Segmentation of bone surface from ultrasound using a lightweight network UBS-Net.

Objective. Ultrasound-assisted orthopaedic navigation held promise due to its non-ionizing feature, portability, low cost, and real-time performance. To facilitate the applications, it was critical to have accurate and real-time bone surface segmentation. Nevertheless, the imaging artifacts and low signal-to-noise ratios in the tomographical B-mode ultrasound (B-US) images created substantial challenges in bone surface detection. In this study, we presented an end-to-end lightweight US bone segmentation network (UBS-Net) for bone surface detection.Approach. We presented an end-to-end lightweight UBS-Net for bone surface detection, using the U-Net structure as the base framework and a level set loss function for improved sensitivity to bone surface detectability. A dual attention (DA) mechanism was introduced at the end of the encoder, which considered both position and channel information to obtain the correlation between the position and channel dimensions of the feature map, where axial attention (AA) replaced the traditional self-attention (SA) mechanism in the position attention module for better computational efficiency. The position attention and channel attention (CA) were combined with a two-class fusion module for the DA map. The decoding module finally completed the bone surface detection.Main Results. As a result, a frame rate of 21 frames per second (fps) in detection were achieved. It outperformed the state-of-the-art method with higher segmentation accuracy (Dice similarity coefficient: 88.76% versus 87.22%) when applied the retrospective ultrasound (US) data from 11 volunteers.Significance. The proposed UBS-Net for bone surface detection in ultrasound achieved outstanding accuracy and real-time performance. The new method out-performed the state-of-the-art methods. It had potential in US-guided orthopaedic surgery applications.

Acute normovolemic hemodilution in combination with tranexamic acid is an effective strategy for blood management in lumbar spinal fusion surgery.

BACKGROUND: The retrospective study was designed to compare the effectiveness and safety of acute normovolemic hemodilution (ANH), tranexamic Acid (TXA), and a combination of ANH and TXA in lumbar spinal fusion surgery. METHODS: Data of 120 patients underwent multi-level posterior spinal fusion for treating degenerative lumbar disease between June 2013 and December 2017 was collected, retrospectively. Four treatment strategies were enrolled, including ANH, TXA, a combination of ANH and TXA, and without any patient blood management. Intraoperative blood loss, hemoglobin and PCV at the end of surgery and at the postoperative first day, and postoperative drain collection, and intraoperative and postoperative transfusion and rate of transfusion were also collected. RESULTS: Intraoperative blood loss and postoperative drain collection of the TXA group, ANH combined with TXA group were statistically lower than those in the control group and ANH group (P < 0.05). Intraoperative and postoperative transfusion amount and rate of intra-operative allogenic transfusion of the ANH group, TXA group, and ANH combined with TXA group were statistically lower than those of the control group (P < 0.05). Hemoglobin and PCV at postoperative the first day in the ANH group, TXA group, and ANH combined with TXA group were significant higher than those in the control group (P < 0.05). The combination of TXA and ANH group achieved the lowest intraoperative blood loss, postoperative drain collection and allogenic transfusion rate. CONCLUSION: A combination of TXA and ANH might be an effective strategy for reducing the rate of transfusion and blood loss in patients underwent lumbar spinal fusion surgery.

Role of MK2 signaling pathway mediating microglia/macrophages polarization in chronic compression injury of cervical spinal cord.

