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// Qing-Bo Lv 1 , Xiang Gao 1 , Xiang Liu 1 , Zhen-Xuan Shao 1 , Qian-Hui Xu 1 , Li Tang 1 , Yong-Long Chi 1 and Ai-Min Wu 1 1 Department of Orthopedics, Bone Research Institute, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Second Medical School of Wenzhou Medical University, Wenzhou, Zhejiang, China Correspondence to: Ai-Min Wu, email: // Keywords : serum 25-hydroxyvitamin D, hip fracture, meta-analysis, dose-response Received : December 14. 2016 Accepted : February 13, 2017 Published : March 17, 2017 Abstract Hip fracture has increasingly become a social and economic burden. The relationship between serum 25-hydroxyvitamin D levels and the risk of hip fracture reported by previous studies remains controversial. We searched Pubmed and Embase to identify studies reporting the relationship between serum 25-hydroxyvitamin D levels and risk of hip fracture. Fifteen prospective cohort studies with a total of 51239 participants and 3386 hip fracture cases were included. By pooling the Relative Risk of the lowest vs. the highest categories indicated that lower levels of serum 25-hydroxyvitamin D were more likely to be a risk factor for hip fracture with adjusted Relative Risk (95%Confidence Interval) of 1.58 (1.41, 1.77). Subgroup meta-analysis examining the stability of the primary results achieved the same results. A dose-response meta-analysis showed that the risk of hip fracture was a descending curve below the line of RR=1. The descending trend was obvious when serum 25-hydroxyvitamin D levels were less than 60 nmol/L and was flat when serum 25-hydroxyvitamin D levels were more than 60 nmol/L. We found that individuals with low levels of serum 25-hydroxyvitamin D have an increased risk of hip fracture, and this effect was evident when the serum 25-hydroxyvitamin D levels were less than 60 nmol/L.

Purpose. To investigate the evidence of minimally invasive (MI) versus open (OP) posterior lumbar fusion in treatment of lumbar spondylolisthesis from current prospective literatures.Methods. The electronic literature database of Pubmed, Embase, and Cochrane library was searched at April 2016. The data of operative time, estimated blood loss and length of hospital stay, visual analog scale (VAS) of both lower back pain and leg pain, Oswestry disability index (ODI), SF-36 PCS (physical component scores) and SF-36 MCS (mental component scores), complications, fusion rate, and secondary surgery were extracted and analyzed by STATA 12.0 software.Results. Five nonrandom prospective comparative studies were included in this meta-analysis. The meta-analysis showed that the MI group had a significantly longer operative time than OP group, less blood loss, and shorter hospital stay. No significant difference was found in back pain, leg pain, ODI, SF-36 PCS, SF-36 MCS, complications, fusion rate, and secondary surgery between MI and OP groups.Conclusion. The prospective evidence suggested that MI posterior fusion for spondylolisthesis had less EBL and hospital stay than OP fusion; however it took more operative time. Both MI and OP fusion had similar results in pain and functional outcomes, complication, fusion rate, and secondary surgery.

STUDY DESIGN A prospective study of anterior transarticular screw (ATS) fixation patients. OBJECTIVE To develop a method to determine screw tip position through plain radiography after percutaneous ATS fixation to prevent occipitocervical joint (OCJ) violation. SUMMARY OF BACKGROUND DATA No studies using plain radiography to prevent OCJ violation during percutaneous ATS fixation have been performed. METHODS In total, 34 subjects (with 68 screws) who had undergone percutaneous ATS fixation were enrolled. To evaluate the screw tip location in relation to the C1 lateral mass (LM), the screw tip positions were graded 1, 2, or 3 on anteroposterior (AP) radiographs, and I, II, or III on lateral radiographs. OCJ violation was analyzed by postoperative computed tomography (CT). RESULTS Screws with tips located lower (tip I) in the LM did not result in OCJ violation. Only one tip in the tip 3 position showed OCJ perforation, and this screw was also located in tip III. Screw perforation rates of tip 1-tip II, tip 1-tip III, and tip 2-tip III were the highest (100%), followed by tip 2-tip II (10.5%) and tip3-tip III (10%). CONCLUSION This study provides insights into OCJ violation during percutaneous ATS fixation. According to AP radiography, a percutaneous ATS with the screw tip located in the lateral part of the LM resulted in a lower rate of OCJ perforation, whereas screws located in the medial LM resulted in the highest rate of perforation. Percutaneous ATS with the screw tip located in the neutral part of the LM should ensure that the screw tip is below the upper part of the LM, preventing OCJ violation. These findings may help surgeons assess screw positioning both during and after the operation. LEVEL OF EVIDENCE 3.

To describe the technique and clinical results of percutaneous atlantoaxial anterior transarticular fixation combined with limited exposure posterior C1/2 arthrodesis in patients with a high-riding vertebral artery.Zhejiang Spine Center, China.Five patients with a high-riding vertebral artery and an upper cervical fracture.Percutaneous atlantoaxial anterior transarticular screw fixation combined with limited exposure posterior C1/2 wire fusion.Computed tomography scans were used to assess the high-riding vertebral artery and feasibility of anterior transarticular screw fixation preoperatively. A Philadelphia collar was used to immobilize the neck postoperatively. Anteroposterior (open-mouth) and lateral views were obtained at pre/postoperation and at the follow-up.The operation was performed successfully on all of the patients, and no intraoperative operation-related complications such as nerve injury, vertebral artery, and soft tissue complications occurred. The mean follow-up period was 33.8 months (range: 24 to 58 months). No screw breakage, loosening, pullout, or cutout was observed. Bone union was achieved in all patients at the last follow-up.Our small case series results suggested that percutaneous anterior transarticular screw fixation combined with mini-open posterior C1/2 wire fusion is a technically minimally invasive, safe, feasible, and useful method to treat patients with a high-riding vertebral artery.

We did a clinical trial to determine whether olfactory mucosa lamina propria (OLP) transplants promote regeneration and functional recovery in chronic human spinal cord injury (SCI). The trial randomized 12 subjects to OLP transplants ( n = 8) or control sham surgery ( n=4). The subjects received magnetic resonance imaging (MRI), electromyography (EMG), urodynamic study (UDS), American Spinal Injury Association impairment scale (AIS), and other functional assessments. OLP-transplanted subjects recovered more motor, sensory, and bladder function compared to sham-operated subjects. At 3 years after OLP transplant, one patient improved from AIS A to C and another recovered from AIS A to B, two recovered more than three segmental sensory levels, two had less spasticity, two had altered H-reflexes and SSEP, two regained bladder and anorectal sensation and had improved bladder compliance on UDS. OLP-treated patients had partial or complete tissue bridges at the injury site compared to cavitary gaps in sham-operated patients. The limited recovery suggests that OLP transplants alone do not have significant benefits but may provide a rationale for larger randomized trials or combination therapies.

