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ABSTRACT: A retrospective review and analysis of consecutive patients who underwent single-level vertebroplasty at our institute between March 2002 and March 2006.
To analyze the risk factors for subsequent fractures after vertebroplasty and to predict the postoperative fracture-free time and rate. The effect of bone cement volume injected was also evaluated.
Previous studies of subsequent fractures after vertebroplasty showed conflicting conclusions about risk factors. The frequency of refracture also varied, ranging from 12% to 52%. Most new fractures occurred at adjacent levels, with different risk factors identified. No data were available on the effect of injected bone cement volume, and no consensus had been reached as to the optimal cement volume.
All enrolled patients were treated with single-level vertebroplasty and followed a standardized postoperative care protocol. Data from medical records and radiographs were collected and analyzed. Variables included patient constitutional factors, radiographic parameters, and volume of injected bone cement.
A total of 166 patients (76 men, 90 women) with a mean age of 73.4 years were enrolled in this study. The mean follow-up time was 15.3 months. The overall refracture rate was 38%, with a mean fracture-free interval of 32 months. Both a greater volume of bone cement injected and a greater degree of vertebral height restored contributed significantly to the risk of subsequent adjacent fracture. No risk factor for subsequent remote fracture was identified. A greater volume of bone cement injected was positively correlated with deformity correction after vertebroplasty.
Most subsequent fractures occurred at the adjacent level within the first 3 months. Patient preoperative condition did not help predict refracture. Although a greater volume of bone cement injected when performing vertebroplasty contributed to the risk of subsequent adjacent fracture, it resulted in a greater improvement of kyphosis.
Spine 01/2011; 37(3):179-83. · 2.08 Impact Factor
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ABSTRACT: Musculoskeletal fibromatosis remains a disease of unknown etiology. Surgical excision is the standard of care, but the recurrence rate remains high. Superficial fibromatosis typically presents as subcutaneous nodules caused by rapid myofibroblast proliferation followed by slow involution to dense acellular fibrosis. In this study, we demonstrate that fibromatosis stem cells (FSCs) can be isolated from palmar nodules but not from cord or normal palm tissues. We found that FSCs express surface markers such as CD29, CD44, CD73, CD90, CD105, and CD166 but do not express CD34, CD45, or CD133. We also found that FSCs are capable of expanding up to 20 passages, that these cells include myofibroblasts, osteoblasts, adipocytes, chondrocytes, hepatocytes, and neural cells, and that these cells possess multipotentiality to develop into the three germ layer cells. When implanted beneath the dorsal skin of nude mice, FSCs recapitulated human fibromatosis nodules. Two weeks after implantation, the cells expressed immunodiagnostic markers for myofibroblasts such as α-smooth muscle actin and type III collagen. Two months after implantation, there were fewer myofibroblasts and type I collagen became evident. Treatment with the antifibrogenic compound Trichostatin A (TSA) inhibited the proliferation and differentiation of FSCs in vitro. Treatment with TSA before or after implantation blocked formation of fibromatosis nodules. These results suggest that FSCs are the cellular origin of fibromatosis and that these cells may provide a promising model for developing new therapeutic interventions.
PLoS ONE 01/2011; 6(8):e24050. · 4.09 Impact Factor
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ABSTRACT: For treatment of displaced transverse patellar fractures, open reduction and internal fixation is the standard reconstructive method. The role of percutaneous osteosynthesis is still unclear and worth of further investigation. Our hypothesis is that satisfactory reduction and rigid fixation is possible for the treatment of displaced transverse patellar fractures with some percutaneous techniques. Here, we present and evaluate a minimally invasive technique for these patellar fractures.
This is a retrospective study. Twenty-one patients with 21 transverse patellar fractures were treated with our percutaneous technique in acute phase. The minimally invasive surgery was achieved by closed reduction and fixation with modified Carpenter's technique, using figure-eight wiring through two parallel cannulated screws under the assistance of arthroscopy and fluoroscopy. The patients were followed up to an average of 38.8 months (range 26-48). Main outcome measurements included radiographic assessment, range of motion, Lysholm scores, complications, and reoperations.