BACKGROUND: The role of inflammatory factors in the chronic compression injury of cervical spinal cord has drawn more attenion recently, however, the mechanism of which is still unclear. In this study, microglia/ macrophages polarization in the inflammatory responses to the injury and its regulation by MK2 signaling pathway have been investigated. METHODS: twy/twy mice at the age of 6-24 weeks were used in the animal model for the chronic compression of cervical spinal cord. ICR (Institute of Cancer Research) mice were used as the control group. MK2 inhibitor (PF-3644022, 30 mg/kg) was administrated intragastrically to twy/twy mice from weeks 20 to 24. The compression of cervical spinal cord was identified by CT/MRI. The cervical spinal cord between C2 and C3 of vertebral segments were investigated by Western blot and Real-time PCR. The animal behaviors were evaluated by BMS score. RESULTS: Western blot and Real-time PCR showed that the expressions of iNOS and Arg-1 in the compressed spinal cord of twy/twy mice were significantly higher than those of the control group. After treatment with PF-3644022, the expression of Arg1 was increased while that of iNOS decreased. Realtime PCR revealed the increased expressions of inflammation related factors (such as IL-1ß, NF-κB, TNF-α, MK2) and pro-apoptotic gene (Bax) except the decreased expression of anti-apoptotic gene (Bcl-2). Nevertheless, such increases were vanished after treatment of PF-3644022 except an increased expression of Bcl-2. The BMS score showed a reduced motor function of the twy/twy mice. The motor function was enhanced again with the treatment of PF-3644022. CONCLUSIONS: Microglia/macrophages polarization may be involved in the inflammatory response to the chronic compression of cervical spinal cord. It can be regulated by the MK2 signaling pathway. Therefore, it is possible to relieve the chronic compression of cervical spinal cord by regulating microglia/macrophages polarization through MK2 signaling pathway.

In Vitro Generation of Anti-Osteosarcoma Cytotoxic Activity Using Dendritic Cells Loaded with Heat Shock Protein 70-Peptide Complexes.

Introduction: This study aimed at evaluating the anti-osteosarcoma activity of cytotoxic T lymphocytes (CTLs) induced by dendritic cells (DCs) pulsed with heat shock protein 70-peptide complexes (Hsp70-PCs). Materials and methods: Human recombinant Hsp70 expression was analyzed using thin layer scanning and Western blot assay. Tumor antigens from Saos-2 cells were extracted to reconstitute Hsp70-PCs. Maturation of cord blood-derived DC was evaluated by alkaline phosphatase-anti-alkaline phosphatase kit and inverted microscope. The anti-osteosarcoma activity of CTLs evoked by DCs loaded with Hsp70-PCs was determined using Thiazolyl Blue Tetrazolium Bromide (MTT) assay. Results: Hsp70 protein level in BL21 (DE3) increased in a time-dependent manner after induction. The expression of surface markers was upregulated and a typical dendritic morphology was observed in mature DCs. Allogeneic CTLs exhibited strong cytotoxic activity against Saos-2 cells. Conclusion: Our in vitro experiment demonstrated the potent induction of cytotoxic activity against osteosarcoma using DC-based vaccine loaded with Hsp70-PCs.

Synthesis of cerium oxide nanoparticles loaded on chitosan for enhanced auto-catalytic regenerative ability and biocompatibility for the spinal cord injury repair.

Biomedical applications like spinal cord injury repair; anticancer requires functional platforms and specific properties like antioxidant, autocatalytic and biocompatibility. This work demonstrated the synthesis of CeO2 nanoparticles which is shown to have promising applications in various fields exclusively biomedical field like scavenging of reactive oxygen species which is mainly responsible for carcinogenic effects. CeO2 nanoparticles were synthesized using the biocompatible ionic liquid followed by their loading with biopolymeric chitosan which was obtained by the deacetylation processing of chitin arrived from the shells of crab. The prepared CeO2 samples were characterized using FT-IR, XRD, SEM and TEM studies. FT-IR studies illustrated the formation of CeO2 nanoparticles and their loading with chitosan. A morphological study reveals the CeO2 nanoparticles are in the nano-size range of 15-20 nm with the uniformly distributed spherical shaped structure. Exploited CeO2 nanoparticles with the biocompatible property may improve outcomes profound with the pharmaceutical applications. The results of UV-visible spectrum were established that addition of cerium oxide nanoparticles into the chitosan polymer has great ability of catalytic oxidative recovery from the spectrum shifting from lower to higher and higher to lower oxidation states. This specifies that cerium oxide nanoparticles loaded material has been provided enhanced auto-regenerative and neuroprotective activity in spinal card regeneration.

Intravertebral clefts in osteoporotic compression fractures of the spine: incidence, characteristics, and therapeutic efficacy.