To evaluate the relationship between height ratio of the iliac crest to L4 (HR), width ratio of the iliac crest to L4 (WR) and L5–S1 disc degeneration. On T2-weighted sagittal images of the 50 randomly selected patients, two observers graded L5–S1 discs and some other parameters were measured. Then, relative signal intensity (RSI) of the L5–S1 nucleus pulposus was calculated. On anteroposterior and lateral radiographs of the same 50 patients’ lumbar spine, the parameters such as the height of the iliac crest were measured and then HR and WR were calculated. Finally, HR, WR and the percentage of the sROM of L5–S1 in L1–S1 segments of the other 51 randomly selected patients were calculated. Positive correlations were found between HR, WR and RSI of the L5–S1 disc. Negative correlations were found between HR, WR and modified Pfirrmann scores of L5–S1 nucleus pulposus. A statistically significant negative correlation was found between HR and the percentage of sROM of L5–S1 in L1–S1 segments. Low HR and (or) WR were the risk factors for L5–S1 disc degeneration. High HR could reduce the percentage of sROM of L5–S1 in L1–S1 segments and high HR and (or) WR could reduce the incidence of L5–S1 disc degeneration.

To design and investigate a novel technique of percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion. CT scans of 45 patients were collected and imported into Mimics software for three-dimensional (3D) reconstruction. Cylinders were drawn to simulate the trajectory of the oblique screw. Six measurements were obtained for each unit to design a right size cage: a the distance between the intersection of the simulated trajectory of the screw with the inferior border of the upper vertebra and its anteroinferior corner; b the distance between the intersection of the simulated trajectory of the screw with the superior border of the inferior vertebra and its anterosuperior corner; h the height of the intervertebral space; θ the angle between simulated trajectory of screw and the upper endplate of inferior vertebra; uw: the width of the inferior endplate of upper vertebra; iw: the width of upper endplate of inferior vertebra. Three intact adult fresh-frozen cadaveric specimens were obtained, percutaneous posterior transdiscal oblique screw fixation was performed under X-ray apparatus, and interbody cage was implanted by assistance with special self-retaining retractor system and endoscope. According to the results of data measured from 3D images, trapezoid shape interbody cages with suitable size were designed. Percutaneous posterior oblique screw fixation with lateral interbody fusion was performed on three cadaveric specimens successfully. Using specially designed trapezoid shape interbody cages, assisted by intra-operative image intensification and endoscope, it is feasible to perform percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion technique.

Osteoporotic fracture is a significant cause of morbidity and mortality and is a challenging global health problem. Previous reports of the relation between vitamin A intake or blood retinol and risk of fracture were inconsistent. We searched Medline and Embase to assess the effects of vitamin A (or retinol or beta-carotene but not vitamin A metabolites) on risk of hip and total fracture. Only prospective studies were included. We pooled data with a random effects meta-analysis with adjusted relative risk (adj.RR) and 95% confidence interval (CI). We used Q statistic and I2 statistic to assess heterogeneity and Egger's test to assess publication bias. Eight vitamin A (or retinol or beta-carotene) intake studies (283,930 participants) and four blood retinol level prospective studies (8725 participants) were included. High intake of vitamin A and retinol were shown to increase risk of hip fracture (adj.RR [95% CI] = 1.29 [1.07, 1.57] and 1.40 [1.03, 1.91], respectively), whereas beta-carotene intake was not found to increase the risk of hip fracture (adj.RR [95% CI] = 0.82 [0.59, 1.14]). Both high or low level of blood retinol was shown to increase the risk of hip fracture (adj.RR [95% CI] = 1.87 [1.31, 2.65] and 1.56 [1.09, 2.22], respectively). The risk of total fracture does not differ significantly by level of vitamin A (or retinol) intake or by blood retinol level. Dose-response meta-analysis shows a U-shaped relationship between serum retinol level and hip fracture risk. Our meta-analysis suggests that blood retinol level is a double-edged sword for risk of hip fracture. To avoid the risk of hip fracture caused by too low or too high a level of retinol concentration, we suggest that intake of beta-carotene (a provitamin A), which should be converted to retinol in blood, may be better than intake of retinol from meat, which is directly absorbed into blood after intake. © 2014 American Society for Bone and Mineral Research.

Imaging study.X-ray and computed tomography (CT) sagittal reconstruction images are used to evaluate the stability of the spine. However, we did not know the extent of difference between them.The aim of the study was to compare the differences seen in thoracolumbar burst fractures on lateral radiographs and CT sagittal reconstruction images and investigate their clinical relevance.Lateral radiographs and CT sagittal reconstruction images of 45 patients with thoracolumbar burst fractures were used to record the following measurements: the compressed area of the fractured vertebrae, from lateral radiographs, and the sagittal compressed area, bony fragment area, and total fracture-involved area, from CT sagittal reconstruction images.The percentage of compressed area of fractured vertebrae was 29.32±13.80% on lateral radiographs and 27.93±12.21% on CT sagittal reconstruction images; there was no significant difference between them (P0.05). The percentage of total fracture-involved area was 53.20±20.64% on CT sagittal reconstruction images, higher than the compressed area measured on lateral radiographs (P0.01) and CT sagittal reconstruction images (P0.01). The percentage of bony fragment area was 25.27±15.18% on CT sagittal reconstruction images; there was no significant relationship between bony fragment area and the compressed area (r=0.1258, P0.05).The compressed area of fractured vertebrae on lateral radiographs could not represent the fracture-involved area and underestimated the total fracture-involved area. We suggested that the above 3 parameters could be easily obtained on CT sagittal reconstruction images, which might be better for assessing the potential instability of the thoracolumbar burst fracture and could become a valuable and indispensable examination for therapeutic decision making.

Study design A retrospective comparative study. Objective The purpose of this study is to assess radiologic features of intravertebral cleft (IVC) in nonacute osteoporotic vertebral compression fractures (OVCFs) patients, and analyze the existence of IVC impact on outcomes of percutaneous kyphoplasty (PKP). Summary of background data The IVC sign is regarded as vertebral instability and the cause of persisting pain. It is more likely to happen at nonacute OVCFs patients. Patients with IVC sign have different outcomes from these without IVC treated by percutaneous vertebroplasty. There were rare reports about the outcomes of patients with IVC sign treated by PKP. Materials and methods We divided 92 nonacute OVCFs patients (total of 113 vertebrae) into 2 groups according to the existence of IVC. Preoperative and postoperative Visual Analogue Scales, Oswestry Disability Index, kyphotic angulation (KA), and anterior vertebral height were recorded; the incidence and radiologic features of IVC were analyzed. Results The diagnostic sensitivity of IVC on plain radiograph, computed tomography, and magnetic resonance imaging were 35.4%, 89.3%, and 83.3%, respectively. The IVC group had an average correction KA of 9.14 degrees and reduction of ratio of compression of 20.09%, and the non-IVC group was 8.76 degrees and 20.23%, respectively. Cleft pattern of cement accounted for 64.6% in IVC group and 27.7% in non-IVC group. Five/7 of cement leakage in IVC group was intradiscal leakage, whereas 7/9 of cement leakage in non-IVC group was perivertebral leakage. Conclusions Computed tomography and magnetic resonance imaging were more sensitivity to diagnose IVC sign than X-ray. PKP could improve pain, functional activity, KA, and anterior height of both IVC and non-IVC groups, however, there was more cleft pattern of cement and higher intradiscal cement leakage in the IVC group.