Radiographically, all fractures healed at a mean of 11.0 weeks (range 9-13). Mean total range of motion of knee joint was 140.1° (range 127-152). Functional assessment of Lysholm scores was 93.9 points (range 86-100). Malreduction, loss of reduction, and infection were not observed in 21 patients. Complications were three cases (14%) of hardware irritation, and needed a second operation for removal.
Under the control of arthroscopy and fluoroscopy, we successfully treated 21 displaced transverse patellar fractures by percutaneously osteosynthesis. This is a safe and reproducible method for transverse patellar fractures. However, it is not indicated for severely comminuted fractures.
Archives of Orthopaedic and Trauma Surgery 12/2010; 131(7):949-54. · 1.37 Impact Factor
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ABSTRACT: This article describes the effect of closed reduction and internal fixation with 3 different screw configurations for acute completely displaced femoral neck fractures in young adults. From 2001 to 2006, 136 patients (age range, 20-50 years) who had acute unilaterally completely displaced femoral neck fractures were evaluated retrospectively. All fractures were managed with closed reduction and internal fixation with 3 cannulated screws. The follow-up period was 55 months on average (range, 36-90 months). One hundred twenty-two patients were available for final evaluation of union condition and late complication. Twenty-three patients (18.9%) had nonunion, 15 (12.3%) had fixation failure, and 21 (17.2%) had avascular necrosis of the femoral head. The average duration from injury to surgery was 18.4 hours in the union group and 23.3 hours in the nonunion group, with no statistical significance (P=.196). The average duration from injury to surgery was 17.3 hours in the avascular necrosis of the femoral head group and 22.3 hours in the non-avascular necrosis of the femoral head group, with no statistical significance (P=.155). Vertical- and separated-type screw configurations resulted in a significantly higher nonunion rate (P=.001 and P=.0017, respectively) than parallel configuration. The complication rate in treating completely displaced femoral neck fractures with internal fixation in young adults is high, and screw configuration may further affect results.
Orthopedics 12/2010; 33(12):873. · 2.66 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the effect of high-density foam (HDF) pads versus viscoelastic polymer (VP) pads in the prevention of pressure ulcer formation during spinal surgery and their cost-effectiveness. Subjects were 30 patients who underwent spinal surgery for more than 3 hr in a prone position. One side of the chest and iliac crest was padded with HDF pads and the other side was padded with VP pads. An Xsensor® pressure measuring sheet was placed between the pad and the patient. Bilateral chest and iliac crest points were observed for the presence of pressure ulcers at 30 min after the operation. Results showed that a pressure ulcer had occurred at 9 of 120 compression points (7.5% of the total), 30 min after the operation. Risk evaluation showed that female gender, weight <50 kg, and body mass index (BMI) <18 kg/m(2) as well as location (the iliac crest) were all risk factors for development of pressure ulcers. The most significant factor was BMI <18 kg/m(2). The average and peak pressures measured at the points padded with the VP pads were significantly lower than those padded with the HDF pads. However, there was no significant difference between the VP and the HDF pads regarding ulcer prevention. Because the cost of a VP pad is 250 times greater than that of an HDF pad of similar size, the VP pad should only be considered for use in high-risk patients.
Biological Research for Nursing 12/2010; 13(4):419-24. · 1.28 Impact Factor
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ABSTRACT: Trichostatin A (TSA) is a histone deacetylase inhibitor (HDACi) known to modulate differentiation of many cells. However, its effect on chondrogenesis remains elusive. This study was aimed to investigate the effects of TSA on in vitro transforming growth factor-β1 (TGF-β1)-induced chondrogenesis of human mesenchymal stem cells (hMSCs). The pellet cultures of hMSCs in a chondrogenic medium were exposed to TGF-β1 and TSA. Quantitative reverse transcription/polymerase chain reaction (PCR) analysis, Alcian blue staining, and immunohistochemistry staining were used to confirm and compare the differences in chondrogenesis by analyzing the mRNA of chondrogenic genes (Sox9, Aggrecan, and Col2A1), synthesis of chondrogenic proteins and type II collagen, respectively. TGF-β1 signaling and its downstream targets were determined by western blot analysis. TGF-β1 led to significant increases in chondrogenic gene expression and the synthesis of chondrogenic proteins. However, TSA significantly decreased chondrogenic gene expression and the synthesis of chondrogenic proteins in a dose-dependent manner. TGF-β1 increased phosphorylation of Smad 2/3 and Sp1 expression around half an hour after induction. The increase of Sp1, but not Smad 2/3 activation was almost completely blocked by the addition of TSA. The chondrogenic effect of TGF-β1 was also suppressed by the Sp1-binding inhibitor mithramycin A. Finally, overexpression of Sp1 abolished TSA-mediated inhibition of TGF-β1-induced chondrogenesis. Our study showed that TSA inhibited chondrogenesis through inhibition of TGF-β1-induced Sp1 expression. Furthermore, Sp1 could be a useful tool in future studies looking into biological mechanisms by which chondrogenesis of hMSCs can be augmented, especially in the area of clinical application.
