Dae-Chul Cho

Palliative surgery for metastatic thoracic and lumbar tumors using posterolateral transpedicular approach with posterior instrumentation

BACKGROUNDnThe purpose of this study was to evaluate the clinical outcomes of patients with metastatic thoracic and lumbar tumors after palliative surgery using PTA with posterior instrumentation.nnnMETHODSnTwenty-one consecutive patients with metastatic thoracic and lumbar spine tumors were treated using a PTA with posterior instrumentation. The patient group is composed of 14 men and 7 women with mean age of 56.6 years (range, 32-76 years). The average extent of vertebral involvement was 2.2 segments.nnnRESULTSnThe mean operative time was 3.1 hours (range, 2-4.5 hours), and the mean blood loss was 1400 mL (range, 600-2500 mL). All patients with pain showed improved or similar pain levels after surgery, and Frankel grades were decreased significantly by operation. Postoperative mean survival was 8.9 months and ranged from 2 to 36 months. There were 4 (26.7%) patients who died at less than 3 months after surgery and 3 patients (14%) who required a repeat operation. Of 5 patients treated using a PTA despite a Tomitas prognostic score of more than 8, 3 patients (with preoperative ECOG grade IV) died within 6 weeks postoperatively, and the other 2 patients (with preoperative ECOG grade III) survived longer than 10 weeks (1 patient survived for 10 weeks, and the other for 12 weeks).nnnCONCLUSIONnThe PTA with posterior instrumentation for metastatic thoracic and lumbar spinal tumors achieved good surgical results. Palliative surgery for patients with a Tomitas prognostic score of more than 8 may be considered in selected cases, especially in those with ECOG grade III.

The Change of Bone Metabolism in Ovariectomized Rats : Analyses of MicroCT Scan and Biochemical Markers of Bone Turnover

Objective The purpose of this study was to verify the appropriateness of ovariectomized rats as the osteoporosis animal model. Methods Twelve female Sprague-Dawley rats underwent a sham operation (the sham group) or bilateral ovariectomy [the ovariectomy (OVX) group]. Eight weeks after operations, serum biochemical markers of bone turnover were analyzed; osteocalcin and alkaline phosphatase, which are sensitive biochemical markers of bone formation, and C-terminal telopeptide fragment of type I collagen C-terminus (CTX), which is a sensitive biochemical marker of bone resorption. Bone histomorphometric parameters and microarchitectural properties of 4th lumbar vertebrae were determined by micro-computed tomographic (CT) scan. Results The OVX group showed on average 75.4% higher osteocalcin and 72.5% higher CTX levels than the sham group, indicating increased bone turnover. Micro-CT analysis showed significantly lower bone mineral density (BMD) (p=0.005) and cortical BMD (p=0.021) in the OVX group. Furthermore, the OVX group was found to have a significantly lower trabecular bone volume fraction (p=0.002). Conclusion Our results showed that bone turnover was significantly increased and bone mass was significantly decreased 8 weeks after ovariectomy in rats. Thus, we propose that the ovariectomized rat model be considered a reproducible and reliable model of osteoporosis.

A synergistic bone sparing effect of curcumin and alendronate in ovariectomized rat