This study is a computed tomographic (CT)-based morphometric analysis of the pediatric occipital condyles as related to occipital condyle screw placement.To quantify reference data concerning the dimensions of the immature occipital condyles to guide the placement of occipital condyle screw.To the best of our knowledge, no published study has provided insight into the anatomy of occipital condyle of the pediatric population with different age groups.Sixty-nine pediatric patients were divided into 4 age groups, and their occipital condyles were studied on CT scans. Condylar length, width, height, sagittal angle, and sagittal angle lengths were measured on Philips Brilliance 16 CT.The mean pediatric coronal height, sagittal length, and axial width noted statistically significant age-related differences were 9.0 mm, 21.3 mm, and 9.8 mm, respectively. The mean sagittal angle for all patients was 27.2 ± 5.1° (range, 15.1-41.0°). In 82.6% (114/138) of the occipital condyles, the anatomy could accept the occipital condyle screw (width ≥8 mm and height ≥6.5 mm).Our investigation provides insight into the anatomy of occipital condyle of the pediatric population with different age groups. As the pediatric occipital condyles have sufficient occipital bone for appropriate fixation or fusion, the occipital condyle screws fixation is a feasible technique for children. Even so, given the evolution of this technique being still in its infancy and the complexity inherent to the craniovertebral junction, a careful radiological analysis of occipital condyle must be required in preoperative planning and feasibility determination.N/A.

Supplemental Digital Content is available in the text, Background: Anterior cervical discectomy and fusion (ACDF) was almost the “golden standard” technique in treatment of symptomatic cervical degenerative disc disease, however, it cause motion loss of the indexed level, increase the intradiscal pressure and motion of the adjacent levels, and may accelerate the degeneration of adjacent level. Cervical disc arthroplasty (CDA) was designed to preserve the motion of index level, avoid the over-activity of adjacent levels and reduce the degeneration of adjacent disc levels, the process of degeneration of adjacent level is very slowly, long term follow up studies should be conducted, this study aim to compare the more than 5 years’ long-term clinical outcomes and safety between CDA and ACDF. Methods: A systematic review and meta-analysis that will be performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The electric database of Medline, Embase, and Cochrane library will be systematic search. A standard data form will be used to extract the data of included studies. We will assess the studies according to the Cochrane Handbook for Systematic Reviews of Interventions, and perform analysis in software STATA 12.0. Fixed-effects models will be used for homogeneity data, while random-effects will be used for heterogeneity data. The overall effect sizes will be determined as weighted mean difference (WMD) for continuous outcomes and Relative risk (RR) for dichotomous outcomes. Results: The results of study will be disseminated via both international conference and peer-review journal. Conclusion: The conclusion of our study will provide the long-term and updated evidence of clinical outcomes and safety between CDA and ACDF, and help surgeon to change better surgical technique for patients.

The purpose of this study was to determine whether it would be feasible to use oblique lumbar interbody fixation for patients with degenerative lumbar disease who required a fusion but did not have a spondylolisthesis. A series of CT digital images from 60 patients with abdominal disease were reconstructed in three dimensions (3D) using Mimics v10.01: a digital cylinder was superimposed on the reconstructed image to simulate the position of an interbody screw. The optimal entry point of the screw and measurements of its trajectory were recorded. Next, 26 cadaveric specimens were subjected to oblique lumbar interbody fixation on the basis of the measurements derived from the imaging studies. These were then compared with measurements derived directly from the cadaveric vertebrae. Our study suggested that it is easy to insert the screws for L1/2, L2/3 and L3/4 fixation: there was no significant difference in measurements between those of the 3-D digital images and the cadaveric specimens. For L4/5 fixation, part of L5 inferior articular process had to be removed to achieve the optimal trajectory of the screw. For L5/S1 fixation, the screw heads were blocked by iliac bone: consequently, the interior oblique angle of the cadaveric specimens was less than that seen in the 3D digital images. We suggest that CT scans should be carried out pre-operatively if this procedure is to be adopted in clinical practice. This will assist in determining the feasibility of the procedure and will provide accurate information to assist introduction of the screws. Cite this article: Bone Joint J 2013;95-B:977–82.

Purpose This is a meta-analysis of randomized and non-randomized studies comparing the clinical and radiological efficacy of minimally invasive (MI) and conventional open transforaminal lumbar interbody fusion (open-TLIF) for degenerative lumbar diseases.

To investigate the feasibility of mini-open anterior approach to the cervicothoracic junction (CTJ) in cadaveric specimens.Four adult fresh-frozen cadaveric specimens were used for this study. On the cadaveric specimen, an osteotomy window was made in manubrium sterni to remove the bony obstacle. To bypass the vital vascular and neural structures over the operative field, we used the surgical corridor which was located medially by the brachiocephalic artery and laterally by the right brachiocephalic vein, or in combination with another surgical corridor between the ascending aorta and the superior vena cava. And we used a special self-retaining retractor system and an endoscope to facilitate the procedures.Surgical procedures performed on the four fresh-frozen cadaveric specimens to expose the CTJ through mini-open anterior approach were successful. The anterior surface of C6-T5 could be exposed, allowing complete decompression and application of locking plate and screws. The most caudal accessible vertebral body was T5 vertebral body in our study.It is feasible to expose the CTJ through this mini-open anterior approach.

To assess the feasibility and efficacy of TLIF with unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation for the treatment of lumbar degenerative disorders.A series of computed tomography (CT) digital images from 60 patients (30 males and 30 females) with L3-S1 segments, were reconstructed in three dimensions using a software named Xelis 3D. Linear and angular measurements of the facets were recorded. Fifty-six patients were divided to either bilateral pedicle screw fixation (BPS) (n=30) or unilateral pedicle screw and contralateral percutaneous transfacet screw fixation (UPFS) (n=26) groups. The operating time, blood loss, length of hospital stay, clinical outcomes, fusion and complication rates were compared between the two groups.The parameters of the facets we recorded were no significant differences between the left and right sides (p0.05). No statistically significant differences between males and females were observed, except the maximum width of superior facet at L4 and S1, and length of screw at all levels. Intraoperative parameters, such as operating time, blood loss and postoperative hospital stay had significantly larger in the BPS group than UPFS group (p0.05). No significant differences were found between the two groups in clinical results, fusion and complication rates (p0.05).Because of the similar clinical outcomes but less operative time, blood loss and length of postoperatively hospital stay, unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation might be an attractive technique compared to bilateral pedicle screw fixation for treating lumbar degenerative disorders with TLIF. Nevertheless differences of the anatomical parameters for the lumbosacral facets fixation between Chinese and Westerners should be noted.