Differentiation 11/2010; 81(2):119-26. · 2.81 Impact Factor
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ABSTRACT: Shoulder joint laxity over anteroinferior and posteroinferior labral–capsular structure inpatients with traumatic anterior glenohumeral instability was reported in the previous literature. The purpose of this study was to report our experience in arthroscopic treatment of traumatic anterior–inferior shoulder instability by Bankart lesion stabilisation with rotator interval closure and posteroinferior capsular plication.
From August 2000 to November 2004, 45 patients with traumatic anterior–inferior shoulder instability were retrospectively enrolled. Each shoulder was treated with absorbable suture for rotator interval closure and posteroinferior capsular plication after anteroinferior stabilisation. The assessments were performed using the Rowe score, the University of California at Los Angeles (UCLA) shoulder rating scale, the American Shoulder and Elbow Surgeons (ASES) score) and shoulder range of motion (ROM).
With the average follow-up time of 77.1 months, all shoulder scores improved after surgery(P < 0.001). The average ROM deficit of the operated shoulders was not significant (P > 0.05) as compared with the healthy side. A total of 42 shoulders remained stable (93.3%) and there were three recurrences (6.6%). All patients without recurrence returned to their pre-injury levels of athletic activity.
In patients with anterior glenohumeral instability, arthroscopic stabilisation of anteroinferior capsulolabral structure with rotator interval closure and posteroinferior capsular plication provided a reasonable result without significant loss of ROM at a minimum follow-up of 5 years.
Injury 10/2010; 41(10):1075-8. · 1.98 Impact Factor
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ABSTRACT: There has been minimal literature reporting on results of osteoporotic burst fracture with spinal canal compromise treated with percutaneous vertebroplasty. Vertebroplasty for treatment of osteoporotic burst fracture is controversial. We want to clarify whether the osteoporotic burst fracture with spinal canal compromise is a contraindication to percutaneous vertebroplasty. To compare the clinical and radiological results between osteoporotic burst and compression fractures treated with percutaneous vertebroplasty.
From 2005 through 2006, 23 osteoporotic burst fracture patients with asymptomatic spinal canal compromise and 41 osteoporotic compression fracture patients underwent percutaneous vertebroplasty. Pre- and post-operative pain scores, functional and radiographic results and complications were analyzed.
The average canal compromise in study group was 15% (5-49%). The mean post-operative Oswestry Disability Index (ODI), Visual Analogue Score (VAS), kyphotic angle, vertebral body height measurement from the anterior, central and posterior part of the body are all significantly improved in both the study and control groups when compared to pre-operative data. However, there was no significant difference between study and control groups in pre- and post-operative ODI, VAS, kyphotic angle and improvement of body height. There were no significant differences (P=0.3797) in cement leakage rate between burst and compression groups (47.8% vs 36.6%). All the leakages were minor and without neurological deficit. The percentage of adjacent fractures in both groups also had no significant differences (39.1% in burst and 41.5% in compression group).
Osteoporotic burst fracture with asymptomatic spinal canal compromise is not a contraindication for percutaneous vertebroplasty. This procedure is suitable for both osteoporotic burst and compression fracture with careful surgical technique.
Clinical neurology and neurosurgery 10/2010; 112(8):678-81. · 1.30 Impact Factor
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ABSTRACT: Displacement-controlled finite element analysis was used to evaluate the mechanical behavior of the lumbar spine after insertion of the Dynesys dynamic stabilization system.
This study aimed to investigate whether different depths of screw placement of Dynesys would affect load sharing of screw, range of motion (ROM), annulus stress, and facet contact force.
