Analysis of Bone Mineral Density and Area of Newly Formed Bone Around Implants Using Micro-CT After Pull-Out Tests

We have developed a new Ti alloy, Ti-15%Zr-4%Nb-4%Ta alloy (Ti-15-4-4) that showed higher biological safety and mechanical properties than the currently used Ti-6%Al-4%V alloy. The purpose of this study is to determine the biological performance of the new alloy. Ti-15-4-4 implants (machined or blasted) were placed in surgically created defects in rabbit femurs. The rabbits were sacrificed after 4, 8, 16, 24 and 48 weeks. Bone mineral density (BMD) and area of newly formed bone around the implants were measured using micro-CT. Results showed that the Ti-15-4-4 alloy is biocompatible and forms new bone around the Ti-15-4-4 implant, regardless of the surface treatment. The BMD and area of newly formed bone around the blasted implant surfaces were significantly greater than those around the machined surfaces. These results indicate that the new Ti-15-4-4 alloy has a potential for use as implants and has the advantage of improved mechanical properties described in earlier studies.

Download Full-text

Anchor Design and Bone Mineral Density Affect the Pull-Out Strength of Suture Anchors in Rotator Cuff Repair

The American Journal of Sports Medicine ◽

10.1177/0363546503262644 ◽

2004 ◽

Vol 32 (6) ◽

pp. 1466-1473 ◽

Cited By ~ 120

Author(s):

Markus J. Tingart ◽

Maria Apreleva ◽

Janne Lehtinen ◽

David Zurakowski ◽

Jon J. P. Warner

Keyword(s):

Bone Mineral Density ◽

Rotator Cuff ◽

Bone Mineral ◽

Rotator Cuff Repair ◽

Suture Anchors ◽

Mineral Density ◽

Pull Out ◽

Anchor Design ◽

Cuff Repair ◽

Pull Out Strength

Download Full-text

Correlation between the Computed Tomography Values of the Screw Path and Pedicle Screw Pullout Strength: An Experimental Study in Porcine Vertebrae

Asian Spine Journal ◽

10.31616/asj.2019.0170 ◽

2020 ◽

Vol 14 (3) ◽

pp. 265-272

Author(s):

Atsushi Ikeura ◽

Taketoshi Kushida ◽

Kenichi Oe ◽

Yoshihisa Kotani ◽

Muneharu Ando ◽

...

Keyword(s):

Computed Tomography ◽

Bone Mineral Density ◽

Pedicle Screw ◽

Bone Mineral ◽

Lumbar Vertebrae ◽

Pedicle Screws ◽

Mineral Density ◽

Screw Insertion ◽

Pull Out ◽

Pull Out Strength

Study Design: Biomechanical study.Purpose: To assess the correlation between the computed tomography (CT) values of the pedicle screw path and screw pull-out strength.Overview of Literature: The correlation between pedicle screw pull-out strength and bone mineral density has been well established. In addition, several reports have demonstrated a correlation between bone mineral density and CT values. However, no previous biomechanical studies investigated the correlation between CT values and pedicle screw pull-out strength.Methods: Sixty fresh-frozen lumbar vertebrae from 6-month-old pigs were used. Before screw insertion, the CT values of the screw path were obtained for each sample. Specimens were then randomly divided into three equal groups. Each group had one of three pedicle screws inserted: 4.0-mm LEGACY (4.0-LEG), 4.5-mm LEGACY (4.5-LEG), or 4.5-mm SOLERA (4.5-SOL) (all from Medtronic Sofamor Danek Inc., Memphis, TN, USA). Each screw had a consistent 30-mm thread length. Axial pull-out testing was performed at a rate of 1.0 mm/min. Correlations between the CT values and pedicle screw pull-out strength were evaluated using Pearson’s correlation coefficient analysis.Results: The correlation coefficients between the CT values of the screw path and pedicle screw pull-out strength for the 4.0-LEG, 4.5-LEG, and 4.5-SOL groups were 0.836 (p <0.001), 0.780 (p <0.001), and 0.873 (p <0.001), respectively. Greater CT values were associated with greater screw pull-out strength.Conclusions: The CT values of the screw path were strongly positively correlated with pedicle screw pull-out strength, regardless of the screw type and diameter, suggesting that the CT values could be clinically useful for predicting pedicle screw pull-out strength.

