Does pedicle screw fixation under age 5 cause spinal canal narrowing? A CT study with minimum 5 years follow-up

Purpose

The aim of this retrospective study was to evaluate the changes in the vertebral body and spinal canal area in a group of patients who had pedicle screw fixation under age 5 for the treatment of congenital spinal deformity at least 5 year follow-up.

Methods

11 patients who had been operated due to spinal deformity under age 5 with who had a CT examination at least 5 years after the initial operation were included in the study. All patients underwent hemivertebrectomy and transpedicular fixation procedures at an average age of 3.18 years (range 2–5 years). All had preoperative CT to evaluate the congenital deformities. Measurements were done at the instrumented vertebrae as well as the un-instrumented ones above and below them to evaluate; vertebral body parameters, pedicle parameters and spinal canal area of upper instrumented vertebra (UIV), lower instrumented vertebra (LIV), upper adjacent un-instrumented vertebra and lower adjacent un-instrumented vertebra.

Results

The average follow-up was 7.2 (range 5–12) years. Six of the patients were over age 10 during the final CT examination while 5 were at age 7. Female-to male ratio was 8–3. Measurement of all the parameters in 22 instrumented and 22 non-instrumented segments showed a proportional increase rather than a decrease at each segment. The percentage of canal area growth at UIV and LIV was 21 and 17.5 %, respectively.

Conclusion

Pedicle screw instrumentation has no adverse effect on further spinal body, pedicle and canal growth and does not result in iatrogenic spinal canal stenosis.

     

The role of DTI in early detection of cervical spondylotic myelopathy: a preliminary study with 3-T MRI

Introduction  

The radiological diagnosis of cervical spondylotic myelopathy (CSM) has to be made as soon as possible, since surgery performed in earlier stages during the course of CSM was reported to be more successful when compared with later stages. We hypothesized that diffusion tensor imaging (DTI) may detect CSM in earlier stages, before the appearance of signal increase in T2-weighted sequences.     

Accuracy and diagnostic yield of stereotactic biopsy in the diagnosis of brain masses: Comparison of results of biopsy and resected surgical specimens

The aim of this retrospective study was to investigate the diagnostic yield and accuracy of stereotactic biopsy in patients harboring brain mass. Stereotactic biopsy was performed in 130 patients between 1995 and 2000 in an educational and research hospital in Turkey. The results of histological analysis were compared to the resected specimens in 23 patients. The lesions were lobar in 62% of cases and deep‐seated in 38% of cases. During the biopsy procedures, the pathologist was in the operating theatre and a very small fragment was used for cytological examination. No frozen section was used in any of the cases. Samples were diagnostic in 122 cases. The overall diagnostic yield of the procedure was 94%. A definitive histological diagnosis was not made in eight patients. The histological diagnoses of the two procedures were identical (complete agreement) in 16 cases. In three cases, the histological diagnoses between the two procedures were slightly different without impact on patient care (minor disagreement). The diagnosis of the stereotactic biopsy was completely changed after craniotomy in four cases (major disagreement). The accuracy of the histological diagnosis was 83%. There was only one major complication, which involved intracerebral hemorrhage. Despite the limited number of patients who underwent resection, our data suggest that stereotactic biopsy of brain masses is a safe and accurate technique that can obtain adequate tissue for histological diagnosis, thus providing the best avaible treatment for patients. Cytological evaluation of the streotactic biopsy also is a highly effective tool for obtaining sufficient material during the procedure in many cases.     

Activated carbons from co-carbonization of waste truck tires and spent tea leaves

This study reports the co-carbonization of waste truck tires (WTT) and spent tea leaves (STL) at different blend ratios using chemical activating reagents (KOH and ZnCl₂) carried out at 800 °C. The highest BET surface area from blends was 527.24 m²/g, obtained using ZnCl₂ activation at a blend ratio of 1:3 (WTT/STL). Activated carbons yields in the blends were the highest at a blend ratio of 3:1 (WTT/STL) for both chemical activations. They were 24.37 wt% for KOH activation and 41.59 wt% for ZnCl₂ activation. ZnCl₂ activation produced higher carbon and lower oxygen content than those using KOH activation. Regardless of the type of feed, the oxygen removal efficiency of ZnCl₂ was higher than that of KOH under identical conditions. Among all the activated carbons produced, the BET surface area of the activated carbons obtained from the carbonization of STL alone was highest for both activations. The BET surface area of the activated carbons produced in this study was comparable to that of activated carbons produced commercially.     

Primary spinal extradural hydatid cyst in a child: case report and review of the literature

Spinal hydatid cyst is a rare but serious condition. An 8-year-old boy presented with back pain, progressive weakness and numbness in both legs. Magnetic resonance imaging (MRI) of the lumbar region showed a cystic lesion with regular contour located in extradural space. There was cerebrospinal fluid- (CSF-) like signal intensity on T1- and T2-weighted images. The lesion had excessively compressed the dural sac and caudal roots, and expanded to the L3 and L4 neural foramina. The case was explored with L2, L3, L4 laminectomy and the hydatid cyst was removed totally. The clinical presentation, diagnosis and surgical treatment of this rare case of spinal hydatid disease is discussed, and all available cases of primary extradural hydatid cyst reported in the literature are presented.     

Effects of bone morphogenetic protein on neonatal rat calvarial osteoblast-like cells: an in vitro study

Bone morphogenetic proteins (BMPs) are factors that promote osteoblastic differentiation and osteogenesis. The aim of this study was to examine the behavior of neonatal rat calvarial osteoblast cells cultured on different concentrations of BMP graft materials. Fifty thousand cells per milliliter were seeded and cultured on graft materials for 24 and 48 h. Different concentrations of BMPs (combination of BMPs numbered from 1 to 14) were supplemented to the medium. To evaluate cellular proliferation and differentiation, specimens were examined for DNA synthesis, alkaline phosphatase (ALP) activity, cell numbers, and viability of the cells. Further, transforming growth factor-beta(1) (TGF-beta(1)) and lactate dehydrogenase (LDH) levels were investigated. Morphological appearance of the specimens at 24 and 48 h of incubation was evaluated using scanning electron microcopy. Evaluations of DNA synthesis, cell count, and cell viability data revealed that a significant difference existed at 24 and 48 h (p < 0.05). The TGF-beta(1) and ALP analysis showed only a significant difference between the groups at the end of 24 h (p < 0.05). Regarding the lactate dehydrogenase activity there was not any significant difference at 24 and 48 h (p > 0.05). No morphological differences were observed in cell morphology on BMP graft material and the control group. These results indicate that BMPs have an inductive effect on osteoblast differentiation and a possible inhibitory effect in the early phases of cell proliferation.     

Sound energy absorbance characteristics of cartilage grafts used in type 1 tympanoplasty

Objective

The purpose of this prospective case-control study is to evaluate the sound energy absorbance characteristics of cartilage grafts in patients, who have undergone type 1 cartilage tympanoplasty.