Jau-Ching Wu, Laura Liu, Yu-Chun Chen, Wen-Cheng Huang, Tzeng-Ji Chen and Henrich Cheng
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.
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.
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.
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.
Jau-Ching Wu, Chin-Chu Ko, Yu-Shu Yen, Wen-Cheng Huang, Yu-Chun Chen, Laura Liu, Tsung-Hsi Tu, Su-Shun Lo and Henrich Cheng
This study aimed to determine the age- and sex-specific incidence of cervical spondylotic myelopathy (CSM) and its associated risk of causing subsequent spinal cord injury (SCI).
Using the National Health Insurance Research Database (NHIRD), a 12-year nationwide database in Taiwan, this retrospective cohort study analyzed the incidence of hospitalization caused by CSM. All patients diagnosed with and admitted for CSM were identified during the study period. The CSM patients were divided into 2 groups, a control group and an operated group. An incidence density method was used to estimate age- and sex-specific incidence rates of CSM. The Kaplan-Meier method and Cox regression analyses were performed to compare the risk of SCI between the 2 groups.
From 1998 to 2009, covering 349.5 million person-years, 14,140 patients were hospitalized for CSM. The overall incidence of CSM-related hospitalization was 4.04 per 100,000 person-years. Specifically, males and older persons had a higher incidence rate of CSM. During the follow-up of these patients for 13,461 person-years, a total of 166 patients were diagnosed with SCI. The incidence of SCI was higher in the control group than the operated group (13.9 vs 9.4 per 1000 person-years, respectively). During the follow-up, SCI was more likely to occur in CSM patients who were treated conservatively (crude HR 1.48, p = 0.023; adjusted HR 1.57, p = 0.011) than in those who underwent surgery for CSM.
In a national cohort of eastern Asia, the incidence of CSM-caused hospitalization was 4.04 per 100,000 person-years, with higher incidences observed in older and male patients. Subsequent SCI was more likely to develop in patients who received nonoperative management than in those who underwent surgery. Therefore, patients with CSM managed without surgery should be cautioned about SCI. However, further investigations are still required to clarify the risks and complications associated with surgery for CSM.
Li-Fu Chen, Tsung-Hsi Tu, Yu-Chun Chen, Jau-Ching Wu, Peng-Yuan Chang, Laura Liu, Wen-Cheng Huang, Su-Shun Lo and Henrich Cheng
This study aimed to estimate the risk of spinal cord injury (SCI) in patients with cervical spondylotic myelopathy (CSM) with and without ossification of posterior longitudinal ligament (OPLL). Also, the study compared the incidence rates of SCI in patients who were managed surgically and conservatively.
This retrospective cohort study covering 15 years analyzed the incidence of SCI in patients with CSM. All patients, identified from the National Health Insurance Research Database, were hospitalized with the diagnosis of CSM and followed up during the study period. These patients with CSM were categorized into 4 groups according to whether they had OPLL or not and whether they received surgery or not: 1) surgically managed CSM without OPLL; 2) conservatively managed CSM without OPLL; 3) surgically managed CSM with OPLL; and 4) conservatively managed CSM with OPLL. The incidence rates of subsequent SCI in each group during follow-up were then compared. Kaplan-Meier and Cox regression analyses were performed to compare the risk of SCI between the groups.
Between January 1, 1999, and December 31, 2013, there were 17,258 patients with CSM who were followed up for 89,003.78 person-years. The overall incidence of SCI in these patients with CSM was 2.022 per 1000 person-years. Patients who had CSM with OPLL and were conservatively managed had the highest incidence of SCI, at 4.11 per 1000 person-years. Patients who had CSM with OPLL and were surgically managed had a lower incidence of SCI, at 3.69 per 1000 person-years. Patients who had CSM without OPLL and were conservatively managed had an even lower incidence of SCI, at 2.41 per 1000 person-years. Patients who had CSM without OPLL and were surgically managed had the lowest incidence of SCI, at 1.31 per 1000 person-years. The Cox regression model demonstrated that SCIs are significantly more likely to happen in male patients and in those with OPLL (HR 2.00 and 2.24, p < 0.001 and p = 0.007, respectively). Surgery could significantly lower the risk for approximately 50% of patients (HR 0.52, p < 0.001).
Patients with CSM had an overall incidence rate of SCI at approximately 0.2% per year. Male sex, the coexistence of OPLL, and conservative management are twice as likely to be associated with subsequent SCI. Surgery is therefore suggested for male patients with CSM who also have OPLL.