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The tested bone screws: cortical (a) and cancellous (b) bone screws. The inner and outer diameters of the screws are for cortical (3.0/4.5 mm inner/outer diameter × 45 mm length) and for cancellous (5.0/6.5 mm inner/outer diameter × 45 mm length).
Source publication
Bone cement augmentation is commonly used to improve the fixation stability of orthopaedic implants in osteoporotic bone. The aim of this study was to evaluate the effect of novel bone cements on the stability of bone screw fixation by biomechanical testing and to compare them with a conventional Simplex(®)P bone cement and requirements of the stan...
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Background:
Instrumentation in patients with osteoporosis is challenging. Bone cement-augmented fenestrated pedicle screw fixation is a new procedure for fixation in the osteoporotic bone; and, applying minimally invasive techniques to the above is a challenging and novel concept.
Aims:
To evaluate the clinical and radiological outcome of minima...
Zusammenfassung
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Citations
... [6][7][8][9][10][11] Other bone cements include CortOss s and CompO6t composites containing silica, calcium phosphates and a mixture of dimethacrylate-based polymer matrices. 6,[12][13][14] However, there exists several concerns involving suitability and biological safety of these materials. This includes poor biomechanical suitability and cytotoxicity caused by unreacted monomers and other additives leaching out whilst in service. ...
With a global aging population, there is a high demand for new biomaterials that provide regenerative or fixation modalities following a bone injury. Here, the design and development of newly synthesised poly(l-lactic acid)-dimethacrylate (PLLA-DM) and poly(caprolactone-co-fumarate)-dimethacrylate (PCF-DM) monomer systems serves to address some of the main medical challenges and requirements of surgeons during application and better postoperative outcomes of new bone-healing biomaterials. Synthesis of PLLA-DM and PCF-DM via ring opening polymerisation (ROP) and polycondensation routes led to low MW ‘flowable’ and resorbable monomers that polymerise in-situ at up to 6 mm curing depth. Tensile testing of photocured PLLA-DM/PCF-DM formulations at strain rate 0.05 s⁻¹, revealed elastic moduli of 4.4 ± 0.5 to 11.7 ± 2.5 (SD) GPa, with ultimate tensile strength ranging between 29.7 ± 4.9 to 76.1 ± 13.5 (SD) MPa. Resazurin-based metabolic activity studies via an indirect contact method involving Saos-2 osteoblast-like cell lines revealed enhanced cytocompatibility with metabolic activity of treated Saos-2 cells increasing by up to 20% compared with respective untreated control groups. Attachment of Saos-2 cells on PLLA-DM/PCF-DM specimen surfaces revealed cellular structures such as filopodia extending beyond lamellipodia, indicative of remarkable cell adhesion and favouring colonization. The initial development of the polymer chemistry presented here provides the potential for the design and further development towards a new resorbable biomaterial with enhanced mechanical properties for bone repair and augmentation involving both orthopaedic (bone cement) and restorative dentistry applications.
... Despite the success of this method, it contains many controversial issues, such as the ideal number of screws used and the angle of their insertion. Previous studies showed that the number of screws depends on the size and depth of the loss [15]. ...
Introduction and importance:
Total knee arthroplasty (TKA) can significantly enhance a patient's quality of life and knee function. As a result, it has become a popular procedure among orthopedic surgeons. However, there are some challenging cases that surgeons may encounter, such as treating bony defects in the tibial plateau in patients with advanced degeneration. If not managed properly, these cases can have serious consequences.
Case presentation:
4 patients with severe knee joint degeneration and bone loss in the medial tibial plateau were included in the series. The patients underwent TKA using the cement and screws technique to compensate for the defect in the medial tibial plateau. After (12-24 months) follow-up, all patients showed a clear clinical and functional improvement.
Clinical discussion:
Several ways exist to address bone loss in the tibial plateau in primary total knee joint arthroplasty. Among them, metal prostheses are frequently used. In certain situations, we may need to use more affordable techniques to ensure success for patients facing financial difficulties. This is particularly common in our country, and we may utilize methods such as the cement and screws technique. This study showed a clear improvement in the patient's clinical and functional outcomes according to The Western Ontario and McMaster Universities Arthritis Index (WOMAC) at the end of the follow-up period.
