Post-implantation Deformation of Titanium Rod and Cobalt Chrome Rod in Adolescent Idiopathic Scoliosis

@#Introduction: Post-implantation rod deformation is anticipated in scoliosis surgery but the difference in rod deformation between titanium and cobalt chrome rod has not been elucidated. This study aims to compare the difference in rod deformation between two groups. Materials and Methods: Twenty-one adolescent idiopathic scoliosis (AIS) patients were recruited from a single center. The over-contoured concave rods were traced prior to insertion. Post-operative sagittal rod shape was determined from lateral radiographs. Rod deformation was determined using maximal rod deflection and angle of the tangents to rod end points. The differences between pre- and post-operative rod contour were analysed statistically. Rod deformation and thoracic kyphosis between two types of implants were analysed. Results:Both rods exhibited significant change of rod angle and deflection post-operatively. Curvature of the titanium rod and cobalt chrome rod decreased from 60.5° to 37°, and 51° to 28° respectively. Deflection of titanium rod and cobalt chrome rod reduced from 28mm to 23.5mm and 30mm to 17mm respectively. There was no significant difference between titanium and cobalt chrome groups with regard to rod angle (p=0.173) and deflection (p=0.654). Thoracic kyphosis was increased from 20° to 26° in titanium group but a reduction from 25° to 23° was noticed in cobalt chrome group, but these findings were not statistically significant. Conclusion: There was no statistical difference in rod deformation between the two groups. Thus, the use of titanium rod in correction of sagittal profile is not inferior in outcome compared with cobalt chrome but with lower cost.

Three Level Thoracolumbar Spondylectomy for Recurrent Giant Cell Tumour of the Spine: A Case Report

@#Giant cell tumour (GCT) is a benign tumour but can be locally aggressive and with the potential to metastasise especially to the lungs. Successful treatments have been reported for long bone lesions; however, optimal surgical and medical treatment for spinal and sacral lesions are not well established. In treating spinal GCTs, the aim is to achieve complete tumour excision, restore spinal stability and decompress the neural tissues. The ideal surgical procedure is an en bloc spondylectomy or vertebrectomy, where all tumour cells are removed as recurrence is closely related to the extent of initial surgical excision. However, such a surgery has a high complication rate, such as dura tear and massive blood loss. We report a patient with a missed pathological fracture of T12 treated initially with a posterior subtraction osteotomy, who had recurrence three years after the index surgery and subsequently underwent a three level vertebrectomy and posterior spinal fusion.

Hepatic cyclooxygenase-2 overexpression induced spontaneous hepatocellular carcinoma formation in mice.

Cyclooxygenase (COX)-2 is upregulated in hepatocellular carcinoma (HCC). However, the direct causative effect of COX-2 in spontaneous HCC formation remains unknown. We thus investigate the role and molecular pathogenesis of COX-2 in HCC by using liver-specific COX-2 transgenic (TG) mice. We found spontaneous HCC formation with elevated inflammatory infiltrates and neovessels in male TG mice (3/21, 14.3%), but not in any of male WT mice (0/19). Reduced representation bisulfite sequencing (RRBS) and gene expression microarrays were performed in the HCC tumor and non-HCC liver tissues to investigate the molecular mechanisms of COX-2-driven HCC. By RRBS, DNA promoter hypermethylation was identified in HCC from TG mice. Induction of promoter hypermethylation was associated with reduced tet methylcytosine dioxygenase 1 (TET1) expression by COX-2. TET1 could catalyze the conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC) and prevents DNA hypermethylation. In keeping with this, loss of 5hmC was demonstrated in COX-2-induced HCC. Consistently, COX-2 overexpression in human HCC cell lines could reduce both TET1 expression and 5hmc levels. Integrative analyses of DNA methylation and gene expression profiles further identified significantly downregulated genes including LTBP1, ADCY5 and PRKCZ by promoter methylation in COX-2-induced HCC. Reduced expression of LTBP1, ADCY5 and PRKCZ by promoter hypermethylation was further validated in human HCCs. Bio-functional investigation revealed that LTBP1 inhibited cell proliferation in HCC cell lines, suggesting its potential role as a tumor suppressor in HCC. Gene expression microarrays revealed that signaling cascades (AKT (protein kinase B), STK33 (Serine/Threonine kinase 33) and MTOR (mechanistic target of rapamycin) pathways) were enriched in COX-2-induced HCC. In conclusion, this study demonstrated for the first time that enhanced COX-2 expression in hepatocytes is sufficient to induce HCC through inducing promoter hypermethylation by reducing TET1, silencing tumor-suppressive genes and activating key oncogenic pathways. Inhibition of COX-2 represents a mechanism-based target for HCC prevention.

Multiple atraumatic osteoporotic vertebral fractures in an adolescent with suprasellar germinoma: a case report.

ABSTRACT: We present the case of a patient with multiple atraumatic osteoporotic vertebral fractures in an adolescent with suprasellar germinoma and also review of relevant literature. The patient suffered from a rare adolescent brain tumour with common complications which are often overlooked and give rise to significant morbidity. Suprasellar germinoma is an intracranial neoplasm, that in addition to its rarity, has variable clinical presentation. Despite appropriate treatment and good outcome, tumour related morbidity is still of concern for these patients. KEY WORDS: Secondary osteoporosis, suprasellar germinoma, panhypopituitarism.

