Prevalence, Incidence, Comorbidity, and Mortality Rates of Ossification of Posterior Longitudinal Ligament in the Cervical Spine: A Nested Case-Control Cohort Study.

OBJECTIVE: To evaluate prevalence, incidence, morbidity, and mortality rates of cervical ossification of posterior longitudinal ligament (OPLL) using data from a 12-year national cohort of 1,025,340 Korean people. METHODS: A nested case-control cohort study was performed from 2002 to 2013 using the insurance claims database provided by the National Health Insurance Service. We examined prevalence and incidence of cervical OPLL. Age- and sex-matched control subjects were randomly extracted, with 10 times the number of OPLL cases. Differences in sex, comorbidity, and relative survival rate compared with control subjects were assessed. RESULTS: Cumulative prevalence was 20,960 per 1,025,340 people for 12 years. Annual incidence was approximately 199-371 per 1 million people. Overall crude mortality rate was 7.64%. Relative survival rate of OPLL cases was not significantly different from control cases. Diabetes, hypertension, cardiovascular disease, and cerebrovascular disease, except renal disease, correlated significantly with OPLL compared with control cases (P < 0.001). Additionally, between dead and surviving patients among OPLL cases, all comorbidities correlated more significantly with death (P < 0.001). Furthermore, between surgery and nonsurgery cases of OPLL, diabetes, hypertension, and renal disease (P < 0.05) were significantly associated with surgery. CONCLUSIONS: Annual incidence of OPLL was 199-371 per 1,025,340 people for 10 years. Diabetes, hypertension, cardiovascular disease, and cerebrovascular disease, except renal disease, correlated significantly with OPLL compared with control cases. Especially, diabetes, hypertension, and renal disease were associated with patients with OPLL who underwent surgery.

Life Expectancy After Cervical En Bloc Laminoplasty: Analysis of Data Following More Than 20 Years.

STUDY DESIGN: Case series. OBJECTIVE: To clarify the following questions How long after cervical laminoplasty did the patients die? What were the causes of the death? Was the severity of the neurological dysfunction related to early death? SUMMARY OF BACKGROUND DATA: Life expectancy in patients with cervical myelopathy is unclear. Cervical laminoplasty was performed in 216 patients between 1981 and 1994. It was possible to follow 148 patients for more than 20 years. We used the data of the 68 survivors and the 80 patients had already died. METHODS: As for the patients who died by the final follow-up, the survival rate was analyzed by a Kaplan-Meier plot; the results were compared between the patients with cervical spondylosis (CS) and the patients with ossification of the posterior longitudinal ligament (OPLL). The causes of the death were assessed. The neurological evaluation was graded using the score devised by the Japanese Orthopaedic Association (JOA). The pre- and postoperative scores were compared between the patients in the died group (D group) and the surviving patients group (S group). RESULTS: The mean period from surgery to death was 13.4 ±â€Š7.4 years. There was no difference in the survival rate between patients with CS and patients with OPLL. The most frequent cause of death was malignant tumor followed by ischemic heart disease. Preoperative JOA score in the D group was lower than that in the S group. There was no statistical difference in postoperative JOA score between the two groups. CONCLUSION: The patients who underwent cervical laminoplasty caused by compression myelopathy due to CS and OPLL had a long life expectancy, averaging more than 13 years. Life expectancy did not differ between patients with CS and patients with OPLL. Neurological deficit did not directly affect the life expectancy. LEVEL OF EVIDENCE: 4.

Long-term results of expansive laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine: more than 10 years follow up.

