Cement Pressurization Research Articles

Cement venogram: as a result of high femoral cement pressurisation. A report of 3 cases

Current femoral cementing techniques for total hip arthroplasty (THA) have improved over recent years. High pressurisation is achieved using a cement gun with a proximal seal and a cement restrictor, maximising the microinterlock at the bone cement interface. However, there are concerns regarding over pressurisation of the femoral canal resulting in an increased risk of cardiorespiratory collapse secondary to embolic phenomena. We report on three cases over a one year period of cement within a vein (cement venogram) on a post-operative radiograph following THA. We feel that the cement venogram is an important indicator of high pressurisation and that its incidence may be on the increase with improved cementing techniques.

Mechanical Stability of Total Hip Replacement Using Pressurization of Bone Cement During Curing: Push-out Tests in Cadaver Femora

An experimental model was used to assess the mechanical stability of a cemented hip prosthesis, comparing the result from applied pressurization versus its absence during the curing process. Twelve pairs of cadaveric femora underwent simulated total hip replacement. The right femurs were pressurized for 10 minutes in the upper surface of the construct. The applied pressure was 325.4 KPa. All the femurs were osteotomized 30 days postoperatively and push-out tests were performed. The mean failure load at the cement-bone interface was found to be 58% higher with the pressurization technique (7.619 KN versus 4.817 KN) (P <.001). The amount of pressure we used proved advantageous, however the required physical effort proved exhausting. The design of a new surgical instrument could possibly resolve the problem.

Femoral Cement Pressurization in Hip Arthroplasty: A Comparison of 3 Systems

Cement pressurization is critical to achieving optimal results in cemented arthroplasty of the hip. An in vitro experiment using plastic femoral models (10 per group) was undertaken to measure the pressures developed by 3 cementing systems: the Howmedica Mark 1 (Stryker Howmedica, Limerick, Ireland) and DePuy Cemvac retrograde cementation systems (DePuy CMW, Blackpool, UK), and a novel antegrade system consisting of a 60-mL catheter-tipped syringe and a Miller proximal femoral seal (Zimmer Ltd, Swindon, UK). The mean pressure was higher for the syringe system (161.45 ± 28.9 kPa) than the Mark 1 (103.51 ± 22.0 kPa) or Cemvac (92.65 ± 30.7 kPa) systems ( P = .0001). In addition, fewer cement mantle defects were seen with the syringe system (1, interquartile range [IQR] 1-2) than the Mark 1 (3, IQR 2-4) or Cemvac (3, IQR 1-3) systems ( P = .0256).

Cement Restrictor Function Below the Femoral Isthmus

Cement restrictors rely on achieving an interference fit with the wall of the medullary canal. Depending on the design of the cement restrictor, the intramedullary fit may be compromised as the femur starts to widen distally. Three different designs of cement restrictor were identified; universal, press-fit, and expandable. We determined which design of cement restrictor could resist the greatest pressures in a closed column of cement. Additionally, we recorded leakage of cement past the restrictor. We reamed synthetic femora to recreate the normal distal flare of the femur below the femoral isthmus. After inserting the cement restrictor, low-viscosity cement was gradually pressurized using an electronically controlled pneumatic ram. We then simultaneously recorded cement pressure above the cement restrictor and displacement of the cement restrictor. There was variation in the performance of the cement restrictors. The expandable cement restrictors resisted the greatest pressures. The resorbable expandable (REX Cement Stop) and press-fit cement restrictors reliably prevented cement leakage. The press-fit and universal restrictors failed at low pressures when deployed below the isthmus. The choice of cement restrictor may need to be modified if preoperative templating indicates the restrictor will sit below the femoral isthmus.

Technical Notes and Tips: Cement Restriction in Dynamic Hip Screw Revisions: A Cost-Effective Technique

Conversion of dynamic hip screw to total hip arthroplasty is an operation which poses the challenge of cement pressurisation due to the proximal femoral defect left after removal of the compression screw. We have used a Wrobleski bone-block system for harvesting a cylindrical bone graft from the inter-trochanteric bone after the neck is cut. This bone plug fits the defect very well. External finger pressure prevents dislodgement of the block during cement pressurisation. This method is simple, quick and cheap compared to all other techniques described. It is also advantageous for future revision surgery.

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.