In clinical follow-up, a high rate of screw complications and adjacent segment disease were found after using Dynesys. The pedicle screw in the Dynesys system is not so easy to implant into the standard position and causes the screw to protrude more prominently from the pedicle. Little is known about how the biomechanical effects are influenced by the Dynesys screw profile.
The Dynesys was implanted in a 3-dimensional, nonlinear, finite element model of the L1 to L5 lumbar spine. Different depths of screw position were modified in this model by 5 and 10 mm out of the pedicle. The model was loaded to 150 N preload and controlled the same ROMs by 20, 15, 8, and 20 degrees in flexion, extension, torsion, and lateral bending, respectively. Resultant ROM, annulus stress, and facet contact force were analyzed at the surgical and adjacent level.
Under flexion, extension, and lateral bending, the Dynesys provided sufficient stability at the surgical level, but increased the ROM at the adjacent level. Under flexion and lateral bending, the Dynesys alleviated annulus stress at the surgical level, but increased annulus stress at the adjacent level. Under extension, the Dynesys decreased facet loading at the surgical level but increased facet loading at the adjacent level.
This study found that the Dynesys system was able to restore spinal stability and alleviate loading on disc and facet at the surgical level, but greater ROM, annulus stress, and facet loading were found at the adjacent level. In addition, profile of the screw placement caused only a minor influence on the ROM, annulus stress, and facet loading, but the screw stress was noticeably increased.
Journal of spinal disorders & techniques 08/2010; 23(6):410-7. · 1.21 Impact Factor
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ABSTRACT: Adult soft tissue sarcomas (STS) of extremities are prone to recurrence despite apparently complete resection. This study aimed to explore the impact of clinicopathological factors on outcome and to define an "oncological safe margin" in these patients.
A total of 181 patients with extremity STS were enrolled in a retrospective study. The prognostic influence of margin status and other clinicopathological characteristics on local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-specific survival (DSS), were examined by univariate and multivariate analyses. The influence of surgical margins on postrecurrence survival (PRS) of patients undergoing reoperation for relapsed lesions during follow-up was analyzed by the Kaplan-Meier method.
Surgical margin width <10 mm and deep tumor depth at primary operation were consistently statistically significant independent adverse factors for LRFS, DMFS, and DSS. Patients with liposarcoma or low grade tumors had significantly higher chances of achieving adequate margins. Of 83 patients who experienced recurrence or metastasis, 53 (63.9%) received reoperation for their relapsed lesions. Patients who achieved microscopically negative margins (R0) at reoperation had significantly better PRS than those who did not (P < 0.007). Overall, patients with no recurrences had the best DSS, while relapsed patients receiving R0 reoperation had better DSS than those receiving either non-R0 reoperation or no reoperation at all.
Surgical margins prognostically influence survival in both patients undergoing primary surgery and those undergoing reoperation for relapse of extremity STS. In primary surgery, the chance of achieving adequate margin may reflect the underlying aggressiveness of tumors.
Annals of Surgical Oncology 03/2010; 17(8):2102-11. · 4.17 Impact Factor
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ABSTRACT: Manipulation under anaesthesia (MUA) has been used to speed up recovery. However, the outcome of frozen shoulder after MUA in patients with diabetes has not been well documented in the past. A higher prevalence of frozen shoulder has been reported in diabetes mellitus (DM) patients. In this study, we revealed the short- and long-term outcomes for treatment of frozen shoulders by MUA and compared these results in patients with and without non-insulin dependent DM by adjusted Constant score. The scores showed no significant differences between the two groups at both early and late follow-ups. Our results revealed that MUA for frozen shoulders is a simple and noninvasive procedure to improve symptoms and shoulder function within a short period of time. Even though DM is a predisposing factor to frozen shoulder, non-insulin dependent DM alone does not influence both the short- and long-term outcomes of frozen shoulder.
