Intraoperative pain prediction of percutaneous kyphoplasty under local anesthesia by preoperative experimental pain assessment.

BACKGROUND: Percutaneous kyphoplasty (PKP) is the preferred treatment for osteoporotic vertebral compression fractures (OVCF) Currently, the preoperative anesthesia methods for PKP are mainly local anesthesia and tracheal intubation general anesthesia. OBJECTIVE: To assess whether patient sensitivity to pain measured preoperatively could predict the patients' pain response during PKP treatment under local anesthesia, to facilitate the development of an optimal preoperative anesthesia plan for patients. METHODS: Fifty-five female patients diagnosed with osteoporotic single vertebral fracture who were treated with PKP under local anesthesia were selected. The patients' pain sensitivities, including pain threshold and pain tolerance threshold, were evaluated with a pain test device on the day before the operation in the ward. Heart rate (HR), mean arterial pressure (MAP), and blood oxygen saturation (SpO2) were recorded before anesthesia, post-anesthesia, after needle puncture, and after balloon dilatation. At the same time, blood was drawn at the above time points to determine the level of norepinephrine (NA) as an indicator of intraoperative pain stress response. The numerical rating scale (NRS) during surgery was recorded at the end of the surgery. RESULTS: The preoperative pain tolerance threshold of 55 surgical patients was correlated with the intraoperative NRS score (r=-0.768, P< 0.001), as well as with the preoperative and intraoperative changes in HR (r=-0.791, P< 0.001), MAP (r=-0.819, P< 0.001), and NA (r=-0.553, P< 0.001). Thus, the lower the preoperative pain tolerance threshold, the more severe the patient's response to pain during PKP treatment under local anesthesia, and the greater the hemodynamic changes. Consequently, the intraoperative experience becomes worse. However, there was no correlation between preoperative pain threshold and NRS scores (r=-0.069, P= 0.616) nor between the preoperative and intraoperative changes in HR (r= 0.103, P= 0.453), MAP (r= 0.086, P= 0.535), and NA (r=-0.058, P= 0.674). CONCLUSION: The results indicated that preoperative pain assessment could predict the level of pain response in OVCF patients during PKP surgery under local anesthesia.

Congenital hepatic hemangioma: an unusual case report of pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) in newborns is a rare but serious condition that often requires immediate intervention and quick diagnosis of the correct etiology to prevent mortality. Congenital hepatic hemangioma (CHH) is an example of an extrathoracic etiology of PH. CASE PRESENTATION: Herein, we report the case of a newborn with a giant liver hemangioma, who presented with an early onset of PH and was successfully treated with intra-arterial embolization. CONCLUSIONS: This case illustrates the importance of suspicion and prompt evaluation of CHH and related systemic arteriovenous shunts among infants with unexplained PH.

Comparison of unipedicular and bipedicular kyphoplasty for treating acute osteoporotic vertebral compression fractures in the lower lumbar spine: a retrospective study.

BACKGROUND: Unipedicular and bipedicular approaches for percutaneous kyphoplasty are reportedly both effective in treating osteoporotic vertebral compression fractures (OVCFs). However, most studies have reported thoracolumbar fractures, with few reports describing the treatment of the lower lumbar spine. Here, we compared the clinical and radiological results of unipedicular and bipedicular approaches for percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures. METHODS: We retrospectively reviewed the records of 160 patients who underwent percutaneous kyphoplasty for lower lumbar (L3-L5) osteoporotic vertebral compression fractures between January 2016 and January 2020. Patient characteristics, surgical outcomes, operation time, blood loss, clinical and radiological features, and complications were compared between two groups. Cement leakage, height restoration, and cement distribution were calculated from the radiographs. Visual pain analog scale (VAS) and Oswestry Disability Index (ODI) were calculated before surgery, immediately post-surgery, and 2 years after surgery. RESULTS: The mean age, sex, body mass index, injury time, segmental distribution, and morphological classification of fractures before surgery did not differ significantly between the groups. The results showed significant improvements in the VAS score, ODI score, and vertebral height restoration in each group (p < 0.05), with no significant differences between the two groups (p > 0.05). The mean operation time and extent of blood loss were lower in the unipedicular group than those in the bipedicular group (p < 0.05). Different types of bone cement leakage were observed in both groups. Leakage rate was higher in the bipedicular group than in the unipedicular group. Patients in the bipedicular group showed greater improvement in bone cement distribution than those in the unipedicular group (p < 0.05). CONCLUSIONS: The clinical and radiological results of unipedicular percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures in the lower lumbar region were similar to those of bipedicular percutaneous kyphoplasty. However, the unipedicular approach resulted in shorter surgical time, less blood loss, and less bone cement leakage. Thus, the unipedicular approach may be preferable owing to its several advantages.