OBJECTIVE: To determine the pathogenesis and characteristics and to assess the long-term effectiveness of polymethylmethacry late (PMMA) vertebroplasty treatment in patients with intravertebral cleft (IVC) in osteoporotic compression fractures. METHODS: A retrospective analysis of radiological and clinical parameters was performed on 388 patients who underwent percutaneous vertebroplasty or kyphoplasty to treat osteoporotic compression fractures from January 2010 to October 2012. IVC sign was observed in the MRI of 47 patients. Postoperative follow-ups were conducted for at least 2 years after surgery. RESULTS: IVC incidence was associated with older age and lower bone mineral density. Other baseline measurements, such as preoperative visual analogue scale and Oswestry Disability Index (ODI), showed no significant difference between IVC and non-IVC fracture patients. Vertebral height and kyphotic angle were corrected after percutaneous vertebroplasty or kyphoplasty with no significant difference in outcome between the two procedures. Restored vertebral height collapsed and the kyphotic angle became aggravated during the 2 years following surgery in patients with IVC. Similarly, initial improvements in visual analogue scale and ODI decreased over time. Non-IVC patients' had a slight recurrence of compression and kyphosis that began to normalize after 1 year. Visual analogue scale and ODI at 2 years' post-surgery was also significantly lower in non-IVC than IVC patients. CONCLUSION: Polymethylmethacrylate vertebroplasty treatment of osteoporotic compression fractures is initially effective for patients with signs of IVC, but compression and kyphosis gradually reoccur. Therefore, we strongly recommend strict observation and follow-up after vertebroplasty.

Anterior Lumbar Interbody Fusion for Degenerative Discogenic Low Back Pain: Evaluation of L4-S1 Fusion.

The treatment of degenerative discogenic pain is controversial, and anterior lumbar fusion for the treatment of degenerative discogenic low back pain has also been a controversial topic for over a generation.The aim of this systematic review was to evaluate the outcome of different anterior lumbar fusion levels for degenerative discogenic low back pain.In this study, we performed a clinical outcome subgroup analysis. The outcomes of 84 consecutive patients who underwent anterior lumbar interbody fusion from 2004 to 2009 were reviewed. The operative time, intraoperative blood loss, hospital stay, Oswestry Disability Index (ODI), visual analog scale (VAS) results, and complication rate were recorded separately.Medical indications were degenerative disc disease (73.8%), postdiscectomy disc disease (16.1%), and disc herniation (9.5%). Patients with severe spondylolysis or disc degeneration, with more than 3 or multilevel lesions, were excluded.The mean operative time was 124.5 ±â€Š10.9 min (range 51-248 min), the mean intraoperative blood loss was 242.1 ±â€Š27.7 mL (range 50-2700 mL), the mean hospital stay was 3.9 ±â€Š1.1 days (range 3-6 days), the mean preoperative VAS score was 7.5 ±â€Š1.4, and the mean preoperative ODI score was 60.0 ±â€Š5.7. At the 1-year follow-up, the mean postoperative VAS score was 3.3 ±â€Š1.3 and the mean postoperative ODI score was 13.6 ±â€Š3.4 (P < 0.05). L4-L5 disc fusion led to better clinical results than 2-level L4-L5/L5-S1 disc fusion. Additionally, the 2-level fusion of L4-L5/L5-S1 had better clinical results than the L5-S1 disc fusion at both the 1 and 2-year postoperative follow-ups regarding the VAS score and the ODI score. The rate of complications was more frequent in the 2-level L4-L5/L5-S1 group (27.3%) (group C) than in the L4-L5 group (9.1%) (group A) and the L5-S1 group (12.5%) (group B). There was no difference between the L4-L5 group (9.1%) and the L5-S1 group (12.5%). A venous tear occurred during surgery and was successfully repaired in 6 of the 84 patients. Also, out of the 84 patients, 6 were found with pseudarthrosis during the follow-up, and these patients underwent a spinal fusion with instrumentation, with a posterior approach after a mean of 1 year. The complications secondary to the surgical approach were persistent abdominal pain (1/84, 1.2%) and wound dehiscence (1/84, 1.2%).Anterior lumbar interbody fusion for L4-L5 had better clinical results than the 2-segmental L4-L5/L5-S1 disc fusion, and the 2-segmental L4-L5/L5-S1 disc fusion had better clinical results than the L5-S1 disc fusion. Also, the 2-segmental L4-L5/L5-S1 disc fusion had a higher complication rate (27.3%), but there was no difference between the L4-L5 group (9.1%) and the L5-S1 group (12.5%).

