OBJECTIVE: The aim of this study was to compare the clinical and radiological outcomes associated with the use of hydroxyapatite (HA) spacer and allogeneic bone (AB) spacer in laminoplasty. METHODS: From January 2006 to July 2014, 79 patients with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament underwent cervical laminoplasty. The radiologic parameters were obtained from plain radiography and three-dimensional computed tomography. All images were taken before and after surgery. Cervical lordosis, spinal canal dimension, fusion between lamina and spacer, and resorption of spacer were checked. Clinical outcomes were assessed using visual analog scale and Japanese Orthopedic Association. RESULTS: Double-door laminoplasty was performed on 280 levels : 182 in the HA group and 98 in the AB group. The mean follow-up was 23.1 months (range : 4–69 months). Similar fusion rates were found in these groups (p=0.3). The resorption rate between lamina and spacer was lower in the HA group (p<0.001). During the immediate postoperative period, the canal dimension of both groups increased compared with the results in the preoperative period. However, the canal dimension of the AB group decreased over time compared with that of the HA group (p<0.001). CONCLUSION: Double-door laminoplasty improved the clinical outcomes of both groups. However, the spinal canal dimension in the AB group showed a greater degree of reduction than in the HA group at the final postoperative follow-up. Therefore, we suggest that surgeons consider the use of larger-sized AB spacers in double-door laminoplasties.
Allografts ; Animals ; Asian Continental Ancestry Group ; Durapatite* ; Follow-Up Studies ; Humans ; Hydroxyapatites ; Laminoplasty* ; Longitudinal Ligaments ; Lordosis ; Orthopedics ; Ossification of Posterior Longitudinal Ligament ; Postoperative Period ; Preoperative Period ; Radiography ; Spinal Canal ; Spinal Cord Diseases ; Spinal Fusion ; Surgeons ; Visual Analog Scale

Pycnodysostosis is an autosomal recessive disorder characterized by osteosclerosis, small stature, acro-osteolysis of the distal phalanges, loss of the mandibular angle, separated cranial sutures with open fontanels, and frequent fractures. One identified cause of the disease is reduced activity of the cysteine protease cathepsin K. A 48-year-old woman with a history of frequent fractures presented with a severe gait disturbance. Radiography, computed tomography, magnetic resonance imaging, and gene analysis were performed. Physical examination revealed open fontanels, and radiographs showed increased bone density. DNA sequence analysis revealed a deletion mutation of the cathepsin K gene. We diagnosed pycnodysostosis based on these findings. The magnetic resonance and computed tomography images demonstrated multilevel spinal canal stenosis due to ossification of the yellow ligament. We performed a laminectomy, and the patient's neurological signs and symptoms improved. To our knowledge, this is the first case of pycnodysostosis with ossification of the yellow ligament.
Acro-Osteolysis ; Bone Density ; Cathepsin K ; Constriction, Pathologic* ; Cranial Sutures ; Cysteine Proteases ; Female ; Gait ; Humans ; Laminectomy ; Ligaments* ; Magnetic Resonance Imaging ; Middle Aged ; Osteosclerosis ; Physical Examination ; Pycnodysostosis* ; Radiography ; Sequence Analysis, DNA ; Sequence Deletion ; Spinal Canal*

The height, width, and cross-sectional area of the vertebral canal and spinal cord along with the area ratio of spinal cord to vertebral canal in the cervical vertebra were evaluated in images obtained using computed tomography (CT). Measurements were taken at the cranial, middle, and caudal point of each cervical vertebra in eight clinically normal small breed dogs (two shih tzu, two miniature schnauzers, and four mixed breed), 10 beagles, and four German shepherds. CT myelography facilitated the delineation of the epidural space, subarachnoid space, and spinal cord except at the caudal portion of the 7th cervical vertebra. The spinal cord had a tendency to have a clear ventral border in the middle portion of the vertebral canal and lateral borders near both end plates. The height, width, and area of the vertebral canal and spinal cord in the cervical vertebra were increased as the size of dog increased. However, the ratio of the spinal cord area to vertebral canal area in the small dogs was higher than that of the larger dogs. Results of the present study could provide basic and quantitative information for CT evaluation of pathologic lesions in the cervical vertebra and spinal cord.
Animals ; Body Size ; Cervical Vertebrae/*anatomy & histology/radiography ; Dogs/*anatomy & histology/growth & development ; Reference Values ; Spinal Canal/*anatomy & histology/radiography ; Spinal Cord/*anatomy & histology/radiography ; Tomography, X-Ray Computed/*veterinary

