Does Central Sensitization Influence Outcomes of Lumbar Discectomy Surgery in Patients With Lumbar Disc Herniation? A Multicenter Prospective Study.

STUDY DESIGN: Multicenter prospective study. OBJECTIVE: Patients with central sensitization (CS) are reported to be at high risk of poor outcomes after spinal surgery. However, the influence of CS on surgical outcomes for lumbar disc herniation (LDH) remains unknown. This study aimed to examine the association between preoperative CS and surgical outcomes in LDH patients. METHODS: A total of 100 consecutive patients with LDH (mean age 51.2) who underwent lumbar surgery were included in this study. The extent of CS was evaluated using the central sensitization inventory (CSI), a screening tool for CS-related symptoms. The patients completed the following CSI and clinical outcome assessments (COAs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for back pain, JOA back pain evaluation questionnaire (JOABPEQ), and Oswestry Disability Index (ODI). The association between preoperative CSI scores, and preoperative and postoperative COAs was analyzed, and the postoperative changes were statistically evaluated. RESULTS: The preoperative CSI score significantly decreased 12 months postoperatively. Preoperative CSI scores showed a significant correlation with most COAs; however, a significant correlation was only identified in the social function and mental health domains of JOABPEC postoperatively. Higher preoperative CSI showed worse preoperative COAs; however, all COAs significantly improved regardless of CSI severity. There were no significant differences in any COAs among the CSI severity groups 12 months postoperatively. CONCLUSIONS: The results of this study showed that lumbar surgeries significantly improved the COAs regardless of preoperative severity of CS in patients with LDH.

Central sensitization as a predictive factor for the surgical outcome in patients with lumbar spinal stenosis: a multicenter prospective study.

PURPOSE: The impact of central sensitization (CS) on neurological symptoms and surgical outcomes in patients with lumbar spinal stenosis (LSS) remains unknown. This study aimed to investigate the influence of preoperative CS on the surgical outcomes of patients with LSS. METHODS: A total of 197 consecutive patients with LSS (mean age 69.3) who underwent posterior decompression surgery with or without fusion were included in this study. The participants completed the CS inventory (CSI) scores and the following clinical outcome assessments (COAs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for back pain, JOA back pain evaluation questionnaire, and Oswestry Disability Index (ODI). The association between preoperative CSI scores and preoperative and postoperative COAs was analyzed, and postoperative changes were statistically evaluated. RESULTS: The preoperative CSI score significantly decreased at 12 months postoperatively and was significantly correlated with all COAs preoperatively and 12 months postoperatively. Higher preoperative CSI showed worse postoperative COAs and inferior postoperative improvement rates in the JOA score, VAS score for neurological symptoms, and ODI. Multiple regression analysis demonstrated that preoperative CSI was significantly associated with postoperative low back pain (LBP), mental health, quality of life (QOL), and neurological symptoms at 12 months postoperatively. CONCLUSIONS: Preoperative CS evaluated by CSI had a significantly worse impact on surgical outcomes, including neurological symptoms, disability, and QOL, especially related to LBP and psychological factors. CSI can be used clinically as a patient-reported measure for predicting postoperative outcomes in patients with LSS.

Incidence and Characteristics of Clinical L5-S1 Adjacent Segment Degeneration after L5 Floating Lumbar Fusion: A Multicenter Study.