Percutaneous Endoscopic Transforaminal LumbarDiscectomy An Early Experience

Percutaneous endoscopic spinal surgery performed in the awake state offers a new paradigm for treatment of symptomatic lumbar disc prolapse. We report the outcome of 23 patients who underwent this procedure. Visual analogue scale for pain improved from 7.3 to 2.1; 19 of the 23 patients achieved good to excellent results according to the MacNab criteria. Patient acceptance of the procedure was 91.3%. All but one patient were discharged from hospital within 24 hours. One patient developed foot drop post oper

Cystoid macular oedema and changes in retinal thickness after phacoemulsification with optical coherence tomography.

AIMS: To study the incidence of cystoid macular oedema and changes in retinal thickness after phacoemulsification with optical coherence tomography (OCT). METHODS: In all, 131 eyes of 131 patients were studied at the ophthalmology clinic at Tung Wah Eastern Hospital from September 2001 to October 2002. All the patients had clinical assessment and OCT preoperatively and at weeks 2, 4, and 8 postoperatively. The incidence of postoperative cystoid macular oedema (CMO) was evaluated. The foveal thickness (FT) and central 1 mm retinal thickness (CT) at different time intervals were analysed. RESULTS: Four (3.05%) patients developed CMO after phacoemulsification, which was evident clinically and tomographically. Fluorescein angiogram confirmed leakage in all cases. For other patients, the mean preoperative FT was 189.36 +/- 26.83 microm. The mean FT, were 175.74 +/- 26.79 microm, 180.25 +/- 27.13 microm, 176.58 +/- 26.45 microm at 2 weeks, 4 weeks, and 8 weeks postoperatively, respectively. The preoperative FT was significantly thicker than those in the postoperative period. The same trend was noted for CT. CONCLUSION: OCT is useful for detecting and confirming clinical CMO after cataract surgery; however, its use in detecting subtle changes in retinal thickness is limited by the normal variation in retinal thickness. The measurement of retinal thickness with OCT may also be affected by the status of the lens.

Expression of axon guidance molecules and their related genes during development and sexual differentiation of the olfactory bulb in rats.

Axon guidance molecules and related proteins such as semaphorin 3A, neuropilin-1, plexin-1, netrin-1, growth-associated protein, olfactory marker protein, cypin and collapsin response mediator proteins guide the development of neural circuits in the olfactory bulb. In this study, transcriptions of these genes were examined in the olfactory bulb of female, male and neonatal testosterone propionate-treated female rats at the ages of 2, 5, 10, 15, 20, 25, 30 and 45 days. The semaphorin 3A, neuropilin-1, growth-associated protein and collapsin response mediator protein 1-5 genes were expressed significantly higher during the early development stages than in adulthood while the opposite is true for the olfactory marker protein. The expression profile of cypin and netrin-1 was relatively constant through development. A late effect of the neonatal testosterone propionate treatment on netrin-1, growth-associated protein, olfactory marker protein, collapsin response mediator proteins 1, 3, 4 and cypin gene expression was observed. The expression profiles of collapsin response mediator proteins and their related genes in the developing olfactory bulb confirmed most studies on the relationship between collapsin response mediator proteins and development in the brain. Sex differences of semaphorin 3A, neuropilin-1 as well as collapsin response mediator protein 3 at the early development stage and the late effect of neonatal testosterone propionate treatment on the expressions of netrin-1, growth-associated marker protein, cypin and collapsin response mediator proteins 1, 3 and 5 genes may indicate a possible role of these molecules on sexual differentiation of the olfactory bulb.

Methods used for reconstruction in aggressive bone tumours: an early experience

Improvements in the overall treatment of patients with aggressive, large tumours involving the bone have made it possible to preserve and salvage limbs instead of amputating them. Each patient is unique in his clinical presentation and social circumstance. The different reconstructive options available allow us to choose the most appropriate method suited to the particular patient and with minimal delay, even when resources are limited. The patient and the relatives actively participate in the choice. The early experience of the different techniques for reconstructing these bone defects at our hospital are presented in this paper.

Correlational study of central corneal thickness measurements on Hong Kong Chinese using optical coherence tomography, Orbscan and ultrasound pachymetry.

BACKGROUND: Central corneal thickness (CCT) of 74 eyes from 39 normal Hong Kong Chinese subjects with ages ranging from 39 to 86 years were studied. AIM & PURPOSE: To compare the measurements of different devices and to compare the results of ethnic groups in other studies. METHODS: Non-contact measurements by Orbscan and Optical Coherence Tomography (OCT) were first carried out, followed by contact measurement using Ultrasound Pachymetry. The results of five measurements of Ultrasound Pachymetry and three measurements of OCT and Orbscan were each averaged and compared using correlation, linear regression and one-way analysis of variance methods. RESULTS: The measurements of three devices were significantly correlated (P < 0.01). The mean CCT in our study group measured by Orbscan (with an acoustic factor set at 0.92), Ultrasound Pachymetry and OCT were 555.96 +/- 32.41, 555.11 +/- 35.30 and 523.2 +/- 33.54 microm respectively. A linear regression model (using ultrasound measurements as standard) was presented. CONCLUSIONS: When a correction factor of 32 microm was applied to OCT measurements, the means of three devices became significantly equal. The adjusted OCT measurements were less precise within subjects but more accurate than Orbscan when compared with ultrasound pachymetry as a reference standard. The mean CCT measurement of our sample was comparable to some studies on Hong Kong Chinese, Caucasians and Japanese but higher than those on some Europeans, Asian and North Americans of African origin.