To investigate biomechanical properties of posterior transpedicular–transdiscal (TPTD) oblique lumbar screw fixation whereby the screw traverses the inferior pedicle across the posterior disc space into the super-adjacent body and lateral trapezoidal interbody spacer. Eight fresh–frozen osteoligamentous human cadaveric spines (L1–S1) were tested in flexion–extension (FE), lateral bending (LB), and axial rotation (AR), with pure bending moment set at 7.5 Nm. Surgical constructs included (1) intact spine; (2) bilateral pedicle screw (BPS) fixation at L3–L4; (3) TPTD screw fixation at L3–L4; (4) lateral L3–L4 discectomy; (5) TPTD screw fixation with lateral interbody spacer (TPTD+S); and (6) BPS fixation with lateral interbody spacer (BPS+S). Peak range of motion (ROM) at L3–L4 was normalized to intact for statistical analysis. In FE and LB, all posterior fixation with or without interbody spacers significantly reduced motion compared with intact and discectomy. BPS and BPS+S provided increased fixation in all planes of motion; significantly reducing FE and LB motion relative to TPTD (p = 0.005, p = 0.002 and p = 0.020, p = 0.004, respectively). In AR, only BPS significantly reduced normalized ROM to intact (p = 0.034); BPS+S provided greater fixation compared with TPTD+S (p = 0.005). Investigators found less stiffness with TPTD screw fixation than with BPS regardless of immediate stabilization with lateral discectomy and spacer. Clinical use should be decided by required biomechanical performance, difficulty of installation, and extent of paraspinal tissue disruption.

The relationship between weight change and risk of hip fracture is still controversial. We searched PubMed and Embase for studies on weight change and risk of hip fracture. Eight prospective studies were included. The weight loss studies included 85592 participants with 1374 hip fractures and the weight gain studies included 80768 participants with 732 hip fractures. Weight loss is more likely a risk factor of hip fracture, with an adjusted RR (Relative Risk) (95% CI) of 1.84 (1.45, 2.33). In contrast, weight gain can decrease the risk of hip fracture, with an adjusted RR (95% CI) of 0.73 (0.61, 0.89). Dose-response meta-analysis shows that the risk of hip fracture is an ascending curve, with an increase of weight loss above the line of RR = 1; this trend is consistent with the results of forest plots that examine weight loss and hip fracture. For weight gain and risk of hip fracture, the descending curve below the line of RR = 1; this trend is consistent with the results of forest plots that examine weight gain and hip fracture. Our meta-analysis suggests that weight loss may be a risk factor for hip fracture and that weight gain may be a protective factor for hip fracture.

Prospective consecutive series.To evaluate the efficacy and safety of percutaneous pedicle screw fixation (PPSF) for thoracolumbar AO type A3 fractures with a specially designed surgical instrument system.Minimally invasive surgery including PPSF is becoming increasingly widespread in the spine surgery. The technique of PPSF was mostly used as supplemental fixation combined with minimally invasive posterior or anterior lumbar interbody fusion in management of lumbar degenerative disorders. There are fewer studies available in literature regarding PPSF without additional kyphoplasty or vertebroplasty for management of thoracolumbar burst fractures.Thirty-six adult patients, who had single thoracolumbar AO type A3 fractures and the load-sharing score of 6 or less, underwent application of percutaneous short-segment pedicle screw fixation. Radiologic parameters including kyphotic angle and vertebral height loss were assessed before and after surgery, and functional outcome was evaluated by Prolo questionnaire.All patients were successfully managed with percutaneous minimal invasive procedures. The average operative time was 78 minutes (range 62 to 117 min). The average intraoperative blood loss was 75 mL (range 50 to 220 mL). After a mean follow-up of 48.5 months (range 32 to 63 mo), 31 of 36 (86.1%) patients had a satisfactory result (19 excellent and 12 good) and 5 of them fair.Our clinical results suggest that PPSF can be an alternative for management of thoracolumbar AO type A3 fractures that have no neurologic deficits. With a specially designed percutaneous instrument and pedicle screw system, the procedure has been proved as relatively safe and a minimally invasive approach for the management of thoracolumbar burst fracture without neurologic deficit.

To determine the location of left brachiocephalic vein (BCV) and tracheal bifurcation (TB) relative to the vertebral levels, and to ascertain the accessibility of three different corridors (C1: between the esophagus and trachea medially and the carotid sheath laterally, C2: between the right BCV and the brachiocephalic artery, and C3: between the ascending aorta and superior vena cava) for preoperative planning. From August 2008 to April 2009, normal chest CT scans of 150 subjects ranging in age from 18 to 78 years were selected. According to our definition, of the 150 studies, 132 T2 vertebral bodies (VBs) could be accessed through C1 (88.0%), 100 T3 VBs could be reached through C2 (66.7%), and 110 T4 VBs could be exposed through C3 (73.3%). The results suggest that the surgical accessibility of three different corridors is different and we conclude that T2, T3, and T4 are, respectively, readily accessible through C1, C2, and C3.

Bone marrow stromal cells (BMSCs) could be induced to differentiate into neural cells under certain conditions, nevertheless, optimal protocols that could be reproducible and reliable in generating transplantable BMSCs in vitro are still not available. We studied for the first time the neural differentiation of BMSCs induced by coculturing with olfactory ensheathing cells (OECs). BMSCs and OECs were isolated from bone marrow and nasal olfactory lamina propria of adult SD rats respectively, then brought to coculture with transwell culture dishes. At various time points (0h, 6h, 12h, 24h, 72h, 1 week and 2 weeks post-coculture), BMSCs were morphologically observed and processed for immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). The number of cells assuming neural morphology dramatically increased at 1- and 2-week-post-coculture, so as the number of immunoreactive cells labeled by neural markers NSE, beta-III-tubulin, MAP2, GFAP and p75(NTR). Our findings demonstrate that BMSCs can efficiently differentiate into neural cells when coculturing with OECs, and the present protocol provides an alternative neurogenesis pathway for generating sufficient numbers of neural cells from BMSCs.