BackgroundThe purpose of this study was to evaluate the therapeutic effects of combination therapy with curcumin and alendronate on bone remodeling after ovariectomy in rats.MethodsEighty female Sprague-Dawley rats underwent either a sham operation (the sham group) or bilateral ovariectomy (OVX). The ovariectomized animals were randomly distributed amongst four groups: untreated OVX group, curcumin-administered group, alendronate-administered group, and the combination therapy group. At 8 and 12xa0weeks after surgery, rats from each of the groups were euthanized. Serum biochemical markers of bone turnover, including osteocalcin and alkaline phosphatase (ALP), and the telopeptide fragment of type I collagen C-terminus (CTX) were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae were determined by micro-computed tomography (CT). In addition, mechanical strength was determined by a three-point bending test.ResultsSerum biochemical markers of bone turnover in the experiment groups (curcumin administered group, alendronate administered group, and the combination therapy group) were significantly lower than in the untreated OVX group (pu2009<u20090.05). The combination therapy group had lower ALP and CTX-1 concentrations at 12xa0weeks, which were statistically significant compared with the curcumin only and the alendronate only group (pu2009<u20090.05). The combination therapy group had a significant increase in BMD at 8xa0weeks and Cr.BMD at 12xa0weeks compared with the curcumin-only group (pu2009=u20090.005 and pu2009=u20090.013, respectively). The three point bending test showed that the 4th lumbar vertebrae of the combination therapy group had a significantly greater maximal load value compared to that of the curcumin only and the alendronate only group (pu2009<u20090.05).ConclusionsThe present study demonstrated that combination therapy with a high dose of curcumin and a standard dose of alendronate has therapeutic advantages over curcumin or alendronate monotherapy, in terms of the synergistic antiresorptive effect on bone remodeling, and improving bone mechanical strength.

Feasibility of C2 translaminar screw as an alternative or salvage of C2 pedicle screws in atlantoaxial instability.

Study Design A retrospective outcome study. Objective The purpose of this study was to analyze the clinical outcomes of our experience with the C2 translaminar screw technique and evaluate its feasibility as an alternative or salvage of the pedicle screw. Summary of Background Data Pedicle screws are the most biomechanically stable screws for use in atlantoaxial fixation. However, in cases with elevated risk of neurovascular complications or failure of screw insertion attempts, a reliable alternative technique is required. Methods Fourteen patients with atlantoaxial instability underwent posterior fixation with C2 translaminar screws. Indications included traumatic instability, atlantoaxial subluxation, os odontoideum, and fusion failure after anterior fixation of a type II odontoid process fracture. A total of 26 screws were inserted and all patients were assessed both clinically and radiographically. Results No procedure-related complications or hardware failures were observed during the follow-up. Postoperative computed tomographic scans revealed laminar breach in 3 patients and none of these resulted in neurological symptoms. Radiographically demonstrated bony fusion was established in 11 patients (91.7%) at follow-up over 6 months, and 5 patients with initial neurological deficit demonstrated at least 1 grade improvement by Frankel grade. Conclusions C2 translaminar screws provide surgeons with an expanded option for posterior fusion in high cervical lesions. This technique is safe and easy to adopt with a favorable rate of successful fusion. We believe that preoperative planning using computed tomographic scan is mandatory and use of an additional connector may reduce the stress and strain of the screws.

The Neuroprotective Effect of Treatment with Curcumin in Acute Spinal Cord Injury: Laboratory Investigation

The purpose of this study was investigating the effects of curcumin on the histological changes and functional recovery following spinal cord injury (SCI) in a rat model. Following either sham operation or SCI, 36 male Sprague–Dawley rats were distributed into three groups: sham group, curcumin-treated group, and vehicle-injected group. Locomotor function was assessed according to the Basso, Beattie, and Bresnahan (BBB) scale in rats who had received daily intraperitoneal injections of 200 mg/kg curcumin or an equivalent volume of vehicle for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. BBB scores were significantly higher in rats receiving curcumin than receiving vehicle (P < 0.05). The cavity volume was significantly reduced in the curcumin group as compared to the control group (P = 0.039). Superoxide dismutase (SOD) activity was significantly elevated in the curcumin group as compared to the vehicle group but was not significantly different from the sham group (P < 0.05, P > 0.05, respectively) at one and two weeks after SCI. Malondialdehyde (MDA) levels were significantly elevated in the vehicle group as compared to the sham group (P < 0.05 at 1 and 2 weeks). MDA activity was significantly reduced in the curcumin group at 2 weeks after SCI when compared to the vehicle group (P = 0.004). The numbers of macrophage were significantly decreased in the curcumin group (P = 0.001). This study demonstrated that curcumin enhances early functional recovery after SCI by diminishing cavitation volume, anti-inflammatory reactions, and antioxidant activity.