STUDY DESIGN: Retrospective study. PURPOSE: This study aimed to evaluate the incidence, characteristics, and risk factors for clinical L5-S1 adjacent segment degeneration (ASD) after L5 floating lumbar fusion. OVERVIEW OF LITERATURE: ASD is known to occur after lumbar spine fusion at a certain frequency. Several studies on radiological L5- S1 ASD have been reported. However, there are only a few studies on L5-S1 ASD with clinical symptoms, including back pain and/or radiculopathy. METHODS: In total, 306 patients who received L5 floating lumbar fusion were included in this study. Clinical L5-S1 ASD was defined as newly developed radiculopathy in relation to the L5-S1 segment. Patients' medical records and imaging data were retrospectively analyzed. The risk factors for clinical ASD were assessed by an inverse probability of treatment weighting-adjusted logistic regression analysis. RESULTS: Clinical L5-S1 ASD occurred in 17 patients (5.6%). The mean onset time of L5-S1 ASD was 12.9±7.5 months after the primary surgery. Among these patients, 10 (58.8%) presented with clinical L5-S1 ASD within 12 months. Reoperation was performed in three patients (1.0%). The severity of L5-S1 disk degeneration did not affect the occurrence of L5-S1 ASD. Logistic regression analysis showed that the number of fusion levels was a significant risk factor for clinical L5-S1 ASD. CONCLUSIONS: The incidence and characteristics of clinical L5-S1 ASD after L5 floating lumbar fusion were retrospectively investigated. This study established that the number of fusion levels was a significant candidate factor for clinical L5-S1 ASD. Careful clinical follow-up is deemed necessary after L5 floating lumbar fusion surgery, especially for patients who received multiple-level fusions.

Evaluation of Central Sensitization Inventory in Patients Undergoing Elective Spine Surgery in a Multicenter Study.

STUDY DESIGN: This study is a retrospective review. OBJECTIVE: Central sensitization (CS) is a neurological phenomenon that involves hypersensitivity of the central nervous system. The central sensitization inventory (CSI) was developed as a screening tool to assess CS-related symptoms. The purpose of this study was to evaluate the association of preoperative CSI scores with patient-reported outcome measures (PROMs) including neurological symptoms for patients who underwent spine surgeries in a multicenter study. METHODS: A consecutive 673 patients who underwent spine surgery at 8 different institutions were included in this study. Preoperative CSI scores were assessed for all subjects. The participants completed the following PROMs: the Oswestry Disability Index (ODI), the Japanese Orthopaedic Association (JOA) back pain evaluation questionnaire (JOABPEQ) for lumbar spinal diseases, and the JOA cervical myelopathy evaluation questionnaire (JOACMEQ) for cervical spinal diseases. The association of CSI scores with PROMs was statistically evaluated. RESULTS: The average CSI score for the total subjects was 23.6 ± 13.5. The subjects with CS-related symptoms (CSI ≥ 40) were 13.2% (n = 89). The CSI score showed a significant and weak-to-moderate correlation with the PROMs including neurological symptoms that included all the domains of the JOACMEQ for cervical spinal diseases, and JOABPEQ and ODI for lumbar spinal diseases. Among these, psychological factors had the most influence on the correlation with CSI score. CONCLUSION: Central sensitization evaluated by the CSI is related to neurological symptoms and health-related quality of life in patients undergoing elective spine surgery.

Influence of Central Sensitization on Surgical Outcomes of Patients With Degenerative Cervical Myelopathy After Posterior Decompression Surgery: A Multicenter Prospective Study.

STUDY DESIGN: Multicenter prospective study. OBJECTIVE: The influence of central sensitization (CS) on neurological symptoms and surgical outcomes in patients with degenerative cervical myelopathy (DCM) remains unknown. This study aimed to investigate the effects of preoperative CS on surgical outcomes of patients with DCM following posterior decompression surgery. METHODS: 77 consecutive patients with DCM (mean age 67.1) who received posterior decompression surgery were included in this study. The participants completed CS inventory (CSI) scores and the following patient-reported outcome measures (PROMs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for cervical myelopathy and JOA cervical myelopathy evaluation questionnaire (JOACMEQ) for cervical spinal diseases. The association of preoperative CSI scores with preoperative and postoperative PROMs was analyzed, and their changes were statistically evaluated. RESULTS: The preoperative CSI score was significantly decreased at 12 months postoperatively, and it was significantly associated with the JOA score and JOACMEQ preoperatively and at 12 months postoperatively. However, no significant association was observed between preoperative CSI and the postoperative change of any PROMs at 12 months. The posterior decompression surgery significantly improved the JOA scores and 'lower extremity function' and 'quality of life (QOL)' domains of the JOACMEQ, independent of the severity of preoperative CSI score. Multiple regression analysis demonstrated that preoperative CSI was significantly associated with the 'QOL' domain of JOACMEQ and original JOA score at 12 months postoperatively. CONCLUSION: The CSI score can be an auxiliary indicator of surgical outcomes of patients with DCM following posterior decompression surgery.