Study Design. An in vitro biomechanical investigation. Objectives. The purpose of this study was to investigate the association between various load-sharing score and the acute flexibility of thoracolumbar fractures by measuring the 3-dimensional flexibility data. of Background Data. The load-sharing classification is a way to describe the injury severity of a spinal fracture and can be very useful in determining successful candidates for the choice of operative approaches. However, this classification needs to be validated by biomechanical and more clinical studies before its widespread use. To date, no biomechanical study was available. Methods. Eighteen fresh bovine T12-L3 specimens were harvested and divided into 3 groups, and subjected to axial compressive impact with 63.8, 107.8, and 137.2 J energy, respectively. Radiograph films and computed tomography scans of the experimental spine were taken in neutral posture after trauma. Multidirectional flexibility of each specimen was measured under flexion-extension, right/left lateral bending, and right/left axial rotation before and after trauma. The association between the multidirectional instabilities and the vertebral injuries to each of load-sharing point score was analyzed. Results. The load-sharing score of a fracture increased with the level of impact energy. Significant positive correlations were found between the load-sharing score and the motion parameters (average R 2 = 0.434, average P = 0.004). Fractures with mild comminution (≤6 points) showed more stability as compared to those with more comminution (a7 points) (P ≤ 0.016). Conclusion. This study confirms that assessing the load-sharing score should be helpful in evaluating the acute instability of thoracolumbar fractures, and justifies the use of load-sharing classification in the thoracolumbar fractures.

Purpose. To determine whether unilateral pedicle screw fixation is comparable with unilateral pedicle screw and contralateral percutaneous transfacet screw fixation in single-level lumbar spinal fusion. Methods. Fifty-eight patients were divided into either unilateral (n = 32) or unilateral pedicle screw and contralateral percutaneous transfacet screw fixation (n = 26) instrumentation groups. The operating time, blood loss, length of hospital stay, clinical outcomes, total lumbar scoliotic changes, and fusion and complication rates were compared between the two groups. Results. There were no significant differences between the two groups in blood loss, length of hospital stay, clinical results, total lumbar scoliotic changes, and fusion and complication rates. There were significant differences in duration of operating time between 2 groups. Conclusions. Unilateral pedicle screw fixation may be as effective as unilateral PS with contralateral percutaneous transfacet screw fixation for the treatment of lum...

To explore the operative skills and effect of unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation in treating degenerative low lumbar disease.From January 2009 to December 2011,22 patients with degenerative low lumbar disease were treated with transforaminal lumbar interbody fusion, during the operations, unilateral pedicle screw and contralateral percutaneous transfacet screw fixation were performed. There were 16 males and 6 females, aged from 32 to 71 years old with an average of (51.1 ± 10.6) years, including single segment in 20 cases and two segments in 2 cases. Clinical effects were evaluated according to visual analogue score (VAS) and Oswestry Disability Index (ODI).All patients were followed up from 1 to 2.5 years with an average of 18 months. One case complicated with leakage of cerebrospinal fluid after operation and 1 case with lower limb pain of decompression-side on the 3rd day after operation. Twenty-two patients got bony fusion. There were no instability and evidence of instrument failure during follow-up. The VAS and ODI score decreased from preoperative 8.24 ± 0.72, 36.72 ± 6.84 respectively to 3.18 ± 0.66, 4.36 ± 1.12 at the final follow-up (P0.05).Unilateral pedicle screw combined with contralateral percutaneous transfacet screw fixation is safe and feasible surgical technique in treating low lumbar degenerative disease. It has advantages of little trauma, rigid fixation, high fusion rate, and less complication. etc.

Background To study the morphology of the human spine and new spinal fixation methods, scientists require cadaveric specimens, which are dependent on donation. However, in most countries, the number of people willing to donate their body is low. A 3D printed model could be an alternative method for morphology research, but the accuracy of the morphology of a 3D printed model has not been determined. Methods Forty-five computed tomography (CT) scans of cervical, thoracic and lumbar spines were obtained, and 44 parameters of the cervical spine, 120 parameters of the thoracic spine, and 50 parameters of the lumbar spine were measured. The CT scan data in DICOM format were imported into Mimics software v10.01 for 3D reconstruction, and the data were saved in .STL format and imported to Cura software. After a 3D digital model was formed, it was saved in Gcode format and exported to a 3D printer for printing. After the 3D printed models were obtained, the above-referenced parameters were measured again. Results Paired t-tests were used to determine the significance, set to P0.800. The other ICC values were 0.600; none were

STUDY DESIGN Laminoplasty was simulated using a computer-assisted technique to assess the amount of canal expansion. OBJECTIVES This study was designed to clarify the relationship between laminoplasty opening size and increase in sagittal canal diameter, increase in canal area, and the angle of the opened lamina following laminoplasty, and to determine whether a spinous process-splitting laminoplasty achieves the similar canal expansion as a single open-door method. SUMMARY OF BACKGROUND DATA Single and double-door cervical laminoplasty (SDCL and DDCL, respectively) have been widely used in the treatment of multilevel stenotic conditions. However, the relationship between laminoplasty opening size and spinal canal expansion following laminoplasty, and the comparison of postoperative spinal canal expansion between single and double-door techniques have not been well investigated. METHODS SDCL and DDCL, based on preoperative computerized tomography scans of 34 patients who had undergone the laminoplasty surgery, were simulated using a computer-assisted technique. Laminoplasty with an opening size of 6, 8, 10, 12, 14, 16, and 18 mm were simulated to determine the amount of canal enlargement with the various opening size. RESULTS Sagittal diameter, canal area, and lamina angle were increased steadily following either single or double-door laminoplasty with the door opened from 6 to 18 mm. Significant positive correlation was found between laminoplasty opening size and increase in sagittal diameter (R2 = 0.969 and P = 0.001 in SDCL; R2 = 0.926 and P < 0.001 in DDCL), increase in canal area (R2 = 0.961 and P < 0.001 in SDCL; R2 = 0.937 and P < 0.001 in DDCL), and lamina angle (R2 = 0.959 and P < 0.001 in SDCL; R2 = 0.943 and P < 0.001 in DDCL). No significant correlation was observed between preoperative sagittal diameter and increase in sagittal diameter of the spinal canal, whereas significant positive correlation was found between preoperative cross-section area and increase in cross-section area of the spinal canal. The differences between postoperative canal increase in sagittal diameter and canal area for the single versus double-door technique were statistically significant when the door was opened by more than 12 mm (P < 0.05). CONCLUSIONS Our investigation provides insight into canal expansion after laminoplasty. The increased amount of canal following laminoplasty can be predicted by the regression equations. This may allow preoperative determination of the optimal size of the opening needed to establish adequate canal space for the spinal cord. Both single and double-door techniques of laminoplasty provide sufficient room for posterior migration of the spinal cord, although gaining different canal expansion.