BACKGROUNDAmong the various treatments of neurologically involved unstable thoracolumbar burst fractures, the combination of anterior and posterior instrumentation provides the most stable reconstruction. However, the use of both approaches on a trauma patient may increase the morbidity. This study is a retrospective matched cohort study to evaluate the advantages of a single stage posterior approach for spinal canal decompression in combination with circumferential reconstruction by comparing the clinical and radiographic results.

METHODSFrom March 2005 to September 2009, patients with matched type spinal fracture, ages at surgery, and involved levels in our institute underwent either a single stage posterior approach (group one, n = 12) or traditional combined approach (group two, n = 14) for spinal canal decompression and circumferential reconstruction were reviewed. Pre- and post-operative X-ray flms were reviewed and changes in Cobb angle of thoracolumbar spine were documented. Intra-operative, post-operative, and general complications were registered.

RESULTSThe mean follow-up was (27.7 ± 9.6) months (range, 14 to 56 months) in group one and (29.2 ± 7.4) months (range, 20 to 60 months) in group two (P > 0.05). The mean operation time was 214 minutes (range, 186 ± 327 minutes) in group one and 284 minutes (range, 219 ± 423 minutes) in group two (P < 0.05). The average volume of intraoperative blood loss was 1856 ml (range, 1250 ± 3480 ml) in group one and 2453 ml (range, 1600 ± 3680 ml) in group two (P < 0.05). There was no statistical difference between the groups one and two in average vertebral body height loss at the injured level and the average Cobb angle in sagittal plane before and immediately after surgery. Postoperatively, there was an epidural hematoma in one patient in group one and two patients in group two. Bony union after stabilization was obtained in all patients, without loosening or breakage of screws. Loss of correction (5°) was seen in 1 patient in group one at the 6th month owing to the subsidence of the Titanium mesh cages into the vertebra. In group two, totally four patients suffered respiratory-related complication, including pneumonia in two, severe atelectasis in one and pleural effusions in one. Importantly, there were no intraoperative or postoperative deaths in any group. All patients with incomplete neurologic deficits improved at least 1 Frankel grade.

CONCLUSIONSingle-stage posterior vertebra resection in combination with circumferential reconstruction is a new option to manage severe thoracolumbar burst fractures.

Decompression, Surgical ; adverse effects ; methods ; Humans ; Lumbar Vertebrae ; injuries ; surgery ; Operative Time ; Radiography ; Reconstructive Surgical Procedures ; methods ; Retrospective Studies ; Rotation ; Spinal Canal ; surgery ; Spinal Fractures ; diagnostic imaging ; surgery ; Thoracic Vertebrae ; injuries ; surgery

STUDY DESIGN: Retrospective study OBJECTIVE: This study examined the causative factors of cement leakage in an osteoporotic compression fracture that had received percutaneous vertebroplasty. SUMMARY OF LITERATURE REVIEW: Percutaneous vertebroplasty is simple and safe for the treatment of osteoporotic compression fractures. However, serious complications, such as pulmonary emboli and paraplegia, can occur if the bone cement leaks into the pulmonary artery or spinal canal. MATERIALS AND METHODS: Between Oct. 2002 and Apr. 2008, 95 patients (148 vertebral bodies) underwent percutaneous vertebroplasty for the treatment of an osteoporotic compression fracture. The presence of cement leakage was evaluated by plain radiography and computed tomography. The correlations between cement leakage and gender, age, level of fractured vertebra, fracture type, bone density, procedure, injecting amount, preoperative vertebral body compression rate, timing of surgery, and the existence of an intravertebral cleft on magnetic resonance imaging (MRI) were analyzed. RESULTS: Leakage was found in 37 bodies on plain radiography and 56 on the CT-scan. A comparison of the leakage and non-leakage groups revealed the bone density (p=0.046) and amount injected (p=0.000) to be related to cement leakage. Multivariate logistic regression showed that injecting more than 4.0ml was related to cement leakage with an odds ratio of 2.23(95% CI, 1.476~3.377). CONCLUSIONS: Cement leakage after percutaneous vertebroplasty is associated with the amount injected. Therefore, the cement volume should be restricted to the amount required for pain relief.
Bone Density ; Factor Analysis, Statistical* ; Fractures, Compression ; Humans ; Logistic Models ; Magnetic Resonance Imaging ; Odds Ratio ; Paraplegia ; Pulmonary Artery ; Radiography ; Retrospective Studies ; Spinal Canal ; Spine ; Vertebroplasty*