911 人工股関節置換術におけるセメントマントル圧力の測定(OS3-2 挑戦するバイオエンジニアリング(3),オーガナイズドセッション:3 挑戦するバイオエンジニアリング)

911 人工股関節置換術におけるセメントマントル圧力の測定(OS3-2 挑戦するバイオエンジニアリング(3),オーガナイズドセッション:3 挑戦するバイオエンジニアリング)

An Innovative Laboratory Box for Testing Nail Pull-Out Resistance in Soil

Abstract This paper introduces a new soil nail pull-out box with full instrumentation for investigating the soil nail pull-out shear resistance under different controlled conditions. The new box has overcome some limitations of previous pull-out boxes developed by other researchers, the first author, and his co-workers. The box has the following new features: (a) comprehensive transducers are installed, (b) an extension chamber is provided to house an extension part of the soil nail to keep the nail length inside the box constant throughout the testing, (c) a waterproof front cap is placed to cover and seal the soil nail head so that back water pressure can be applied to accelerate the saturation of the soil, and (d) a pressure grouting apparatus is constructed to make it possible to investigate the influence of the cement grouting pressure. The pull-out box can be used to study influences of (a) hole drilling process and stress release, (b) degree of saturation of the soil, (c) cement pressure grouting, (d) overburden pressure, etc. Two copies of such a new soil nail pull-out box have been constructed to accelerate the testing program. A series of soil nail pull-out tests has been conducted using the two boxes. This paper presents details of the new pull-out box, from design, boundary effect analysis, and instrumentation to setup. Typical results from soil nail pull-out tests are presented and discussed.

Cement pressurisation in the acetabulum

Cement pressurisation is an important step in total hip arthroplasty that determines the long-term integration at the cement-bone interface. Our aim was to evaluate the performance of a new pressuriser designed by us against the standard existing pressurisers in an in vitro experimental set-up using two parameters: cement penetration and cement pressurisation. A polypropylene cup model was designed to represent the acetabulum. DePuy's T-handle, Exeter and our own plunger type pressuriser were each tested for cement pressurisation in this acetabular model. Cement penetration and pressures were measured. The cement intrusion into the capillaries with the DePuy pressuriser was found to vary between 2 and 8 mm (mean: 5 mm at the pole and 4.6 mm at the rim), with the Exeter pressuriser it varied between 3 and 9 mm (mean: 5.8 mm at the pole and 7.8 mm at the rim) and with the plunger type pressuriser it varied between 4 and 6 mm (mean 5.2 mm at the pole and 4.8 mm at the rim). The peak pressure achieved with the DePuy pressuriser was 60 kPa whereas it was 70 kPa with the plunger type pressuriser. The mean penetration with the plunger type pressuriser was found to be better than the other types. The penetration was found to be more uniform with equal penetration at the rim as well as at the pole.

Tissue response to in situ polymerization of a new two‐solution bone cement: Evaluation in a sheep model

A two-solution bone cement (2-SC) was evaluated in a non-load bearing sheep model that simulated insertion of a cemented total joint replacement. A commercial powder-liquid bone cement formulation (Palacos R) was used as the control. The systemic response to the two cements was determined by monitoring changes in arterial blood pressure (ABP) and serum concentrations of methyl methacrylate monomer at intervals after insertion of the cement. The short-term tissue response to the two cements was assessed by quantifying histomorphometric parameters of new bone formation at 2, 4, and 12 weeks postsurgery. Intraoperatively, injection and pressurization of bone cement were well tolerated, with no significant changes in ABP in either group and no detectable circulating monomer in any animal. Several interesting trends were identified in the histomorphometry data. In the trabecular specimens, new bone formation immediately adjacent to the cement mantle was apparently suppressed in the first 2 weeks postsurgery, increased dramatically at 4 weeks, and then returned to baseline values by 12 weeks. This pattern was seen with both Palacos and 2-SC. In the cortical specimens, new bone formation was reduced on the endosteal surface when compared with the periosteal surface, with this effect being more noticeable at 2 and 4 weeks than at 12 weeks. There were no significant histopathological findings in either the bone or the draining lymph nodes. These data indicate that the biological response to 2-SC is substantially equivalent to that of Palacos R. Additional testing in a functional, load-bearing animal model is now recommended to more fully characterize the long-term biological response to 2-SC and to determine the mechanical performance of this new cement in vivo.

Inferior stability of a biodegradable cement plug

Modern cementing technique demands high intramedullar cement pressure to create an optimum fixed cement support of the femoral stem. Pressure resistant, stable closure of the canal therefore is absolutely necessary. Biodegradable cement restrictors, if corresponding to above mentioned attributes, could be of immense advantage in case of potential revision surgery. A prospective, randomized trial was performed on a consecutive series of 130 patients who underwent primary cemented total hip arthroplasty due to hip arthrosis to compare a degradable cement restrictor and a non-degradable cement restrictor in their ability to resist distal migration during stem insertion. The median cement plug length measured 27 mm (range -12 to 126 mm, 95% confidence interval (CI) 20-33 mm) in the biodegradable restrictor group and 15 mm (range 0-61 mm, 95% CI 12-18 mm) in the non-degradable restrictor group (P=0.003). A significant effect of the relationship between the difference of restrictor size and the diameter of the femoral canal on length of cement distal of the tip of the stem in between the two groups was evident (P=0.031). The results indicate insufficient intramedullary plug fixation of the degradable restrictor probably due to the elastic material properties which also may lead to inferior precision in restrictor size choice.