Analysis of risk factors associated with fusion failure after anterior odontoid screw fixation.

Study Design. Retrospective study. Objective. To evaluate the incidence of fusion failure after anterior screw fixation of type II and rostral shallow type III fractures and to identify related risk factors. Summary of Background Data. Although several studies have reported fusion rates after anterior odontoid screw fixation of type II and rostral shallow type III fractures, few reports have analyzed in detail the risk factors associated with fusion failure. Methods. Forty-one patients with a type II and rostral shallow type III odontoid fracture were treated using anterior screw fixation. The patients were 33 men and 8 women mean age = 46.6 years; age range = 15–79 years. Range of follow-up was 7 to 48 months. Results. Anterior odontoid screw fixation resulted in solid bony union in 33 patients (80.5%), fibrous union in 3 (7.3%), and nonunion in 5 (12.2%). When surgery was delayed for more than 1 week, the incidence of fusion failure significantly increased (P = 0.0051). Furthermore, a fracture gap of 2 mm or more was found to be significantly associated with fusion failure (P = 0.0172). However, patient age and fracture displacement were not found to be significantly associated with fusion failure (P = 0.8236 and P = 0.5762, respectively). Conclusion. Our study of anterior odontoid screw fixation reveals that the risk of fusion failure is 37.5 times greater in patients with a delay of more than 1 week before operation, and 21 times greater in patients with a fracture gap of greater than 2 mm.

Therapeutic advantages of treatment of high-dose curcumin in the ovariectomized rat.

Objective Although curcumin has a protective effect on bone remodeling, appropriate therapeutic concentrations of curcumin are not well known as therapeutic drugs for osteoporosis. The purpose of this study was to compare the bone sparing effect of treatment of low-dose and high-dose curcumin after ovariectomy in rats. Methods Forty female Sprague-Dawley rats underwent either a sham operation (the sham group) or bilateral ovariectomy (OVX). The ovariectomized animals were randomly distributed among three groups; untreated OVX group, low-dose (10 mg/kg) curcumin administered group, and high-dose (50 mg/kg) curcumin group. At 4 and 8 weeks after surgery, serum biochemical markers of bone turnover were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae were determined by micro-computed tomography (CT). In addition, mechanical strength was determined by a three-point bending test. Results High-dose curcumin group showed significantly lower osteocalcin, alkaline phosphatase, and the telopeptide fragment of type I collagen C-terminus concentration at 4 and 8 weeks compared with the untreated OVX group as well as low-dose curcumin group. In the analyses of micro-CT scans of 4th lumbar vertebrae, the high-dose curcumin treated group showed a significant increase in bone mineral densities (p=0.028) and cortical bone mineral densities (p=0.036) compared with the low-dose curcumin treated group. Only high-dose curcumin treated group had a significant increase of mechanical strength compared with the untreated OVX group (p=0.015). Conclusion The present study results demonstrat that a high-dose curcumin has therapeutic advantages over a low-dose curcumin of an antiresorptive effect on bone remodeling and improving bone mechanical strength.

Chronic idiopathic myelofibrosis presenting as cauda equina compression due to extramedullary hematopoiesis: a case report.

Extramedullary hematopoiesis (EMH) is occasionally reported in idiopathic myelofibrosis and is generally found in the liver, spleen, and lymph nodes several years after diagnosis. Myelofibrosis presenting as spinal cord compression, resulting from EMH tissue is very rare. A 39-yr-old man presented with back pain, subjective weakness and numbness in both legs. Sagittal magnetic resonance imaging showed multiple anterior epidural mass extending from L4 to S1 with compression of cauda equina and nerve root. The patient underwent gross total removal of the mass via L4, 5, and S1 laminectomy. Histological analysis showed islands of myelopoietic cells surrounded by fatty tissue, consistent with EMH, and bone marrow biopsy performed after surgery revealed hypercellular marrow and megakaryocytic hyperplasia and focal fibrosis. The final diagnosis was chronic idiopathic myelofibrosis leading to EMH in the lumbar spinal canal. Since there were no abnormal hematological findings except mild myelofibrosis, additional treatment such as radiothepary was not administered postoperatively for fear of radiotoxicity. On 6 month follow-up examination, the patient remained clinically stable without recurrence. This is the first case of chronic idiopathic myelofibrosis due to EMH tissue in the lumbar spinal canal in Korea.

