Ossification posterior longitunal ligament (OPLL)

 

 

Definition

 

Ossification of the posterior longitudinal ligament (OPLL)

 

Heterotopic ossification of the posterior longitudinal ligament

 

Epidemiology

 

2:1 Male:Female

 

More common in Japanese and East Asian populations

 

Fujimori et al Spine 2016

- CT of 1500 Japanese patients

- incidence of cervical OPLL 6%

 

Natural history

 

Matsunaga et al Spine 2012

- of those myelopathy free at baseline, 71% remained free at 30 year follow up

- 64% of patients with OPLL and myelopathy had progressive neurological deterioration

 

Clinical

 

Radiculopathy

Myelopathy

Risk of spinal cord injury

 

Xray

 

 

MRI

 

Can miss OPLL in stenosis

 

MRI and CT in same patient with OPLL

 

CT

 

OPLL on CT

 

Occupancy ratio

 

 

Matsunaga et al Spine 2008

- 156 patients with OPLL with 10 years of follow up

- occupancy ratio < 60% - 49% developed myelopathy

- occupancy ratio > 60% - 100% developed myelopathy

 

Classification

 

1. Localized - with a solitary OPLL lesion
2. Segmental - multiple, separate vertebral level lesions
3. Continuous - single uninterrupted lesion involving multiple segments
4. Mixed

 

Management

 

Options

 

Anterior approach (ACDF / corpectomy)

 

Advantage

- direct decompression

- suitable for patients with kyphosis

- possible better for patients with worse disease / higher canal occupancy ratios

 

Disadvantage

- dural tears

Posterior approach (laminotomy / laminectomy and fusion)

 

Advantage

- indirect decompression

- indicated for multilevel disease i.e 3 or more levels

- lower risk of dural tear

 

Disadvantage

- contra-indicated with kyphosis > 10 - 15 degrees

- wound issues

- increased risk of C5 nerve palsy

 

Outcomes

 

OPLL versus other forms of stenosis

 

Nakashima et al JBJS 2016

- prospective study of 135 patients with OPLL undergoing decompression

- no difference in outcomes compared with those without OPLL

- higher risk of complications

 

Anterior versus posterior approach

 

Feng et al Int J Surg 2016

- anterior versus posterior approach

- systematic review and meta-analysis of 13 studies

- better outcomes with anterior decompression, especially with canal occupancy ratio > 50-60%

- increased complications, blood loss, and operative time with anterior approach

- dural tear rate 31% with anterior approach

 

Posterior approaches

 

Nakoshima et al Sci Rep 2022

- 189 patients with OPLL

- compared laminoplasty to posterior fusion

- equivalent outcomes

- reduced complications and C5 nerve palsy, with increase ROM with laminoplasty