Percutaneous mesh-container-plasty versus percutaneous kyphoplasty for the treatment of Kümmell's disease: a retrospective cohort study.

BACKGROUND: Both percutaneous kyphoplasty (PKP) and percutaneous mesh-container-plasty (PMCP) were important procedures for the treatment of Kümmell's disease. This study aimed to compare the clinical and radiological results of PKP and PMCP for the treatment of Kümmell's disease. METHODS: This study included patients with Kümmell's disease treated at our center between January 2016 and December 2019. A total of 256 patients were divided into two groups according to the surgical treatment they received. Clinical, radiological, epidemiological, and surgical data were compared between the two groups. Cement leakage, height restoration, deformity correction, and distribution were evaluated. The visual analog scale (VAS), Oswestry Disability Index (ODI), and short-form 36 health survey domains "role-physical" (SF-36 rp) and "bodily pain" (SF-36 bp) were calculated preoperatively, immediately after surgery, and 1-year postoperatively. RESULTS: The VAS and ODI scores improved in the PKP [preoperative: 6 (6-7), 68.75 ± 6.64; postoperative: 2 (2-3), 23.25 ± 3.50, respectively] (p < 0.05) and the PMCP [preoperative: 6 (5-7), 67.70 ± 6.50; postoperative: 2 (2-2), 22.24 ± 3.55, respectively] groups (p < 0.05). There were significant differences between the two groups. The mean cost in the PKP group was lower than that in the PMCP group (3697 ± 461 vs. 5255 ± 262 USD, p < 0.05). The cement distribution in the PMCP group was significantly higher than that in the PKP group (41.81 ± 8.82% vs. 33.65 ± 9.24%, p < 0.001). Cement leakage was lower in the PMCP group (23/134) than in the PKP group (35/122) (p < 0.05). The anterior vertebral body height ratio (AVBHr) and Cobb's angle improved in the PKP (preoperative: 70.85 ± 16.62% and 17.29 ± 9.78°; postoperative: 80.28 ± 13.02% and 13.05 ± 8.40°, respectively) and PMCP (preoperative: 70.96 ± 18.01% and 17.01 ± 10.53°; postoperative: 84.81 ± 12.96% and 10.76 ± 9.23°, respectively) groups (p < 0.05). There were significant differences in vertebral body height recovery and segmental kyphosis improvement between the two groups. CONCLUSIONS: PMCP had advantages over PKP in terms of pain relief and functional recovery for the treatment of Kümmell's disease. Moreover, PMCP is more effective than PKP in preventing cement leakage, increasing cement distribution, and improving vertebral height and segmental kyphosis, despite its higher cost.

Percutaneous mesh-container-plasty versus percutaneous kyphoplasty in the treatment of malignant thoracolumbar compression fractures: a retrospective cohort study.