International Orthopaedics 02/2010; 34(8):1227-32. · 2.03 Impact Factor
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ABSTRACT: We have previously isolated and identified stem cells from human anterior cruciate ligament (ACL). The purpose of this study was to evaluate the differences in proliferation, differentiation, and extracellular matrix (ECM) formation abilities between bone marrow stem cells (BMSCs) and ACL-derived stem cells (LSCs) from the same donors when cultured with different growth factors, including basic fibroblast growth factor (bFGF), epidermal growth factor, and transforming growth factor-beta 1 (TGF-beta1). Ligament tissues and bone marrow aspirate were obtained from patients undergoing total knee arthroplasty and ACL reconstruction surgeries. Proliferation, colony formation, and population doubling capacity as well as multilineage differentiation potentials of LSCs and BMSCs were compared. Gene expression and ECM production for ligament engineering were also evaluated. It was found that BMSCs possessed better osteogenic differentiation potential than LSCs, while similar adipogenic and chondrogenic differentiation abilities were observed. Proliferation rates of both LSCs and BMSCs were enhanced by bFGF and TGF-beta1. TGF-beta1 treatment significantly increased the expression of type I collagen, type III collagen, fibronectin, and alpha-smooth muscle actin in LSCs, but TGF-beta1 only upregulated type I collagen and tenascin-c in BMSCs. Protein quantification further confirmed the results of differential gene expression and suggested that LSCs and BMSCs increase ECM production upon TGF-beta1 treatment. In summary, in comparison with BMSCs, LSCs proliferate faster and maintain an undifferentiated state with bFGF treatment, whereas under TGF-beta1 treatment, LSCs upregulate major tendinous gene expression and produce a robust amount of ligament ECM protein, making LSCs a potential cell source in future applications of ACL tissue engineering.
Tissue Engineering Part A 02/2010; 16(7):2237-53. · 4.64 Impact Factor
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ABSTRACT: The role of the vertebral body's rotation and the loading conditions of the brace has not been clearly identified in adolescent idiopathic scoliosis. This study aimed to implement a finite element (FE) model of C-type scoliotic spines to investigate the influence of different loading conditions on variations of Cobb's angle and the vertebral rotation. The scoliotic FE model was constructed from C7 to L5, and its geometry was the right thoracic type (37.4°) with an apex over T7. Three loading conditions included a medial-lateral (ML) and anteroposterior (AP) force with a magnitudes of 100-0, 80-20 and 60-40 N. Those forces were respectively applied over the 6th, 7th and 8th ribs. According to an analysis of Cobb's angle, the 100 N ML force that was applied over the 8th rib could achieve the best correction effect. Furthermore, the ML force was dominant in alterations of Cobb's angle, whereas the AP force was dominant in alterations of the axial vertebral rotation. Additionally, the level below the apex was the most appropriate level to apply the force to correct C-type scoliosis.
Bio-medical materials and engineering 01/2010; 20(5):251-9. · 1.23 Impact Factor
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ABSTRACT: Children with spina bifida (SB) can exhibit excessive arm swing, trunk sway, and pelvic tilt during walking. To understand the relationship between abnormal low back forces (LBF) and gait disorders in SB, we derived a mathematical model for evaluating LBF in this population. One unimpaired child and a child with SB were tested. A 3D motion analysis system and force plate were used to collect kinematic and ground reaction force data during walking. A mathematical model created using MATLAB software was used to calculate LBF for each child. The LBF for the child with SB was three times greater in the medio-lateral direction than for the unimpaired child. In the anterior-posterior direction, the LBF for the child with SB acted mostly towards the anterior trunk. In addition, the LBF of the child with SB increased by 24.5% of body weight at the fastest walking speed.
Gait & posture 08/2009; 30(3):388-90. · 2.58 Impact Factor
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ABSTRACT: A retrospective study of the clinical results of conservative treatment of patients with acute postoperative deep spinal infection.
To determine the efficacy of antibiotic only treatment of postoperative deep spinal infection.
Traditionally, aggressive surgical treatment combined with antibiotics has been viewed as the gold standard for treating postoperative deep spinal infection. There are, however, disadvantages to surgical treatment including higher treatment cost, multiple anesthesia and surgeries, and the risk of perioperative morbidity and mortality particularly in immunocompromised patients. Although many new antibiotics and new methods of antibiotic treatment have recently become available, the role of conservative treatment using antibiotics alone to treat postoperative acute infection has not yet been determined.
