scholarly journals Biomechanical assessment of the stability of osteochondral grafts implanted in porcine and bovine femoral condyles

2019 ◽  
Vol 234 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Philippa Bowland ◽  
Raelene M Cowie ◽  
Eileen Ingham ◽  
John Fisher ◽  
Louise M Jennings
Keyword(s):  
Bone Tissue ◽  
Cartilage Damage ◽  
Primary Stability ◽  
Preparation Technique ◽  
Recipient Site ◽  
Osteochondral Grafts ◽  
Press Fit ◽  
Bone Properties ◽  
The Stability ◽  
Push Out

Osteochondral grafts are used clinically to repair cartilage and bone defects and to restore the congruent articulating surfaces of the knee joint following cartilage damage or injury. The clinical success of such osteochondral grafts is heavily reliant on the biomechanical and tribological properties of the surgical repair; however, a limited number of studies have investigated these factors. The aim of this study was to evaluate the influence of graft harvesting and implantation technique as well as bone properties on the primary stability of press-fit implanted osteochondral grafts using a series of uniaxial experimental push-in and push-out tests. Animal (porcine and bovine) knees were used to deliver models of different bone properties (elastic modulus and yield stress). The study showed the graft harvesting method using either a chisel or drill-aided trephine to have no influence on primary graft stability; however, the preparation technique for the graft recipient site was shown to influence the force required to push the graft into the host tissue. For example, when the length of the graft was equal to the recipient site (bottomed), the graft was more stable and dilation of the recipient site was shown to reduce short-term graft stability especially in immature or less dense bone tissue. The push-out tests which compared tissue of different skeletal maturities demonstrated that the maturity of both the graft and host bone tissue to influence the stability of the graft. A higher force was required to push out more skeletally mature grafts from mature bone tissue. The study demonstrates the importance of surgical technique and bone quality/properties on the primary stability and ultimately, the success of osteochondral grafts in the knee.

Primary Stability of Press-Fit-Implanted Osteochondral Grafts

2000 ◽  
Vol 28 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Jochen Duchow ◽  
Thomas Hess ◽  
Dieter Kohn
Keyword(s):  
Primary Stability ◽  
Osteochondral Grafts ◽  
Press Fit

scholarly journals An experimental study on the effects of the cortical thickness and bone density on initial mechanical anchorage of different Straumann® implant designs

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Marie Emmert ◽  
Aydin Gülses ◽  
Eleonore Behrens ◽  
Fatih Karayürek ◽  
Yahya Acil ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Cortical Bone ◽  
Frequency Analysis ◽  
Primary Stability ◽  
Longitudinal Axis ◽  
Resonance Frequency Analysis ◽  
Recipient Site ◽  
Distal Epiphysis ◽  
Bone Level ◽  
The Stability

Abstract Background The aim of the current study was to comparatively assess the primary stability of different Straumann® implant designs (BLX, Straumann Tapered Effect, Bone Level Tapered, and Standard Plus) via resonance frequency analysis by using an implant insertion model in freshly slaughtered bovine ribs with and without cortical bone. Tapered Effect (4.1 × 10 mm), Bone Level Tapered (4.1 × 10 mm), Standard Plus (4.1 × 10 mm), and BLX (4.0 × 10 mm) implants were inserted into the distal epiphysis on the longitudinal axis of the freshly slaughtered bovine ribs. As a control, implants with the same sizes were inserted into the proximal diaphysis. The stability of the implants was examined with resonance frequency analysis. Results BLX and Tapered Effect implants showed higher implant stability quotient values in both study and control groups. All implant systems showed a significant decrease of mechanical anchorage in the study group. BLX and Bone Level Tapered designs had a significantly lower loss of mechanical anchorage in the lack of cortical bone. Conclusion Both Tapered Effect and BLX designs could ensure sufficient initial stability; however, BLX implants could be an appropriate option in the lack of cortical bone and poor bone quality at the implant recipient site. Clinical relevance BLX is a novel implant system, which could be especially beneficial in the presence of spongious bone type at posterior maxillae.

Primary Stability of Short Implants Inserted Using Piezoelectric or Drilling Systems: An In Vitro Comparison

2019 ◽  
Vol 45 (4) ◽  
pp. 259-266
Author(s):  
Claudio Stacchi ◽  
Matteo De Biasi ◽  
Lucio Torelli ◽  
Massimo Robiony ◽  
Roberto Di Lenarda ◽  
...  
Keyword(s):  
Cancellous Bone ◽  
Operative Time ◽  
Primary Stability ◽  
Site Preparation ◽  
Preparation Technique ◽  
Implant Stability ◽  
Implant Stability Quotient ◽  
Custom Made ◽  
Implant Site Preparation