Intraosseous lipoma of the third lumbar spine: a case report.

INTRODUCTION: Intraosseous lipoma is a benign bone tumor, and the tumor occurs more frequently in the lower extremities. We present a very rare case of intraosseous lipoma occurring in the lumbar vertebral arch and spinous process. CASE PRESENTATION: A 54-year-old Japanese man presented with a three-month history of lumbar pain. Magnetic resonance imaging of the L3 vertebral arch and spinous process revealed high intensity on T1- and T2-weighted imaging, and it was suppressed on fat-suppression imaging and no enhancement showed on gadolinium contrast-enhanced imaging. Computed tomography imaging revealed an osteolytic change accompanied by marginal osteosclerosis in his third lumbar vertebral arch and spinous process, as well as a thinned and bulging bone cortex. An analgesic had been administered prior to his visit, but low back pain had persisted, so we performed curettage and filled the defect with hydroxyapatite bone. His low back pain was improved immediately after surgery, and no recurrence of tumor has been observed on computed tomography imaging as of three years postoperatively. CONCLUSIONS: Symptomatic intraosseous lipoma of spine is very rare, but the patient may be surgically well-treated by curettage and reconstruction of the benign tumor.

A novel hyperthermia treatment for bone metastases using magnetic materials.

Patients with bone metastases in the extremities sometimes require surgical intervention to prevent deterioration of quality of life due to a pathological fracture. The use of localized radiotherapy combined with surgical reinforcement has been a gold standard for the treatment of bone metastases. However, radiotherapy sometimes induces soft tissue damage, including muscle induration and joint contracture. Moreover, cancer cells are not always radiosensitive. Hyperthermia has been studied since the 1940s using an experimental animal model to treat various types of advanced cancer, and studies have now reached the stage of clinical application, especially in conjunction with radiotherapy or chemotherapy. Nevertheless, bone metastases have several special properties which discourage oncologists from developing hyperthermic therapeutic strategies. First, the bone is located deep in the body, and has low thermal conductivity due to the thickness of cortical bone and the highly vascularized medulla. To address these issues, we developed new hyperthermic strategies which generate heat using magnetic materials under an alternating electromagnetic field, and started clinical application of this treatment modality. The purpose of this review is to summarize the latest studies on hyperthermic treatment in the field of musculoskeletal tumors, and to introduce the treatment strategy employing our novel hyperthermia approach.

Spinal neurocutaneous melanosis without cutaneous nevi.

STUDY DESIGN: A case report of spinal neurocutaneous melanosis without cutaneous nevi. OBJECTIVE: To show a case and review the epidemiology, diagnosis and treatment of neurocutaneous melanosis without cutaneous nevi. SUMMARY OF BACKGROUND DATA: Neurocutaneous melanosis is a rare congenital syndrome consisting of benign or malignant melanocytic tumors of the central nervous system and cutaneous nevi. Symptomatic neurocutaneous melanosis has extremely poor prognosis, even in the absence of malignancy. Because leptomeningeal lesions of the neurocutaneous melanosis usually undergo malignant transformation, the life expectancy of almost all patients with malignant transformation is <1 year. In general, patients are treated with palliative therapy, such as shunt placement to reduce intracranial pressure or tumor resection to reduce compression of the brain or spine. METHODS: A 29-year-old man presented with marked hypesthesia and spastic gait. No skin abnormalities were evident. Magnetic resonance imaging (MRI) of the spine revealed intradural tumor at the T5 level. Computed tomography myelography showed intradural extramedullary tumor. Because symptoms progressed, he underwent surgery to decompress the spinal cord. After the pigmented dura was opened, a pigmented tumor was resected. RESULTS: Histologically, the pigmented tumor represented low grade. The pigmented dura and bone comprised melanin-bearing cells without tumor cells. Meningeal melanocytoma with leptomeningeal melanosis in the absence of cutaneous nevi was diagnosed. Neurologic symptoms recovered immediately after surgery. No evidence of local recurrence has been seen after 3 years. CONCLUSION: This patient displayed spinal meningeal melanocytoma and leptomeningeal melanosis without cutaneous nevi. The diagnosis in this case was speculated to represent a forme fruste of neurocutaneous melanosis.