Cauda equina syndrome: an uncommon symptom of aortic diseases.

BACKGROUND: In order to help diagnose and deal with the fetal aortic diseases in time, we retrospectively reviewed 8 patients who presented with cauda equina syndrome (CES) but actually suffered from low spinal nerve ischemia due to aortic diseases. MATERIAL AND METHODS: 8 patients were initially diagnosed as CES. 7 patients were confirmed with aortic diseases. 1 patient was confirmed with aortic saddle embolism post emergent laminectomy. Relief of CES symptoms was evaluated during preoperation and follow-up period. RESULTS: 1 patient was diagnosed as aortic dissection and 5 patients as AAA. These 6 patients underwent endovascular aortic repair (EVAR). The CES was relieved in 5-10 d post procedure. The 7th patient was diagnosed with acute abdominal aortic occlusion and then underwent catheter directed thrombolysis with recombinant tissue plasminogen activator (rTPA) for 20 h and CES disappeared. The JOA scores of the 7 patients were recovered from preoperative 15.14±1.21 to 21.00±2.16 within 5-10 d (P<0.01), and evaluated to be 24.12±1.34, 25.88±1.21 and 26.29±1.11 at 3 m-, 6 m- and 12 m-follow-up point, respectively. The 8th patient was initially diagnosed as lumbar spinal stenosis and lumbar disc herniation. The patient underwent emergent vertebral canal decompression and presented with serious CES symptoms. CTA confirmed that the patient had been suffered from aortic saddle embolism (ASE). CONCLUSION: CES caused by abdominal aortic diseases is a special event with fetal consequences if it is not recognized and treated promptly. Orthopedists and neurosurgeons should pay attentions particularly to this issue to preserve the cauda equina functions to their maximums.

TGF-ß1 related inflammation in the posterior longitudinal ligament of cervical spondylotic myelopathy patients.

AIM: This study aimed to elucidate the pathogenesis of posterior longitudinal ligament (PLL) hypertrophy. METHODS: Cervical PLL specimens were collected from CSM patients during surgery (n = 30) and during routine autopsy (n = 14), and processed for histological examination (HE staining and Masson's Trichrome staining) and IHC (CD3, CD68, CD31, TGF-ß1 and collagen II). In addition, the mRNA expression of collagen I was detected in cervical PLL specimens from 16 CSM patients (n = 16) and from routine autopsy (n = 16) by RT-PCR. RESULTS: Obvious fibrosis, cartilage metaplasia and calcification were found in the cervical PLL of CSM patients. In the degenerated PLL, CD68(+) macrophages were frequently identified, CD3(+) T lymphocytes were occasionally found, and many newly generated small vessels were also present. In the degenerated PLL, of the number of TGF-ß1 positive cells increased markedly when compared with control group. IHC indicated TGF-ß1 was secreted by macrophages. RT-PCR showed a significantly lower mRNA expression of collagen I in the PLL of CSM patients as compared to control group. CONCLUSIONS: Macrophages are the major type of inflammatory cells involved in the cervical PLL degeneration, and TGF-ß1 is related to the cervical PLL degeneration. TGF-ß1 is mainly secreted by macrophages. Anti-inflammation may serve as an alternative non-surgical treatment and prophylactic strategy for PLL degeneration.

Regulation of gene expression in rats with spinal cord injury based on microarray data.