Conclusion:
The cement and screw technique might be a good solution for moderate bone loss in the tibial plateau. It might be a safe and simple method for patients, and it's also a viable option for those who can't afford pricier alternatives like metal augmentation or structural allografts.
... We measured the biomechanical stability of the specimen using the dynamic testing machine based on the biaxial fluid pressure (Instron 8500 ® ; Instron Corp., Norwood, MA, USA), for which we repeatedly applied a loading stress at a constant rate of 2 Hz [43,44]. The magnitude of loading stress ranged between 60 and 300 kg; it was five times higher as compared with the non-loading condition. ...
... Thus, we attempted to measure the bond strength at the largest bone defects (Figure 4). We measured the biomechanical stability of the specimen using the dynamic testing machine based on the biaxial fluid pressure (Instron 8500 ® ; Instron Corp., Norwood, MA, USA), for which we repeatedly applied a loading stress at a constant rate of 2 Hz [43,44]. The magnitude of loading stress ranged between 60 and 300 kg; it was five times higher as compared with the non-loading condition. ...
Background and Objectives: Currently, only patients with osteonecrosis of the femoral head (ONFH), who had bone defects involving 30–33.3% of the remaining femoral head, are indicated in hip resurfacing arthroplasty (HRA). In an experimental cadaver model of ONFH involving up to 50% of the remaining femoral head, the initial stability of the femoral head implant (FHI) at the interface between the implant and the remaining femoral head was measured. Materials and Methods: The ten specimens and the remaining ten served as the experimental group and the control group, respectively. We examined the degree of the displacement of the FHI, the bonding strength between the FHI and the retained bone and that at the interface between the FHI and bone cement. Results: Changes in the degree of displacement at the final phase from the initial phase were calculated as 0.089 ± 0.036 mm in the experimental group and 0.083 ± 0.056 mm in the control group. However, this difference reached no statistical significance (p = 0.7789). Overall, there was an increase in the degree of displacement due to the loading stress, with increased loading cycles in both groups. In cycles of up to 6000 times, there was a steep increase. After cycles of 8000 times, however, there was a gradual increase. Moreover, in cycles of up to 8000 times, there was an increase in the difference in the degree of displacement due to the loading stress between the two groups. After cycles of 8000 times, however, such difference remained almost unchanged. Conclusions: In conclusion, orthopedic surgeons could consider performing the HRA in patients with ONFH where the bone defects involved up to 50% of the remaining femoral head, without involving the femoral head–neck junction in the anterior and superior area of the femoral head. However, more evidence-based studies are warranted to justify our results.
... Bone cement and screw technique has been used for more than 40 years to repair uncontained tibial defects during primary or revised total knee arthroplasty (TKA) [1], and successful results from short-to long-term follow-up have been reported [2][3][4]. Compared to metal augmentation or other techniques, it is less expensive and easier to perform [5][6][7]. In our previous study, we compared different screw angles for the repairment of tibial defects in TKA and found that screws perpendicular to the proximal osteotomy surface can provide better mechanical stability than those parallel to the proximal cortical bone of tibia [8]. ...
Cement can be reinforced with cancellous screws for repairing tibial defect in total knee arthroplasty (TKA). However, it is still unknown which size (diameter, length) of screws is better, and the purpose of this study was to perform a finite element analysis (FEA) to determine it. Twelve FEA models were set to represent the cement-screw technique with different diameters (3.5 mm, 5 mm and 6.5 mm) and lengths (20 mm, 25 mm, 30 mm and 35 mm). Contact stresses on the surface of cancellous bone in different areas were calculated. Compared to screws with diameter of 3.5 mm, stresses on the surface of bone defect reduced 5.75% of 5 mm and 10.68% of 6.5 mm for the screw length of 20 mm, 4.23% of 5 mm and 9.16% of 6.5 mm for 25 mm, 6.65% of 5 mm and 12.30% of 6.5 mm for 30 mm, and 5.05% of 5 mm and 12.16% of 6.5 mm for 35 mm. Compared to screws with diameter of 5 mm, stresses on the surface of defect reduced 5.24%, 5.15%, 6.05%, and 7.49% of 6.5 mm for the screw length of 20, 25, 30, and 35 mm. However, it did not show any significant difference in other comparisons. For the treatment of tibial defect in TKA with cement-screw technique, longer screw may not achieve better stability, but the thicker screw can reduce more stresses on the surface of tibial defect and achieve better stability. However, the depth of bone defect must be considered when making a choice.
