Depth Of Cement Penetration Research Articles

Tibial cleaning method for cemented total knee arthroplasty: An experimental study.

Background:The survival rate of cemented knee prosthesis depends among other factors on optimal cement-bone contact, nevertheless no standard exists for cementing technique of tibial components. The aim of this study was to determine which tibial surface preparation technique leads to the best bone-cement contact.Materials and Methods:Human tibial plateau specimens were cleaned in four different ways before cementing: a) no cleaning, b) manual syringe irrigation, c) fracture brush cleaning, and d) pulsatile jet-lavage. The specimens were cut into transverse sections and the bone cement contact distance was calculated for every 10 mm and the cement penetration depth was measured. Both values were statistically analyzed (ANOVA).Results:The longest bone-cement contact (62 mm) was seen after PJL, the shortest (10.6 mm) after no cleaning at all. The deepest cement penetration (4.1 mm) again was seen after PJL, the least (0.7 mm) after no cleaning. Statistically, PJL yielded the longest bone-cement contact and deepest cement penetration.Conclusion:The results supports the use of pulsatile jet-lavage before cementing tibial components in knee arthroplasty.

What Is The Upper Limit Of Cement Penetration For Different Femoral Hip Resurfacing Components?

We used a validated femoral resurfacing model to obtain measurements of pressure and temperature and quantify cement distribution as a function of inner geometry and cementing technique of five different femoral hip resurfacing components. The purpose was to investigate if manufacture cementing recommendations are reliable. ASR showed only with the recommended manual cementing technique low cement pressures of 58.0±50.2kPa and low interface temperatures of 33.3±4.1°C. BHR had large cement defects of 10.4±1.1mm. Conserve Plus caused the smallest cement penetration depths of 2.9±0.6mm. Durom was tolerant against changes of the cementing technique but showed the widest spread of temperature data 42.8±7.0°C. ReCap showed the highest risk for incomplete seating with a cement mantle thickness of 4.3±0.9mm. Polymerization heat did not exceed the threshold of 45°C with a cement penetration depth of less than 4.2mm in any circumstances of this study.

Cementation and interface analysis of early failure cases after hip-resurfacing arthroplasty

The use of inappropriate cementation techniques has been suggested as an adverse factor for the long-term survival of hip-resurfacing arthroplasty. Inadequate initial fixation, thermal osteonecrosis and interface biological reactions are possible causes of failure. We analysed morphological changes associated with the cementation technique in a large collection of retrieved femoral components. One hundred and fifty femoral components (mean time to failure of 8.3 months±11.0) obtained at revision surgery were analysed morphometrically and histopathologically. Cement mantle and penetration were quantified in six different regions of interest. Histopathological analysis of the bone-cement interface was performed on undecalcified processed bone tissue. The vast majority of the cases differed substantially from laboratory-based cement-penetration depth recommendations. Fifty-nine cases had a fibrous membrane at the cement-bone interface. This membrane was significantly thicker in cases with osteonecrosis compared to cases viable bone. Our results demonstrate that most failures were cemented inappropriately. We suggest that poor cementation was an important adverse factor; however, the cause of the failures was obviously multifactorial. The thickness of the fibrous membrane at the cement-bone interface differed significantly between cases with osteonecrosis and specimens with viable bone tissue.

The influence of cementing technique in hip resurfacing arthroplasty on the initial stability of the femoral component

In clinical and retrieval analyses, over-penetration of cement, incomplete seating of the prosthesis with a resultant polar cement mass, or both, have been associated with early femoral failures of resurfacing arthroplasties. We used human bone specimens to experimentally compare the initial stability of different cementing techniques. Twenty-six pairs of fresh frozen femora were prepared for resurfacing using original instruments (DePuy ASR). ASR femoral resurfacing prostheses were implanted using two different cementing techniques: (1) component filling and (2) cement applicator. Real-time measurements of pressure and temperature during implantation, analyses of cement penetration and micro motions under torque application were performed. Applicator use reduced significantly the cement penetration depth (9.2 mm vs 5.3 mm with the applicator, p = 0.001), polar mantle (8.1 mm vs 2.6 mm, p = 0.008), cement defects (3.7 mm vs 0.1 mm, p = 0.008) and interface temperatures (40.3°C vs 33.1°C, p < 0.001 ). Initial rotational stability showed statistically significant less extreme values with the cement applicator technique (range 3.4-51.7 m°/Nm, 11.0-29.7 m°/Nm, p = 0.024). The cement applicator technique significantly reduces cement defects, incomplete seating, over-penetration and interface temperatures with a more consistent initial stability of the ASR femoral resurfacing prostheses.

