scholarly journals Pullout strength of adjusting pedicle screw with or without self-bone grafting in the previous trajectory using an osteoporotic human vertebral body

2020 ◽  
Author(s):  
Sen Liu ◽  
Jia Li ◽  
Hong-Yang Gao ◽  
Wei Wang ◽  
Wei Dong ◽  
...  

Abstract Objectives The aim of this study is to explore the pullout strength of adjusting pedicle screw with or without self-bone grafting in the previous trajectory using an osteoporotic human vertebral body. Methods Thirty vertebrae from six cadavers were collected and all of the vertebrae were divided into two groups according to bone mineral density: control group with normal bone mineral density; osteoporosis group with osteoporosis. The osteoporosis group was randomly and evenly divided into five subsamples according to direction of reinsert pedicle screw: the normal angle, sagittal angle, sagittal bone grafting, horizontal angle, horizontal bone grafting. Axial pullout strength testing of the pedicle screw was performed and the maximum axial pullout force (Fmax) was applied to analyse. Result The bone mineral density of the control group was 1.115±0.065 g/cm3, and the bone mineral density of the osteoporosis group was 0.678±0.055 g/cm3, presenting significantly different between the two group (P<0.001). Compared with the control group, the Fmax of the normal angle group was smaller (600.64±43.10 vs 1100.74±49.08 N, P<0.001). Compared with the normal angle group, the Fmax of the sagittal angle group (339.13±38.90 vs 600.64±43.10 N, P<0.001) and the horizontal angle group (342.06±33.01 vs 600.64±43.10 N, P<0.001) were smaller. The Fmax in sagittal bone grafting group was higher than that with non-implanted bone in primary screw canal (492.30±42.06 vs 342.06±33.01 N, P<0.001), and the Fmax of the horizontal bone grafting group was higher than that with non-implanted bone in primary screw canal (502.02± 50.26 vs 342.06±33.01 N, P<0.001). Conclusion The pullout strength of adjusting pedicle screw is seriously decreased in osteoporotic human vertebral body and self-bone grafting in the previous trajectory is an effective remedial measure.

2009 ◽  
Vol 11 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Mario J. Cardoso ◽  
Anton E. Dmitriev ◽  
Melvin D. Helgeson ◽  
Frederick Stephens ◽  
Victoria Campbell ◽  
...  

Object Transpedicular instrumentation at C-7 has been well accepted, but salvage techniques are limited. Lamina screws have been shown to be a biomechanically sound salvage technique in the proximal thoracic spine, but have not been evaluated in the lower cervical spine. The following study evaluates the anatomical feasibility of lamina screws at C-7 as well as their bone-screw interface strength as a salvage technique. Methods Nine fresh-frozen C-7 cadaveric specimens were scanned for bone mineral density using dual energy x-ray absorptiometry. Prior to testing, all specimens were imaged using CT to obtain 1-mm axial sections. Caliper measurements of both pedicle width and laminar thickness were obtained. On the right side, pedicle screws were first inserted and then pulled out. Salvage intralaminar screws were inserted into the left lamina from the right spinous process/lamina junction and then pulled out. All screws were placed by experienced cervical spine surgeons under direct fluoroscopic visualization. Pedicle and lamina screws were 4.35- and 3.5-mm in diameter, respectively. Screws sizes were chosen based on direct and radiographic measurements of the respective anatomical regions. Insertional torque (IT) was measured in pounds per inch. Tensile loading to failure was performed in-line with the screw axis at a rate of 0.25 mm/sec using a MiniBionix II system with data recorded in Newtons. Results Using lamina screws as a salvage technique generated mean pullout forces (778.9 ± 161.4 N) similar to that of the index pedicle screws (805.3 ± 261.7 N; p = 0.796). However, mean lamina screw peak IT (5.2 ± 2.0 lbs/in) was significantly lower than mean index pedicle screw peak IT (9.1 ± 3.6 lbs/in; p = 0.012). Bone mineral density was strongly correlated with pedicle screw pullout strength (r = 0.95) but less with lamina screw pullout strength (r = 0.04). The mean lamina width measured using calipers (5.7 ± 1.0 mm) was significantly different from the CTmeasured mean lamina width (5.1 ± 0.8 mm; p = 0.003). Similarly, the mean pedicle width recorded with calipers (6.6 ± 1.1 mm) was significantly different from the CT-measured mean pedicle width (6.2 ± 1.3 mm; p = 0.014). The mean laminar width measured on CT at the thinnest point ranged from 3.8 to 6.8 mm, allowing a 3.5-mm screw to be placed without difficulty. Conclusions These results suggest that using lamina screws as a salvage technique at C-7 provides similar fixation strength as the index pedicle screw. The C-7 lamina appears to have an ideal anatomical width for the insertion of 3.5-mm screws commonly used for cervical fusions. Therefore, if the transpedicular screw fails, using intralaminar screws appear to be a biomechanically sound salvage technique.


