
Liu X, Chen Y, Yang H et al (2017) Expansive open-door laminoplasty versus laminectomy and instrumentedfusion for cases with cervical ossification of the posterior longitudinal ligamentand straight lordosis. Eur Spine J 26(4):1173–1180
Aita I, Wadano Y, Yabuki T (2000) Curvature and range of motion of the cervical spine after laminaplasty. J Bone Jt Surg Am 82(12):1743–1748
Machino M, Ando K, Kobayashi K et al (2020) Postoperative kyphosis in cervical spondylotic myelopathy: cut-off preoperative angle for predicting the post-laminoplasty kyphosis. Spine (Phila Pa 1976) 45(10):641–648
Sugrue PA, McClendon J Jr, Halpin RJ et al (2011) Surgical management of cervical ossification ofthe posterior longitudinalligament: natural history and the role of surgical decompression and stabilization. Neurosurg Focus 30(3):E3
Suk KS, Kim KT, Lee JH et al (2007) Sagittal alignment of the cervical spine after the laminoplasty. Spine (Phila Pa 1976) 32(23):E656-660
Sakai K, Okawa A, Takahashi M et al (2012) Five-year follow-up evaluation of surgical treatment for cervical myelopathycaused by ossification of the posteriorlongitudinalligament: a prospectivecomparative study of anterior decompression and fusion with floating methodversus laminoplasty. Spine (Phila Pa 1976) 37(5):367–376
Miyazaki M, Ishihara T, Notani N et al (2018) Relationship of T1 slope with loss of lordosis and surgical outcomes after laminoplasty for cervical ossification of the posterior longitudinal ligament. Clin Neurol Neurosurg 164:19–24
Cho JH, Ha JK, Kim DG et al (2014) Does preoperative T1 slope affect radiological and functional outcomes aftercervical laminoplasty? Spine (Phila Pa 1976) 39(26):E1575-1581
Kim SW, Hai DM, Sundaram S et al (2013) Is cervical lordosis relevant in laminoplasty? Spine J 13(8):914–921
Lee CK, Shin DA, Yi S et al (2016) Correlation between cervical spine sagittal alignment and clinical outcome after cervical laminoplasty for ossification of the posterior longitudinal ligament. J Neurosurg Spine 24(1):100–107
Yoshii T, Yamada T, Hirai T et al (2014) Dynamic changes in spinal cord compression by cervical ossification of the posterior longitudinal ligament evaluated by kinematic computed tomographymyelography. Spine (Phila Pa 1976) 39(2):113–119
Ito K, Yukawa Y, Ito K et al (2015) Dynamic changes in the spinal cord cross-sectional area in patients with myelopathy due to cervical ossification of posterior longitudinal ligament. Spine J 15(3):461–466
Koda M, Mochizuki M, Konishi H et al (2016) Comparison of clinical outcomes between laminoplasty, posterior decompression with instrumented fusion, and anterior decompression with fusion for K-line (−) cervical ossification of the posterior longitudinal ligament. Eur Spine J 25(7):2294–2301
Funding
There is no funding source.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
This article does not contain any studies with human participants or animals performed by any of the authors.
Informed consent
Informed consent was obtained from all individual participants included in the study.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Li, C., Zha, G., Yang, Z. et al. K-line in patients with cervical ossification of the posterior longitudinal ligament: relationship with change in sagittal cervical curvature and laminoplasty outcomes. Arch Orthop Trauma Surg 142, 1743–1751 (2022). https://doi.org/10.1007/s00402-020-03741-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00402-020-03741-8