Long-term Follow-up After Open-window Corpectomy in Patients With Advanced Cervical Spondylosis and/or Ossification of the Posterior Longitudinal Ligament

Ossification of the Posterior Longitudinal Ligament in Cervical Spine: Prevalence, Management, and Prognosis

Ossification of the posterior longitudinal ligament (OPLL) in the cervical spine and related neurological complications are not uncommon in East Asian countries. The estimated prevalence of cervical OPLL-related hospitalization is 7.7 per 100,000 person-years in Taiwan, and higher incidence rates have been observed in elderly and male patients. Although cervical OPLL is frequently insidious, it can eventually cause myelopathy and predispose patients to spinal cord injury (SCI). There are multiple options for managing cervical OPLL, ranging from observation to many kinds of surgical procedures, including posterior laminoplasty, laminectomy with or without fusion, anterior corpectomy with or without instrumentation, and circumferential decompression and fusion. None of these surgical approaches is free of complications. However, to date, there is still a lack of consensus regarding the choice of the surgical approach and the timing of surgical intervention. Cervical SCI and related neurological disabilities are more likely to occur in OPLL patients, who should therefore be cautioned regarding the possibility of a subsequent SCI if treated without surgery. This article aimed to review the prevalence, management strategies, and prognosis of cervical OPLL.

Prevalence of adjacent segment disease following cervical spine surgery: A PRISMA-compliant systematic review and meta-analysis

Prevalence estimates of adjacent segment degeneration (ASD) following cervical spine surgery varied greatly in current studies. We conducted a systematic review and meta-analysis to summarize the point prevalence of ASD after cervical spine surgery.

METHODS

Comprehensive electronic searches of PubMed, Embase, Web of Knowledge, and Cochrane Library databases were conducted to identify any study published from initial state to January 2016. Those reporting the prevalence of ASD after cervical surgery were included. A random-effects model was used to estimate the prevalence of radiographic ASD, symptomatic ASD, and reoperation ASD. Univariate meta-regression analyses were conducted to explore the potential associations between prevalence and length of follow-up. All analyses were performed using R version 3.2.3 (R Foundation for Statistical Computing).

RESULTS

A total of 83 studies were included in the meta-analysis. The prevalence of radiographic ASD, symptomatic ASD, and reoperation ASD after cervical surgery was 28.28% (95% confidence interval [CI], 20.96-36.96), 13.34% (95% CI, 11.06-16.00), and 5.78% (95% CI, 4.99-6.69), respectively, in a general analysis. It was found 2.79%, 1.43%, and 0.24% additions per year of follow-up in the incidence of radiographic ASD, symptomatic ASD, and reoperation ASD, respectively.

CONCLUSION

This meta-analysis provides some details about the prevalence of radiographic ASD, symptomatic ASD, and reoperation ASD after cervical spine surgery. However, the results of this meta-analysis should be interpreted with caution because of the heterogeneity among the studies.

Anterior approaches for cervical spondylotic myelopathy: which? When? How?

Cervical spondylotic myelopathy is a degenerative disorder with an unfavorable natural history. Surgical treatment options have evolved substantially over time, with both anterior and posterior methods proving successful for certain patients with specific characteristics. Anterior decompression of the spinal canal plus fusion techniques for stabilization has several advantages and some disadvantages when compared to posterior options. Understanding the pros and cons of the approaches and techniques is critical for the surgeon to select the best operative treatment strategy for any given patient to achieve the best outcome. Multiple decision-making factors are involved, such as sagittal alignment, number of levels, shape of the pathoanatomy, age and comorbidities, instability, and pre-operative pain levels. Any or all of these factors may be relevant for a given patient, and to varying degrees of importance. Choice of operative approach will therefore be dependent on patient presentation, risks of that approach for a given patient, and to some degree surgeon experience.

Prevalence of adjacent segment degeneration after spine surgery: a systematic review and meta-analysis

STUDY DESIGN

Systematic review of published prevalence of adjacent segment degeneration (ASD) after spine surgery.