Ten consecutive patients with acute postoperative spinal infection were treated using antibiotics alone. The mean onset of the symptoms of infection after surgery was 15.4 days (range, 5-18 days). Seven patients had purulent wound drainage; 3 had healed wounds without discharge. Bacterial culture of the discharge showed methicillin-resistant Staphylococcus aureus (1 patient), methicillin-resistant coagulase negative Staphylococcus (4 patients), methicillin-sensitive coagulase negative Staphylococcus (1 patient). One patient had a negative culture. Patients with wound drainage were treated with intravenous vancomycin or teicoplamin for 4 to 6 weeks followed by oral antibiotics (quinolone with/without rifampin) for 1 to 3 months. All other patients were treated with oral antibiotics for 3 months.
One patient could not complete treatment because of allergy to antibiotics. Infection was controlled in the remaining patients without surgical intervention and did not reoccur. All wound drainage ceased within 2 weeks. The C-reactive protein level of most patients returned to normal range within 10 weeks.
Antibiotic treatment alone may be effective in the treatment of acute postoperative spinal infection when diagnosis is prompt. Aggressive surgery may be not necessary and may be reserved for patients who fail conservative treatment.
Spine 11/2008; 33(22):2473-8. · 2.08 Impact Factor
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ABSTRACT: Preliminary reporting of a group of patients with multiple level cervical spinal stenosis treated with a simple technique using lateral mass anchoring screw and unabsorbable suture line for securing the lamina position after expansive open-door laminoplasty.
To develop an improved method for laminoplasty fixation.
Laminoplasty is considered the standard procedure for treating multiple-level cervical spinal stenosis with myelopathy. Keys to successful laminoplasty are expanding and maintaining the spinal canal. There are many techniques for maintaining and securing of the expanded spinal canal such as fascial or joint capsule anchoring suture, spacer interposition, allograft, autograft, or miniplate fixation. However, many reports have indicated that these complicated and/or costly techniques are not superior to other techniques. This study reports a simple, reliable technique using a lateral mass anchoring screw for augmentation of laminoplasty fixation.
Five patients with multiple level cervical spinal stenosis underwent laminoplasty. A unilateral open door technique was done for the lesion level and the elevated lamina was fixed to lateral mass anchoring screws at each level using unabsorbable suture line.
The mean follow-up period was 14.5 months (9 to 34 mo). Postoperatively, the Japanese Orthopedic Association score improved from an average of 8.6 (range: 7 to10 points) to 14.2 points (range: 13 to 15 points). The average recovery rate was 67% (60% to 75%). Follow-up computed tomography scans showed the average improvement in anterioposterior diameter at each level of the cervical canal to be about 4.0 to 7.7 mm. The average open angle at each level was 19.0 to 23.8 degrees. All hinged sides had bony fusion.
Although this is a small series, the preliminary results suggest that this simple lateral mass anchoring screw technique can provide a firm and secure anchor for elevated open lamina in laminoplasty.
Journal of spinal disorders & techniques 09/2008; 21(6):387-92. · 1.21 Impact Factor
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ABSTRACT: A retrospective study to evaluate the clinical results of patients with osteoporosis and various spinal diseases treated surgically with polymethylmethacrylate (PMMA) augmented pedicle screw.
To report a novel technique using PMMA for pedicle screw augmentation in osteoporotic spinal surgery.
Many studies have proved that the stiffness and strength of pedicle screw fixation can be significantly increased when the pedicle screw is augmented with various cements. However, most of those studies were experimental. Clinical reports using those materials for pedicle screw augmentation are rare and a practical and reliable technique for primary pedicle screw augmentation with cement has not yet been established.
Forty-one patients [23 female, 18 male, mean age 75.1 (50-90) years] with osteoporosis and various spinal diseases underwent spinal decompression and instrumentation with PMMA augmentation of pedicle screw. Pre-and postoperative scores for visual analogue scale for pain and Oswestry disability index questionnaire were analyzed. The screw migration, which is the distance from the screw tip to the anterior cortex and upper endplate of vertebra, was also evaluated immediately after the operation and at the mean 22.3 months final follow-up. RESULTS.: Totally 291 of 300 screws were augmented with PMMA. There was neither neurologic deterioration nor symptomatic cement leakage after surgery. The mean visual analogue scale pain score of these patients improved from 9.2 to 1.5 (P < 0.01) and the functional Oswestry disability index score improved from 77.5% to 44.2% (P < 0.01). Kyphotic deformity was improved from average 23.2 degrees to 11.9 degrees after surgery, and to 14.9 degrees at final follow-up (P < 0.01). The average loss of kyphosis correction was 3 degrees. There was no significant screw migration when the screws distances just after operation and at the final follow-up were compared (P > 0.01).
