Stand-alone anchored cage versus cage with plating for single-level anterior cervical discectomy and fusion: a prospective, randomized, controlled study with a 2-year follow-up.

To avoid complications associated with plating in anterior cervical discectomy and fusion (ACDF), stand-alone anchored PEEK cage was developed and favourable outcomes with a low rate of dysphasia have been described. The objective of this study was to compare the clinical and radiological outcomes of ACDF using a standalone anchored PEEK cage (PREVAIL; Medtronic Sofamor Danek, Memphis, TN) with those of a PEEK cage with plating in a prospective randomized manner. Fifty patients with single-level cervical radiculopathy were randomly assigned to a PREVAIL or a PEEK cage with plating. Following 3, 6, 12, and 24 months, clinical and radiological outcomes were assessed. The mean surgical time for the patients with a PREVAIL was significantly shorter than that for those with a PEEK cage with plating. The clinical outcomes evaluated by visual analogue scale for pain and the Odom's criteria were comparable between both the groups. Both the groups demonstrated the high fusion rate (92% in PREVAIL; 96% in PEEK cage with plating). The subsidence rate and the improvement of cervical alignment were comparable between both the groups. The incidence of adjacent-level ossification was significantly lower for patients with a PREVAIL than that for those with a PEEK cage with plating. The rate of dysphasia graded by the method of Bazaz and measurement of prevertebral soft tissue swelling indicated no significant differences between both the groups. Our prospective randomized study confirmed that stand-alone anchored PEEK cage is a valid alternative to plating in ACDF with a low rate of adjacent-level ossification. However, the potential to reduce the incidence of dysphasia was not confirmed.

A longitudinal study for incidence of low back pain and radiological changes of lumbar spine in asymptomatic Japanese military young adults.

INTRODUCTION: The relation between radiological abnormalities on lumbar spine and low back pain (LBP) has been debated, presumably because of potential biases related to heterogeneity in selection of the subjects, radiological abnormalities at entry, or its cross-sectional observation in nature. Therefore, the aim of this study of a selected population of asymptomatic Japanese Self Defense Forces (JSDF) young adults male with normal lumbar radiographs was to investigate the incidence of newly developed lumbar degenerative changes at middle age and to study their association to LBP. SUBJECTS AND METHODS: In 1990, 84 JSDF male military servicemen aged 18 years, without a history of LBP and radiological abnormal findings, were enrolled. After 20 years, 84 subjects were underwent repeated X-ray and completed questionnaires on current LBP and lifestyle factors. RESULTS: The prevalence of LBP was demonstrated 59 %, with 85 % of them showing mild pain. Analysis of lumbar radiographs revealed that 48 % had normal findings and 52 % had degenerative changes. The association between LBP and life style factors was not demonstrated. Lumbar spine in subjects with LBP was more degenerated than in those without. Although disc space narrowing and LBP did not achieve a statistical significance, a significant correlation existed between vertebral osteophyte and LBP in univariate and multivariate analysis (OR 3.0; 95 % CI 1.227-7.333). DISCUSSION AND CONCLUSIONS: This longitudinal study demonstrated the significant association between vertebral osteophyte and incidence of mild LBP in initially asymptomatic and radiologically normal subjects. These data provide the additional information concerning the pathology of LBP, but further study is needed to clarify the clinical relevance.

[Nerve root compression by gas containing lumbar disc herniation--case report].

The radiographic appearance of gas collection in the intervertebral disc represents the so-called "vacuum phenomenon." Incidence of the vacuum phenomenon on plain radiographs is reported to be 1-20%, whereas gas-containing disc herniations are rarely observed. We present a case report involving a patient with L4/5 gas-containing disc herniation, which was demonstrated by CT and MRI scans and was also surgically documented. A 48-year-old man with no previous back trauma presented with a 14-day history of left leg pain. On neurologic examination, the straight leg raising test was positive at 60degrees. Leg muscle strength was weak on the extensor hallucis longus. Sensory disturbances and abnormalities in deep-tendon reflexes were not observed. Lumbar roentogenograms showed "vacuum phenomenon" at L2/3, L4/5 and the L5/S disc space. MRI indicated a herniated disc at L4/5 displacing the dural sac and a focal low intensity in the lesion. Administration of an epidural block relieved the patient's symptoms. Ten months later, the patient reported a gradual return of similar left leg pain. His symptoms did not respond to conservative management. Lumbar spine films indicated abnormalities identical to the original results. MRI showed an enlarged area of low intensity with compression of the left L5 nerve root. In addition to recurrent pain, discography with metrizamide injections confirmed the presence of intradiscal gas and compression of the left L5 nerve root. During surgery, a gray-bluish air mass compressing the L5 nerve root was identified. Manipulation of the mass resulted in rupture and the release of gas. The displaced nerve root immediately relaxed to its normal position. Seven months after the operation, the patient remains free of pain.