How would CT-based criteria correlate with dynamic X-rays in documenting posterior cervical fusion? To study this, CT and dynamic radiographic studies were prospectively evaluated 3, 6, and up to 12 months postoperatively in 14 patients with severe myeloradiculopathy (Nurick Grade IV) undergoing dorsal decompression with fusion). “Focal” 1-2 level laminectomies with undercutting of adjacent levels were accompanied by average 6.5 level posterior fusions utilizing a rod/eyelet/braided cable system in conjunction with iliac crest autograft and demineralized bone matrix. Fusion on dynamic X-rays was defined by less than 1 mm of motion between adjacent spinous processes with less than 3 mm of translation between the vertebral bodies. Four CT-based indicators for fusion were evaluated: facet fusion, graft fusion [bone continuity overlying facet joints/ lamina], new anterior vertebral fusion, and >50% of total graft mass remaining. CT-based facet fusion most closely correlated with dynamic X-ray confirmation of fusion. At 3 months, 10 patients showed facet fusion while 8 demonstrated stability on dynamic films; all 14 patients met both fusion criteria by 6 months and continued to demonstrate these findings at one year postoperatively. At 3 and 6 months, graft fusion increased from 5 to 9 while anterior vertebral body fusion increased from 3 to 5; by 1 year, 12 demonstrated graft fusion and 7 anterior fusion. However, CT-based graft mass regressed rather than progressed over time; 7 showed graft mass of over 50% 3 months postoperatively which further diminished to 7 at 6 months and 6 by 1 year postoperatively. Together, dynamic X-rays and 4 CT-based criteria of fusion provided a more complete picture of the evolution of posterior cervical fusion.

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Authors have developed a new device to navigate the trajectory of screw insertion in the axial plane for posterior cervical fixation. The device is composed of two, long and short, stainless wires which were welded together at an angle of 25 degrees at its top. The device was used as the long wire was adjusted to the vertical line to the floor and the short wire for adjustment of the axial direction of the screw. Between 2002 and 2005, screws were inserted in the lateral mass of the atlas and the middle to lower cervical spine and C2 pedicle in 14 cases using this device in addition to a fluoroscopic guide. All 82 screws were inserted successfully without any complication. Our technique with the new device was useful for posterior cervical fixation.

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With a lesser donor-site morbidity and a better initial stability, various kinds of titanium cages have been introduced as a fusion device for the cervical spine. We have been using a threaded cylinder-shaped fusion cage for single- or two-level anterior fusion since 1994, and reviewed the radiographs retrospectively in patients who were followed up for one year or longer. In twenty cervical cases vertebrae were fixed with double cages for each disc space and in 5 cases with a single large cage. Subsidence occurred in 6 cases. Most of the patients with subsidence were older than 70 years, and the incidence was higher in cases fixed with a single large cage. Cervical lordosis decreased in 4 patients in whom the subsidence occurred. Since the cage always subsides into the lower vertebrae, it is indispensable to preserve the upper bony endplate of the lower vertebrae, especially in elder patients. A solid fusion was achieved in 96% of the cases evaluated by flexion and extension radiographs. In comparison to the previous reports using an autograft on anterior fixation, threaded fusion cages reduced the incidence of subsidence and loss of lordosis and increased the fusion rate. Our medium-term radiographic results show that the threaded titanium cage is a safe and effective device with the current anterior cervical fusion techniques.

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The surgical treatment of injuries to the thoracolumbar spine remains controversial. The purpose of this study is to evaluate the surgical management of thoracic and lumbar vertebral fractures. Injury categories were as follows: 4 fracture-dislocation injuries, 10 burst fractures, 12 osteoporotic vertebral collapse, 63 osteoporotic compression fractures. The formulation of a treatment plan for patients with injuries to the thoracolumbar spine depends on the presence and extent of neurologic injury and deformity and an estimate concerning spinal stability. Recently we have selected vertebroplasty and posterior lateral fusion by posterior approach only. For certain patients, this technique is an insightful option for overcoming the pitfalls of conventional thoracolumbar fracture treatment. Percutaneous vertebroplasty is a safe and effective treatment for relieving the pain associated with osteoporotic fracture and leads to early mobilization and avoidance of the dangers of conservative therapy of bed-rest. However, roughly one-fifth of osteoporotic fracture with acute/subacute fracture treated with vertebroplasty will have a subsequent fracture within 2 years.