The primary objective of the present in vitro study was to evaluate the influence of implant site preparation technique (drills vs ultrasonic instrumentation) on the primary stability of short dental implants with two different designs inserted in simulated low-quality cancellous bone. Eighty implant sites were prepared in custom-made solid rigid polyurethane blocks with two different low cancellous bone densities (5 or 15 pounds per cubic foot [PCF]), equally distributed between piezoelectric (Surgysonic Moto, Esacrom, Italy) and conventional drilling techniques. Two short implant systems (Prama and Syra, Sweden & Martina) were tested by inserting 40 fixtures of each system (both 6.0 mm length and 5.0 mm diameter), divided in the four subgroups (drills/5 PCF density; drills/15 PCF density; piezo/5 PCF density; piezo/15 PCF density). Insertion torque (Ncm), implant stability quotient values, removal torque (Ncm), and surgical time were recorded. Data were analyzed by 3-way ANOVA and Scheffé's test (α = 0.05). With slight variations among the considered dependent variables, overall high primary implant stability was observed across all subgroups. Piezoelectric instrumentation allowed for comparable or slightly superior primary stability in comparison with the drilling procedures in both implant systems. The Prama implants group showed the highest mean reverse torque and Syra implants the highest implant stability quotient values. Piezoelectric implant site preparation took prolonged operative time compared to conventional preparation with drills; among the drilling procedures, Syra system required fewer surgical steps and shorter operative time.

A decreased subchondral trabecular bone tissue elastic modulus is associated with pre-arthritic cartilage damage

2001 ◽  
Vol 19 (5) ◽  
pp. 914-918 ◽  
Author(s):  
J. S. Day ◽  
M. Ding ◽  
J. C. van der Linden ◽  
I. Hvid ◽  
D. R. Sumner ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Trabecular Bone ◽  
Bone Tissue ◽  
Cartilage Damage ◽  
Trabecular Bone Tissue

Developing Stability of Posterior Mandibular Implants Placed With Osteotome Expansion Technique Compared With Conventional Drilling Techniques

2017 ◽  
Vol 43 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Yen-Ting Lin ◽  
Adrienne Hong ◽  
Ying-Chin Peng ◽  
Hsiang-Hsi Hong
Keyword(s):  
Bone Density ◽  
Surgical Techniques ◽  
Primary Stability ◽  
Conventional Technique ◽  
Implant Stability ◽  
Implant Stability Quotient ◽  
Expansion Technique ◽  
The Stability ◽  
Conventional Drilling ◽  
Secondary Stability

Clinical decisions regarding the stability and osseointegration of mandibular implants positioned using the bone expansion techniques are conflicting and limited. The objective was to evaluate the stability of implants placed using 2 surgical techniques, selected according to the initial width of the mandibular posterior edentulous ridge, with D3 bone density, during a 12-week period. Fifty-eight implants in 33 patients were evaluated. Thirty-two implants in 24 patients were positioned using the osteotome expansion technique, and 26 fixtures in 17 patients were installed using the conventional drilling technique. The implant stability quotient values were recorded at weeks 0, 1, 2, 3, 4, 6, 8, 10, and 12 postsurgery and evaluated using analysis of variance, independent, and paired t tests. Calibrated according to the stability reading of a 3.3-mm diameter implant, the osteotome expansion group was associated with a lower bone density than the conventional group (64.96 ± 6.25 vs 68.98 ± 5.06, P = .011). The osteotome expansion group achieved a comparable primary stability (ISQb-0, P = .124) and greater increases in secondary stability (ISQb-12, P = .07) than did the conventional technique. A D3 quality ridge with mild horizontal deficiency is expandable by using the osteotome expansion technique. Although the 2 groups presented similar implant stability quotient readings during the study period, the osteotome expansion technique showed significant improvement in secondary stability. The healing patterns for these techniques are therefore inconsistent.

Effect of cup medialization on primary stability of press-fit acetabular cups

2020 ◽  
Vol 80 ◽  
pp. 105172
Author(s):  
Federico Morosato ◽  
Luca Cristofolini ◽  
Francesco Castagnini ◽  
Francesco Traina
Keyword(s):  
Primary Stability ◽  
Press Fit

scholarly journals On the mechanism of trailing vortex wandering

2016 ◽  
Vol 801 ◽  
Author(s):  
Adam M. Edstrand ◽  
Timothy B. Davis ◽  
Peter J. Schmid ◽  
Kunihiko Taira ◽  
Louis N. Cattafesta
Keyword(s):  
Particle Image ◽  
Particle Image Velocimetry Data ◽  
Primary Stability ◽  
Measured Velocity ◽  
Naca0012 Airfoil ◽  
Image Velocimetry ◽  
The Stability ◽  
Proper Orthogonal ◽  
Tunnel Effects ◽  
Helical Mode