Download Full-text

Changes in Local Bone Mineral Density in Patients With Rupture of the Anterior Cruciate Ligament and Its Guiding Significance for Treatment

10.21203/rs.3.rs-33751/v1 ◽

2020 ◽

Author(s):

Hao Liu ◽

Sanjun Gu ◽

Jun Liu ◽

Yongwei Wu ◽

Yongjun Rui

Keyword(s):

Bone Mineral Density ◽

Bone Mineral ◽

Cruciate Ligament ◽

Lysholm Score ◽

Mineral Density ◽

Pull Out ◽

Local Bone ◽

History Of ◽

Healthy Side ◽

Anterior Cruciate

Abstract Background:It is recognized that there are many factors that affect the outcomes of anterior cruciate ligament(ACL) reconstruction. However, there were few studies on the effect of local bone conditions on the reconstruction of the ACL. This study aimed to summarize the changes in local bone mineral density (BMD) of the knee after rupture of the ACL and to guide the treatment. Methods: Eighty patients with ACL rupture treated in our department from January 2017 to April 2019 were routinely measured for local bone mineral density before surgery, and according to the bone mineral density, the appropriate method of ligament reconstruction and fixation under arthroscopy was selected: if the local bone mineral density of the affected knee was not significantly lower than that of the healthy side, squeeze fixation was used, and suspension fixation was used when the local bone mineral density of the affected knee was lower than that of the healthy knee. The conditions of tunnel cutting or screw splitting and tunnel enlargement or screw pull-out were observed during the operation, and the fixation mode was adjusted in time according to the situation. The function of the knee joint was evaluated regularly by physical examination, imaging data, the IKDC scale and the Lysholm score table after the operation. Results:A total of 80 patients with unilateral ACL rupture were included in this group. There were 44 males and 36 females. Sixty-eight patients had decreased bone mineral density in the affected knee. The bone mineral density of patients with a history of more than 3 months was lower than that of patients with a history of less than 3 months. Tunnel enlargement and screw pull-out occurred in 2 patients, screw splitting occurred in 1 patient, and no adverse conditions occurred in the rest of the patients. In 3 patients, the fixation mode was adjusted in time during the operation. The patients were followed for 12 months (mean 20.65±5.12 months). The IKDC score increased from 43.07±2.66 before the operation to 89.17±3.28 at the final follow-up, and the Lysholm score increased from 43.49±2.38 to 89.67±2.97. Conclusions:The measurement of local bone mineral density before surgery is of guiding significance for the selection of reconstruction and fixation of the ACL. It is recommended that patients undergo surgical reconstruction within 3 months after injury. When the bone mineral density of the affected knee decreases significantly to at least 70% lower than that of the healthy side, suspension fixation is recommended and the brace fixation time is prolonged.

Download Full-text

Bone mineral density

The Angle Orthodontist ◽

10.2319/031811-192.1 ◽

2011 ◽

Vol 82 (1) ◽

pp. 62-66 ◽

Cited By ~ 25

Author(s):

Mariana Marquezan ◽

Thiago Chon Leon Lau ◽

Claudia Trindade Mattos ◽

Amanda Carneiro da Cunha ◽

Lincoln Issamu Nojima ◽

...

Keyword(s):

Bone Mineral Density ◽

Trabecular Bone ◽

Cortical Bone ◽

Bone Mineral ◽

Primary Stability ◽

Bone Block ◽

Insertion Torque ◽

Bovine Bone ◽

Mineral Density ◽

Pull Out

Abstract Objective: To verify whether bone mineral density (BMD) of cortical bone, trabecular bone, and total bone influence the primary stability of orthodontic miniscrews and to verify whether there is a correlation between the measurement of BMD by cone-beam computed tomography (CBCT) and central dual-energy x-ray absorptiometry (DEXA). Materials and Methods: Twenty bovine bone sections were extracted from the pubic and iliac bones from regions with cortical thicknesses of approximately 1 mm. The BMD of the total bone block was evaluated using two methods: CBCT and DEXA. The BMD of cortical, trabecular, and total bone in the region of interest (ROI) were also evaluated by CBCT. After scanning the bone blocks, 20 self-drilling miniscrews (INP®) 1.4 mm in diameter and 6 mm long were inserted into them. The peak implant insertion torque (IT) was registered. After this, the pull-out test (PS) was performed and the maximum force registered. The Pearson correlation test was applied to verify the correlations between variables. Results: The BMD of the total bone block verified by CBCT and DEXA showed a positive and strong correlation (r = 0.866, P = .000). The BMD of the ROI for cortical bone influenced the IT (r = 0.518, P = .40) and the PS of miniscrews (r = 0.713, P = .001, Table 2). However, the total bone BMD (verified by CBCT and DEXA) and trabecular bone BMD presented weak and not statistically significant correlations with primary stability. Conclusions: There was a positive correlation between total bone block BMD measured by DEXA and CBCT. The cortical BMD influenced the IT and PS.

Download Full-text