OBJECTIVE: This study aimed to compare the clinical and radiological results of percutaneous mesh-container-plasty versus percutaneous kyphoplasty in the treatment of malignant thoracolumbar compression fractures. METHODS: Patients with malignant thoracolumbar compression fractures treated in a single tertiary care center between January 2011 and December 2020 were retrospectively reviewed and included in the study. Ninety-four patients who were diagnosed by pathological biopsy were divided into 2 groups according to the type of surgical treatment: the percutaneous kyphoplasty group (50 patients: 24 male, 26 female; mean age=73.02 ± 7.79 years) and the percutaneous mesh-container-plasty group (44 patients: 21 male, 23 female; mean age=74.68 ± 7.88 years). The epidemiological data, surgical outcomes, and clinical and radiological features were compared between the 2 groups. Cement leakage, height restoration, deformity correction, and cement distribution were calculated from the radiographs. The visual analog scale, Oswestry disability index, Karnofsky performance scale scores, and short-form 36 health survey domains role physi cal and bodily pain were calculated preoperatively, immediately, and 1 year postoperatively. RESULTS: The visual analog scale score improved from 5 (range=4-6) preoperatively to 2 (range=2-3) immediately postoperatively in the percutaneous kyphoplasty group and from 5 (range=4-6) preoperatively to 2 (range=2-2) immediately postoperatively in the percutane ous mesh-container-plasty group; there was a significant difference between the 2 groups (P=.018). Although Oswestry disability index, Karnofsky performance scale, short-form 36 health survey domains bodily pain and role physical significantly improved in both groups after surgery compared to the preoperative period, there was no significant difference between the 2 groups (P > .05). The mean cost in the percutaneous kyphoplasty group was lower than that in the percutaneous mesh-container-plasty group (5563 ± 439 vs. 6569 ± 344 thousand dollars, P < .05). There was no difference between the cement volume in the 2 groups, and cement distribution in the percutaneous mesh-container-plasty group was higher than that in the percutaneous kyphoplasty group (44.30% ± 10.25% vs. 32.54% ± 11.76%, P < .05). Cement leakage was found to be lesser in the percutaneous mesh-container-plasty group (7/44) than in the percutane ous kyphoplasty group (18/50, P < .05). There were no statistically significant differences in the recovery of vertebral body height and improvement of segmental kyphosis between the 2 groups (P > .05). CONCLUSION: Percutaneous kyphoplasty and percutaneous mesh-container-plasty both have significant abilities in functional recovery, height restoration, and segment kyphosis improvement in treating malignant thoracolumbar compression fractures. Percutaneous mesh container-plasty may be better able to relieve pain, inhibit cement leakage, and improve cement distribution than percutaneous kypho plasty. However, percutaneous mesh-container-plasty requires a relatively longer procedure and is more expensive than percutaneous kyphoplasty. LEVEL OF EVIDENCE: Level III, Therapeutic Study.

Effectiveness and safety of ultrasound-guided thoracic paravertebral block versus local anesthesia for percutaneous kyphoplasty in patients with osteoporotic compression fracture.

BACKGROUND: Kyphoplasty for osteoporotic vertebral compression fractures (OVCF) is a short but painful intervention. Different anesthetic techniques have been proposed to control pain during kyphoplasty; however, all have limitations. OBJECTIVE: To compare the effectiveness and safety of ultrasound-guided thoracic paravertebral block with local anesthesia for percutaneous kyphoplasty (PKP). METHODS: In this prospective study, non-randomized patients with OVCF undergoing PKP received either ultrasound-guided thoracic paravertebral block (group P) or local anesthesia (group L). Perioperative pain, satisfaction with anesthesia, and complications were compared between the groups. RESULTS: Mean intraoperative (T1-T4) perioperative visual analog scale (VAS) scores were significantly lower in group P than in group L (2 [1-3] vs. 3 [2-4], 2 [2-3] vs. 4 [2-4], 2 [2-3] vs. 5 [3-5], and 3 [2-3] vs. 5 [3-5], respectively; P< 0.05). Investigators' satisfaction scores, patients' anesthesia satisfaction scores, and anesthesia re-administration intention rate were significantly higher in group P than in group L (4 [3-5] vs. 3 [2-4], 2 [2-3] vs. 2 [1-3], 90.63% vs. 69.70%; P< 0.05). There was no significant intergroup difference in complications. CONCLUSIONS: Ultrasound-guided thoracic paravertebral block has similar safety to and better effectiveness than local anesthesia in PKP.

Safety and efficacy studies of kyphoplasty, mesh-container-plasty, and pedicle screw fixation plus vertebroplasty for thoracolumbar osteoporotic vertebral burst fractures.