Comparison of flanged and unflanged acetabular cup design

Background and purpose Adequate depth of cement penetration and cement mantle thickness is important for the durability of cemented cups. A flanged cup, as opposed to unflanged, has been suggested to give a more uniform cement mantle and superior cement pressurization, thus improving the depth of cement penetration. This hypothesis was tested experimentally.Materials and methods The same cup design with and without flange (both without cement spacers) was investigated regarding intraacetabular pressure, cement mantle thickness, and depth of cement penetration. With machine control, the cups were inserted into open-pore ceramic acetabular models (10 flanged, 10 unflanged) and into paired cadaver acetabuli (10 flanged, 10 unflanged) with prior pressurization of the cement.Results No differences in intraacetabular pressures during cup insertion were found, but unflanged cups tended to migrate more towards the acetabular pole. Flanged cups resulted in thicker cement mantles because of less bottoming out, whereas no differences in cement penetration into the bone were observed.Interpretation Flanged cups do not generate higher cementation pressure or better cement penetration than unflanged cups. A possible advantage of the flange, however, may be to protect the cup from bottoming out, and there is possibly better closure of the periphery around the cup, sealing off the cement-bone interface.

The effect of the Rim Cutter™ on cement pressurization and penetration on cemented acetabular fixation in total hip arthroplasty: An in vitro study

The Rim Cutter (Stryker Orthopedics, Mahwah, New Jersey) is a tool designed to cut a ledge inside the rim of the acetabulum, onto which a precisely trimmed, cemented, flanged cup can be fitted. The aim was to investigate the effect of the Rim Cutter on the intra-acetabular cement mantle pressure and the depth of cement penetration during cup insertion. The study had two parts. In the first part, hemi-pelvis models were fitted with pressure sensors. Pressure in the acetabulum was measured on insertion of a conventional cemented flanged cup with and without the use of a Rim Cutter to prepare the rim of the acetabulum. The second part assessed cement penetration when the same cups were inserted into a foam shell model. The shell was mounted in a jig and had holes drilled in it; the distance that cement penetrated into the holes was measured. A significant increase in cement pressure at the apex (p = 0.04) and the rim (p = 0.004) is seen when the Rim Cutter is used. Cement penetration in the Rim Cutter group was significantly increased at the rim of the acetabulum (p = 0.003). Insertion of a flanged cup after the acetabulum is prepared with the Rim Cutter leads to a significant increase in cement pressure and penetration during cup insertion in vitro when compared with conventional flanged cups.

Self-sealing ability of OCP-mediated cement as a deciduous root canal filling materia

The densification process and canal sealing ability of octacalcium phosphate (OCP)-mediated cement were investigated for developing biocompatible and biodegradable root canal filling material for deciduous root. The results of the characterization revealed that the starting paste, which consisted of monocalcium phosphate monohydrate, calcium carbonate, and α-tricalcium phosphate, gradually transformed into carbonate apatite for 6 weeks of immersion in medium with 30% fetal bovine serum (MEM30). The canal sealing ability was estimated by dye penetration test. Three kinds of conditions were chosen for the test: one was the cement just after filling the single-rooted extracted human roots; the others were the cement aged in MEM30 for 1 and 6 weeks after filling, respectively. All roots were then immersed in India ink for 3 days. The penetration depth of OCP-mediated cement decreased significantly with time. This demonstrates that OCP-mediated cement has self-sealing ability.

