Trends in the Use of High-Viscosity Cement in Patients Undergoing Primary Total Knee Arthroplasty in the United States
ARTICLES & DATA
- Trends in the Use of High-Viscosity Cement in Patients Undergoing Primary Total Knee Arthroplasty in the United States
Aseptic loosening remains the most common mode of failure following total knee arthroplasty (TKA). Although the risk of loosening is multifactorial, recent studies reported early failure via debonding at the tibial implant-cement interface and a potential association with high viscosity cement (HVC). The purpose of this study is to determine the type of cement used by surgeons performing elective, primary TKA in the United States.
A retrospective cohort study was performed using data reported to the American Joint Replacement Registry from 2012 to 2017. The primary variable assessed was the type of cement used in each primary TKA, categorized as HVC, medium viscosity cement, or low viscosity cement based on the manufacturer’s specifications. The use of antibiotic-impregnated cement was also assessed.
A total of 554,935 primary TKA procedures were reviewed over the 7-year period. The use of HVC steadily increased from 46.0% of TKAs in 2012 to 61.3% of TKAs in 2017. Conversely, the use of low viscosity cement decreased in use from 47.9% of TKAs in 2012 to 30.9% in 2017. The percentage of TKAs performed using antibiotic-impregnated cement also decreased from 44.2% in 2012 to 34.5% in 2017.
This study demonstrates that the percentage of TKAs performed using HVC has continued to increase over the most recent 7 years for which the American Joint Replacement Registry has data. The risk of aseptic loosening is clearly multifactorial, but close monitoring is necessary to determine whether this change in surgeon preference will affect component survivorship.
- Mortality After Total Knee and Total Hip Arthroplasty in a Large Integrated Health Care System
Context The number of excess deaths associated with elective total joint arthroplasty in the US is not well understood.
Objective To evaluate one-year postoperative mortality among patients with elective primary and revision arthroplasty procedures of the hip and knee.
Design A retrospective analysis was conducted of hip and knee arthroplasties performed in 2010. Procedure type, procedure volume, patient age and sex, and mortality were obtained from an institutional total joint replacement registry. An integrated health care system population was the sampling frame for the study subjects and was the reference group for the study.
Main Outcome Measures Standardized 1-year mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated.
Results A total of 10,163 primary total knee arthroplasties (TKAs), 4963 primary total hip arthroplasties (THAs), 606 revision TKAs, and 496 revision THAs were evaluated. Patients undergoing primary THA (SMR = 0.6, 95% CI = 0.4–0.7) and TKA (SMR = 0.4, 95% CI = 0.3–0.5) had lower odds of mortality than expected. Patients with revision TKA had higher-than-expected mortality odds (SMR = 1.8, 95% CI = 1.1–2.5), whereas patients with revision THA (SMR = 0.9, 95% CI = 0.4–1.5) did not have higher-than-expected odds of mortality.
Conclusion Understanding excess mortality after joint surgery allows clinicians to evaluate current practices and to determine whether certain groups are at higher-than-expected mortality risk after surgery.
- The Relationship Between Porosity and Fatigue Characteristics of Bone Cements
In this study, the fatigue strengths of acrylic cement prepared by various commercially available reduced pressure mixing systems were compared with the fatigue strength of cement mixed by hand (control) under atmospheric conditions. The following observations were made from this investigation. The mean fatigue strength of reduced pressure mixed acrylic bone cement is double that of cement mixed by hand using an open bowl, 11,354+/-6,441 cycles to failure for reduced pressure mixing in comparison with 5,938+/-3,199 cycles for mixing under atmospheric conditions. However, the variability in mean fatigue strengths of reduced pressure mixed bone cement is greater for some mixing devices. The variation in fatigue strengths for the different mixing techniques is explained by the different porosity distributions. The design of the reduced pressure mixing system and the technique employed during mixing strongly contribute to the porosity distribution within the acrylic bone cement. The level of reduced pressure applied during cement mixing has an effect on the fatigue strength of bone cement, but the mixing mechanism is significantly more influential.
- Comparison of Various Vacuum Mixing Systems and Bone Cements as Regards Reliability, Porosity and Bending Strength
BACKGROUND: There are several vacuum mixing systems on the market which are arbitrarily used with various bone cements in clinical work. Hardly any studies have been done on the performance and handling of these systems in combination with different cement brands.
MATERIAL AND METHODS: We therefore tested 6 vacuum mixing systems (Palamix, Summit, Cemvac, Optivac, Vacumix, MixOR) in combination with 6 cement brands (Palacos R, Simplex P, CWM 1, CWM 2000, Palamed G, VersaBond) concerning their reliability, user-friendliness, porosity and bending strength.
RESULTS: Our study indicated that each system has weak points. The preparation of the mixed cement for gun injection can present problems. If cement collection under vacuum fails, porosity is increased. Manual collection without a vacuum carries the risk of intermixing air. For comfortable and effective retrograde cement application, cement guns should have a stable connection with the cartridge and a high piston stroke. There are marked differences between the systems as regards overall porosity when all tested cements are considered (range 2-18%), and between the cements when all tested systems are considered (range 2-17%). All test samples exceeded the required bending strength of 50 MPa, according to ISO 5833. Palaces specimens showed excessive plastic deformation in the bending test.
INTERPRETATION: There are better and worse mixing system/cement combinations for a given system and a given cement. Systems with cement collection under vacuum reduce porosity best.
- Multinational Comprehensive Evaluation of the Fixation Method Used in Hip Replacement: Interaction with Age in Context
BACKGROUND: Fixation in total hip replacements remains a controversial topic, despite the high level of its success. Data obtained from major orthopaedic registries indicate that there are large differences among preferred fixation and survival results.