1998 ◽  
Vol 39 (5) ◽  
pp. 538-542 ◽  
Author(s):  
R. Andresen ◽  
S. Radmer ◽  
D. Banzer

Objective: the clinical value of spinal quantitative CT (sQCT) and the structural patterns of the vertebral bone were studied Material and Methods: sQCT was performed on 246 patients with a mean age of 57 years for whom conventional lateral radiographies of the thoracic and lumbar spine were available. All patients were suffering from back pain of unknown etiology. the bone mineral density (BMD) of the midvertebral section of 3 lumbar vertebral bodies was determined by means of single-energy-(SE)-weighted QCT (85 kV). Spongiosa architecture and density profile analyses were made in the axial images. This was contrasted to BMD values ascertained in SE QCT. the mean BMD was compared to the number of fractures and the patients were divided into three groups: group I — no fracture; group II — one fracture; and group III 1 fracture Results: the mean BMD was: 134.3 (74.1–187.5) mg hydroxyapatite (HA)/ml in group I; 79.6 (58.6–114.3) mg HA/ml in group II; and 52.4 (13.1–79.1)mg HA/ml in group III. A significant deterioration in spongiosa structure was found with increasing demineralization: strongly rarefied patterns predominated in the fracture groups II and III Conclusion: sQCT provides a good risk assessment of the occurrence of vertebral body insufficiency fractures


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
A. Sánchez ◽  
L. R. Brun ◽  
H. Salerni ◽  
P. R. Costanzo ◽  
D. González ◽  
...  

The aim of this study was to evaluate the effect of denosumab (Dmab) on bone mineral density (BMD) and bone turnover markers after 1 year of treatment. Additionally, the effect of Dmab in bisphosphonate-naïve patients (BP-naïve) compared to patients previously treated with bisphosphonates (BP-prior) was analyzed. This retrospective study included 425 postmenopausal women treated with Dmab for 1 year in clinical practice conditions in specialized centers from Argentina. Participants were also divided according to previous bisphosphonate treatment into BP-naïve and BP-prior. A control group of patients treated with BP not switched to Dmab matched by sex, age, and body mass index was used. Data are expressed as mean ± SEM. After 1 year of treatment with Dmab the bone formation markers total alkaline phosphatase and osteocalcin were significantly decreased (23.36% and 43.97%, resp.), as was the bone resorption marker s-CTX (69.61%). Significant increases in BMD were observed at the lumbar spine, femoral neck, and total hip without differences between BP-naïve and BP-prior. A better BMD response was found in BP-prior group compared with BP treated patients not switched to Dmab.Conclusion. Dmab treatment increased BMD and decreased bone turnover markers in the whole group, with similar response in BP-naïve and BP-prior patients. A better BMD response in BP-prior patients versus BP treated patients not switched to Dmab was observed.


2013 ◽  
Vol 141 (5-6) ◽  
pp. 329-332 ◽  
Author(s):  
Milena Dimic ◽  
Aleksandar Dimic ◽  
Zoran Milosevic ◽  
Jelena Vojinovic

Introduction. Vitamin D active metabolites deficit that is altered by negative calcium and phosphorus balance is a potential complication during long?term antiepileptic drug therapy. Objective. The aim of this study was to examine lumbar bone mineral density (BMD) in epileptic children receiving antiepileptic drug therapy longer than one year. methods. The examined sample consisted of 34 epileptic children, 18 male and 16 female, aged 6?12 (9.77?2.01) years, treated with carbamazepine, valproate, phenobarbital, lamotrigine or their combination without vitamin D supplementation. The lumbar spine BMD (L1?L4) was estimated by a Lunar densitometer and obtained results were compared with results of 35 matched population of healthy children from the control group. results. Lumbar BMD Z?score was significantly lower in female patients treated with antiepileptic therapy compared with those in the control group (?1.048?1.35 vs. ?0.399?0.518; p=0.03). Bone mineral density Z?score decrease of both gender groups receiving antiepileptic polytherapy was significantly lower compared to the control group (?1.153?0.938 vs. ?0.043?0.815; p=0.007). Therapy duration had no influence on the lumbar BMD level decrease either in boys (rxy=0.33; p=0.174) or in girls (rxy=0.02; p=0.935) treated with antiepileptic therapy. Conclusion. Our results have indicated that antiepileptic drug therapy usage longer than one year can have adverse affects on the lumbar spine BMD (L1?L4) in epileptic children, and that prophylactic vitamin D supplementation is also necessary in these patients.