BACKGROUND: Percutaneous kyphoplasty (PKP), percutaneous mesh-container-plasty (PMCP), and pedicle screw fixation plus vertebroplasty (PSFV) were three methods for osteoporotic vertebral burst fractures (OVBF). The purpose of the current study was to evaluate the clinical safety and efficacy of PKP, PMCP, and PSFV for OVBFs. METHODS: This retrospective study included 338 consecutive patients with thoracolumbar OVBFs who underwent PKP (n = 111), PMCP (n = 109), or PSFV (n = 118) and compared their epidemiological data, surgical outcomes, and clinical and radiological features. Clinical evaluations of VAS and ODI and radiological evaluations of height restoration, deformity correction, cement leakage, and canal compromise were calculated preoperatively, postoperatively, and 2 years postoperatively. RESULTS: Cement leakage (31/111 vs. 13/109 and 16/118, P < 0.05) was significantly higher in group PKP than in groups PSFV and PMCP. VAS and ODI scores improved postoperatively from 7.04 ± 1.15 and 67.11 ± 13.49 to 2.27 ± 1.04 and 22.00 ± 11.20, respectively, in group PKP (P < 0.05); from 7.04 ± 1.29 and 67.26 ± 12.79 to 2.17 ± 0.98 and 21.01 ± 7.90, respectively, in group PMCP (P < 0.05); and from 7.10 ± 1.37 and 67.36 ± 13.11 to 3.19 ± 1.06 and 33.81 ± 8.81, respectively, in the PSFV group (P < 0.05). Moreover, postoperative VAS and ODI scores were significantly higher in group PSFV than in groups PKP and PMCP (P < 0.05). However, VAS scores were not significantly different in the three groups 2 years postoperatively (P > 0.05). Postoperative anterior (81.04 ± 10.18% and 87.51 ± 8.94% vs. 93.46 ± 6.42%, P < 0.05) and middle vertebral body height ratio (83.01 ± 10.16% and 87.79 ± 11.62% vs. 92.38 ± 6.00%, P < 0.05) were significantly higher in group PSFV than in groups PMCP and PKP. Postoperatively, Cobb angle (10.04 ± 4.26° and 8.16 ± 5.76° vs. 4.97 ± 4.60°, P < 0.05) and canal compromise (20.76 ± 6.32 and 19.85 ± 6.18 vs. 10.18 ± 6.99, P < 0.05) were significantly lower in group PSFV than in groups PMCP and PKP. CONCLUSION: Despite relatively worse radiological results, PMCP is a safe and minimally invasive surgical method that can obtain better short-term clinical results than PKP and PSFV for OVBFs.

The preconditioning of lithium promotes mesenchymal stem cell-based therapy for the degenerated intervertebral disc via upregulating cellular ROS.

Adipose-derived stem cell (ADSC) is one of the most widely used candidate cell for intervertebral disc (IVD) degeneration-related disease. However, the poor survival and low differentiation efficacy in stressed host microenvironment limit the therapeutic effects of ADSC-based therapy. The preconditioning has been found effective to boost the proliferation and the functioning of stem cells in varying pathological condition. Lithium is a common anti-depression drug and has been proved effective to enhance stem cell functioning. In this study, the effects of preconditioning using LiCl on the cellular behavior of ADSC was investigated, and specially in a degenerative IVD-like condition. METHOD: The cellular toxicity on rat ADSC was assessed by detecting lactate dehydrogenase (LDH) production after treatment with a varying concentration of lithium chloride (LiCl). The proliferative capacity of ADSC was determined by detecting Ki67 expression and the relative cell number of ADSC. Then, the preconditioned ADSC was challenged by a degenerative IVD-like condition. And the cell viability as well as the nucleus pulpous (NP) cell differentiation efficacy of preconditioned ADSC was evaluated by detecting the major marker expression and extracellular matrix (ECM) deposit. The therapeutic effects of preconditioned ADSC were evaluated using an IVD degeneration rat model, and the NP morphology and ECM content were assessed. RESULTS: A concentration range of 1-10 mmol/L of LiCl was applied in the following study, since a higher concentration of LiCl causes a major cell death (about 40%). The relative cell number was similar between preconditioned groups and the control group after preconditioning. The Ki67 expression was elevated after preconditioning. Consistently, the preconditioned ADSC showed stronger proliferation capacity. Besides, the preconditioned groups exhibit higher expression of NP markers than the control group after NP cell induction. Moreover, the preconditioning of LiCl reduced the cell death and promoted ECM deposits, when challenged with a degenerative IVD-like culture. Mechanically, the preconditioning of LiCl induced an increased cellular reactive oxidative species (ROS) level and activation of ERK1/2, which was found closely related to the enhanced cell survival and ECM deposits after preconditioning. The treatment with preconditioned ADSC showed better therapeutic effects than control ADSC transplantation, with better NP preservation and ECM deposits. CONCLUSION: These results suggest that the preconditioning with a medium level of LiCl boosts the cell proliferation and differentiation efficacy under a normal or hostile culture condition via the activation of cellular ROS/ERK axis. It is a promising pre-treatment of ADSC to promote the cell functioning and the following regenerative capacity, with superior therapeutic effects than untreated ADSC transplantation.

Percutaneous mesh-container-plasty for osteoporotic thoracolumbar burst fractures: A prospective, nonrandomized comparative study.