Novel hyperthermia for metastatic bone tumors with magnetic materials by generating an alternating electromagnetic field.

We have developed a novel hyperthermic treatment modality using magnetic materials for metastatic bone tumors. The purpose of this study is to show the results of novel hyperthermia for metastatic bone tumors. This novel hyperthermic treatment modality was used for 15 patients with 16 metastatic bone lesions. In seven lesions, after curettage of the metastatic lesion followed by reinforcement with a metal intramedullary nail or plate, calcium phosphate cement (CPC) containing powdery Fe3O4 was implanted into the cavity. In one lesion, prosthetic reconstruction was then performed after an intralesional tumor excision. For the remaining eight lesions, metal intramedullary nails were inserted into the affected bone. Hyperthermic therapy was started at 1 week postoperatively. To comparatively evaluate the radiographic results of patients who underwent hyperthermia (HT group), we also assessed eight patients who received a palliative operation without either radiotherapy or hyperthermia (Op group), and 22 patients who received operation in combination with postoperative radiotherapy (Op + RT group). In HT group, all patients had an acceptable limb function with pain relief without any complications. On radiographs, 87, 38, and 91% were, respectively, considered to demonstrate an effective treatment outcome in HT group, Op group, and Op + RT group. The patients in HT group showed a statistically better radiographic outcome than the patients in Op group (P = 0.0042). But when compared between HT group and Op + RT group, there were no significant difference (P = 0.412). This first series of clinical hyperthermia using magnetic materials achieved good local control of metastatic bone lesion.

Effects of down-regulating the Id genes in human colorectal cancer cells on early steps of haematogenous metastasis.

Id genes (inhibitor of DNA binding/differentiation) play important roles in tumour growth. We have previously described crucial roles of Id gene over-expression in endothelial cells for tumour angiogenesis. Here, we have evaluated direct effects of Id gene down-regulation on tumour cells, namely on cell proliferation, motility, and adhesion to lung microvasculature during haematogenous metastasis. For this purpose, Id genes were stably down-regulated by RNA interference in human colorectal cancer cells. These cells showed delayed proliferation, inhibited motility and decreased expression of integrin alpha6 and consequently reduced adhesion to lung microvasculature in mice. Static adhesion assays and laminar flow assays revealed decreased laminin binding capacity of these cells, and blocking experiments confirmed that it could be attributed to decreased expression of integrin alpha6. The present results indicate important roles of Id genes in tumour cells during early steps of haematogenous metastasis and suggest dual effects from their therapeutic inhibition.

Heating and coagulation volume obtained with high-intensity focused ultrasound therapy: comparison of perflutren protein-type A microspheres and MRX-133 in rabbits.