The Distribution of Cement Penetration into Bovine Acetabular Bone Utilising Various Pressurisation Techniques

Most mechanical failures of acetabular fixation within ten years of primary cemented hip replacement are attributable to a failure to achieve good initial fixation of bone and cement. Several studies have suggested that to achieve good fixation between bone and cement between 3 mm and 5 mm of cement penetration into bone is desirable. Whilst several acetabular cement pressurisation systems exist, little is known about the effects of cement pressurisation on the pattern of penetration of cement into cancellous bone within the pelvis. The current paper assesses the penetration of bone cement into bovine acetabular bone by various pressurisation techniques. We found that pressurisation with the use of a swab in glove or the DePuy pressuriser led to improvement in cement penetration both in terms of maximum depth and also percentage cover of the cup by cement (p &lt; 0.05). There was no significant difference in mean maximal penetration between the use of the pressuriser and the swab in a glove technique (p = 0.3). If only a plain cup was used as a pressuriser, the penetration achieved was significantly lower in comparison to use of a pressuriser (p &lt; 0.02). When compared to previously documented acrylic models, the pattern of intrusion noted in the bovine model was different: penetration was lower at the equatorial and base regions of the acetabulum.

Femoral Cementing Techniques: Current Trends in the UK

The results of a survey conducted amongst hip surgeons in Great Britain on the use of bone cement and femoral cementing techniques are reported. A postal questionnaire was sent out to the members of the British Orthopaedic Association for their opinion on cement usage and femoral cementing techniques in primary hip arthroplasty. A majority of surgeons use high viscosity cement (82%) and cement containing antibiotics (77%). Almost a fifth of the respondents were unaware of the place of storage of the cement and of the ambient theatre temperature. Over two-thirds experienced inconsistencies in the handling of cement and attributed this to inconsistent theatre temperature (40%) and storage temperature (14%). A majority of the surgeons followed the 'modern' femoral cementing technique of vacuum mixing (94%), plugging the femoral canal (98%), pulsed lavage (87%), retrograde cement introduction (95%), use of stem centralisers (62%) and cement pressurisation. Four-fifths of the surgeons used time as a guide for cement and stem insertion rather than consistency of the cement. Though most of the surgeons follow contemporary cementing techniques, it appears that inconsistency of the working properties of the cement is a major impediment. Many surgeons are also unaware of the variables that can influence polymerisation and working time of the cement.

Cement Venogram—A Risk of Satisfactory Cement Pressurization

Longevity of cemented femoral components is dependent upon many factors. It is certainly related to the cementing technique. A dilemma exists between adequate cement pressurization and risk of embolic events. A cementation pressure above bleeding pressure, to allow optimum cement bone interdigitation but not high enough to produce embolic or cardiorespiratory events, is the ideal situation. We present a case where cement pressurization resulted in the appearance of a cement venogram on the routine postoperative x-ray.

Performance of 3 gelatine-based resorbable cement plugs: A study on 15 synthetic femurs and a prospective randomized study on 103 patients

Background Intramedullary plugs are key factors in improving cement fixation of the femoral component. We investigated the performance of 3 commercially available resorbable cement restrictors in vitro and in vivo.Methods We measured the migration of the SEM II, the C-plug, and the REX plug in 15 Sawbones synthetic femurs and in 103 patients during total hip surgery. Cement pressures were also measured distally and proximally in vitro.Results and interpretation Our in vitro results showed poor performance of the C-plug compared with the REX and SEM II plugs. In vivo, the mean migration was least for the SEM plug and most for the C-plug. The smaller sizes performed significantly better than the larger ones for all 3 plug types. The overall in vivo performance of all 3 plug types was unsatisfactory. Differences between the SEM II and REX plugs were small and therefore not significant. The SEM II performed better than the REX, the former being much cheaper and easier to insert. The Rex plug looks promising; however, the insertion device must be improved for better results. The C-plug proved to be unstable.