Background. Recent innovations in dynamic devices have promised a reduction in stress shielding, protection of adjacent segment degeneration, and decreased implant failure. However, there have been few studies comparing the biomechanical properties of a rigid device in comparison to a dynamic posterior fixation device. The purpose of this study was to compare the immediate stability of a new dynamic pedicle screw fixation device with an equivalent rigid device. Methods. Six thoracolumbar cadaver spines (T10–L4) were fixed in a biomechanical testing frame. Pure moments of 10 N m were loaded in six directions: flexion, extension, right and left lateral bending, and right and left axial rotation. For each spine, four different stages were tested: intact, destabilization of the middle segment, fixation with the dynamic device, and fixation with the rigid device. Ranges of motion were measured using stereophotogrammetry. The specimens with each device were then subjected to flexion–compression loading for five cycles on a MTS 858 Universal Testing Machine. The average stiffness of the last three cycles was recorded. Findings. Both dynamic and rigid devices were found to provide stability for the injured segment in flexion–extension and lateral bending. In axial rotation, the devices could restore the stability to levels similar to those in an intact spine. Results also indicated a slight increase in range of motion in flexion–extension and significant reduction in stiffness of flexion–compression with the dynamic device (P Interpretation. The dynamic device offers a system that may alter favorably the movement and load transmission of a spinal motion segment without sacrificing construct stability.

Anterior occiput-to-axis screw fixation is more suitable than a posterior approach for some patients with a history of posterior surgery. The complex osseous anatomy between the occiput and the axis causes a high risk of injury to neurological and vascular structures, and it is important to have an accurate screw trajectory to guide anterior occiput-to-axis screw fixation. Thirty computed tomography (CT) scans of upper cervical spines were obtained for three-dimensional (3D) reconstruction. Cylinders (1.75 mm radius) were drawn to simulate the trajectory of an anterior occiput-to-axis screw. The imitation screw was adjusted to 4 different angles and measured, as were the values of the maximized anteroposterior width and the left-right width of the occiput (C0) to the C1 and C1 to C2 joints. Then, the 3D models were printed, and an angle guide device was used to introduce the screws into the 3D models referring to the angles calculated from the 3D images. We found the screw angle ranged from α1 (left: 4.99 ± 4.59°; right: 4.28 ± 5.45°) to α2 (left: 20.22 ± 3.61°; right: 19.63 ± 4.94°); on the lateral view, the screw angle ranged from β1 (left: 13.13 ± 4.93°; right: 11.82 ± 5.64°) to β2 (left: 34.86 ± 6.00°; right: 35.01 ± 5.77°). No statistically significant difference was found between the data of the left and right sides. On the 3D printed models, all of the anterior occiput-to-axis screws were successfully introduced, and none of them penetrated outside of the cortex; the mean α4 was 12.00 ± 4.11 (left) and 12.25 ± 4.05 (right), and the mean β4 was 23.44 ± 4.21 (left) and 22.75 ± 4.41 (right). No significant difference was found between α4 and β4 on the 3D printed models and α3 and β3 calculated from the 3D digital images of the left and right sides. Aided with the angle guide device, we could achieve an optimal screw trajectory for anterior occiput-to-axis screw fixation on 3D printed C0 to C2 models.

It is still debate of the relationship between the dietary protein consumption and risk of fracture. We searched Medline and Embase to assess the effects of dietary protein consumption on risk of fracture. Twelve prospective cohort studies with 407,104 participants were included, higher total protein consumption may be decrease 11% risk of hip fractures, with adj. RR of 0.89 (0.82, 0.97), no significant difference was found for total protein and risk of all fractures and limb fracture; for animal protein consumption and risk of all fractures and hip fracture, with adj.RR of 0.79 (032, 1.96) and 1.04 (0.70, 1.54); for vegetable protein consumption and risk of all fractures, hip fracture and limb fractures with adj.RR of 0.77 (0.52, 1.12), 1.00 (0.53, 1.91) and 0.94 (0.40, 2.22), the subgroup of vegetable protein consumption and risk of all fractures of postmenopausal women with adj.RR of 0.78(0.52,1.16). Dose-response meta-analysis the relationship of total/animal/vegetable protein and hip fracture was consistent to the results of forest plot, the line of total protein and hip fracture was below the Y = 1.0 line. This meta-analysis showed that total dietary protein consumption may be decrease the risk of hip fracture, but not for animal or vegetable protein.

ObjectivesThis study presents the successful posterior surgical reduction and fusion on a 26-month-old child with chronic unilateral locked facet joint and spinal cord injury (SCI).MethodsA 26-month-old child with chronic unilateral locked facet joint and SCI treated by posterior surgical reduction and fusion. Plaster external fixation was applied and rehabilitation exercise was trained post-operatively.ResultsChronic unilateral locked facet joint was reduced successfully and bone fusion of C4/5 was achieved 3 months after surgery. The function of both lower limbs was improved 1 year after surgery, aided with physical rehabilitation.ConclusionUnilateral locked facet joint in pediatric population is rare. Few clinical experiences were found in the literature. Non-surgical treatment has advantages of not being invasive and is preferred for acute patients; however, it may not be suitable for chronic unilateral locked facet joint with SCI, in which surgical intervention is needed.

Background context Surgical stabilization is recommended for odontoid fractures with mechanical instability. Compared with C1–C2 fusion, percutaneous anterior odontoid screw fixation has the advantages of preserving C1/C2 motion and being a minimally invasive procedure. However, determining the optimal screw trajectory is often difficult. When an initial suboptimal K-wire hole is drilled, it is especially difficult to drill a second optimal K-wire trajectory because the initial hole will be entered inadvertently. Purpose To design a novel device, two-hole guide tube, to make drilling a second optimal K-wire trajectory easier, and thus, avoid unnecessary additional surgical time and reduce the likelihood of needing to change the procedure to traditional open surgery. Study design A technical report. Methods Fifty-three patients with odontoid fractures were treated by percutaneous anterior odontoid screw fixation in our hospital, and the initial K-wire trajectories of 16 cases (12 men and 4 women) among the 53 patients were imperfect. The two-hole guide tube was applied for drilling the second trajectory in each of these 16 cases. Results No complications associated with this technique occurred. Satisfactory results and good screw placement was achieved in all patients. Radiographic fusion was confirmed for 15 of 16 patients. None of the patients experienced clinical symptoms or screw loosening or breakage in this study. Conclusions Our novel device, two-hole guide tube, can be used to reduce the difficulty associated with redrilling an optimal K-wire trajectory if the initial trajectory is imperfect during percutaneous anterior odontoid screw fixation. Moreover, by referring to the initial misplaced K-wire, a more accurate trajectory for the second K-wire can be achieved.