The mechanical effects of different levels of cement penetration at the cement–bone interface

The mechanical effects of varying the depth of cement penetration in the cement–bone interface were investigated using finite element analysis (FEA) and validated using companion experimental data. Two FEA models of the cement–bone interface were created from micro-computed tomography data and the penetration of cement into the bone was varied over six levels each. The FEA models, consisting of the interdigitated cement–bone constructs with friction between cement and bone, were loaded to failure in tension and in shear. The cement and bone elements had provision for crack formation due to excessive stress. The interfacial strength showed a strong relationship with the average interdigitation ( r 2=0.97 and r 2=0.93 in tension and shear, respectively). Also, the interface strength was strongly related with the contact area ( r 2=0.98 and r 2=0.95 in tension and shear, respectively). The FEA results compared favorably to the stiffness–strength relationships determined experimentally. Overall, the cement–bone interface was 2.5 times stronger in shear than in tension and 1.15 times stiffer in tension than in shear, independent of the average interdigitation. More cracks occurred in the cement than in the bone, independent of the average interdigitation, consistent with the experimental results. In addition, more cracks were generated in shear than in tension. In conclusion, achieving and maintaining maximal infiltration of cement into the bone to obtain large interdigitation and contact area is key to optimizing the interfacial strength.

Use of Cement Gun for Fixation of Tibia Component in Total Knee Arthroplasty

We evaluated the efficacy of a cement gun to improve the depth of cement penetration in total knee arthroplasty. Ninety-one consecutive patients from two hospitals were recruited for this study. For Group I cement was applied to the tibial baseplate and the proximal tibia with fingers. Group 2 had similar application of cement to the tibial baseplate but cement was pressurized into the proximal tibia using a cement gun.. The knee was kept extended until the cement hardened. Standard post-operative x-rays were reviewed to assess cement penetration into the proximal tibia. The mean cement penetration was 2.1 mm in Group 1 and 3.1 mm in Group 2 and the difference was statistically significant. The use of the cement gun improves cement penetration into the proximal tibia and facilitates early stability of the implant fixation to the bone.

The Influence of a Suction Device on Fixation of a Cemented Cup using RSA

The quality of technique used at the time of socket cementation is crucial in ensuring a durable long-term result of the implant. We asked whether a new instrument, an aspirator retractor introduced into the wing of the ilium before socket preparation and cementation, would enhance cement fixation as defined by RSA and radiographic examination. We randomized 38 patients into two groups. The surgical technique was identical between the groups with the exception of the use of the aspirator retractor. Patients were followed clinically and with radiostereometry at a minimum of 2 years. We compared gross radiographic appearances, including the depth of penetration of cement and the incidence of postoperative and 2-year radiolucent lines. There was no difference in proximal migration between the two groups. No improvement of fixation was proven from the measured translations and rotations of the socket in the suction group. We found no difference in the number or extent of radiolucent lines or the depth of cement penetration when the iliac suction device was used in conjunction with contemporary cementing techniques. Although the data suggest no short-term advantage in this small study, we will continue to follow these patients presuming there will be improved outcomes in the longer term and since the device provides an easier method of obtaining adequate fixation, especially if technical difficulties are encountered during the pressurization procedure.

The influence of initial pressurization and cup introduction time on the depth of cement penetration in an acetabular model

Background Acetabular cementation during total hip arthroplasty is considered difficult mainly due to the appearance and anatomy of the acetabulum. Improved cementation technique has been shown to improve the longevity of acetabular components.Method We designed a ceramic model to investigate the effect of varying the initial cement pressurization and cup introduction times on the depth of cement penetration. 4 groups were prepared, 2 of which involved varying initial cement pressurization and cup introduction times. Group 3 involved initial cement pressurization with no cup introduction, while group 4 involved cup introduction with no prior cement pressurization.Results and interpretation Most cement penetration occurred in the early pressurization phase, and we conclude that a relatively early and longer cement pressurization time and late cup introduction are positive factors for increased cement penetration in the acetabulum model.