The distribution of cement penetration into bovine acetabular bone utilising various pressurisation techniques

Most mechanical failures of acetabular fixation within ten years of primary cemented hip replacement are attributable to a failure to achieve good initial fixation of bone and cement. Several studies have suggested that to achieve good fixation between bone and cement between 3 mm and 5 mm of cement penetration into bone is desirable. Whilst several acetabular cement pressurisation systems exist, little is known about the effects of cement pressurisation on the pattern of penetration of cement into cancellous bone within the pelvis. The current paper assesses the penetration of bone cement into bovine acetabular bone by various pressurisation techniques. We found that pressurisation with the use of a swab in glove or the DePuy pressuriser led to improvement in cement penetration both in terms of maximum depth and also percentage cover of the cup by cement (p<0.05). There was no significant difference in mean maximal penetration between the use of the pressuriser and the swab in a glove technique (p=0.3). If only a plain cup was used as a pressuriser, the penetration achieved was significantly lower in comparison to use of a pressuriser (p<0.02). When compared to previously documented acrylic models, the pattern of intrusion noted in the bovine model was different: penetration was lower at the equatorial and base regions of the acetabulum.

Effect of cement pressurization on stem in-vitro stability with impaction allografting

Effect of cement pressurization on stem in-vitro stability with impaction allografting

An improved acetabular cementing technique in total hip arthroplasty

We have evaluated the effect of vacuum aspiration of the iliac wing on the osseointegration of cement into the acetabulum. We entered a total of 40 patients undergoing primary total hip arthroplasty into two consecutive study groups. Group 1 underwent acetabular cement pressurisation for 60 seconds before insertion of the acetabular component. Group 2 had the same pressurisation with simultaneous vacuum suction of the ilium using an iliac-wing aspirator. Standard post-operative radiographs were reviewed blindly to assess the penetration of cement into the iliac wing. Penetration was significantly greater in the group with aspiration of the iliac wing.

An In-Vitro Investigation into the Cement Pressurization Achieved During Insertion of Four Different Femoral Stems

Adequate cement pressurization during stem insertion improves the interdigitation of cement into bone. This increases the strength of the cement-bone interface, thus contributing to the reduction of the incidence of aseptic loosening, the commonest cause of revision surgery. This in-vitro study compared the cement pressurization achieved during insertion of four different stems of equivalent sizes: the Elite Plus (DePuy, UK), C-Stem (DePuy, UK), Exeter (Stryker, USA), and CPS-Plus (Plus Orthopedics, Switzerland). The maximum pressures attained at the time of stem insertion were recorded at proximal, mid and distal stem levels. The Elite Plus generated significantly higher distal pressures than the other stems. The CPS-Plus generated significantly greater proximal cement pressures than the Elite Plus, C-Stem, and Exeter prostheses. The triple taper of the C-Stem increased the cement pressurization medial to the stem. The stem shape and the presence or absence of a proximal stem centralizer affect cement pressurization. The presence of a proximal stem centralizer, a large stem volume, and a lateral-medial taper are all factors associated with increased cement pressurization during stem insertion.

Zementierte Hüftendoprothetik in Deutschland - ein Update

The results of a national survey from 1998 had shown at the time that only around 10 % of orthopaedic surgeons in Germany had strictly implemented modern cementing techniques in total hip arthroplasty (THA). The same study was repeated 5 years later to evaluate the current situation and to determine whether modern cementing techniques have become more popular. A detailed, slightly modified questionnaire regarding cement and bone preparation, cementing techniques on acetabulum and femur, and implant types was sent to 572 German orthopaedic and trauma hospitals, as well as to visiting surgeons with an interest in THA. In total, 293 questionnaires were available for evaluation and statistical analysis. Palacos bone cement remained the most widely used cement (> 90 %). The mixing times given varied significantly. Vacuum mixing systems had become more popular (67.9 %). In the femur 81.8 % of the surgeons attempted to preserve cancellous bone and 57.2 % used pulsatile lavage (jet-lavage). Retrograde cement application via a cement gun was done in 71.1 %. Cement restrictors were used in more than 95 %. Only two-thirds of the surgeons implemented sustained cement pressurisation and preferred a cement mantle thickness > 2mm (64 %). Only 16.9 % made multiple small acetabular keyholes and 48.6 % used jet-lavage. In 73.1 % no cement gun was used and in 68.3 % the cement was applied at high viscosity. Manual cement pressurisation was done in 58.1 %. The Muller straight stem device remained the most popular implant. For only 5 of the over 50 stem designs implanted have long-term results been published as yet. Only 10.6 % of surgeons/centres performed > 20 and almost 50 % implanted > 100 cemented THAs/year. The results of this survey demonstrated that, in comparison to 1998, the current state of cemented THA, in particular cementing technique has significantly improved. Future emphasis should be on continued surgeon education and training, as the operative, i. e., cementing techniques are of utmost importance for long-term success.