Elsevier

World Neurosurgery

Volume 148, April 2021, Pages e617-e626
World Neurosurgery

Original Article
Surgical Options in Treating Ossification of the Posterior Longitudinal Ligament: Single-Center Experience

https://doi.org/10.1016/j.wneu.2021.01.046Get rights and content

Background

Ossified posterior longitudinal ligament (OPLL) of the cervical spine can lead to spinal stenosis and become clinically symptomatic. The optimal approach in addressing OPLL is a debated topic and dependent on factors such as preoperative lordosis and levels affected.

Methods

In this study, we retrospectively identified patients undergoing operative management for OPLL. Demographics, operative details, radiographic parameters, outcome measurements, and complications were compared between the different approaches for OPLL treatment.

Results

We identified a total of 44 patients with 16 undergoing laminoplasty (Plasty), 18 anterior corpectomy and diskectomy (Ant), and 10 laminectomy and instrumentation (Linst). Ant had least OPLL levels with median (range) 3 (2–5), compared with Plasty 4 (2–7) and Linst 4 (3–6). Plasty was associated with the shortest operative time and hospital stay. Ant showed significant correction in kyphosis from 0.5° (−13 to 16°) to 9.5° (−7 to 20°). There was loss in lordosis in Plasty and Linst. Sagittal balance significantly increased irrespective of surgical approach with the least increase in the Ant group. Complications were least in the Plasty group with similar overall improvement in outcome measurements.

Conclusions

All 3 approaches in the management of OPLL were associated with clinical improvement without 1 approach surpassing the others. Laminoplasty had the advantage of addressing more levels of stenosis than the anterior approach and was associated with a shorter operating time. Laminoplasty patients had a shorter hospital stay than those undergoing laminectomy and instrumentation and appeared to have fewer complications than the other approaches. Laminoplasty is the preferred approach in patients with preserved motion and lordosis, with the anterior approach effective in the correction of kyphosis.

Introduction

Ossified posterior longitudinal ligament (OPLL) involves the abnormal ectopic calcification of the posterior longitudinal ligament most often in the cervical spine.1, 2, 3, 4, 5 The prevalence of OPLL is reported to range from 1.9%−4.3% among the East Asian population and 0.1%−2.5% in the North American and European populations.2 Genetic factors encoding collagen (collagen type VI alpha 1 chain [COL6A1] and collagen type XI alpha 2 chain [COL11A2]) have been implicated in the pathogenesis of OPLL. Other genes important in the formation of bone, such as transforming growth factor beta (TGF-B) and bone morphogenic protein (BMP), also have increased expression in OPLL.3,4 The development of OPLL can lead to stenosis of the spinal canal and present with symptoms of radiculopathy or myelopathy and myelomalacia on magnetic resonance imaging (MRI) in severe cases. The definitive management of symptomatic OPLL is surgical decompression.

The optimal approach in addressing OPLL is a debated topic and dependent on factors such as preoperative lordosis and the levels affected.2 The anterior approach is often advocated in severe focal stenosis and kyphosis and is associated with better restoration of cervical lordosis.5, 6, 7, 8, 9 The posterior approach (laminoplasty or laminectomy and fusion) can often be effective in the decompression of multilevel stenosis where lordosis is still present.6,7 Laminoplasty may offer better retention of cervical motion, while laminectomy and fusion may offer better protection against the progression of kyphosis.10

In this study, we reviewed our department's experience managing patients with OPLL treated with laminoplasty (Plasty), anterior (Ant), or laminectomy and fusion (Linst) approaches. We examined the indications, radiographic parameters, complications, and outcomes associated with each approach.

Section snippets

Patient Population

We reviewed the records of patients with the diagnosis of OPLL with retrievable diagnostic imaging treated by our department since 2007. Our search (IRB 202002195) yielded 44 patients, 16 of whom were treated with laminoplasty, 18 with anterior corpectomy and diskectomy, and 10 with posterior laminectomy and instrumentation. Imaging studies reviewed included plain radiographs, MRI, and computed tomography (CT) scans of the cervical spine. Health-related outcomes were assessed before surgery and

Demographics and Operative Details

In the entire group, there were 27 men and 17 women with median ages of 58, range 39–74 years, and median BMI of 33, range 21–54. There was no significant difference in age or BMI between the 3 cohorts treated with Plasty, Ant, or Linst approaches (Table 1). The Linst group had the highest percentage (80%) of males. Presenting diagnosis was myelopathy in 10 (63%), 12 (67%), and 9 (90%) patients in the Plasty, Ant, and Linst groups, respectively. The remaining patients presented with neck or

Demographics and Diagnostics

There was no significant difference in the 3 cohorts in age and BMI. Linst had the highest percentage of males (80%), likely a result of small sample size, but all 3 cohorts showed a higher percentage of males compared with females. The frequency of OPLL at presentation in the sixth decade and predominance of males is reflected in other reports as well.2,7,9,15 There were also notable differences between the groups in presenting symptoms and K-line despite not reaching statistical significance

Conclusion

All 3 approaches in the management of OPLL were associated with clinical improvement without 1 approach surpassing the others. In our experience we continue to advocate for laminoplasty in the setting of multilevel stenosis without kyphosis because of our lower complication rate and shorter operating time with similar clinical benefit. We consider Linst in select cases with multilevel stenosis without kyphosis and various combinations of myelopathy, myelomalacia, or K-line negativity and Ant

CRediT authorship contribution statement

Brian J. Park: Conceptualization, Data curation, Formal analysis, Investigation, Validation, Writing - original draft, Writing - review & editing. Scott C. Seaman: Data curation, Formal analysis, Investigation, Validation, Writing - review & editing. Royce W. Woodroffe: Data curation, Formal analysis, Investigation, Validation, Writing - review & editing. Jennifer Noeller: Data curation, Formal analysis, Investigation, Writing - review & editing. Patrick W. Hitchon: Conceptualization, Data

References (30)

  • M. Iwasaki et al.

    Surgical strategy for cervical myelopathy due to ossification of the posterior longitudinal ligament: part 2: advantages of anterior decompression and fusion over laminoplasty

    Spine

    (2007)
  • T. Yoshii et al.

    Anterior cervical corpectomy and fusion using a synthetic hydroxyapatite graft for ossification of the posterior longitudinal ligament

    Orthopedics

    (2017)
  • S.K. Mehdi et al.

    Comparison of clinical outcomes in decompression and fusion versus decompression only in patients with ossification of the posterior longitudinal ligament: a meta-analysis

    Neurosurg Focus

    (2016)
  • N. Tsuyama

    Ossification of the posterior longitudinal ligament of the spine

    Clin Orthop

    (1984)
  • P.W. Hitchon et al.

    Anterior and posterior approaches for cervical myelopathy: clinical and radiographic outcomes

    Spine

    (2019)
  • Cited by (0)

    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

    View full text