Osteoporotic fracture is a significant cause of morbidity and mortality and is a challenging global health problem. Previous reports of the relation between vitamin A intake or blood retinol and risk of fracture were inconsistent. We searched Medline and Embase to assess the effects of vitamin A (or retinol or beta-carotene but not vitamin A metabolites) on risk of hip and total fracture. Only prospective studies were included. We pooled data with a random effects meta-analysis with adjusted relative risk (adj.RR) and 95% confidence interval (CI). We used Q statistic and I(2) statistic to assess heterogeneity and Egger's test to assess publication bias. Eight vitamin A (or retinol or beta-carotene) intake studies (283,930 participants) and four blood retinol level prospective studies (8725 participants) were included. High intake of vitamin A and retinol were shown to increase risk of hip fracture (adj.RR [95% CI] = 1.29 [1.07, 1.57] and 1.40 [1.03, 1.91], respectively), whereas beta-carotene intake was not found to increase the risk of hip fracture (adj.RR [95% CI] = 0.82 [0.59, 1.14]). Both high or low level of blood retinol was shown to increase the risk of hip fracture (adj.RR [95% CI] = 1.87 [1.31, 2.65] and 1.56 [1.09, 2.22], respectively). The risk of total fracture does not differ significantly by level of vitamin A (or retinol) intake or by blood retinol level. Dose-response meta-analysis shows a U-shaped relationship between serum retinol level and hip fracture risk. Our meta-analysis suggests that blood retinol level is a double-edged sword for risk of hip fracture. To avoid the risk of hip fracture caused by too low or too high a level of retinol concentration, we suggest that intake of beta-carotene (a provitamin A), which should be converted to retinol in blood, may be better than intake of retinol from meat, which is directly absorbed into blood after intake.

Objective The aim of this study was to compare outcomes when the upper and lower thoracic regions were used as the site of proximal instrumentation to treat adult spinal deformity. Methods MEDLINE, Embase and Cochrane library searches were performed to identify studies that compared outcome measures when the upper and lower thoracic vertebrae (UTV and LTV, respectively) were used as the site of proximal instrumentation. The weighted mean difference (WMD) was calculated for continuous outcomes, and the relative risk (RR) was calculated for dichotomous outcomes. Results Seven articles (n=554 patients) met the final inclusion criteria, and we compared the outcome measures of a long fusion extending to the upper and lower thoracic regions. The pooled analysis revealed that extending fixation into the upper thoracic region decreased the risk of proximal junctional kyphosis (PJK) revision surgery (RR: 0.36, 95% CI 0.14 to 0.90, p

BACKGROUND: Anterior odontoid screw fixation (AOSF) has been one of the most popular treatments for odontoid fractures. However, the true efficacy of AOSF remains unclear. In this study, we aimed to provide the pooled rates of non-union, reoperation, infection, and approach related complications after AOSF for odontoid fractures. METHODS: We searched studies that discussed complications after AOSF for type II or type III odontoid fractures. A proportion meta-analysis was done and potential sources of heterogeneity were explored by meta-regression analysis. RESULTS: Of 972 references initially identified, 63 were eligible for inclusion. 54 studies provided data regarding non-union. The pooled non-union rate was 10% (95% CI: 7%-3%). 48 citations provided re-operation information with a pooled proportion of 5% (95% CI: 3%-7%). Infection was described in 20 studies with an overall rate of 0.2% (95% CI: 0%-1.2%). The main approach related complication is postoperative dysphagia with a pooled rate of 10% (95% CI: 4%-17%). Proportions for the other approach related complications such as postoperative hoarseness (1.2%, 95% CI: 0%-3.7%), esophageal/retropharyngeal injury (0%, 95% CI: 0%-1.1%), wound hematomas (0.2%, 95% CI: 0%-1.8%), and spinal cord injury (0%, 95% CI: 0%-0.2%) were very low. Significant heterogeneities were detected when we combined the rates of non-union, re-operation, and dysphagia. Multivariate meta-regression analysis showed that old age was significantly predictive of non-union. Subgroup comparisons showed significant higher non-union rates in age ≥ 70 than that in age ≤ 40 and in age 40 to

We sought to evaluate the motor-sensory specificity of the motor and primary sensory neurons after the end-to-side neurorrhaphy. We divided 90 rats into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve as donor nerve and the musculocutaneous nerve as recipient nerve; (2) normal control; and (3) transected nerve with the stumps buried. At 5 months, we monitored the grooming test, the electromyographic recordings, the histologic changes in the nerve, and quantitatively evaluated motoneurons and dorsal root ganglion (DRG) neurons following their retrograde labeling by Fluoro-Gold (Sigma, St. Louis, MO) applied to the musculocutaneous nerve and its biceps brachii branch. Grooming and electrophysiological investigations recovered successfully in the end-to-side group. The implanted musculocutaneous nerve contained varying but satisfactory numbers of axons. In the end-to-side group, the proportion of motoneurons for the biceps brachii branch of musculocutaneous nerve was very similar to the musculocutaneous nerve sections proximal to this branch (17.3% ± 2.7% and 21.7% ± 3.7%, respectively), but it did not correspond with the proportion of the biceps brachii branch of musculocutaneous nerve in the normal group (28.3% ± 3.5%). The present study confirms that limited but functional reinnervation can occur after the end-to-side neurorrhaphy, and the motor-sensory specificity is not important.

To compare clinical efficacy between discectomy and discectomy plus Coflex fixation for lumbar disc herniation.From December 2007 to August 2008, 50 patients (31 males and 19 females) were treated by surgery of discectomy and discectomy plus Coflex fixation. The average age was 52.5 years (range, 30 - 72 years). There were 24 cases in the group of discectomy plus Coflex fixation and 26 cases in the group of discectomy. Preoperative and postoperative visual analogue scales (VAS), Japanese Orthopadic Association (JOA) and Oswestry disability index (ODI) were recorded, as well as radiological index. And use a paired t-test and one-way analysis of variance (one-way ANOVA) statistical method to evaluate the Coflex dynamic stabilization system in value in the treatment of lumbar disc herniation.Both groups received significant improvement of JOA, ODI and VAS (t = -33.2 - 64.5, P0.01), but the group of discectomy was found with deterioration of ODI at last follow-up, 12 months after surgery 6.7 ± 1.5 to 10.2 ± 2.3 (t = -19.3, P0.05). The group of discectomy plus Coflex fixation was found with significant increase of height of dorsal intervertebral discs (HD), distance across the two adjacent spinous processes (DS), distance of intervertebral foramina (DIF) and spinal canal area(SA) (t = -34.4 - 4.5, P0.05). In contrast, the group of discectomy was found with significant decrease of HD, DS, DIF and SA (t = 3.4 - 52.8, P0.05). Coflex fixed group in HD, DIF, DS significant difference with simple discectomy group, with a statistically significant (F = 14.1 - 25.6, P0.05).Both discectomy and discectomy plus Coflex fixation are apparently effective when treating lumbar disc herniation. Coflex can significantly increase the HD and DIF when used for lumbar disc herniation, and it has positive influence for keeping height of lumbar vertebral space and treating the nerve root symptom of lumbar disc herniation. Discectomy plus Coflex is better than pure discectomy in preventing lumbar degeneration.

