Dorsal Bone–Ligament–Bone Reconstruction of Chronic Lunotriquetral Instability: Biomechanical Testing

Objectives. In this study, we performed a novel type of posterior en bloc elevation cervical laminoplasty (PEEL) to keep the integrity of the posterior structure, aiming to reduce axial symptoms complicated by a conventional cervical laminoplasty procedure. Methods. Twelve human cervical cadaveric spines (C2-T1) were sequentially tested in the following order: intact condition, open-door laminoplasty (ODL) through bilateral intermuscular approach (mini-invasive ODL), PEEL, and laminectomy (LN). After bilateral transecting at the junction of lamina and lateral mass through the tubular retraction system, the PEEL procedure symmetrically elevated all the posterior structure which was further stabilized with bone grafts and titanium plates. Computed tomography (CT) scan and biomechanical testing were performed after each condition. Results. Both mini-invasive ODL and PEEL procedures were accomplished with 2 small incisions on each side. Two types of laminoplasties could enlarge the spinal canal significantly both in cross-sectional area and anteroposterior diameter comparing with intact condition. The PEEL procedure demonstrated a significantly higher enlargement rate on a canal area and a symmetrical expansion pattern. Compared with intact condition, mini-invasive ODL performed from C3-C7 demonstrated significantly decreased motion in all testing directions except the flexion range of motion (ROM); the PEEL procedure showed mild and insignificant decrease on ROM in all directions. Laminectomy resulted in a statistically significant increase in all directions except the lateral bending ROM. Conclusions. Posterior en bloc elevation cervical laminoplasty can enlarge the canal more effectively and preserve better ROM after operation than the ODL procedure. Although technically challenging, the PEEL procedure probably would decrease the common complications associated with ODL laminoplasty.

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The effect of table olive wastewater extract administration on the adult ovariectomized rat model of osteoporosis

British Journal Of Nutrition ◽

10.1017/s0007114521000465 ◽

2021 ◽

pp. 1-26

Author(s):

Alexandros S. Zervas ◽

Pavlos P. Lelovas ◽

Antonios Galanos ◽

Dimitris Galanis ◽

Maria Makropoulou ◽

...

Keyword(s):

Low Density Lipoprotein ◽

Biomechanical Testing ◽

Density Lipoprotein ◽

Hdl Cholesterol ◽

Abdominal Fat ◽

Ovariectomized Rats ◽

Mineral Density ◽

Final Body Weight ◽

Significant Difference ◽

Table Olive

Abstract Recent efforts for alternative non-pharmaceutical treatments for postmenopausal osteoporosis are focused on nutritional measures. The aim of this study was to investigate the effect of table olive wastewater extract (OE) administration on bone mineral density (BMD) and biomechanical strength in ovariectomized rats. Thirty mature 9-month-old female Wistar rats were separated into 3 groups of ten; Control, Ovariectomized (OVX) and OVX+OE. BMD was measured before ovariectomy, 3 and 6 months afterwards. At the end of the study, blood, both femurs and tibias, internal organs and abdominal fat were collected. After three months, the percentage changes from baseline of the total and proximal tibial BMD of the OVX+OE group were both higher compared to the OVX group (p<0.005). Similar results were found after six months, when the percentage changes from baseline of the total and proximal tibial BMD of the OVX+OE group were both higher compared to the OVX group (p<0.005). Biomechanical testing of the femurs did not reveal any statistically significant difference between the groups. Body weights throughout the study, organs’ and abdominal fat ratios to final body weight, blood results (alanine aminotransferase; ALT, Gamma-glutamyltransferase; γ-GT, total cholesterol, high-density lipoprotein; HDL-cholesterol, low-density lipoprotein; LDL-cholesterol, calcium, phosphorus) were within normal limits and did not show any significant difference between the treated and untreated groups. As a conclusion, the administration of table olive wastewater extract for 6 months protected tibial BMD loss in comparison to the untreated OVX group without causing adverse effects.

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Trans-obturator cable fixation of open book pelvic injuries

Scientific Reports ◽

10.1038/s41598-021-92755-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Martin C. Jordan ◽

Veronika Jäckle ◽

Sebastian Scheidt ◽

Fabian Gilbert ◽

Stefanie Hölscher-Doht ◽

...

Keyword(s):

Pelvic Ring ◽

Testing Machine ◽

Biomechanical Testing ◽

Pubic Symphysis ◽

Cadaver Study ◽

Steel Cable ◽

Reliable Technique ◽

Peak Displacement ◽

Total Displacement ◽

Cable Fixation

AbstractOperative treatment of ruptured pubic symphysis by plating is often accompanied by complications. Trans-obturator cable fixation might be a more reliable technique; however, have not yet been tested for stabilization of ruptured pubic symphysis. This study compares symphyseal trans-obturator cable fixation versus plating through biomechanical testing and evaluates safety in a cadaver experiment. APC type II injuries were generated in synthetic pelvic models and subsequently separated into three different groups. The anterior pelvic ring was fixed using a four-hole steel plate in Group A, a stainless steel cable in Group B, and a titan band in Group C. Biomechanical testing was conducted by a single-leg-stance model using a material testing machine under physiological load levels. A cadaver study was carried out to analyze the trans-obturator surgical approach. Peak-to-peak displacement, total displacement, plastic deformation and stiffness revealed a tendency for higher stability for trans-obturator cable/band fixation but no statistical difference to plating was detected. The cadaver study revealed a safe zone for cable passage with sufficient distance to the obturator canal. Trans-obturator cable fixation has the potential to become an alternative for symphyseal fixation with less complications.