The presented technique of PMMA for augmentation of pedicle screw is a safe, reliable, and practical technique for osteoporotic patients who also had various spinal diseases and need spinal instrumentation.
Spine 05/2008; 33(10):E317-24. · 2.08 Impact Factor
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ABSTRACT: The natural history of congenital scoliosis with hemivertebrae is unpredictable and the management is also controversial.
Between 1986 and 2004, 22 patients (eight male and fourteen female, mean 19.3 years old) with single-level hemivertebrae related congenital scoliosis underwent non-operative or operative treatment at our institution with an average follow-up period of 8.8 years.
Only a 5 degrees curve progression was noted in upper thoracic hemivertebrae after followed up 6 years. By one stage combined anterior hemivertebrae excision, posterior instrumentation, and arthrodesis, up to 61% curve correction can be achieved. Posterior instrumentation, correction and arthrodesis showed a 25% correction. The result of pain relief is promising in skeletal-matured patients.
Surgical instrumentation, correction and arthrodesis showed good results. The optimal treatment of choice may differed from one to the other.
Archives of Orthopaedic and Trauma Surgery 05/2008; 129(4):431-8. · 1.37 Impact Factor
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ABSTRACT: Osteoarthritis and osteoporosis are the two most common musculoskeletal diseases found in the aged population. It is of interest to measure and study the material properties of the femoral head and neck of these two groups, and hopefully to offer explanation of the observed phenomenon that most patients suffer from one of the two disorders, not both.
Seven osteoarthritic and seven osteoporotic femoral heads were used for this study. The principal compressive region of the femoral heads were cut to determine the Young's modulus and yielding stress by a material testing machine. Comparisons between these two groups were conducted by using material properties and the properties normalized by individual patient physical parameters, including body weight, body height and femoral head diameter, respectively. The finite element model of femoral neck cuboid in OA and OP were obtained based on the micro-CT-scan cross-section. The intrinsic material properties were calculated from the solid FE models.
The results showed significant differences in density, modulus and strength between the osteoarthritic and osteoporotic femoral heads as measured, with the former having 2-3 times the values of the latter. Femoral head diameter has stronger influence in mechanical properties than patient's body weight and body height. Regarding to bone volume (BV), bone surface (BS), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and true trabecular elastic modulus, the intrinsic material properties of femoral neck with OA were higher than OP.
It is still unknown why patients do not suffer from both osteoporosis and osteoarthritis at the same time. Many studies aimed to investigate the mechanical property of two groups. However, individual difference of the femoral head and neck is too difficult to obtain a reasonable comparison between these two groups. This study investigated the two groups more quantitatively and further estimated the factors which influence mechanical properties from a biomechanical point of view.
Clinical Biomechanics 02/2008; 23 Suppl 1:S39-47. · 2.07 Impact Factor
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ABSTRACT: De Quervain's tenosynovitis is often observed on repetitive flexion of the thumb. In the clinical setting, the conservative treatment is usually an applied thumbspica splint to immobilize the thumb. However, the traditional thumbspica splint is bulky and heavy. Thus, this study used the finite element (FE) method to remove redundant material in order to reduce the splint's weight and increase ventilation. An FE model of a thumbspica splint was constructed using ANSYS9.0 software. A maximum lateral thumb pinch force of 98 N was used as the input loading condition for the FE model. This study implemented topology optimization and design optimization to seek the optimal thickness and shape of the splint. This new design was manufactured and compared with the traditional thumbspica splint. Ten thumbspica splints were tested in a materials testing system, and statistically analyzed using an independent t test. The optimal thickness of the thumbspica splint was 3.2 mm. The new design is not significantly different from the traditional splint in the immobilization effect. However, the volume of this new design has been reduced by about 35%. This study produced a new thumbspica splint shape with less volume, but had a similar immobilization effect compared to the traditional shape. In a clinical setting, this result can be used by the occupational therapist as a reference for manufacturing lighter thumbspica splints for patients with de Quervain's tenosynovitis.
Medical & Biological Engineering & Computing 01/2007; 44(12):1105-11. · 1.88 Impact Factor