PURPOSE: To compare the efficiency of different microbubble contrast agents in the heating and coagulation of rabbit liver tissue by using high-intensity focused ultrasound therapy. MATERIALS AND METHODS: The use of and protocols for Japan white rabbits were approved by the University of Tokyo Committee on Animal Resources. In vitro experiments were conducted in a 1-mL cylindric space of polyacrylamide gel, which contained different microbubble contrast agents (MRX-133 or perflutren protein-type A microspheres). In vivo experiments were performed in six Japan white rabbits (two for the perflutren protein-type A microsphere group, two for the MRX-133 group, and two for the control group). In each rabbit, the liver was directly subjected to high-intensity focused ultrasound after intravenous injection of different microbubble contrast agents. Natural saline was used as a control. High-intensity focused ultrasound was applied for 30 seconds by using a 2.18-MHz transducer, and the temperature increase and volume of coagulation necrosis were evaluated. Statistical analysis was performed by using an analysis of variance test, which was followed by a Student-Newman-Keuls test; a P value of <.05 was considered to indicate a statistically significant difference. RESULTS: In the MRX-133 group, the mean temperature increase was significantly greater and faster than that in the control group (P < .01) or in the perflutren protein-type A microsphere group (P < .05). In the perflutren protein-type A microsphere group, the mean temperature increase was greater and faster than that of the control group (P < .01) for both in vitro and in vivo experiments. The mean volume of the coagulation necrosis lesion was 117.9 mm3 +/- 48.4 (+/-standard deviation) for the MRX-133 group, 45.4 mm3 +/- 24.9 for the perflutren protein-type A microsphere group, and 17.7 mm3 +/- 9.0 for the control group. In the MRX-133 group, the mean volume of coagulation necrosis was significantly greater than that of the control or the perflutren protein-type A microsphere group (P < .01), and in the perflutren protein-type A microsphere group, the volume of coagulation necrosis was greater than that of the control group (P < .05). CONCLUSION: MRX-133 had greater efficiency than perflutren protein-type A microspheres in high-intensity focused ultrasound-induced heating and coagulation of rabbit liver tissue.

Osteogenic protein-1 is most effective in stimulating nucleus pulposus and annulus fibrosus cells to repair their matrix after chondroitinase ABC-induced in vitro chemonucleolysis.

BACKGROUND CONTEXT: Chondroitinase ABC (C-ABC) is used in chemonucleolysis to degrade, with great specificity, the chondroitin sulfate and dermatan sulfate chains of proteoglycans (PGs). A recent study showed that osteogenic protein-1 (OP-1) is very effective in stimulating the production and formation of the extracellular matrix by rabbit intervertebral disc cells. PURPOSE: To test the hypothesis that the repair of the extracellular matrix of the intervertebral disc after chemonucleolysis by C-ABC can be stimulated by exposure to a low dose of a growth factor, OP-1. STUDY DESIGN: An alginate bead cell culture system was used to monitor the effects of OP-1 on the repair of damaged matrices after in vitro chemonucleolysis with C-ABC. METHODS: Rabbit nucleus pulposus (NP) or annulus fibrosus (AF) cells cultured for 2 weeks in alginate gel were briefly exposed to low concentrations of C-ABC and then cultured in the presence or absence of OP-1. The control group was cultured without enzyme treatment for the same period in the absence of OP-1. At each time point, the contents of DNA and proteoglycan accumulation and proteoglycan synthesis were measured. RESULTS: NP or AF cells cultured in alginate beads, which were digested with C-ABC and then treated with OP-1, recover PG content more rapidly than those cultured in the absence of OP-1. The major contributor to the superior matrix repair in the cells treated with OP-1 was an up-regulation of proteoglycan synthesis. CONCLUSIONS: OP-1 was effective in stimulating matrix repair by NP and AF cells after their matrices were nearly totally depleted of sulfated glycosaminoglycans. The use of OP-1 after chemonucleolysis might help the disc to regain biomechanical strength, weakened by enzyme digestion, by stimulating matrix metabolism.

Erythrocytes, as well as microbubble contrast agents, are important factors in improving thermal and therapeutic effects of high-intensity focused ultrasound.

Erythrocytes, as well as microbubble contrast agents, are important factors in improving thermal effect of high-intensity focused ultrasound (US), or HIFU, and increasing the coagulation volume produced by HIFU irradiation. In vitro experiments used human plasma with various concentrations of human erythrocytes in combination with or without Levovist. In vivo experiments used eight Japan white rabbits with three degrees of anemia. Using a 2.17-MHz transducer, HIFU was applied for 60 s, and the temperature rise and the volume of coagulation necrosis was evaluated. There was a significant correlation between the HIFU-induced temperature rise and hematocrit, with a correlation coefficient of 0.998 (p=0.0001). Although the temperature rise was smaller at low hematocrit, it was significantly increased by adding Levovist in the suspension (p<0.01). The mean volume of coagulation necrosis was significantly greater in the rabbits with higher hematocrits (p<0.01), and that in the moderate anemia group was significantly increased by using Levovist (p<0.01).