... Compared to other techniques, a cement-screw approach is less time-consuming, easier to perform, and less expensive [5,6]. Successful short-term to long-term follow-up of a cement-screw technique to correct tibial defects have been reported [7][8][9]. ...
... There are many types of basic reconstruction methods, depending on the situation. Compared to other methods, cement-screw technique has many advantages, such as being more stable and reinforced than a cementonly technique and a simpler procedure than metal augmentation [5,6]. Traditionally, bone cement only was used to ll defects less than 5 mm in depth after proximal tibial resection [12]. ...
Background: The cement-screw technique is an effective method for repairing tibial plateau defects in total knee arthroplasty (TKA). However, it is unknown which depth for the screw is better. This study aimed to perform a finite element analysis (FEA) to determine the advantage of a cement-screw technique and confirm the optimal screw depth.
Results: Four FEA models were set to represent the cement-screw or cement-only techniques. In the cement-screw technique, screws were inserted into the defect area obliquely with an angle of 45 degrees from the mechanical axis with 3 different depths. The FEA models showed that cement-only technique had more stress-shielding areas in the tibial plateau and medullary cervicitis, while higher stress areas were in the defect and medullary cervicitis. For the cement-screw technique, stresses were lower on the surface of cancellous bone around screw when it was inserted below the upper surface of tibia.
Conclusion: From the FEA data, we found that cement-screw technique is superior to cement-only technique for repairing a tibial plateau defect in TKA; for the former, it may be more beneficial to insert the screw below the upper surface of tibia plateau.
... The cancellous screw is the metal reinforcement used on a defect filled with bone cement. Compared to other techniques, the cement-screw technique is less time-consuming, easier to perform, and less expensive [2,3]. Although successful short-term and long-term follow-up is reported for the cement-screw technique, it may not be that simple [4][5][6]. ...
Background
The cement-screw technique is a convenient method to repair tibial plateau defects in primary and revision total knee arthroplasty (TKA). However, the optimal angle of screw insertions is unknown. This study aimed to perform a finite element analysis (FEA) to determine the optimal screw angle for the repair of tibial plateau defects in TKA.
Methods
Seven FEA models were set and two common different defects (defect 1: area < 12%, depth < 12 mm; defect 2: area > 12%, depth > 12 mm) were simulated. One screw was used in defect 1, and one or two screws were used in defect 2. Screws were parallel to the proximal cortical bone (oblique screw) or perpendicular to the upper surface (vertical screw) of the tibia. Contact stresses on cancellous bone in different areas were determined. Maximum principal stress on the cancellous bone around each screw was also compared.
Results
The FEA models showed that stresses on the surface of cancellous bone in tibial defect (0.13–0.39 MPa) and stress focus spot (0.45 MPa) around the screw were lower when one vertical screw was used in defect 1. The stresses on the surface of cancellous bone in tibial defect (0.09–0.44 MPa), stresses in the medial tibial plateau (0.14–0.21 MPa), and stress focus spot around the screws were lowest (0.42 MPa and 1.37 MPa) when two vertical screws were used in defect 2, followed by of one vertical and one oblique (0.16–0.48 MPa; 0.15–0.21 MPa; 1.63 MPa and 1.11 MPa). No other statistically significant differences were found.
Conclusions
Either for one or two screws, those perpendicular to the upper surface achieve better stability than those parallel to the proximal cortical bone of the tibia. If two vertical screws cannot be performed, one vertical and one oblique is also acceptable.
... The cancellous screw is often used to reinforce the defect to be lled with bone cement as the metal reinforcement used to construct other cement structures. Compared to other techniques, cement-screw technique is less time-consuming, easier to perform, and less expensive [2,3]. Although successful short-term to long-term follow-up of a cement-screw technique to correct tibial defects have been reported, this technique may be not as simple as we think [4][5][6]. ...