Factors affecting the cement penetration of a hip resurfacing implant: An in vitro study

An understanding of how the cementing technique influences cement penetration is important for surgeons to plan and conduct hip resurfacing procedures. Therefore the aim of this study is to determine the influence of the following parameters on cement penetration: use of pulse lavage, type of cement, and the standing period of the cement. Nine fresh frozen paired whole cadaver femora were used to investigate cement penetration. The femora were divided into three paired groups: (A) compared the use of pulse lavage to no pulse lavage, (B) compared two low viscosity bone cements SULCEM-3 (Zimmer GmbH, Switzerland) and Surgical Simplex (Stryker Orthopaedics, USA), and (C) compared bone cement viscosities using standing times of 1.5 min. and 3 min. The Durom Hip Resurfacing implant (Zimmer GmbH, Switzerland) was used in all groups. A single slice was taken out of the center of each head. Cement penetration ratio (penetration area divided by the bone area enclosed by implant) and mean cement penetration depth were measured. Cement penetration is increased using pulse lavage, and has the tendency to increase with increasing the cement standing time from 1.5 to 3 min. No difference in cement penetration was found when different cement brands of comparable viscosity were used.

Factors Affecting the Cement Penetration of a Hip Resurfacing Implant: An in Vitro Study

An understanding of how the cementing technique influences cement penetration is important for surgeons to plan and conduct hip resurfacing procedures. Therefore the aim of this study is to determine the influence of the following parameters on cement penetration: use of pulse lavage, type of cement, and the standing period of the cement. Nine fresh frozen paired whole cadaver femora were used to investigate cement penetration. The femora were divided into three paired groups: (A) compared the use of pulse lavage to no pulse lavage, (B) compared two low viscosity bone cements SULCEM-3 (Zimmer GmbH, Switzerland) and Surgical Simplex (Stryker Orthopaedics, USA), and (C) compared bone cement viscosities using standing times of 1.5 min. and 3 min. The Durom Hip Resurfacing implant (Zimmer GmbH, Switzerland) was used in all groups. A single slice was taken out of the center of each head. Cement penetration ratio (penetration area divided by the bone area enclosed by implant) and mean cement penetration depth were measured. Cement penetration is increased using pulse lavage, and has the tendency to increase with increasing the cement standing time from 1.5 to 3 min. No difference in cement penetration was found when different cement brands of comparable viscosity were used.

Accuracy of implantation of components in the Oxford knee using the minimally invasive approach

Screened postoperative X-rays of 224 Oxford knees implanted through the minimally invasive approach were analysed using 16 criteria. The technique was as recommended by the Oxford Group except that the femoral intramedullary rod was used only as a guide to flexion/extension of the femoral component. All femoral components were within the recommended range for varus/valgus and mediolateral position. Eighteen femoral components were either too flexed or extended, but by a maximum of only 10°. Tibial components were inserted in slight varus (mean 1.8°, S.D. 8.8, range 10 to −10). All were within the range for posterior slope in spite of difficulty in establishing objective landmarks. Tibial coverage was imprecise with the phase 3 implants which were short and broad relative to the cut surface. In 36% of knees the tibial tray was implanted too anterior resulting in posterior under hang. There have been no clinical signs to indicate tipping of the meniscus in deep flexion. The depth of cement penetration under the keel was excessive in three cases, resulting from porotic bone rather than technical error in the depth of the cut. There has been one case of femoral component loosening following a fall and no tibial loosening in spite of imprecise alignment of some components.

Cement Penetration and Stiffness of the Cement-Bone Composite in the Proximal Tibia in a Porcine Model

To assess the stiffness of the cement bone composite and the depth and uniformity of cement penetration into the surface of the tibial component during total knee reconstruction in a porcine model. The effectiveness of 3 protocols were compared: 2 commonly used cementing techniques-finger-packing of cement on the cut surface followed by impaction, and coating of the undersurface of the prosthesis with cement followed by impaction-and a new method using a tibial cement-pressurising device. Cement penetration was measured by computed tomography; stiffness was determined by hydraulic penetration testing. Cement penetration at a depth of 1 mm was significantly greater following coating the undersurface of the prosthesis than following finger-packing (p=0.008). There was no significant difference at deeper levels or between the tibial-pressurising device group and either of the 2 other groups at any level (p>0.3 in all cases). Differences in surface stiffness by tibial plateau region were found in tibiae that had been cemented using finger-packing and in those that had had their undersurface coated, but not in tibiae that had been cemented using the tibial-pressurising device. The tibial cement-pressurising device eliminated regional differences in stiffness seen with other cementing methods. Elimination of these differences by using this device should reduce micromotion and the incidence of aseptic loosening of tibial base plates in total knee arthroplasty.