2019 ◽  
Vol 5 (1) ◽  
pp. 30
Author(s):  
Edy Waliyo ◽  
Nopriantini Nopriantini ◽  
Shelly Festilia Agusanty

Abstract: Effect of Lampung Banana Potassium on Bone Mineral Density in the Elderly. This study aims to determine the effect of banana lampung on bone mineral density in the elderly in the Social Welfare Tresna Werdha and Werdha Graha Kasih Father’s home). This research is a research with experimental design with the separate sample pretest posttest control group design. The research was carried out in the Tresna Werdha Social Institution and the Werdha Graha Kasih Father’s house, from May to July 2017. The sampling technique was taken by random sampling The result of potassium feeding on 150 grams of banana per day for 30 days by increasing BMD T-score of 0.17 while in control group (without banana lampung) BMD T-score decreased by - 0.32. After intervention in both groups showed a difference of BMD T-score of 0.49. Abstrak: Pemberian Kalium Buah Pisang Lampung terhadap Densitas Mineral Tulang pada Lansia. Penelitian ini bertujuan untuk mengetahui mengetahui pengaruh pemberian buah pisang lampung terhadap bone mineral density pada lansia di wilayah Panti Sosial Tresna Werdha dan panti Werdha Graha Kasih Bapa). Penelitian yang dilakukan ini adalah penelitian dengan desain eksperimen dengan rancangan the separate sample pretest posttest control group design. Penelitian dilaksanakan di wilayah Panti Sosial Tresna Werdha dan panti Werdha Graha Kasih Bapa), mulai bulan Mei s/d Juli 2017. Teknik sampling diambil dengan cara random sampling Hasil pemberian kalium pada buah pisang lampung sebanyak 150 gr setiap hari selama 30 hari dengan dapat meningkatkan BMD T-score sebesar 0,17 sedangkan pada kelompok control (tanpa pemberian buah pisang lampung) BMD T-score menurun sebesar - 0,32. Setelah intervensi pada ke dua kelompok menunjukkan adanya perbedaan BMD T-score sebesar 0,49.


Author(s):  
Guilherme Henrique de Lima Matias ◽  
◽  
André dos Santos Costa ◽  
Romulo Maia Carlos Fonseca

Objective: To verify the effect of recreational soccer on bone mineral density and sarcopenia in the elderly. Methods: Fourteen elderly people aged 65.9 ± 3.4 years were selected. They were separated into two groups: the intervention group and the control group; the intervention group played recreational soccer for 12 weeks on two days of the week. Assessments were performed for bone mineral density and body muscle mass before and after the intervention. For statistical analysis, the repeated measures ANOVA with Bonferroni’s post hoc test was used. Results: After 12 weeks, there was a significant change in bone mineral density in the region of the total femur (p = 0.020). Analyzing the participants’ sarcopenia, no significant results were found after the intervention period. Conclusion: Playing recreational soccer causes a significant improvement in the total femur and maintains bone regions in the spine, whole body, and femoral neck. Also, it promotes a removal from the threshold for sarcopenia screening in the elderly.


2021 ◽  
Author(s):  
Keiji Kamo ◽  
Hiroaki Kijima ◽  
Koichiro Okuyama ◽  
Tetsuya Kawano ◽  
Nobutoshi Seki ◽  
...  

Abstract Background: Bone mineral density (BMD) of the proximal femur around the stem decreases due to stress shielding after cementless total hip arthroplasty (THA). When severe stress shielding occurs, the risk of periprosthetic femoral fractures increases, and this bone loss can also increase the difficulty of future revision THA. Denosumab is known to improve the quality and strength of cortical bone in the proximal femurs of patients with osteoporosis. The purpose of this study was to investigate whether denosumab prevents loss of proximal femoral periprosthetic BMD in cementless THA using a tapered wedge stem in patients with osteoporosis.Methods: Sixty-three consecutive patients who had undergone unilateral primary THA using a tapered wedge stem were included in this retrospective study. Twenty-four patients who received denosumab for osteoporosis were the denosumab group, and the 39 without denosumab were the control group. At 2 weeks, 6 months, and 12 months after THA, bone turnover markers and femoral periprosthetic BMD were measured.Results: BMD in zone 1 was significantly increased from baseline at both 6 and 12 months after THA in the denosumab group and significantly decreased in the control group. BMD in zone 7 was significantly decreased compared to baseline at both 6 and 12 months after THA in the control group, but not in the denosumab group. The use of denosumab for THA patients with osteoporosis was independently related to preventing loss of periprosthetic BMD of the femur at 12 months after surgery in zones 1 and 7 on multivariate analysis.Conclusions: Denosumab significantly increased proximal femoral periprosthetic BMD in zone 1 and prevented loss of BMD in zone 7 in patients with osteoporosis after cementless THA using a tapered wedge stem at both 6 and 12 months after surgery.