OBJECTIVE

To evaluate the prevalence of ASD in patients after cervical and lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

ASD is a common complication after spine surgery in long-term follow-up. A large body of literature has been reported on the topic, but no meta-analysis of the epidemiological data on ASD has been published

METHODS

We searched the MEDLINE until March 2012 published in English language that reported the prevalence of ASD after spine surgery. We determined the ASD rates by calculating proportions and 95% confidence interval (CI) for each study and then pooled the data to derive a pooled proportion and 95% CI.

RESULTS

A total of 94 studies with 34,716 patients from 19 countries were included. The occurrence of radiograph ASD ranged from 4.8% to 92.2%, and the pooled prevalence was 29.3% (95% CI, 22.7%-35.8%) by the random-effects model. The occurrence of symptoms ASD ranged from 0.0% to 30.3%, and the pooled prevalence was 7.4% (95% CI, 6.4%-8.5%). In cervical position, the occurrence of radiograph ASD and symptoms ASD was 32.8% (95% CI, 17.8%-47.9%) and 6.3% (95% CI, 4.8%-7.8%); in lumbar position, the occurrence of radiograph ASD and symptoms ASD was 26.6% (95% CI, 21.3%-31.9%) and 8.5% (95% CI, 6.4%-10.7%). In the 0.5- to 2- or less, more than 2- to 5- or less, and more than 5- to 20- or less year diagnosis time, the radiograph ASD prevalence was 21.8% (16.0%-27.6%), 33.6% (21.8%-45.4%), and 37.4% (10.7%-64.1%), respectively; and the symptoms ASD prevalence was 6.5% (4.8%-8.1%), 12.1% (8.2%-16.0%), and 3.2% (2.5%-4.0%), respectively.

CONCLUSION

Spine surgery is associated with significant risk of ASD. These figures may be useful in the estimation of the burden of the ASD after spine surgery.

Ossification of the posterior longitudinal ligament in the cervical spine: an 11-year comprehensive national epidemiology study

OBJECT

This study aimed to calculate the incidence and prevalence of ossification of the posterior longitudinal ligament (OPLL) in the cervical spine with its comorbid disability.

METHODS

Using an 11-year nationwide database in Taiwan (National Health Insurance Research Database), this retrospective study cohort analyzed the incidences of cervical OPLL causing hospitalization. All patients admitted for the diagnosis of OPLL, regardless of surgery, were identified. Age- and sex-specific incidences, Poisson regression, and multivariate logistic regression analysis were conducted.

RESULTS

Between 1997 and 2007 covering 241,800,725.8 person-years, 1651 patients were admitted for OPLL. The overall incidence of OPLL-related admission was 6.1 per 1 million person-years. Specifically, male sex and older age were associated with higher OPLL incidences (both p < 0.001). Among the 1651 OPLL patients, 542 (32.8%) received conservative management, 612 (37.1%) had anterior only surgery, 353 (21.4%) had posterior only surgery, and 144 (8.7%) had anterior and posterior surgery. Eighty-five patients were moderately to severely disabled (5.2% cumulative incidence rate). The incidences of disability varied by age, in a decreasing trend, except for the 60- to 69-year-old age group (p = 0.05). Patients who received posterior-only surgery were more likely to have disability.

CONCLUSIONS

In a large cohort of the Chinese population, the incidence of cervical OPLL-related admission is 6.1 per 1 million person-years, and the prevalence rate is 7.7 per 100,000 person-years. Higher incidences are observed in elderly and male patients, which implies the disease's degenerative nature. After adjustments for demographics, the incidences and trends of OPLL-related comorbid disability are associated with age and surgical approaches.

Conservatively treated ossification of the posterior longitudinal ligament increases the risk of spinal cord injury: a nationwide cohort study