OBJECTIVE: This study aimed to compare the clinical and radiological results of percutaneous mesh-container-plasty (PMCP) versus percutaneous kyphoplasty (PKP) in the treatment of osteoporotic thoracolumbar burst fractures. METHODS: A prospective study of 122 patients with osteoporotic thoracolumbar burst fractures was conducted. The patients were nonrandomly assigned to receive PKP (62; 16 men, 46 women) and PMCP (60; 14 men, 46 women). The epidemiological data, surgical outcomes, and clinical and radiological features were compared between the 2 groups. Cement leakage, height restoration, deformity correction, canal compromise, and cement distribution were calculated from the radiographs. Visual pain analog scale (VAS), the Oswestry disability index (ODI), and short-form 36 health survey domains role physical (SF-36 rp) and bodily pain (SF-36 bp) were calculated before surgery and immediately and 2 years after surgery. RESULTS: Although VAS, ODI, SF-36 bp, and SF-36 rp scores improved from 7 (6-9), 71.28±16.38, 22 (0-32), and 25 (0-50) preoperatively to 2 (1-3), 20.02±8.97, 84 (84-84), and 75 (75-100) immediately postoperatively in the PMCP group (p<0.05) and from 7 (6-8), 71.40±13.52, 22 (10.5-31.75), and 25 (0-50) preoperatively to 2 (1-3), 21.78±11.21, 84 (84-84), and 75 (75-100) immediately postoperatively in the PKP group (p<0.05), there was no difference between the 2 groups. The mean cost in the PKP group was less than that in the PMCP group ($5109±231 vs. $6699±201, p<0.05). Anterior, middle, and posterior vertebral body height ratios in the PMCP group were greater than those in the PKP group postoperatively (88.44%±3.76% vs. 81.10%±11.78%, 86.15%±3.50% vs. 82.30%±11.02%, and 93.91%±3.01% vs. 91.43%±6.71%, respectively, p<0.05). The Cobb angle in the PMCP group was lower than that in the PKP group postoperatively (6.67°±4.39° vs. 8.99°±4.06°, p<0.05). Cement distribution in the PMCP group was higher than that in the PKP group (30.48%±5.62% vs. 27.18%±4.87%, p<0.05). Cement leakage was observed to be lesser in the PMCP group (2/60) than in the PKP group (10 vs. 62, p<0.05). CONCLUSION: Both PKP and PMCP treatments seem to have significant ability in pain relief and functional recovery. Despite its higher cost, PMCP treatment may have a better inhibition ability of cement leakage, cement distribution, height restoration, and improvement in segmental kyphosis than PKP treatment for osteoporotic thoracolumbar burst fractures. LEVEL OF EVIDENCE: Level II, Therapeutic Study.

Clinical characteristics and treatment of fracture-dislocation of thoracic spine with or without minimal spinal cord injury.

BACKGROUND: It is important to evaluate clinical efficacy and safety of posterior internal fixation using pedicle screw system. OBJECTIVES: To investigate clinical characteristics of patients diagnosed with fracture-dislocation of the thoracic spine with or without minimal spinal cord. METHODS: Twenty-eight patients with fracture-dislocation of thoracic spine with or without minimal spinal cord injury were retrospectively analyzed. All patients received posterior reduction and internal fixation using pedicle screw system. RESULTS: The mean follow-up duration was 11.4 months. Among 28 patients, 24 cases were complicated with bilateral pedicle or laminal fracture. Preoperatively, the percentage of vertebral displacement was (32.1 ± 20.6)%, significantly declined to (7.5 ± 6.0)% (t= 4.575, P= 0.001) and maintained at (7.9 ± 6.3)% at the final follow-up. Preoperative local kyphosis angle was measured as (16.2 ± 11.3)∘, restored to (15.4 ± 5.9)∘ postoperatively and (15.8 ± 5.4)∘ during the final follow-up. No statistical significance was observed at three time points (all P> 0.05). The remaining 25 patients were evaluated with normal and complete neurological function. No severe complications were observed intra- and postoperatively. CONCLUSIONS: Posterior internal fixation using pedicle screw is an efficacious and safe therapy which achieves proper reduction and preserves spinal cord function.

Characterization and Comparison of Postnatal Rat Meniscus Stem Cells at Different Developmental Stages.