Background: The cement-screw technique is always used to repair tibial plateau defects in primary or revision total knee arthroplasty (TKA). However, it is unknown which screw angle is better. This study aimed to perform a finite element analysis (FEA) to determine the optimal screw angle for the repairment of tibial plateau defects in TKA.
Methods: Seven FEA models were set and two common different defects (defect 1: area<12%, depth <12 mm; defect 2: area>12%, depth >12 mm) were simulated. One screw was used in defect 1, one or two screws were used in defect 2. Screws were parallel to the proximal cortical bone (oblique screw) or perpendicular to the upper surface (vertical screw) of tibia. Contact stresses on cancellous bone in different areas were determined. Besides, maximum principal stress of cancellous bone around each screw were also compared.
Results: The FEA models showed that stresses on the surface of cancellous bone in tibial defect (0.13-0.39 MPa) and stress focus spot (0.45 MPa) around the screw were lower when one vertical screw was used in defect 1. Meanwhile, stresses on the surface of cancellous bone in tibial defect (0.09-0.44 MPa), stresses in medial tibial plateau (0.14-0.21 MPa) and stress focus spot (0.42 MPa and 1.37 MPa) around the screws were lowest when two vertical screws were used in defect 2, followed by two screws consisting of one vertical and one oblique (0.16-0.48 MPa; 0.15-0.21 MPa; 1.63 MPa and 1.11 MPa). No other statistically significant difference was found.
Conclusions: Either for one screw or two screws, screw perpendicular to the upper surface can achieve better stability than paralleling to the proximal cortical bone of tibia. If two vertical screws cannot be performed, one vertical screw and one oblique screw are also acceptable.
... Bone drilling and screw selection are usually required in open reduction and internal fixation (ORIF) performed as a surgical treatment for fractures (1,2). Despite previous studies about optimal drilling parameters to reach maximum accuracy (2)(3)(4)(5)(6)(7), there are still concerns about rapid and accurate screw selection intraoperatively. ...
... Bone drilling and screw selection are usually required in open reduction and internal fixation (ORIF) performed as a surgical treatment for fractures (1,2). Despite previous studies about optimal drilling parameters to reach maximum accuracy (2)(3)(4)(5)(6)(7), there are still concerns about rapid and accurate screw selection intraoperatively. Excessively long screws may rupture the soft tissues and tendons, causing pain and injury to blood vessels and nerves (8)(9)(10)(11)(12)(13)(14). ...
Background: It is important to select appropriate screws in orthopedic surgeries, as excessively long or too short a screw may results failure of the surgeries. This study explored factors that affect the accuracy of measurements in terms of the experience of the surgeons, passage of drilled holes and different depth gauges.
Methods: Holes were drilled into fresh porcine femurs with skin in three passages, straight drilling through the metaphysis, straight drilling through the diaphysis, and angled drilling through the diaphysis. Surgeons with different surgical experiences measured the holes with the same depth gauge and using a vernier caliper as gold standard. The length of selected screws, and the time each surgeon spent were recorded. The measurement accuracy was compared based on the experiences of the surgeons and the passage of drilled holes. Further, parameters of depth gauges and 12-mm cortical bone screws from five different manufacturers were measured.
Results: A total of 13 surgeons participated in 585 measurements in this study, and each surgeon completed 45 measurements. For the surgeons in the senior, intermediate, and junior groups, the average time spent in measurements was 689, 833, and 785 s with an accuracy of 57.0, 42.2, and 31.5%, respectively. The accuracy and measurement efficiency were significantly different among the groups of surgeons ( P < 0.001). The accuracy of measurements was 45.1% for straight metaphyseal drilling, 43.6% for straight diaphyseal drilling, and 33.3% for angled diaphyseal drilling ( P = 0.036). Parameters of depth gauges and screws varied among different manufacturers.
Conclusion: Both observer factor and objective factors could affect the accuracy of depth gauge measurement. Increased surgeon's experience was associated with improvements in the accuracy rate and measurement efficiency of drilled holes based on the depth gauge. The accuracy rate varied with hole passages, being the lowest for angled drilled holes.