The present study aimed to investigate the molecular mechanisms of spinal cord injury (SCI) in rats. First, the differentially expressed genes (DGEs) were screened based on GSE45006 microarray data downloaded from Gene Expression Omnibus using the significant analysis of microarray (SAM) method. Screening was performed for DEGs which were negatively or possibly correlated with time and subsequently subjected to gene ontology (GO) functional annotation. Furthermore, pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes was also performed. In addition, a protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins database. Finally, GeneCodis was used to seek transcription factors and microRNAs that are involved in the regulation of DEGs. A total of 806 DEGs were upregulated and 549 DEGs were downregulated in the rats with SCI. Cholesterol metabolism-associated genes (e.g. HMGCS1, FDFT1 and IDI1) were negatively correlated with time, while injury genes (e.g. SERPING1, C1S and RAB27A) were positively correlated with time after SCI. PCNA, MCM2, JUN and SNAP25 were the hub proteins of the PPI network. The transcription factors LEF1 and SP1 were observed to be associated with the regulation of two DEGs that were involved in the cholesterol-associated metabolism as well as injury responses. A number of microRNAs (e.g. miR210, miR-487b and miR-16) were observed to target cholesterol metabolism-associated DGEs. The hub genes PCNA, MCM2, JUN and SNAP25 presumably have critical roles in rats with SCI, and the transcription factors LEF1 and SP1 may be important for the regulation of cholesterol metabolism and injury responses following SCI.

Radiological evaluation of anterior lumbar fusion using PEEK cages with adjacent vertebral autograft in spinal deformity long fusion surgeries.

PURPOSE: The aim of this study was to evaluate the radiographic characteristics of polyetheretherketone (PEEK) cages packed with adjacent vertebral autograft material in lumbar anterior lumbar interbody fusion (ALIF) in spinal deformity long fusion surgeries. METHODS: This is a retrospective radiographic study. From April 2008 to April 2012, 40 patients (5 males and 35 females, mean age 67 ± 9 years) with coronal and/or sagittal spine deformities underwent staged corrective surgery combined with lumbar ALIF using PEEK cages at the L3-L4, L4-L5 or L5-S1 segment with posterior long (≥ 4 levels) instrumentation. The mean follow-up time was 27.5 months (13-49 months). We examined the interbody fusion rate and cage subsidence at 3 months postoperatively and final follow-up. Additionally, we evaluated the distance of cage migration at final follow-up and the improvement in lumbar lordosis. The rate of "collapse" of the adjacent vertebra where the autograft was harvested was assessed at the final follow-up. Finally, we examined the cage-related postoperative complications in this series. RESULTS: Solid interbody fusion was achieved in 96.4 % (81/84) of the levels at the final follow-up. A mild forward cage migration was observed, and the mean migration distance at final follow-up was 0.83 mm in L3/4, 0.36 mm in L4/5 and 0.55 mm in L5/S1. There was cage subsidence observed in 8.3 % (7/84) of the levels. In all patients, the PEEK cage maintained a significant increase in segmental lordosis at all postoperative visits. However, a mild reduction in segmental lordosis still occurred with time. The adjacent lumbar vertebral bodies where the autografts were harvested appeared to be intact in height radiologically at the final follow-up. There were no postoperative complications due to bone harvesting or cage insertion. Proximal junctional kyphosis was found in one patient who underwent a subsequent revision surgery. CONCLUSIONS: The use of lumbar ALIF with PEEK cages and adjacent vertebral autografts in spinal deformity long fusion surgeries is an effective and safe procedure. The allograft filler is safe and effective in maintaining the shape of harvested vertebrae. Additional long-term follow-up studies are needed to further justify its use.

Role of MK2 signaling pathway in the chronic compression of cervical spinal cord.