Meniscus-derived stem cells (MeSCs) are a potential cell source for meniscus tissue engineering. The stark morphological and structural changes of meniscus tissue during development indicate the complexity of MeSCs at different tissue regions and stages of development. In this study, we characterized and compared postnatal rat meniscus tissue and MeSCs at different tissue regions and stages of development. We observed that the rat meniscus tissue exhibited marked changes in tissue morphology during development, with day 7 being the most representative time point of different developmental stages. All rat MeSCs displayed typical stem cell characteristics. Rat MeSCs derived from day 7 inner meniscus tissue exhibited the highest self-renewal capacity, cell proliferation, differentiation potential toward various mesenchymal lineage and the highest expression levels of chondrogenic genes and proteins. Transplantation of rat MeSCs derived from day 7 inner meniscus tissue promoted neo-tissue formation and effectively protected joint surface cartilage in vivo. Our results demonstrated for the first time that rat MeSCs are not necessarily better at earlier developmental stages, and that rat MeSCs derived from day 7 inner meniscus tissue may be a superior cell source for effective meniscus regeneration and articular cartilage protection. This information could make a significant contribution to human meniscus tissue engineering in the future. Stem Cells Translational Medicine 2019;8:1318&1329.

A 3D navigation template for guiding a unilateral lumbar pedicle screw with contralateral translaminar facet screw fixation: a study protocol for multicentre randomised controlled trials.

INTRODUCTION: The incidence of lumbar disc degeneration disease has increased in recent years. Lumbar interbody fusion using two unilateral pedicle screws and a translaminar facet screw fixation has advantages of minimal invasiveness and lower costs compared with the traditional methods. Moreover, a method guided by a three-dimensional (3D) navigation template may help us improve the surgical accuracy and the success rate. This is the first randomised study using a 3D navigation template to guide a unilateral lumbar pedicle screw with contralateral translaminar facet screw fixation. METHODS AND ANALYSIS: Patients who meet the criteria of the surgery will be randomly divided into experimental groups and control groups by a computer-generated randomisation schedule. We will preoperatively design an individual 3D navigation template using CATIA software and MeditoolCreate. The following primary outcomes will be collected: screw angles compared with the optimal screw trajectories in 3D digital images, length of the wound incision, operative time, intraoperative blood loss and complications. The following secondary outcomes will be collected: visual analogue scale (VAS) for back pain, VAS for leg pain and the Oswestry Disability Index. These parameters will be evaluated on day 1 and then 3, 6, 12 and 24 months postoperatively. ETHICS AND DISSEMINATION: The study has been reviewed and approved by the institutional ethics review board of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University. The results will be presented at scientific communities and peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR-IDR-17010466.

Clinical Efficacy of Percutaneous Kyphoplasty at the Hyperextension Position for the Treatment of Osteoporotic Kümmell Disease.

SUMMARY OF BACKGROUND DATA: Percutaneous kyphoplasty might be effective for osteoporotic Kümmell disease. OBJECTIVE: To investigate the clinical efficacy of percutaneous kyphoplasty in hyperextension for osteoporotic Kümmell disease. STUDY DESIGN: Retrospective study. METHODS: A retrospective analysis was carried out on data from downstream balloon kyphoplasty treatments in hyperextension for 18 patients with osteoporotic Kümmell disease. All cases were single-segment disease affecting T5 (1 case), T7 (1 case), T8 (2 cases), T11 (6 cases), T12 (4 cases), L1 (2 cases), L2 (1 case), or L4 (1 case). Dual-energy x-ray absorptiometry bone mineral density values ranged from -2.8 to -5.8 SD. The sagittal Cobb angle of the involved segment was measured before and after the operation and the final follow-up also included a visual analog pain score (VAS) and the Oswestry Disability Index (ODI) after comprehensive efficacy assessment. RESULTS: All patients were followed up for 12-36 months, with an average of 15.8 months. Patients showed lower back pain relief and improvement in daily life activities. The kyphosis Cobb angle improved from 32.60±3.82 degrees before surgery to 7.60±1.68 degrees after surgery, and VAS and ODI scores significantly improved from 8.7±0.96 points and 88.6±3.76% to 2.6±0.32 points and 28.6±2.67%, respectively. The last follow-up for the kyphosis Cobb angle yielded a value of 9.60±2.06 degrees, and VAS and ODI averaged 2.2±0.26 points and 26.4±2.46%, respectively. Compared with 2 days postoperatively, the differences were not statistically significant. Intervertebral cement leakage occurred in 1 case, but no symptom was observed and no treatment was performed. CONCLUSION: Percutaneous balloon kyphoplasty in the hyperextension position is an effective method for osteoporosis in Kümmell disease.