Enhancing femoral cement fixation in total knee arthroplasty

Several factors have been shown to be associated with early development of radiolucent lines at the bone-cement interface in total knee arthroplasty (TKA). The posterior condylar surfaces, in particular, seem subject to poor cement technique, which could lead to early loosening. This study compares two cementation techniques in TKA, with respect to depth of cement penetration and radiolucency in the posterior condyles. All penetration depths were greater in group I (injected) versus group II (noninjected). Sixty-seven percent of group I showed penetration depths >1.5 mm compared with 23% of group II. No specimen in group I had gaps in the cement mantle on visual inspection or radiolucency on radiographic evaluation. No statistical differences, however, could be demonstrated between the two groups.

Effect of bone porosity on the mechanical integrity of the bone-cement interface.

Osteopenia is one factor that may influence the decision about the type of implant fixation to use in total hip arthroplasty. However, clinical studies generally do not associate the outcome of an arthroplasty with the degree of osteopenia. The mechanical integrity of the cement fixation of an implant may be affected by the relative degree of osteopenia, which could account for some of the variable long-term results after total hip arthroplasty performed with cement. The purpose of this study was to determine the effects of bone porosity, trabecular orientation, cement pressure, and cement penetration depth on fracture toughness at the bone-cement interface. Trabecular bone from the proximal part of bovine femora was used with a single brand of commercial acrylic bone cement to form compact-tension interface specimens representing a range of bone porosities, orientations, and cement pressures within a clinically achievable range. All specimens were loaded to failure with use of a servohydraulic testing machine, and fracture toughness at the interface was calculated. After testing, images of a representative sample of specimens were made with use of computed tomography to measure the penetration depth of the cement into the bone. Significant correlations were found between fracture toughness and bone porosity, trabecular orientation, and cement pressure, with bone porosity having the strongest effect (p < 0.000015). Examination of the computed tomographic images also showed a significant correlation between fracture toughness and maximum cement penetration depth (p < 0.033), as well as significant partial correlations between maximum and mean penetration depth and bone porosity (p < 0.0037 and p < 0.0028). The fracture resistance of the bone-cement interface is greatly improved when the ability of the cement to flow into the intertrabecular spaces is enhanced.

218 細孔への骨セメントの侵入深さに関する研究(O.S.11-2 バイオエンジニアリングの基礎から応用に至る諸問題2)(オーガナイズドセッション11 : バイオエンジニアリングの基礎から応用に至る諸問題)

218 細孔への骨セメントの侵入深さに関する研究(O.S.11-2 バイオエンジニアリングの基礎から応用に至る諸問題2)(オーガナイズドセッション11 : バイオエンジニアリングの基礎から応用に至る諸問題)

The Effect of Bleeding on the Cement-Bone Interface

A model was developed to simulate bleeding from cancellous bone at the physiologic pressures and flow rates that can occur during total hip arthroplasty. The consequences of simulated bleeding on the penetration of bone cement into cancellous bone, the shear strength of the cement-bone interface, and the shear strength of bone cement were investigated. In the presence of active bleeding, the shear strength of the cement-bone interface was reduced significantly in 50% of interfaces in which cements of lower viscosity were used. The simulated bleeding did not exert a detrimental effect on the depth of cement penetration.

Stress transfer at the femoral bone/bone cement interface as a function of the cement thickness.

When a cement canal prosthesis is used as the femoral component in total hip replacement (THR), the penetration depth of the bone cement can be varied according to the cement implantation pressure. Using experimental data which give a relation between the pressure applied to the cement at implantation and the resulting shape of the cement layer, a three-dimensional finite element study was performed to calculate the stress distribution at the bone/bone cement interface. The calculations show that the interface stresses increase with increasing depth of penetration by the cement layer. The explanation of this effect is that as the bone cement penetrates further into the cancellous bone, the cancellous bone is stiffened and can no longer act as a soft interposition between cortical bone and bone cement. From these results and from the clinical requirement that as little bone as possible be destroyed in any kind of allo-arthroplasty, we conclude that the penetration depth of bone cement into cancellous bone in THR should be minimized to the depth necessary in order to achieve sufficient initial stability of the implant. The results show that a cement-canal prosthesis meets these requirements if a cement implantation pressure of 1.0 bar is used.