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Background: Cylindrical titanium cages have been extensively used as a device in posterior lumbar interbody fusion (PLIF). This interbody fusion cage, when applied effectively, can confer enough stability to the symptomatic motion segment and restore disc height to achieve significant increase in the neuroforamen volume. Recently, however, many complication cases were reported when using cages without supplemental posterior fixation. We report perioperative complications and 3-year follow-up outcome in those who underwent PLIF in which a Ray TFC was implanted.
Methods: A total of 125 patients underwent PLIF with Ray TFC without supplemental fixation (stand-alone PLIF) by a single surgeon. Four died of other diseases, five were under medical treatment for other disease, six were lost and two needed additional PLIF with pedicle screws for migration of cages before three years have passed. A total of 108 patients remained in a stand-alone PLIF group at 3-year follow-up. These patients included 65 males and 43 females with mean age of 52.8 yrs (17-81 yrs). These patients consist of 18 degenerative disc disease, 19 recurrence, 30 spondylolisthesis, 10 spondylolysis, 17 canal stenosis, 1 postlaminectomy syndrome, 10 degenerative scoliosis and 3 ossification of posterior longitudinal ligament (OPLL). Pre- and post-operative functions were evaluated by the Japanese Orthopedic Association (JOA) score. Normal score is 29 points.
Results: Perioperative complications occurred in 10 cases (8%). Dural tear when inserting cages occurred in 3 cases and permanent foot drop occurred in 1 case. Additional operations were needed in 2 cases for migration of cages and in one OPLL case for pseudomeningocele. Although subsidence of the cages occurred in 3 cases, immediate bed-rest for one month rescued from collapse of the vertebral body. Device-related complications needed additional operation or suffered from permanent symptom occurred only in 3 cases(2.4%). Neither superficial nor deep infections occurred. The JOA Score improved from 9.2 before operation to 28.6 points at 3-year follow-up in degenerative disc disease, from 7.3 to 28.1 in recurrent cases, from 10.1 to 28.7 in spondylolisthesis, from 12.4 to 28.6 in spondylolysis, from 11 to 28.2 in canal stenosis, from 5 to 27.0 in postlaminectomy syndrome, from 9.1 to 28.4 in degenerative scoliosis and from 9.0 to 28.3 in OPLL. Only 5 cases needed symptomatic treatment at 3-year follow-up.
Conclusion: A larger cage should be used to avoid retropulsion and migration of cages. Exact aftertreatment with a hard corset is required for 3 to 6 months after surgery, because spine instrumented with cages isn't stiff against postural change in all directions, as it's instrumented with both cages and pedicle screws. Under these conditions, stand-alone PLIF with Ray TFC will achieve good outcome for degenerative lumbar spine disease without serious or permanent complications. This procedure reduced the wound and soft tissue damages, plus risk of infection. Furthermore, patients are free from the pain due to pedicle screws.

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Microscopic bilateral spinal decompression through unilateral laminotomy is a minimally invasive surgical technique for treating lumbar canal stenosis. This technique can accomplish decompression of the thecal sac and bilateral nerve roots without injury to the supra-/inter-spinous ligament complex or contralateral paraspinal muscles. Subsequently, this technique can prevent postoperative pain derived from muscle injury, and allows patients to begin postoperative body exercises earlier resulting in a more prompt return to society. We consider that the superiority of this strategy is particularly apparent in the treatment of patients with multilevel lumbar canal stenosis. In the present study, ten patients with adjacent two-disc-level lumbar canal stenosis were treated by this technique. Surgical outcomes were evaluated by the Japan Orthopedic Association score (JOA score), a Visual Analogue Scale (VAS), lengths of postoperative hospital stay, the period of time to return to work after operations, and by the patients' satisfaction of their operation. The JOA scores ranged from 6 to 23 points (mean, 14.3 points) preoperatively, with improvements resulting in postoperative scores ranging from 23 to 28 points (mean, 24.9 points). The preoperative VAS scores ranged from 6 to 10 (mean, 8.3), and were postoperatively reduced, ranging from 0 to 3 (mean, 1.3). The postoperative hospital stay ranged from 4 to 38 days (mean, 16.4 days). Seven of the patients were unemployed preoperatively, while the remaining three had jobs and returned to work between 8 and 12 days after their operations. None of the patients answered "border-line" or "unacceptable" when they evaluated their operations; five patients answered "very good", and the other five answered "good". In conclusion, we consider microscopic bilateral spinal decompression through unilateral laminotomy to provide an excellent surgical outcome and an early return to society for patients with multilevel lumbar canal stenosis.

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A case of ossification of the upper cervical ligamentum flavum is reported. A 72 year-old-man was presented with numbness of both hands. Neurological examination revealed hypesthesia of the hands and elevated deep tendon reflexes of the both lower extremities. X-ray films of the cervical spine showed separation of the both laminae of C2 vertebral arch and fusion of C2-C3 laminae and spinous processes. MRI showed low intensity mass both on T1- and T2-weighted images and severe compression of the spinal cord at C2. CT myelogram showed ossified mass protruding medially on the surface of both apophyseal joint and compressing of the spinal cord. The symptoms and physical signs of cervical myelopathy improved after C2 and C3 laminectomy and resection of the ossified ligament. Ossification of the ligamentum flavum usually occurs in the lower thoracic spine, and is rare in the upper cervical region. The clinical feature and pathogenesis are discussed.

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Traumatic atlanto-axial subluxation (AAS) is a rare injury which can be diagnosed by flexion-extension dynamic radiograph on the cervical spine. Here we report on a case of delayed progression of AAS in the chronic phase after a cervical spinal injury. The described case is a 58-year-old man who sustained a closed occipital head injury with subsequent severe tetraparesis and was admitted to our hospital. Although, no obvious bony injuries of the cervical spine were revealed on plain radiograph and CT scan, Magnetic resonance imaging demonstrated intramedullary spinal cord injury at the level of C1-2. In the acute phase, the patient was treated conservatively and the motor dysfunction was well ameliorated. However, the patient gradually suffered again from motor deterioration eight months later and the radiological examinations revealed delayed progression of AAS. After the unsuccessful trial of external reduction for AAS, the patient underwent atlas laminectomy and occipito-cervical internal fixation with compact Cotrel-Dubousset instrumentation. The motor disability improved again after the operation. Sufficient decompression of spinal cord and stable fixation of craniovertebral junction have been obtained for over two years post-operatively. The unique clinical course of the present case is discussed.

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