BACKGROUND: This study examined the relationship between four radiological parameters (Pavlov's ratio, sagittal diameter, spinal cord area, and spinal canal area) in patients with a traumatic cervical spine injury, as well as the correlation between these parameters and the neurological outcome. METHODS: A total of 212 cervical spinal levels in 53 patients with a distractive-extension injury were examined. The following four parameters were measured: Pavlov's ratio on the plain lateral radiographs, the sagittal diameter, the spinal cord area, and the spinal canal area on the MRI scans. The Pearson correlation coefficients between the parameters at each level and between the levels of each parameter were evaluated. The correlation between the radiological parameters and the spinal cord injury status classified into four categories, A (complete), B (incomplete), C (radiculopathy), and D (normal) was assessed. RESULTS: The mean Pavlov's ratio, sagittal diameter, spinal cord area and spinal canal area was 0.84, 12.9 mm, 82.8 mm2 and 236.8 mm2, respectively. An examination of the correlation between the radiological spinal stenosis and clinical spinal cord injury revealed an increase in the values of the four radiological parameters from cohorts A to D. Pavlov's ratio was the only parameter showing statistically significant correlation with the clinical status (p = 0.006). CONCLUSIONS: There was a correlation between the underlying spinal stenosis and the development of neurological impairment after a traumatic cervical spine injury. In addition, it is believed that Pavlov's ratio can be used to help determine and predict the neurological outcome.
Adult ; Aged ; Analysis of Variance ; Cervical Vertebrae/*radiography ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neck Injuries/*radiography ; Retrospective Studies ; Spinal Canal/pathology/*radiography ; Spinal Cord Injuries/pathology/*radiography ; Spinal Stenosis/pathology/*radiography ; Young Adult

BACKGROUND: This study was designed to reevaluate the effectiveness of the Pavlov ratio in patients with cervical myelopathy. METHODS: We studied 107 patients who underwent open door laminoplasty for the treatment of cervical myelopathy between the C3 to C7 levels. We determined the Pavlov ratio on preoperative and postoperative cervical spine lateral radiographs, the vertebral body-to-canal ratio on sagittal reconstruction CT scans, and the vertebral body-to-cerebrospinal fluid (CSF) column ratio on T2-weighted sagittal MR images from C3 to C6. The severity of myelopathy was determined using the JOA score on both preoperative and postoperative images. The recovery rate was also calculated. The Pavlov ratio in plain radiographs from patients with myelopathy was compared with the ratio of the vertebral body to the spinal canal on CT and MRI. RESULTS: The average Pavlov ratio between C3 and C6 ranged from 0.71 to 0.76. On CT scan, the average vertebral body-to-canal ratio between C3 and C6 ranged from 0.62 to 0.66. On MRI, the vertebral body-to-CSF column ratio between C3 and C6 ranged between 0.53 and 0.57. A positive correlation was noted between the Pavlov ratio and the vertebral body-to-canal ratio on sagittal-reconstruction CT (correlation coefficient = 0.497-0.627, p = 0.000) and between the Pavlov ratio and the vertebral body-to-CSF column ratio on MRI (correlation coefficient = 0.511-0.649, p = 0.000). CONCLUSIONS: We demonstrated a good correlation between the Pavlov ratio and both the vertebral body-to-canal ratio on CT and the vertebral body-to-CSF column ratio on MRI. Therefore, the Pavlov ratio can be relied upon to predict narrowing of the cervical spinal canal in the sagittal plane.
Adult ; Aged ; Aged, 80 and over ; Cerebrospinal Fluid ; Cervical Vertebrae/*pathology/*radiography/surgery ; Female ; Humans ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Observer Variation ; Predictive Value of Tests ; Reference Values ; Retrospective Studies ; Spinal Canal/radiography ; Spinal Cord Diseases/*pathology/*radiography ; *Tomography, X-Ray Computed