BACKGROUND: Posterior pedicle screw fixation has become a popular method for treating thoracolumbar burst fractures. However, it remains unclear whether additional fusion could improve clinical and radiological outcomes. This meta-analysis was performed to evaluate the effectiveness of fusion as a supplement to pedicle screw fixation for thoracolumbar burst fractures. METHODOLOGY/PRINCIPAL FINDINGS: MEDLINE, OVID, Springer, and Google Scholar were searched for relevant randomized and quasi-randomized controlled trials that compared the clinical and radiological efficacy of fusion versus nonfusion for thoracolumbar burst fractures managed by posterior pedicle screw fixation. Risk of bias in included studies was assessed using the Cochrane Risk of Bias tool. We generated pooled risk ratios or weighted mean differences across studies. Based on predefined inclusion criteria, 4 eligible trials with a total of 220 patients were included in this meta-analysis. The mean age of the patients was 35.1 years. 96.8% of the fractures were located at T12 to L1 level. Baseline characteristics were similar between the fusion and nonfusion groups. No significant difference was identified between the two groups regarding radiological outcome, functional outcome, neurologic improvement, and implant failure rate. The pooled data showed that the nonfusion group was associated with significantly reduced operative time (p

To establish reference data on the dimensions of C2 lamina to guide the use of translaminar screws with Wright’s technique and a modified technique for pediatric patients in different age groups. 113 pediatric patients were divided into six age groups, and their cervical vertebrae were studied on CT scans. Laminar height, width, length and screw angle were measured. Statistical analysis was performed using Student t tests, Pearson’s correlation and linear regression analysis. Mean laminar height was 10.95 ± 2.81 mm, and mean width was 6.01 ± 0.90 mm. For Wright’s technique, mean laminar length was 30.65 ± 3 mm, and the screw angle was 56.02° ± 3.62°. For the modified technique, mean laminar length was 22.07 ± 2.38 mm, and the screw angle was 67.40° ± 3.39°. 95.6 % (108/113) of the children could insert a screw into the lamina (laminar width ≥4.5 mm), 72.6 % (82/113) could accept bilateral translaminar screws (laminar width ≥4.5 mm and laminar height ≥9 mm). Our investigation provides insight into the anatomy of C2 lamina in six pediatric age groups. Compared to adults, the benefits of C2 translaminar screws fixation are more obvious in the pediatric spine which has a large C2 lamina. Compared to Wright’s technique, the modified technique should insert a screw with bigger insert angle and shorter screw length.

An intravertebral vacuum cleft (IVC) is not an uncommon finding; it is more likely to occur in patients with osteoporotic vertebral compression fractures (OVCF). There are scarce data on the treatment of these patients with percutaneous balloon kyphoplasty (PKP). Between August 2005 and March 2010, 35 single vertebral fracture patients with an IVC sign were treated by PKP. Visual Analogue Score (VAS), Oswestry Disability Index (ODI), Kyphotic Angulation (KA), and Compression Ratio (CR) improved significantly postoperatively (p0.05). These values were maintained at the one year follow-up. Balloon kyphoplasty leads less often to leakage (here in only 14.3% of the patients) than vertebroplasty (in 75% according to the literature). On the other hand, balloon kyphoplasty seems to predispose to intradiscal leakage: here in 3 out of 5 cases. This may cause a compression fracture of the adjacent vertebra.

Lumbar interspinous devices are intended to unload the facet joints, restore foraminal height, lower intradisk pressure, and provide motion-preserving stabilization. They are an alternative treatment for patients with spinal degeneration and have increased in popularity in recent years. To the authors’ knowledge, heterotopic ossification has not been previously reported around an interspinous device, and this is the first reported case of interspinous fusion after interspinous device placement. A 66-year-old man presented with a 3-year history of low back pain and a 4-month history of radiating pain down his left leg. A diagnosis was made of lumbar spinal stenosis and left disk herniation at L4–L5 after physical and imaging examinations. A dynamic interspinous device was implanted after the decompressive surgery. The patient’s symptoms were relieved postoperatively. Thirty-two months later, he returned with back pain after being in a traffic accident. Lumbar radiographs showed a massive bony formation around the implant. Radiographs and a computed tomography scan 4.5 years later revealed that the implanted device segments were fused. No implant motion was seen on dynamic radiographs. Because the patient was symptom free, no interventions were performed. Heterotopic bone formation around a dynamic interspinous device may hamper motion preservation, and heterotopic ossification is a potential mid- and long-term complication.

To study indications and complications of interspinous process device Coflex for degenerative disk diseases.One hundred and eight patients with degenerative lumbar disc diseases were underwent procedures of surgical decompression and additional fixation of Coflex between November 2007 and October 2010. Sixty-eight patients were male and the other fourty were female, and their average age was 53.5 years (range from 37 to 75 years). Fifty-nine patients were underwent surgery of excision of nucleus pulposus and Coflex fixation, 41 patients were underwent surgery of decompression by fenestration and Coflex fixation, 6 patients were underwent surgery of topping-off, and 2 patients were underwent surgery of Coflex fixation for two level. Preoperative and postoperative visual analogue scales (VAS) and Oswestry disability index (ODI) were recorded, as well as height of ventral intervertebral space (HV), height of dorsal intervertebral space (HD), height of intervertebral foramen (HIF) and segmental range of motion (ROM). One-way ANOVA was used for statistical analysis. Surgical complications were also recorded.The average follow-up time was 28.8 months. All groups had apparent improvement of VAS and ODI, and maintained well to last follow-up (F = 6.16-25.92, P = 0.00). Statistical analysis showed that HD and HIF increased significantly in group with excision of nucleus pulposus and Coflex fixation and group with decompression by fenestration and Coflex fixation (F = 7.37 - 11.68, P0.05). Although both HD and HIF decreased one-year after surgery, they were still higher than those preoperatively (F = 6.31 and 7.05, P = 0.00). Preoperative segmental ROM was respectively 6.3° ± 1.8° and 6.2° ± 1.7° in group with excision of nucleus pulposus and Coflex fixation and group with decompression by fenestration and Coflex fixation, and 3.1° ± 0.6° and 3.0° ± 0.8° at last follow-up. Three cases were found with device-related complications and five with non-device-related complications, and all five cased were cured after appropriate treatment.Surgical method assisted with Coflex has significant clinical efficacy for degenerative disc disease, it can maintain segmental stability, simultaneously, partly reserve movement. It's key to strictly master indications and precisely choose patients.