OBJECTIVE: In this study, chronic compression of cervical spinal cord was introduced into twy/twy mice and the role of MK2 signaling pathway was investigated in this disease. METHODS: twy/twy mice aged 6-24 weeks were used and the inflammatory response in the cervical spinal cord was observed. The Institute of Cancer Research (ICR) mice were used as controls. MK2 inhibitor (PF-3644022, 30 mg/kg) was administered intragastrically to twy/twy mice. The motor behavior was firstly observed in these three groups by Catwalk gait analysis. And the cervical spinal cord between C2 and C3 of vertebral segments was analyzed by MRI and Western blot assay. RESULTS: The stride length of paws and interlimb coordination reduced in twy/twy mice. However, at 4 weeks after PF-3644022 treatment, a marked improvement was observed in the motor function. The expressions of inflammation related factors (such as IL-1ß, NF-κB, TNF-α, MK2 and p-MK2) and apoptosis related proteins (such as cleaved caspase-8 and bax/bcl-2) in the spinal cord of twy/twy mice significantly increased as compared to controls, but 4-week treatment with PF-3644022 markedly reduced the expressions of these factors and apoptotic proteins in the cervical spinal cord. CONCLUSION: MK2 signaling pathway is involved in the chronic compression induced inflammation of the cervical spinal cord. Thus, to inhibit the MK2 pathway may used to improve the outcome and prevent the deterioration of neurological dysfunction.

[Effects of serum from Ginsenoside saponins on the proliferation and differentiation of osteoblasts].

OBJECTIVE: To explore the effects of serum from ginsenoside saponins (GSS) on the proliferation, differentiation and mineralization in osteoblasts (OB). METHODS: Serum from GSS with different doses were fed to calvaria bone specimens from rats. The proliferation of osteoblasts and the alkaline phosphatase (ALP) activity of OB were analyzed. After alizarin red S staining, the area of calcium nodule was calculated to observe the result of serum from GSS on OB mineralization. RESULTS: Serum from GSS had notable effects on the proliferation of in vitro cultured OB (P < 0.01) and remarkably stimulated the mineralization of OB (P < 0.05) while its effect on the ALP activity of OB was also marked (P < 0.01). CONCLUSION: Serum from GSS can promote the proliferation and mineralization ability of OB and significantly accelerate the formation of OB.

[Clinical outcomes of percutaneous kyphoplasty under local anesthesia for osteoporotic vertebral compression fractures].

OBJECTIVE: To analyze the clinical outcomes of percutaneous kyphoplasty under local anesthesia for osteoporotic vertebral compression fractures. METHODS: In this study, 76 elderly patients with osteoporotic vertebral compression fractures undergoing percutaneous kyphoplasty were followed up for 2-3.1 years. They were divided into 3 groups according to different ages: 60-69 yrs (A group), 70-79 yrs (B group) and 80- 91 yrs (C group). Pre- and post-operative and last follow-up evaluations were conducted. And the parameters of bone mineral density (BMD), kyphotic angle, change of visual analog scale (VAS), Oswestry disability index, average vertebral body height, complications and costs of hospitalization were recorded and analyzed. RESULTS: BMD decreased with advancing age and had statistical significance between three groups (P < 0.05). Three thoracic spine fractures and 6 lumbar spine fractures could not be detected with digital radiography and were observed only on magnetic resonance imaging (MRI). The pre-operative levels of visual analogue scale and Oswestry disability index increased in all groups.No statistical significance existed between A and B groups. But there was statistical significance between A or B and C groups (P < 0.05). Pre- and post-operative assessments showed that statistically significant improvements were found in visual analogue scale and Oswestry disability index in all groups (P < 0.05). And statistically significant improvements were found for the pre- and post-operative kyphotic angles and vertebral body heights in A, C group and B groups (P < 0.05). The sites for symptomatic leakage of cement included paravertebral vein (n = 2), intervertebral disc (n = 1) and paravertebral space (n = 2). Adjacent vertebral fracture occurred in 1 patient at 17 months and underwent percutaneous kyphoplasty. The mean operative duration was 28 minutes per vertebrae and the mean cost of hospitalization at RMB yuan 33 778. CONCLUSION: As a simple and safe procedure for osteoporotic vertebrae compression fractures, percutaneous kyphoplasty may relieve pain quickly, restore vertebral height, prevent further fractures and improve the patient's quality-of-life.

Management of postoperative instrumented spinal wound infection.

