Posterior longitudinal ligament calcification of the cervical spine

Ossification of the posterior longitudinal ligament in non-Asians: demographic, clinical, and radiographic findings in 43 patients

Object

Ossification of the posterior longitudinal ligament (OPLL) is a disorder afflicting as many as 2% of East Asians. However, reports of OPLL in non-Asians have been sporadic in the medical literature. This study describes clinical and radiographic findings with OPLL in non-Asians at a tertiary care center treating a diverse multiethnic population.

Methods

Over a 6-year period, 43 patients not of East Asian descent presented to an urban tertiary medical center with OPLL. Patient data, including ethnicity, spinal cord function, Nurick grade, radiographic findings, OPLL subtype, and degree of cervical stenosis, were recorded.

Results

The average patient age was 59 years (range 32–92 years) with 18 women and 25 men. There were 22 Caucasian patients, 17 Hispanic patients, and 4 Black patients. With respect to the radiographic findings, OPLL morphology was continuous in 19, segmental in 17, mixed in 6, and other in 1. Average canal diameter was 7.6 mm (range 4.2–9.0 mm) at the most stenotic points. The mean Nurick grade was 2.95 at presentation, but 7 of the patients had OPLL identified incidentally and with early or minimal symptoms and signs of myelopathy.

Conclusions

Ossification of the posterior longitudinal ligament in non-Asians demonstrates similar demographic and radiographic characteristics as in East Asians. The representation of different ethnic groups mirrors the demographics of the medical center population in general, showing no specific predilection for particular ethnic groups. Surgical decompression in appropriately selected patients results in similar rates of improvement when compared with the Japanese literature.

Recent progress in the study of pathogenesis of ossification of the posterior longitudinal ligament

The pathogenesis of ossification of the posterior longitudinal ligament (OPLL) is still unknown. Gene analysis and molecular biology have been introduced in recent years, and etiologic and pathological clarifications are being achieved. An important role of the genetic background in the development of this disease was demonstrated by pedigree survey, twin survey, and HLA haplotype study. The results of gene linkage study showed that patients with OPLL have a significantly higher incidence of genetic abnormalities found in the XI collagen (alpha)2 gene (COL11A2) region. From the gene mapping of this abnormality, the abnormal N-propeptide of the COL11A2 gene was found to be responsible. We are planning to undertake genetic analysis of the whole of chromosome VI to find the pathogenic genes responsible for OPLL in addition to COL11A2. A cell biological approach is also necessary to make clear the relationship between abnormalities of the COL11A2 gene and ossification of the ligament. In future, identification of the susceptible gene, elucidation of its function, and study toward the development of preventive and therapeutic drugs will advance.

Ossification of the posterior longitudinal ligament of the cervical spine in Asian Indians--a multiracial comparison

Ossification of the Posterior longitudinal ligament (OPLL) has been thought to be a predominantly Japanese disease with few reports among the non-orientals and Caucasians. A prospective clinicoradiological study of 47 symptomatic Caucasoid Indians is reported. Twenty-seven patients presented with myelopathy, twelve with myeloradiculopathy and six with radiculopathy. 'Total' configuration of OPLL was the most frequent (70%). The most frequent location was at C3 and C4 levels. The thickness of OPLL ranged from 2.5 mm to 11.5 mm. Canal stenosis was most severe in patients with 'total' type of OPLL. Ossification of other spinal ligaments were seen in 50% of the patients. Twenty-one patients underwent decompressive laminectomy and twenty of them improved. The difference in the cervical canal diameters and the configuration of OPLL between the Japanese and our population (Caucasoid Indians) may be of therapeutic relevance.

Ossification of the posterior longitudinal ligament (OPLL) in the cervical spine. Clinical, neuroradiological and neurophysiological study on 9 cases

Ossification of the posterior longitudinal ligament (OPLL) in the cervical spine is considered to be uncommon in western countries, although widely known and studied in Japan. We report on 9 cases of OPLL cervical myelopathy investigated by x-ray films and cervical CT and by somatosensory evoked potentials. The patients reported spastic tetraparesis, sensory disorders of the limbs and, in one case, sphincter incontinence. Neuroradiological examinations showed that the posterior columns of the spinal cord were more affected than the roots. Our data suggest that OPLL is more frequent in the West than has so far been reported and that combined radiological and neurophysiological investigation ensures correct diagnosis and accurate assessment of the cord impairment.

Ossification of the posterior longitudinal ligament in the thoracic spine causing intermittent paraplegia in an Englishman: case report

Compression of the spinal cord due to ossification of the posterior longitudinal ligament (OPLL) often leads to quadriplegia or paraplegia in Japanese patients. This disease is uncommon in other races. We report the case of a middle-aged Englishman who presented with complaints of intermittent paraparesis due to OPLL at the T5-T6 level in his thoracic spine.

Ossification of the posterior cervical longitudinal ligament

Forty patients with cervical myelopathy due to OPLL (Ossification of the Posterior Longitudinal Ligament) of the cervical spine were studied. According to Abe's or Yamamoto's classification, 12 of them had a 50% decrease in the cross-sectional area of the spinal canal. Subtotal vertebrectomy was carried out in 8 of these patients and the remaining 4 patients received posterior decompression. We concluded that anterior decompression, if possible, is the treatment of choice and posterior decompression is recommended only for the longitudinal type involving more than 3 segments.

Ossification of posterior longitudinal ligament of the cervical spine in non-Japanese Asians

"The Japanese disease," ossification of the posterior longitudinal ligament, is not confined to the Japanese only. A similar incidence of 0.8% was found in this study among non-Japanese Asians. Of 5167 patients who attended the Mount Elizabeth Hospital in Singapore for cervical spine complaints, 43 patients were found to have ossification of the posterior longitudinal ligament, forming the largest non-Japanese series. All but one patient were of Mongolian origin, and males were affected four times more commonly than females. Diabetes mellitus was present in 16%. There was a significant association between ossification of the posterior longitudinal ligament and calcification of other cervical paraspinal ligaments. It is suggested that a generalized tendency to calcification may be an important etiological factor in ossification of the posterior longitudinal ligament. Four of the patients required surgery, and in our experience, anterior spinal fusion with removal of the ossified ligament or multilevel laminoplasty gives satisfactory results.

Ossification of the posterior longitudinal ligament: a clinico-radiological study of 74 cases

A clinico-radiological analysis of 74 cases of ossification of the posterior longitudinal ligament is reported. Eighteen cases (24%) were asymptomatic or only had neck or shoulder pain; 16 cases (22%) showed signs of radiculopathy, and the remaining 40 cases (54%) had myelopathy. Ossification of the posterior longitudinal ligament developed most frequently at C5, and was rare in thoracic and lumbar regions. Ossification of the posterior longitudinal ligament led to stenosis of the spinal canal; more marked stenosis caused clinical myelopathy. The data showed that 30% of stenosis caused by ossification of the posterior longitudinal ligament was critical for the production of myelopathy.

Cervical myelopathy due to ossification of the posterior longitudinal ligament

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Cervical myelopathy secondary to ossification of the posterior longitudinal ligament (a case report)

A case of ossification of the posterior longitudinal ligament, documented by spinal X-ray, myelography and CT scanning of the spinal cord is reported. The patient underwent decompressive laminectomy by posterior approach, which was successful. The case is discussed in the light of recent published data.