The mechanism of trailing vortex wandering has long been debated and is often attributed to either wind-tunnel effects or an instability. Using particle image velocimetry data obtained in the wake of a NACA0012 airfoil, we remove the effect of wandering from the measured velocity field and, through a triple decomposition, recover the coherent wandering motion. Based on this wandering motion, the most energetic structures are computed using the proper orthogonal decomposition (POD) and exhibit a helical mode with an azimuthal wavenumber of $|m|=1$ whose kinetic energy grows monotonically in the downstream direction. To investigate the nature of the vortex wandering, we perform a spatial stability analysis of a matched Batchelor vortex. The primary stability mode is found to be marginally stable and nearly identical in both size and structure to the leading POD mode. The strikingly similar structure, coupled with the measured energy growth, supports the proposition that the vortex wandering is the result of an instability. We conclude that the cause of the wandering is the non-zero radial velocity of the $|m|=1$ mode on the vortex centreline, which acts to transversely displace the trailing vortex, as observed in experiments. However, the marginal nature of the stability mode prevents a definitive conclusion regarding the specific type of instability.

scholarly journals Simple geometry tribological study of osteochondral graft implantation in the knee

2018 ◽  
Vol 232 (3) ◽  
pp. 249-256 ◽  
Author(s):  
Philippa Bowland ◽  
Eileen Ingham ◽  
John Fisher ◽  
Louise M Jennings
Keyword(s):  
Knee Joint ◽  
Articular Surface ◽  
Cartilage Damage ◽  
Surface Damage ◽  
Negative Control ◽  
Osteochondral Allograft ◽  
Cartilage Defects ◽  
Osteochondral Grafts ◽  
Osteochondral Repair ◽  
Simple Geometry

Robust preclinical test methods involving tribological simulations are required to investigate and understand the tribological function of osteochondral repair interventions in natural knee tissues. The aim of this study was to investigate the effects of osteochondral allograft implantation on the local tribology (friction, surface damage, wear and deformation) of the tissues in the natural knee joint using a simple geometry, reciprocating pin-on-plate friction simulator. In addition, the study aimed to assess the ability of osteochondral grafts to restore a low surface damage, deformation and wear articulation when compared to the native state. A method was developed to characterise and quantify surface damage wear and deformation of the opposing cartilage-bone pin surface using a non-contacting optical profiler (Alicona Infinite Focus). Porcine 12 mm diameter cartilage-bone pins were reciprocated against bovine cartilage-bone plates that had 6 mm diameter osteochondral allografts, cartilage defects or stainless steel pins (positive controls) inserted centrally. Increased levels of surface damage with changes in geometry were not associated with significant increases in the coefficient of dynamic friction. Significant damage to the opposing cartilage surface was observed in the positive control groups. Cartilage damage, deformation and wear (as measured by change in geometry) in the xenograft (2.4 mm3) and cartilage defect (0.99 mm3) groups were low and not significantly different (p > 0.05) compared to the negative control in either group. The study demonstrated the potential of osteochondral grafts to restore the congruent articular surface and biphasic tribology of the natural joint. An optical method has been developed to characterise cartilage wear, damage and deformation that can be applied to the tribological assessment of osteochondral grafts in a whole natural knee joint simulation model.

scholarly journals Relevant Design Aspects to Improve the Stability of Titanium Dental Implants

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1910 ◽  
Author(s):  
M. Herrero-Climent ◽  
P. López-Jarana ◽  
B. F. Lemos ◽  
F. J. Gil ◽  
C. Falcão ◽  
...  
Keyword(s):  
Primary Stability ◽  
Insertion Torque ◽  
Bovine Bone ◽  
Resonance Frequency Analysis ◽  
Everyday Clinical Practice ◽  
Implant Stability Quotient ◽  
The Stability ◽  
The One ◽  
Implant System ◽  
Titanium Dental Implants

Post-extractional implants and immediate loading protocols are becoming much more frequent in everyday clinical practice. Given the existing literature about tapered implants, the objective of this paper was to understand whether implant shape had a direct influence on the results of the insertion torque (IT) and implant stability quotient (ISQ). Seven tapered implant prototypes were developed and distributed into three groups and compared with a control cylindrical implant—VEGA by Klockner Implant System. The implants were inserted into bovine bone type III according to Lekholm and Zarb Classification. The sample size was n = 30 for the three groups. Final IT was measured with a torquemeter, and the ISQ was measured with Penguin Resonance Frequency Analysis (RFA). Modifications done to the Prototype I did not reveal higher values of the ISQ and IT when compared to VEGA. In the second group, when comparing the five prototypes (II–VI) with VEGA, it was seen that the values of the ISQ and IT were not always higher, but there were two values of the ISQ that were statistically significantly higher with the 4.0 mm diameter Prototypes II (76.3 ± 6.1) and IV (78 ± 3.7). Prototype VII was the one with higher and significant values of the ISQ and IT. In both diameters and in both variables, all differences were statistically significant enough to achieve the higher values of primary stability values (IT and ISQ). Given the limitations of this study, it can be concluded that when there is an increase of the diameter of the implant and body taper, there is an increase of the ISQ and IT, showing that the diameter of the implant is an important criteria to obtain higher values of primary stability.

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