BACKGROUND: Wound infection following spinal instrumented surgery is a frequent complication. The optimal treatment of acute deep wound infection following spinal instrumentation fusion remains controversial because of variability in cohort identification, definition of an infection, and the instrument used to measure outcomes. This retrospective study evaluated the clinical curative effect for postoperative spinal infection after instrumented spine fusion with extensive debridement, or implant removal. METHODS: From January 2004 to October 2009, 851 patients were identified who underwent surgical treatment of spinal diseases. The medical records of patients who developed infections were reviewed in detail. RESULTS: Of 851 patients, 41 (4.9%) developed an infection. Thirty-three were acute, and eight were delayed. Acute infected cases were managed with antibiotic therapy, and aggressive debridement of the wound and soft tissues leaving all instrumentation in situ in all but one patient. The most common symptoms of acute infection included: posterior incisional drainage (26 of 33 patients), back pain (22 of 33 patients) and fever (13 of 33 patients). Among patients with delayed onset infection, five of eight patients had local pain, four of eight patients had incision drainage, and one patient had a prolonged period of intermittent fever. The most frequent causative organism for postoperative spinal infection following spine surgery is Staphylococcus aureus. Pseudarthrosis was noted in long-term follow-up in four of 41 patients. CONCLUSIONS: We recommend irrigation and debridement, no instrumentation removal, and, if necessary, repeat debridement followed by delayed primary closure for the treatment of acute deep infection with instrumentation.

Segmental spinal canal volume in patients with degenerative spondylolisthesis.

BACKGROUND CONTEXT: Lumbar degenerative spondylolisthesis (DS), typically characterized by the forward slippage of the superior vertebra of a lumbar motion segment, is a common spinal pathological condition in elderly individuals. Significant deformation and volume changes of the spinal canal can occur because of the vertebral slippage, but few data have been reported on these anatomic variations in DS patients. Whether to restore normal anatomy, such as reduction of the slippage and restoration of disc height, is still not clear in surgery. PURPOSE: This study was designed to determine the volume change of the spinal canal and detect specific anatomic factors affecting the spinal canal volume in DS patients. STUDY DESIGN/SETTING: A case-control study. METHODS: Nine asymptomatic volunteers (mean age 54.4) and 9 patients with L4/L5 DS (mean age 73.4) were recruited. All patients had intermittent claudication and different extent low back pain, and two patients also had leg pain. L4/L5 vertebral motion segment unit of each subject was reconstructed using three-dimensional computed tomography or magnetic resonance images in a solid modeling software. In vivo lumbar vertebral motion during functional postures (supine, standing upright, flexion, and extension) was determined using a dual fluoroscopic imaging technique. The volume of the spinal canal was measured at each functional posture. Various anatomic parameters (disc height, cross-sectional area of the canal, left-right diameter of the canal, anterior-posterior diameter of the canal, slippage, posture, intervertebral disc angle [DA], etc.) that may potentially affect the canal volume were also measured, and their correlations with the volume change of spinal canal were analyzed. This study was funded by a 2-year, $275,000 grant from the National Institutes of Health. RESULTS: On average, spinal canal volume was larger at supine and flexion postures than at stand and extension postures in both the DS and the asymptomatic groups. Spinal canal volume of the DS patients were significantly lower than that of the asymptomatic subjects under all the four postures (p<.05). Correlation analysis showed that spinal canal volume was strongly affected by the posterior disc height (Pearson correlation coefficient γb=0.822) and the slippage percentage (γb=-0.593) and moderately affected by the anterior disc height (γb=0.300) and the DA (γb=-0.237). CONCLUSIONS: The volume of spinal canal is affected by multiple factors. Increased spinal canal volume at supine and flexion positions may explain the clinical observations of relief of symptoms at these postures in DS patients. The data also suggest that reduction of slipped vertebral body, decrease of DA, intervertebral distraction, and decompression could all be effective to increase the canal volume of DS patients thus to relieve clinical symptoms.

[Risk factors for delirium of elderly patients undergoing hip fracture operation].