OBJECT: The authors report the long-term (more than 10-year) results of cervical laminoplasty for ossification of the posterior longitudinal ligament (OPLL) of the cervical spine as well as the factors affecting long-term postoperative course. METHODS: The authors reviewed data obtained in 92 patients who underwent cervical laminoplasty between 1982 and 1990. Three patients were lost to follow up, 25 patients died within 10 years of surgery, and 64 patients were followed for more than 10 years. Results were assessed using the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy. The recovery rate was calculated using the Hirabayashi method. The mean neurological recovery rate during the first 10 years after surgery was 64%, which declined to 60% at the last follow-up examination (mean follow up 12.2 years). Late neurological deterioration occurred in eight patients (14%) from 5 to 15 years after surgery. The most frequent causes of late deterioration were degenerative lumbar disease (three patients), thoracic myelopathy secondary to ossification of the ligamentum flavum (two patients), or postoperative progression of OPLL at the operated level (two patients). Postoperative progression of the ossified lesion was noted in 70% of the patients, but only two patients (3%) were found to have related neurological deterioration. Additional cervical surgery was required in one patient (2%) because of neurological deterioration secondary to progression of the ossified ligament. The authors performed a multivariate stepwise analysis, and found that factors related to better clinical results were younger age at operation and less severe preexisting myelopathy. Younger age at operation, as well as mixed and continuous types of OPLL, was highly predictive of progression of OPLL. Postoperative progression of kyphotic deformity was observed in 8% of the patients, although it did not cause neurological deterioration. CONCLUSIONS: When the incidence of surgery-related complications and the strong possibility of postoperative growth of OPLL are taken into consideration, the authors recommend expansive and extensive laminoplasty for OPLL.

Quality of life in elderly patients with ossification of the posterior longitudinal ligament.

STUDY DESIGN: A longitudinal cohort study of 216 elderly patients with ossification of the posterior longitudinal ligament for an average of 13 years was performed. OBJECTIVE: To know the quality of life experienced by patients after treatment. SUMMARY OF BACKGROUND DATA: No report is available on the quality of life experienced by elderly patients with ossification of the posterior longitudinal ligament. Because the life prognosis of patients with this condition is relatively good, the quality of life experienced by elderly patients with this disease is an important subject. METHODS: The study participants were 216 elderly patients with ossification of the posterior longitudinal ligament. Conservative therapy was performed for 126 patients, and surgical therapy for 90 patients. Surgery was basically indicated for patients with myelopathy, who were classified using Nurick's grading system. The cumulative survival rate of these patients and their disabilities in daily living were reviewed. The occurrence of fracture resulting from osteoporosis was surveyed, and the relation of such fractures to bone mineral density was examined. RESULTS: The cumulative survival rate of 70-year-old patients exhibiting Nurick Grade 5 severe myelopathy before treatment was 20%, whereas that of patients without myelopathy or those with Grades 1, 2, 3, or 4 myelopathy before treatment was 80%. Patients who underwent surgical therapy for Grade 3 or 4 myelopathy were statistically more likely to be independent of assistance with activities of daily living than those with similar degrees of myelopathy who underwent conservative therapy. The final quality of life was poor for patients with Grade 5 myelopathy at the first examination, regardless of therapeutic method. The prevalence of complication by fracture in patients with ossification of the posterior longitudinal ligament was 1.4% for men and 8.6% for women. The bone mineral density in these patients without myelopathy was significantly higher than in healthy subjects of the same age. CONCLUSION: The study data suggest that surgical treatment should be chosen for patients exhibiting moderate myelopathy to obtain satisfactory quality of life for them over a long period.

Diffuse idiopathic skeletal hyperostosis in the cervical spine.

The disease processes diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, and ossification of the posterior longitudinal ligament are similar in pathology and can lead to unexpected but grossly unstable fractures that may not be diagnosed until neurologic change occurs in cases of trivial trauma. A retrospective study of 29 patients with cervical spinal fractures and diffuse idiopathic skeletal hyperostosis-like pathologies was done. Twenty patients with an average age of 62 years were treated surgically (six neurologically complete, five incomplete, nine intact). Three patients with an average age of 70 years died postoperatively (one complete, two incomplete). Nine patients with an average age of 65 years were treated conservatively (five neurologically complete, two incomplete, two intact). All patients with intact neurologic function survived. It is suggested, therefore, that all elderly patients with diffuse idiopathic skeletal hyperostosis-like pathology, history of trivial trauma, and complaint of neck pain be examined carefully for fractures, because mortality rates increase sharply in patients with decreased neurologic function.