[Percutaneous short segment pedicle screw fixation with vertebral augmentation for the treatment of single level thoracolumbar osteoporosis fracture].

OBJECTIVE: To explore the safety and clinical effects of percutaneous vertebroplasty and pedicle screw fixation in treating osteoporotic thoracolumbar burst fracture. METHODS: From April 2011 to April 2014, 32 patients with osteoporotic thoracolumbar burst fracture were treated with percutaneous vertebroplasty and pedicle screw fixation. There were 13 males and 19 females, aged in ranging from 60 to 73 years old(averaged 65.6 years). All fractures were single thoracolumbar fracture and 4 cases located on T11, 9 on T12, 16 on L3; and 3 on L2. Cobb angle, vertebral anterior compression rate, vertebral posterior compression rate, spinal canal occupying ratio were compared, visual analogue scale (VAS) and Oswestry Disability Index(ODI) were analyzed before and after operation. RESULTS: The mean operation time was 65.7 min(ranged, 60 to 120 min) and blood loss was 25.2 ml (ranged, 20 to 50 ml). The operative incisions obtained primary healing. All patients were followed up from 12 to 48 months with an average of 20.6 months. Vertebral anterior compression rate and vertebral posterior compression rate were respectively corrected from preoperative (49.70±5.89)%, (17.36±4.11)% to (6.00±2.10)%, (5.48±1.65)% at 2 d after operation, and (6.06±1.57)%, (5.68±1.82)% at last follow up. Cobb angle and spinal canal occupying ratio were respectively corrected from preoperative (13.34±3.56)°, (22.77±5.83)% to(2.86±0.95)°, (5.02±1.93)% at 2 d after operation, and (3.04±0.94)°, (5.15±1.93)% at last follow up. VAS and ODI were respectively decreased from preoperative (6.84±0.88)points, (77.50±5.10)% to(1.94±0.72) points, (17.94±4.82)% at 2 d after operation, and (1.63±0.83) points, (15.63±5.19)% at last follow up. Cement leakage occurred in 3 cases. No internal fixation failure and intractable lower back pain were found. CONCLUSIONS: Percutaneous vertebroplasty and pedicle screw fixation could restore vertebral body height, improve spinal canal occupying, correct kyphosis, relieve pain, improve life quality, and it is a safe and effective method in treating osteoporotic thoracolumbar burst fracture.

Biomechanical study of the funnel technique applied in thoracic pedicle screw replacement.

BACKGROUND: Funnel technique is a method used for the insertion of screw into thoracic pedicle. AIM: To evaluate the biomechanical characteristics of thoracic pedicle screw placement using the Funnel technique, trying to provide biomechanical basis for clinical application of this technology. METHODS: 14 functional spinal units (T6 to T10) were selected from thoracic spine specimens of 14 fresh adult cadavers, and randomly divided into two groups, including Funnel technique group (n = 7) and Magerl technique group (n = 7). The displacement-stiffness and pull-out strength in all kinds of position were tested and compared. RESULTS: Two fixed groups were significantly higher than that of the intact state (P < 0.05) in the spinal central axial direction, compression, anterior flexion, posterior bending, lateral bending, axial torsion, but there were no significant differences between two fixed groups (P > 0.05). The mean pull-out strength in Funnel technique group (789.09 ± 27.33) was lower than that in Magerl technique group (P < 0.05). CONCLUSIONS: The Funnel technique for the insertion point of posterior bone is a safe and accurate technique for pedicle screw placement. It exhibited no effects on the stiffness of spinal column, but decreased the pull-out strength of pedicle screw. Therefore, the funnel technique in the thoracic spine affords an alternative for the standard screw placement.

The treatment of osteoporotic thoracolumbar severe burst fractures with short pedicle screw fixation and vertebroplasty.