Effect of Dietary Calcium on Spinal Bone Fusion in an Ovariectomized Rat Model

Objective To evaluate the effect of calcium supplementation on spinal bone fusion in ovariectomized (OVX) rats. Methods Sixteen female Sprague Dawley rats underwent bilateral ovariectomy at 12 weeks of age to induce osteoporosis and were randomly assigned to two groups : control group (n=8) and calcium-supplemented group (OVX-Ca, n=8). Autologous spinal bone fusion surgery was performed on both groups 8 weeks later. After fusion surgery, the OVX-Ca group was supplemented with calcium in drinking water for 8 weeks. Blood was obtained 4 and 8 weeks after fusion surgery. Eight weeks after fusion surgery, the rats were euthanized and the L4-5 spine removed. Bone fusion status and fusion volume were evaluated by manual palpation and three-dimensional computed tomography. Results The mean fusion volume in the L4-5 spine was significantly greater in the OVX-Ca group (71.80±8.06 mm3) than in controls (35.34±8.24 mm3) (p<0.01). The level of osteocalcin, a bone formation marker, was higher in OVX-Ca rats than in controls 4 weeks (610.08±10.41 vs. 551.61±12.34 ng/mL) and 8 weeks (552.05±19.67 vs. 502.98±22.76 ng/mL) after fusion surgery (p<0.05). The level of C-terminal telopeptide fragment of type I collagen, a bone resorption marker, was significantly lower in OVX-Ca rats than in controls 4 weeks (77.07±12.57 vs. 101.75±7.20 ng/mL) and 8 weeks (69.58±2.45 vs. 77.15±4.10 ng/mL) after fusion surgery (p<0.05). A mechanical strength test showed that the L4-5 vertebrae in the OVX-Ca group withstood a 50% higher maximal load compared with the controls (p<0.01). Conclusion Dietary calcium given to OVX rats after lumbar fusion surgery improved fusion volume and mechanical strength in an ovariectomized rat model.

Histomorphometric Analysis of the Spine and Femur in Ovariectomized Rats Using Micro-Computed Tomographic Scan

Objective The purpose of this study was to evaluate the different patterns of bone loss between the lumbar spine and the femur after ovariectomy in rats. Methods Twenty-four female Sprague-Dawley rats underwent a sham operation (the sham group) or bilateral ovariectomy (the ovariectomized group). Four and eight weeks after operation, six rats from each of the two groups were euthanized. Serum biochemical markers of bone turnover including osteocalcin and alkaline phosphatase (ALP), which are sensitive biochemical markers of bone formation, and the telopeptide fragment of type I collagen C-terminus (CTX), which is a sensitive biochemical marker of bone resorption, were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae and femur were determined by micro-computed tomography. Results Ovariectomized rats were found to have higher osteocalcin, ALP and CTX levels than sham controls. Additionally, 8 weeks after ovariectomy in the OVX group, serum levels of osteocalcin, ALP and CTX were significantly higher than those of 4 weeks after ovariectomy. Bone loss after ovariectomy was more extensive in the 4th lumbar spine compared to the femur. Bone loss in the 4th lumbar spine was mainly caused by trabecular thinning, but in the femur, it was mainly caused by trabecular elimination. Conclusion The present study demonstrates different patterns of bone loss between the 4th lumbar spine and the femur in ovariectomized rats. Therefore, when considering animal models of osteoporosis, it is important that bone sites should be taken into account.