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Lumbar Interbody Fusion Conducted on a Porcine Model with a Bioresorbable Ceramic/Biopolymer Hybrid Implant Enriched with Hyperstable Fibroblast Growth Factor 2

Biomedicines ◽

10.3390/biomedicines9070733 ◽

2021 ◽

Vol 9 (7) ◽

pp. 733

Author(s):

Milan Krticka ◽

Ladislav Planka ◽

Lucy Vojtova ◽

Vladimir Nekuda ◽

Premysl Stastny ◽

...

Keyword(s):

Growth Factor ◽

Lumbar Fusion ◽

Biomechanical Testing ◽

Fibroblast Growth Factor 2 ◽

Oxidized Cellulose ◽

Fibroblast Growth ◽

Micro Ct ◽

Bone Autograft ◽

Autograft Group

Many growth factors have been studied as additives accelerating lumbar fusion rates in different animal models. However, their low hydrolytic and thermal stability both in vitro and in vivo limits their workability and use. In the proposed work, a stabilized vasculogenic and prohealing fibroblast growth factor-2 (FGF2-STAB®) exhibiting a functional half-life in vitro at 37 °C more than 20 days was applied for lumbar fusion in combination with a bioresorbable scaffold on porcine models. An experimental animal study was designed to investigate the intervertebral fusion efficiency and safety of a bioresorbable ceramic/biopolymer hybrid implant enriched with FGF2-STAB® in comparison with a tricortical bone autograft used as a gold standard. Twenty-four experimental pigs underwent L2/3 discectomy with implantation of either the tricortical iliac crest bone autograft or the bioresorbable hybrid implant (BHI) followed by lateral intervertebral fixation. The quality of spinal fusion was assessed by micro-computed tomography (micro-CT), biomechanical testing, and histological examination at both 8 and 16 weeks after the surgery. While 8 weeks after implantation, micro-CT analysis demonstrated similar fusion quality in both groups, in contrast, spines with BHI involving inorganic hydroxyapatite and tricalcium phosphate along with organic collagen, oxidized cellulose, and FGF2- STAB® showed a significant increase in a fusion quality in comparison to the autograft group 16 weeks post-surgery (p = 0.023). Biomechanical testing revealed significantly higher stiffness of spines treated with the bioresorbable hybrid implant group compared to the autograft group (p < 0.05). Whilst histomorphological evaluation showed significant progression of new bone formation in the BHI group besides non-union and fibrocartilage tissue formed in the autograft group. Significant osteoinductive effects of BHI based on bioceramics, collagen, oxidized cellulose, and FGF2-STAB® could improve outcomes in spinal fusion surgery and bone tissue regeneration.

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Annular Defects Impair the Mechanical Stability of the Intervertebral Disc

Global Spine Journal ◽

10.1177/21925682211006061 ◽

2021 ◽

pp. 219256822110060

Author(s):

Jun-Xin Chen ◽

Yun-He Li ◽

Jian Wen ◽

Zhen Li ◽

Bin-Sheng Yu ◽

...

Keyword(s):

Intervertebral Disc ◽

Degrees Of Freedom ◽

Mechanical Stability ◽

Biomechanical Testing ◽

Bending Stiffness ◽

Biomechanical Study ◽

Torsional Stiffness ◽

P Value ◽

Lateral Bending ◽

Flexion Extension

Study Design: A biomechanical study. Objectives: The purpose of this study was to investigate the effects of cruciform and square incisions of annulus fibrosus (AF) on the mechanical stability of bovine intervertebral disc (IVD) in multiple degrees of freedom. Methods: Eight bovine caudal IVD motion segments (bone-disc-bone) were obtained from the local abattoir. Cruciform and square incisions were made at the right side of the specimen’s annulus using a surgical scalpel. Biomechanical testing of three-dimensional 6 degrees of freedom was then performed on the bovine caudal motion segments using the mechanical testing and simulation (MTS) machine. Force, displacement, torque and angle were recorded synchronously by the MTS system. P value <.05 was considered statistically significant. Results: Cruciform and square incisions of the AF reduced both axial compressive and torsional stiffness of the IVD and were significantly lower than those of the intact specimens ( P < .01). Left-side axial torsional stiffness of the cruciform incision was significantly higher than a square incision ( P < .01). Neither incision methods impacted flexional-extensional stiffness or lateral-bending stiffness. Conclusions: The cruciform and square incisions of the AF obviously reduced axial compression and axial rotation, but they did not change the flexion-extension and lateral-bending stiffness of the bovine caudal IVD. This mechanical study will be meaningful for the development of new approaches to AF repair and the rehabilitation of the patients after receiving discectomy.

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