METHODS: Using a distributed registry data network, primary total hip arthroplasties performed for osteoarthritis from 2001 to 2010 were identified from six national and regional total joint arthroplasty registries. A multivariate meta-analysis was performed using linear mixed models with the primary outcome revision for any reason. Survival probabilities and their standard errors were extracted from each registry for each unique combination of the covariates. Fixation strategies were compared with regard to age group, sex, bearing, and femoral-head diameter. All comparisons were based on the random-effects model and the fixed-effects model.
RESULTS: In patients who were seventy-five years of age and older, uncemented fixation had a significantly higher risk of revision (p < 0.001) than hybrid fixation, with a hazard ratio of 1.575 (95% confidence interval, 1.389 to 1.786). We found a similar, if lesser, effect in the intermediate age group of sixty-five to seventy-four years (hazard ratio, 1.16 [95% confidence interval, 1.023 to 1.315]; p = 0.021) and in the younger age group of forty-five to sixty-four years (hazard ratio, 1.205 [95% confidence interval, 1.008 to 1.442]; p = 0.041). There were no significant differences between hybrid and cemented bearings across age groups.
CONCLUSIONS: We conclude that cementless fixation should be avoided in older patients (those seventy-five years of age or older), although this evidence is less strong in patients of intermediate and younger ages.
- Intrusion Characteristics of High Viscosity Bone Cements for the Tibial Component of a Total Knee Arthroplasty Using Negative Pressure Intrusion Cementing Technique
BACKGROUND: With the advent of new bone cements with different viscosities, it is important to understand how they respond to different cementing techniques. The purpose of this study was to evaluate the high viscosity (HV) bone cement intrusion characteristics comparing negative pressure intrusion technique (NPI) and finger-packing technique in a cadaveric proximal tibial bone.
METHODS: Soft tissues were removed from twenty- four fresh frozen cadaver proximal tibiae, and standard arthroplasty tibial cuts were performed. Palacos-R (Zimmer, Warsaw, IN) and Simplex-HV (Stryker Howmedica Osteonics, Mahwah, NJ) bone cement were used. Each tibia was randomly assigned to receive one of the two bone cements with finger-packing technique and NPI technique. Forty-five Newton weight was applied along the long axis of the tibia during cement-setting phase. Once the cement had cured, sagittal sections were prepared and analyzed for cement penetration depth using digital photography and stereoscopic micrographs. Area of interest (AOI) for each specimen was also used to quantitatively evaluate the area of cement penetration.
RESULTS: When using Palacos-R, significant dif ferences were detected in cement penetration between the two cementing techniques. On the other hand, when using Simplex-HV, cement penetration was not significantly increased with finger-packing technique when compared to NPI technique. When comparing the two high-viscosity bone cements when using NPI cementing technique, significant differences were detected at Zone 4, where Simplex-HV penetrated deeper than the Palacos-R. When finger-packing technique was used with Simplex-HV, significant differences were detected in bone cement penetration at Zones 3-5. When looking at AOI, no significant differences were found between the Palacos-R and Simplex-HV bone cements in terms of penetration depths with NPI technique. Higher penetration depths were achieved with Simplex-HV bone cement compared to Palacos-R cement in finger packing technique.
CONCLUSION: The data demonstrated that the combination of different bone cement formulations and the cementing technique has a significant effect on cement penetration into the cut bone surface.
- Cementing Techniques for the Tibial Component in Primary Total Knee Replacement
The optimum cementing technique for the tibial component in cemented primary total knee replacement (TKR) remains controversial. The technique of cementing, the volume of cement and the penetration are largely dependent on the operator, and hence large variations can occur. Clinical, experimental and computational studies have been performed, with conflicting results. Early implant migration is an indication of loosening. Aseptic loosening is the most common cause of failure in primary TKR and is the product of several factors. Sufficient penetration of cement has been shown to increase implant stability. This review discusses the relevant literature regarding all aspects of the cementing of the tibial component at primary TKR.
- Hand-Mixed and Premixed Antibiotic-loaded Bone Cement Have Similar Homogeneity
Since low-dose antibiotic-loaded bone cement (ALBC) was approved by the FDA for second-stage reimplantation after infected arthroplasties in 2003, commercially premixed low-dose ALBC has become available in the United States. However, surgeons continue to mix ALBC by hand. We presumed hand-mixed ALBC was not as homogeneous as commercially premixed ALBC. We assessed homogeneity by determining the variation in antibiotic elution by location in a batch, from premixed and hand-mixed formulations of low-dose ALBC. Four hand-mixed methodologies were used: (1) suspension–antibiotic powder in the liquid monomer; (2) no-mix–antibiotic powder added but not mixed with the polymer powder before adding monomer; (3) hand-stirred–antibiotic powder stirred into the polymer powder before the monomer was added; and (4) bowl-mix–antibiotic powder mixed into polymer powder using a commercial mixing bowl before the monomer was added. Antibiotic elution was measured using the Kirby-Bauer bioassay. None of the mixing methods had consistently dissimilar homogeneity of antibiotic distribution from the others. Based upon our data we conclude hand-mixed low-dose ALBC is not less homogeneous than commercially premixed formulations.
- The role of polymethylmethacrylate bone cement in modern orthopaedic surgery
Polymethylmethacrylate remains one of the most enduring materials in orthopaedic surgery. It has a central role in the success of total joint replacement and is also used in newer techniques such as percutaneous vertebroplasty and kyphoplasty. This article describes the current uses and limitations of polymethylmethacrylate in orthopaedic surgery. It focuses on its mechanical and chemical properties and links these to its clinical performance. The behaviour of antibiotic-loaded bone cement are discussed, together with areas of research that are now shedding light upon the behaviour of this unique biomaterial.