BACKGROUND: To investigate the clinical and radiological results of short pedicle screw fixation and vertebroplasty in osteoporotic thoracolumbar severe burst fractures. METHODS: From September 2006 to August 2010, 19 consecutive patients sustained osteoporotic thoracolumbar severe burst fractures with or without neurologic deficit and were included in this prospective study. All patients underwent short pedicle screw fixation and vertebroplasty. Segmental kyphosis, AVBHr and PVBHr, and Canal compromise were calculated on radiographs pre-operatively, post-operative and at final follow up. VAS, ODI and SF-36 were calculated pre-operatively and at final follow up. RESULTS: Mean operative time was 70.8 min (range 60~100 min) and mean blood loss was 92 ml (range 60~160 ml). The mean duration of their hospital stay was 4.5 days (range 3-7 days). The operative incisions were healing well. Average follow up time was 40.1 months (range 24~72 months). The AVBHr was corrected from preoperative (48.1 ± 6.8) % to postoperative (94.1 ± 1.7) % (P < 0.001). The PVBHr was corrected from preoperative (62.7 ± 4.8) % to postoperative (92.8 ± 1.8) % (P < 0.001). Canal compromise was corrected from preoperative (37.3 ± 5.8) % to postoperative (5.9 ± 2.3) % (P < 0.001). The segmental kyphosis was corrected from preoperative (20.6 ± 5.3) degree to postoperative (2.0 ± 3.2) degree (P < 0.001). VAS scores were reduced from preoperative 7.21 ± 0.86 to 2.21 ± 0.98 at final follow up (P < 0.001). SF-36 Bodily pain was reduced from preoperative 75.31 ± 13.85 to 13.74 ± 13.24 at final follow up (P < 0.001), and SF-36 Role Physical was reduced from preoperative 59.21 ± 26.63 to 19.74 ± 22.94 at final follow up (P < 0.001). The ODI scores were reduced from preoperative 81.68 ± 4.44 to 15.37 ± 5.54 at final follow up (P < 0.001). All 4 patients with partial neurological deficit initially had improvement. Cement leakage was observed in 3 cases (two anterior to vertebral body and one into the disc without sequela). There were no instances of instrumentation failure and no patient had persistent postoperative back pain. CONCLUSIONS: Vertebroplasty and short pedicle screw fixation has the advantages of both radiographic and functional results for treating osteoporotic thoracolumbar severe burst fractures using a purely posterior approach.

[Pedicle screw at the fracture level and vertebroplasty via paraspinal approach for the treatment of old thoracolumbar fractures].

OBJECTIVE: To investigate the feasibility and safety of the treatment for thoracolumbar fractures with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. METHODS: From August 2007 to August 2010, 22 old patients with thoracolumbar fractures were treated with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. There were 14 males and 8 females, ranging in age from 60 to 71 years (mean, 64.6 years). The time from injury to surgery varied from 1 to 4 d (mean,2.7 d). All the patients suffered from single thoracolumbar fractures and located at T11 in 2 cases, at T12 in 5 cases, at L1 in 11 cases and at L2 in 4 cases. According to the Denis fracture classification, there were 6 compression fractures and 16 burst fractures. The mean preoperative load-sharing classification of spine fractures was 5.4 score. The mean preoperative thoracolumbar injury classification and scoring was 5.2. Based on the ASIA neurologic grading system, preoperative neurological function was grade B in 2 cases,grade C in 3 cases, grade D in 7 cases and grade E in 10 cases. The neurological function, vertebral central and anterior height, kyphotic angle of the vertebral fractures by radiographs and visual analog scale were calculated pre-operatively, post-operatively and at the last follow-up. RESULTS: Median operating time was 60.8 min (ranged from 50 to 95 min) and median blood loss was 84 ml (ranged from 50 to 130 ml). The operative incisions were healed well. The duration of follow-up averaged 21.6 months (ranged from 12 to 48 months). The anterior vertebral body height was corrected from preoperative (52.3 +/- 10.3) % to postoperative (6.1 +/- 4.2) % and (6.8 +/- 5.4) % at the last follow-up. The central vertebral body height was corrected from preoperative (38.9 +/- 11.2) % to postoperative (8.3 +/- 4.7) % and (9.4 +/- 4.5)% at the last follow-up. The Cobbs angle of the injured vertebral segment was corrected from preoperative (19.5 +/- 9.5) degrees to postoperative (4.3 +/- 4.1) degrees and (6.2 +/- 4.7) degrees at the last follow-up. The VAS scores reduced from preoperative 8.56 +/- 0.88 to post-operative 3.48 +/- 0.91 and 3.20 +/- 0.92 at the last follow-up. The postoperative neurologic function of all 22 patients improved 1 to 2 degrees except 10 patients of grade E. There were no instances of instrumentation failure and no patient had persistent postoperative back pain. CONCLUSION: The pedicle screw at the fracture level and vertebroplasty via paraspinal approach has the advantages of less invasive and blood loss, and could prevent the development of kyphosis and offers improvement of the spinal cord function. Furthermore, it could decrease the risks of postoperative back pain and the failure of instrumentation.