2005 ◽  
Vol 185 (3) ◽  
pp. 415-420 ◽  
Author(s):  
S Mohan ◽  
D J Baylink

Although it is well established that there is considerable inter-individual variation in the circulating levels of IGF-I in normal, healthy individuals and that a genetic component contributes substantially to this variation, the direct evidence that inter-individual variation in IGF-I contributes to differences in peak bone mineral density (BMD) is lacking. To examine if differences in IGF-I expression could contribute to peak BMD differences, we measured skeletal changes at days 23 (prepubertal), 31 (pubertal) and 56 (postpubertal) in mice with haploinsufficiency of IGF-I (+/−) and corresponding control mice (+/+). Mice (MF1/DBA) heterozygous for the IGF-I knockout allele were bred to generate +/+ and +/− mice (n=18–20 per group). Serum IGF-I was decreased by 23% (P<0.001) in mice with IGF-I haploinsufficiency (+/−) group at day 56 compared with the control (+/+) group. Femoral bone mineral content and BMD, as determined by dual energy X-ray absorptiometry, were reduced by 20% (P<0.001) and 12% respectively in the IGF-I (+/−) group at day 56 compared with the control group. The peripheral quantitative computed tomography measurements at the femoral mid-diaphysis revealed that periosteal circumference (7%, P<0.01) and total volumetric BMD (5%, P<0.05) were decreased significantly in the +/− group compared with the +/+ group. Furthermore, serum IGF-I showed significant positive correlations with both areal BMD (r=0.55) and periosteal circumference (r=0.66) in the pooled data from the +/+ and +/− groups. Our findings that haploinsufficiency of IGF-I caused significant reductions in serum IGF-I level, BMD and bone size, together with the previous findings, are consistent with the notion that genetic variations in IGF-I expression could, in part, contribute to inter-individual differences in peak BMD among a normal population.


2020 ◽  
Author(s):  
Melina Bellini ◽  
Michael Andrew Pest ◽  
Manuela Miranda Rodrigues ◽  
Ling Qin ◽  
Jae-Wook Jeong ◽  
...  

Abstract Background: Osteoarthritis (OA) is the most common form of arthritis and characterized by degeneration of articular cartilage. Mitogen-inducible gene 6 (Mig-6) has been identified as a negative regulator of the Epidermal Growth Factor Receptor (EGFR). Cartilage-specific Mig-6 knockout (KO) mice display increased EGFR signaling, an anabolic buildup of articular cartilage and formation of chondro-osseous nodules. Since our understanding of the EGFR/Mig-6 network in cartilage remains incomplete, we characterized mice with cartilage-specific overexpression of Mig-6 in this study. Methods: Utilizing knee joints from cartilage-specific Mig-6 overexpressing (Mig-6over/over) mice (at multiple time points), we evaluated the articular cartilage using histology, immunohistochemical staining and semi-quantitative histopathological scoring (OARSI) at multiple ages. MicroCT analysis was employed to examine skeletal morphometry, body composition, and bone mineral density.Results: Our data show that cartilage-specific Mig-6 overexpression did not cause any major developmental abnormalities in articular cartilage, although Mig-6over/over mice have slightly shorter long bones compared to the control group. Moreover, there was no significant difference in bone mineral density and body composition in any of the groups. However, our results indicate that Mig-6over/over male mice show accelerated cartilage degeneration at 12 and 18 months of age. Immunohistochemistry for SOX9 demonstrated that the number of positively stained cells in Mig-6over/over mice was decreased relative to controls. Immunostaining for MMP13 appeared increased in areas of cartilage degeneration in Mig-6over/over mice. Moreover, staining for phospho-EGFR (Tyr-1173) and lubricin (PRG4) was decreased in the articular cartilage of Mig-6over/over mice. Conclusion: Overexpression of Mig-6 in articular cartilage causes no major developmental phenotype; however, these mice develop earlier OA during aging. These data demonstrate that Mig-6/EGFR pathways is critical for joint homeostasis and might present a promising therapeutic target for OA.


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