OBJECTIVE: To explore the causes for delirium of elderly patients after hip fracture operation. METHODS: A total of 68 cases of delirium were selected from 458 patients aged over 65 years undergoing hip fracture operation via spinal anesthesia from 2009 to 2011. There were 26 males and 42 females with an average age of 72.9 (66-98) years. Their clinical features, such as gender, operative duration, blood loss volume, saturation of arterial oxygen, were observed. After single factor risk analysis, multiple factor analysis was performed by binary Logistic regression. RESULTS: Delirium occurred at certain timepoints during the first postoperative days. The incidence of delirium was 14.9%. The Logistic stepwise regression analysis showed that significant differences existed between delirium and non-delirium in age (P = 0.042), operative duration (P = 0.042), blood loss volume (P = 0.027), hypoxemia (P = 0.019) and preoperative comorbidity (P = 0.029). CONCLUSION: The independent risk factors for postoperative delirium include age, operative duration, blood loss volume, preoperative comorbidity and hypoxemia.

Thoracic curve correction after posterior fusion and instrumentation of structural lumbar curves in patients with adolescent idiopathic scoliosis.

INTRODUCTION: Spontaneous thoracic curve correction may occur following selective anterior spinal fusion in patients with adolescent idiopathic scoliosis (AIS). However, a few reports have described outcomes in patients following selective posterior fusion. The aim of this retrospective study was to assess curve correction in AIS patients with major lumbar curves and secondary thoracic curves after selective posterior fusion of the major curve. METHODS: The records of 42 AIS patients with major lumbar and minor thoracic curves who had received selective posterior lumbar fusion with segmental pedicle screw fixation were examined. Preoperative and follow-up radiographs were examined and the following were determined: curve flexibility, Cobb angle measurements of the major and minor curves, thoracolumbar/lumbar and thoracic Cobb measurements. Also, thoracolumbar/lumbar to thoracic Cobb ratios were determined. Minimum follow-up was 2 years. Patients were compared with respect to whether final thoracic curve improvement was (group A) or was not (group B) apparent. Improvement was indicated by a final thoracic curve that was less than the preoperative thoracic curve. RESULTS: Thoracic curve improvement was apparent in 32 of 42 patients after surgery. The mean preoperative thoracic curve in group A was 22.5° and 15.0° at follow-up, while corresponding values in group B were 35.0° and 39.8°. There were no cases in group A and eight cases in group B in which the preoperative thoracic curve was >30°. All patients in group B had preoperative thoracic curves on lateral bending >20°. Thoracic curvature at final follow-up was strongly correlated with preoperative thoracic curvature (r = 0.911) and thoracic curvature on lateral bending (r = 0.948). CONCLUSIONS: Selective posterior fusion with segmental pedicle screw fixation in patients with major lumbar AIS resulted in curve correction in the majority of cases. Preoperative thoracic curvature and thoracic curvature on lateral bending were strongly correlated with the final thoracic curvature.

Surgical treatment of adult idiopathic scoliosis: long-term clinical radiographic outcomes.

More adults are suffering from adult idiopathic scoliosis and seeking treatment for their spinal deformities. Adult idiopathic scoliosis can lead to painful spinal osteoarthritis, progressive deformity, spinal stenosis with radiculopathy, muscle fatigue from coronal and sagittal plane imbalance, and psychological effects with a visible deformity. Primary treatment of such conditions is conservative; however, some patients are resistant to conservative treatment or are not candidates for it, and they require surgery. Back pain is likely the most common indication for surgical treatment of scoliosis in adult patients. Pedicle screws offer 3-column purchase and a longer arm compared with hook placement on the lamina. This study is a retrospective analysis of a consecutive series of patients with adult idiopathic scoliosis who were treated with pedicle screw placement. Significant back pain relief and satisfaction can be achieved and maintained over the long term. Restoration of coronal and sagittal balance, or improvement thereof, was achieved in all patients with balance problems. This study clarified several important characteristics of adult scoliosis, and we believe that useful conclusions can be drawn regarding its surgical indications and strategies: (1) pedicle screw construct can gain effective results for treatment of adult idiopathic scoliosis due to its perceived superior power of correction; (2) younger patients present for surgery for different reasons than older patients (progressive deformity or pain); and (3) pain improvement is a more reliable outcome in older patients than younger patients, although younger patients rarely have severe pain symptoms.