Use of a microbubble agent to increase the effects of high intensity focused ultrasound on liver tissue.

In order to find out whether high intensity focused ultrasound (HIFU) might be useful against hepatocellular carcinoma, we analyzed the effect of a microbubble agent (Levovist) on the temperature rise and tissue necrosis induced by HIFU. Rabbits were given 7 ml Levovist (300 mg/ml) or saline intravenously. Up to six areas per rabbit liver were exposed to HIFU for 60 s (2.18 MHz, I(SPTA)=400 W/cm(2)). The volume of the tissue coagulated by HIFU was measured 10 min after the start of HIFU. HIFU-induced lesions were larger in the animals given Levovist: (mm(3), Levovist versus saline) 371+/-104 versus 166+/-71 (P<0.001). Temperatures in the animals given Levovist were also higher 60 s after the start of exposure: ( degrees C, Levovist versus saline) 20.3+/-3.5 versus 13.2+/-3.8 (P<0.001). The amount of damage differed greatly, but the pathological changes caused by HIFU with Levovist were the same as those caused by HIFU with saline. Hemorrhagic areas and implosion cysts were seen, and many cells had been disrupted or destroyed. Microbubble agents developed for diagnostic uses could also be used in anticancer therapy.

A case of idiopathic spinal cord herniation with duplicated dura mater.

The patient was a 48-year-old man in whom a slow progression in walking difficulty occurred over a year. Magnetic resonance imaging (MRI) and computed tomography myelography (CTM) revealed duplicated dura mater from T1 to T12 and spinal cord herniation in the inner layer of the dura at the T4-T5 level. Idiopathic spinal cord herniation with duplicated dura mater was diagnosed, and surgery was performed. Intraoperative findings were of an elliptical defect of about 1 cm in the inner layer of the dura at the T4-T5 level, into which the spinal cord was herniated. A 1.5-cm cephalocaudal incision was created in the inner layer of the dura, and the incarcerated spinal cord was released, resulting in resolution of gait disturbance and an excellent postoperative clinical course. We reviewed the reports of 11 cases of idiopathic spinal cord herniation with duplicated dura mater and summarized the clinical and imaging characteristics as follows: 1) A hernial orifice was found at the T4-T6 level, 2) cross-sectional MRI or CTM showed a "snowman-like" deformation of the spinal cord, and 3) symptoms were often improved by widening the hernia orifice.

Phosphoglyceride crystal deposition disease in the spine: a case report.

The authors report phosphoglyceride crystal deposition disease in the spine after a lumbar anesthetic given at the time of appendectomy. A 76-year-old Japanese woman with increasing lumbar pain was transported to our hospital in an ambulance. She had tumor-like lesions that had repeatedly appeared in injured soft tissues for >20 years. Osteolytic changes were detected by x-ray in the 12th thoracic vertebra and the 4th lumbar vertebra. Compression of the left L4 nerve root was detected by myelography, and a tumor corresponding to the left L3-L4 intervertebral foramen was determined by computed tomography. An operation to achieve posterior decompression and fusion was performed. The histopathologic tests on this coarse matter revealed a radial deposition of needle crystals and a strong foreign matter reaction in the periphery. Based on the above analyses, the deposited crystals were regarded as phosphoglyceride. Phosphoglyceride crystal deposition disease is characterized by the deposition of crystals of the phospholipid called phosphoglyceride in sites especially susceptible to invasion, such as surgical sites. To our best knowledge, only three cases of phosphoglyceride crystal deposition disease, including this one, have been reported.

Intradiscal administration of osteogenic protein-1 increases intervertebral disc height and proteoglycan content in the nucleus pulposus in normal adolescent rabbits.