The optimal treatment strategy for ossification of the posterior longitudinal ligament (OPLL) depends on symptoms and is uncertain. Whether the risk of spinal cord injury (SCI) is increased in patients with cervical spinal stenosis or myelopathy caused by OPLL remains unclear. This study aimed to evaluate the risk of SCI in patients with OPLL of the cervical spine when managed with conservative treatment (no surgery). Study subjects were identified from a nationwide cohort of 26,544,883 people from 1998 to 2005 and were divided into the OPLL group (n=265), who were hospitalized for OPLL but had conservative treatment (no surgery), and the comparison group (n=5339), composed of age- and sex-matched people. Until the end of 2008, a total of 5604 subjects were followed-up for 34,723.5 person-years. The propensity score method was used to adjust for covariates. Kaplan-Meier and Cox regression analyses were performed. The incidence rate of cervical SCI in the OPLL group was found to be significantly higher than in the comparison group (4.81 versus 0.18 per 1000 person-years; p<0.001). Cervical SCI was more likely to happen in the OPLL group than in the comparison group (crude hazard ratio [HR] 25.64; p<0.001). After adjustments, the OPLL group had a 32.16-fold (p<0.001) higher risk for cervical SCI. Disability caused by SCI had an even higher risk (HR=110.72, adjusted HR=104.78; p<0.001) for the OPLL group. Therefore, cervical SCI and related disabilities are more likely to happen in OPLL patients, who should be cautioned for subsequent SCI if treated conservatively.

Ossification of the posterior longitudinal ligament: a review

Ossification of the posterior longitudinal ligament (OPLL) is most commonly found in men, the elderly, and Asian patients. There are many diseases associated with OPLL, such as diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, and other spondyloarthropathies. Several factors have been reported to be associated with OPLL formation and progression, including genetic, hormonal, environmental, and lifestyle factors. However, the pathogenesis of OPLL is still unclear. Most symptomatic patients with OPLL present with neurological deficits such as myelopathy, radiculopathy, and/or bowel and bladder symptoms. There are some reports of asymptomatic OPLL. Both static and dynamic factors are related to the development of myelopathy. Plain radiography, CT, and MR imaging are used to evaluate OPLL extension and the area of spinal cord compression. Management of OPLL continues to be controversial. Each surgical technique has some advantages and disadvantages, and the choice of operation should be made case by case, depending on the patient's condition, level of pathology, type of OPLL, and the surgeon's experience. In this paper, the authors attempt to review the incidence, pathology, pathogenesis, natural history, clinical presentation, classification, radiological evaluation, and management of OPLL.

Laminoplasty outcomes: is there a difference between patients with degenerative stenosis and those with ossification of the posterior longitudinal ligament?

Object

Two common causes of cervical myelopathy include degenerative stenosis and ossification of the posterior longitudinal ligament (OPLL). It has been postulated that patients with OPLL have more complications and worse outcomes than those with degenerative stenosis. The authors sought to compare the surgical results of laminoplasty in the treatment of cervical stenosis with myelopathy due to either degenerative changes or segmental OPLL.

Methods

The authors conducted a retrospective review of 40 instrumented laminoplasty cases performed at a single institution over a 4-year period to treat cervical myelopathy without kyphosis. Twelve of these patients had degenerative cervical stenotic myelopathy ([CSM]; degenerative group), and the remaining 28 had segmental OPLL (OPLL group). The 2 groups had statistically similar demographic characteristics and number of treated levels (mean 3.9 surgically treated levels; p > 0.05). The authors collected perioperative and follow-up data, including radiographic results.

Results

The overall clinical follow-up rate was 88%, and the mean clinical follow-up duration was 16.4 months. The mean radiographic follow-up rate was 83%, and the mean length of radiographic follow-up was 9.3 months. There were no significant differences in the estimated blood loss (EBL) or length of hospital stay (LOS) between the groups (p > 0.05). The mean EBL and LOS for the degenerative group were 206 ml and 3.7 days, respectively. The mean EBL and LOS for the OPLL group were 155 ml and 4 days, respectively. There was a statistically significant improvement of more than one grade in the Nurick score for both groups following surgery (p < 0.05). The Nurick score improvement was not statistically different between the groups (p > 0.05). The visual analog scale (VAS) neck pain scores were similar between groups pre- and postoperatively (p > 0.05). The complication rates were not statistically different between groups either (p > 0.05). Radiographically, both groups lost extension range of motion (ROM) following laminoplasty, but this change was not statistically significant (p > 0.05).

Conclusions

Patients with CSM due to either degenerative disease or segmental OPLL have similar perioperative results and neurological outcomes with laminoplasty. The VAS neck pain scores did not improve significantly with laminoplasty for either group. Laminoplasty may limit extension ROM.