... To overcome some of these difficulties, cement augmentation and improved screw design have been used to increase the holding power of bone screws [7][8][9] ; however, previous studies have only evaluated holding power in pure axial pullout experiments [10][11][12][13][14][15] , that represents the exclusive standardized method to test the anchorage strength of medical bone screws 16 . In research of the pedicle screw, pullout strength has been found to be an unsuitable predictor of screw loosening, because it does not simulate physiological loading conditions 17,18 . ...
... Evaluation of the fixation stability of bone screws often focuses on simple axial pullout, which rarely simulates physiological loading conditions, while lateral migration resistance, another important biomechanical characteristic for bone screws, has been neglected [10][11][12][13][14][15] . Axial pullout strength and lateral migration resistance of individual screws correspond to forces which are perpendicular to each other, which means these two characteristics are independent and mutually non-interacting. ...
Conventional evaluation of the stability of bone screws focuses on pullout strength, while neglecting lateral migration resistance. We measured pullout strength and lateral migration resistance of bone screws and determined how these characteristics relate to screw stability of locking plate (LP) and dynamic compression plate (DCP) fixation. Pullout strength and lateral migration resistance of individual bone screws with buttress, square, and triangular thread designs were evaluated in polyurethane foam blocks. The screw types with superior performance in each of these characteristics were selected. LP and DCP fixations were constructed using the selected screws and tested under cyclic craniocaudal and torsional loadings. Subsequently, the association between individual screws’ biomechanical characteristics and fixation stability when applied to plates was established. Screws with triangular threads had superior pullout strength, while screws with square threads demonstrated the highest lateral migration resistance; they were selected for LP and DCP fixations. LPs with square-threaded screws required a larger force and more cycles to trigger the same amount of displacement under both craniocaudal and torsional loadings. Screws with triangular and square threads showed no difference in DCP fixation stability under craniocaudal loading. However, under torsional loading, DCP fixation with triangular-threaded screws demonstrated superior fixation stability. Lateral migration resistance is the primary contributor to locking screw fixation stability when applied to an LP in resisting both craniocaudal and torsional loading. For compression screws applied to a DCP, lateral migration resistance and pullout strength work together to resist craniocaudal loading, while pullout strength is the primary contributor to the ability to resist torsional loading.
... Specimens with cortical fixation of 2 and 3 mm thickness and inserted at an augmentation depth of 15 mm, had a holding strength of 546 and 855 N, respectively, which is comparable to the VS-LA cement. The benefits provided by PMMA bone cement augmentation in improving the fixation strength of cancellous screws in severely osteoporotic bone has been widely described in the literature [75][76][77]. However, the drawbacks of PMMA bone cement, in particular the exothermic polymerization reaction and mismatch in stiffness between cement and cancellous bone, are still concerns, which may be resolved by using the present cement. ...
Acrylic bone cements modified with linoleic acid are a promising low-modulus alternative to traditional high-modulus bone cements. However, several key properties remain unexplored, including the effect of autoclave sterilization and the potential use of low-modulus cements in other applications than vertebral augmentation. In this work, we evaluate the effect of sterilization on the structure and stability of linoleic acid, as well as in the handling properties, glass transition temperature, mechanical properties, and screw augmentation potential of low-modulus cement containing the fatty acid. Neither 1H NMR nor SFC-MS/MS analysis showed any detectable differences in autoclaved linoleic acid compared to fresh one. The peak polymerization temperature of the low-modulus cement was much lower (28–30 °C) than that of the high-modulus cement (67 °C), whereas the setting time remained comparable (20–25 min). The Tg of the low-modulus cement was lower (75–78 °C) than that of the high-stiffness cement (103 °C). It was shown that sterilization of linoleic acid by autoclaving did not significantly affect the functional properties of low-modulus PMMA bone cement, making the component suitable for sterile production. Ultimately, the low-modulus cement exhibited handling and mechanical properties that more closely match those of osteoporotic vertebral bone with a screw holding capacity of under 2000 N, making it a promising alternative for use in combination with orthopedic hardware in applications where high-stiffness augmentation materials can result in undesired effects.