STUDY DESIGN: A study of the disc height and biochemical changes in the rabbit intervertebral disc after injection of osteogenic protein-1 into the nucleus pulposus. OBJECTIVES: To evaluate the in vivo effects of osteogenic protein-1 administered intradiscally to the intervertebral disc of rabbits. SUMMARY OF BACKGROUND DATA: Growth factors, such as osteogenic protein-1 and transforming growth factor-beta, have the ability to stimulate synthesis of proteoglycan and collagen in vitro. No attempts have yet been made to determine the effects of these growth factors in an in vivo model. METHODS: Twenty-four New Zealand adolescent white rabbits were divided evenly into two subject groups. In one group, three consecutive intervertebral discs were injected with saline; whereas in the other group, they were injected with osteogenic protein-1 in saline. At 2, 4, and 8 weeks after the injection, the intervertebral disc heights of the injected specimens were measured by lateral plain radiographs and compared with preinjection measurements. The change in disc height was expressed as the percent disc height index compared with the preinjection value. After the radiographic measurements were obtained, the intervertebral discs were removed and analyzed for DNA, proteoglycan, and collagen contents. RESULTS: At 2 weeks after the injections, the mean disc height index of the osteogenic protein-1-injected discs was 15% greater than that of the saline group. The increase in disc height with osteogenic protein-1 injection was still statistically significant at the 4- and 8-week time points. The proteoglycan content of the nucleus pulposus in discs injected with osteogenic protein-1 was higher than that in the saline group at the 2-week time point. The osteogenic protein-1-induced effect on the proteoglycan content was also present at the 4- and 8- week time intervals; however, these increases were not statistically significant. There were no significant differences in the DNA content, normalized to noninjected control, of the nucleus pulposus between the saline and osteogenic protein-1 groups. However, a significant increase in the DNA content of the anulus fibrosus in the osteogenic protein-1 group, compared with that of the anulus fibrosus in the saline group, was observed after 4 weeks. CONCLUSION: To date, no study has demonstrated the potential in vivo effects of growth factors on the intervertebral disc. The present study reports that the intradiscal administration of osteogenic protein-1 in vivo results in an increased disc height present at 2, 4, and 8 weeks and an increase in PG content of the nucleus pulposus at the 2-week time point. Therefore, osteogenic protein-1 may act to stimulate metabolic activity in the nucleus pulposus. Continued research is needed to evaluate the potential of growth factor-induced reversal of age-related disc degeneration in an appropriate animal model. In addition, studies in a nonhuman primate animal model will be essential before considering intradiscal injection of growth factors in humans.

Polyacrylamide gel containing egg white as new model for irradiation experiments using focused ultrasound.

A polyacrylamide (PAA) gel containing egg white as a new model for irradiation experiments in high-intensity focused ultrasound HIFU is introduced. The gel is transparent except in thermally necrosed regions which are white. The model is similar to, and has the same benefits as, gels containing bovine serum albumin (BSA) protein, but egg is less expensive than BSA. The acoustic properties of the gel are very favorable, similar to those of soft tissues; density 1.0 g/cm(3), sound speed 1540 m/s and acoustic attenuation 0.4 dB/cm at 2 MHz. We illustrate the usefulness of the gel in visualizing HIFU lesions and introduce a new model of gastric submucosal tumor in a rabbit stomach, showing that this gel can be formed into any desired shape. Our PAA gel containing egg white is an attractive candidate for a disposable acoustic material suitable for experimental applications of HIFU.

Irreducible volar subluxation of the metacarpophalangeal joint of the thumb.

An unusual case of irreducible volar metacarpophalangeal (MCP) joint subluxation of the thumb is described. The tendon of the extensor pollicis longus (EPL) was trapped palmar to the metacarpal head and open reduction was necessary.

Colon cancer complicated by vascular and intestinal anomaly.

We present a case of colon cancer in a patient with an anomalous mesenteric artery, a middle mesenteric artery, associated with intestinal nonrotation. At surgery for such a rare case, an exact grasp of the feeding artery, the draining vein, and the lymphatic flow of the tumor is necessary to perform appropriate bowel resection and oncological nodal dissection. Selective angiography and preoperative endoscopic submucosal injection of India ink near the tumor were thought to be essential for surgical decision-making.