OBJECTIVE: The purpose of this study is to evaluate the efficacy and necessity of combined anterior approach (discectomy and fusion) and posterior approach(open-door laminoplasty) in the treatment of cervical spondylotic myelopathy. METHODS: The authors reviewed 14 cases in whom combined anterior and posterior approach performed for cervical myelopathy due to simultaneous anterior and posterior pathology such as huge central disc herniation with narrow spinal canal between January 2000 and December 2002. Clinical symptoms were evaluated by Japanese Orthopaedic Association (JOA) score and then the cervical curvature, change of spinal canal to vertebral body(SC/VB) ratio and canal widening were measured and compared to the clinical symptoms. RESULTS: The mean JOA score increased from 10.4+/-3.1 preoperatively to 14.8+/-1.2 at the final follow up with a mean recovery rate 66.4%. In all cases, there were not neurologic deterioration. Mild postoperative complications developed in two cases. One patient had a limitation of range of neck motion and the other one showed kyphotic change. Postoperative radiography showed an improvement of body to canal ratios (average 0.70+/-0.08 before surgery to 1.05+/-0.12 after surgery) and mainte nance or recovery of cervical lordosis. Canal widening of antero-posterior diameter and dimension after operation is 6.8 mm, 116.61 mm2. CONCLUSION: Combined anterior and posterior procedure could be helpful in decompression of the spinal cord and good functional recovery in spondylotic myelopathy patients with combined anterior and posterior pathology such as huge disc herniation accompanying narrow spinal canal.
Animals ; Asian Continental Ancestry Group ; Decompression ; Follow-Up Studies ; Humans ; Lordosis ; Neck ; Pathology ; Postoperative Complications ; Radiography ; Spinal Canal ; Spinal Cord ; Spinal Cord Diseases*

Pathological changes can occur in the diameters of the lumbar spinal canal. Therefore, assessing the canal size an important diagnostic procedure. Two hundred plain anterioposterior radiographs of the lumbar spine were examined. The sample consisted of 100 males and 100 females. The transverse diameter of the bony spinal canal (interpedicular distance), which was measured as the minimum distance between the medial surfaces of the pedicles of a given vertebra, was measured. In addition, the transverse diameter of the vertebral body, which was measured as the minimum distance across the waist of the vertebra, was measured. The distances were measured to the nearest one tenth of a millimetere using a Vernier caliper. At all levels (L1 - L5) the transverse diameters of the lumbar spinal canal were approximately 1 - 1.5 mm higher in males than in females. The intersegmental differences increased proximodistally, in both sexes. The ratio of the transverse diameter canal to the width of the vertebra ranged from 0.55 to 0.60 mm in both sexes. The distribution of the different lumbar canal types were 47% A, 42% B, 11% C. Additionally, subtypes were determined and classified.
Adult ; Female ; Human ; Lumbar Vertebrae/radiography ; Male ; Middle Aged ; Reference Values ; Spinal Canal/*radiography ; Turkey

Clear-cell meningioma is a rare subtype of meningioma which occurs at a younger age and has a higher recurrence rate than other subtypes. We report two cases of clear-cell meningioma, one in the thoracolumbar spinal canal and the other in the cerebellopontine angle. Though the CT and MR imaging findings were not different from those of ordinary meningioma, after surgical removal the condition recurred repeatedly in the patient with spinal canal involvement.
Adolescent ; Case Report ; Cerebellar Neoplasms/*diagnosis/radiography ; *Cerebellopontine Angle ; Female ; Human ; Infant ; *Magnetic Resonance Imaging ; Meningioma/*diagnosis/radiography ; *Spinal Canal ; Spinal Neoplasms/*diagnosis/radiography ; *Tomography, X-Ray Computed