Aims. The primary objective of this registry-based study was to compare patient-reported outcomes of cementless and cemented medial unicompartmental knee arthroplasty (UKA) during the first postoperative year. The secondary objective was to assess one- and three-year implant survival of both fixation techniques. Methods. We analyzed 10,862 cementless and 7,917 cemented UKA cases enrolled in the Dutch Arthroplasty Registry, operated between 2017 and 2021. Pre- to postoperative change in outcomes at six and 12 months’ follow-up were compared using mixed model analyses. Kaplan-Meier and Cox regression models were applied to quantify differences in implant survival. Adjustments were made for patient-specific variables and annual hospital volume. Results. Change from baseline in the Oxford Knee Score (OKS) and activity-related pain was comparable between groups. Adjustment for covariates demonstrated a minimally greater decrease in rest-related pain in the cemented group (β = -0.09 (95% confidence interval (CI) -0.16 to -0.01)). Cementless fixation was associated with a higher probability of achieving an excellent OKS outcome (> 41 points) (adjusted odds ratio 1.2 (95% CI 1.1 to 1.3)). The likelihood of one-year implant survival was greater for cemented implants (adjusted hazard ratio (HR) 1.35 (95% CI 1.01 to 1.71)), with higher revision rates for periprosthetic fractures of cementless implants. During two to three years’ follow-up, the likelihood of implant survival was non-significantly greater for cementless UKA (adjusted HR 0.64 (95% CI 0.40 to 1.04)), primarily due to increased revision rates for tibial loosening of cemented implants. Conclusion. Cementless and cemented medial UKA led to comparable improvement in physical function and pain reduction during the initial postoperative year, albeit with a greater likelihood of achieving excellent OKS outcomes after cementless UKA. Anticipated differences in early physical function and pain should not be a decisive factor in the choice of fixation technique. However, surgeons should consider the differences in short- and long-term implant survival when deciding which implant to use. Cite this article: Bone Jt Open 2024;5(5):401–410

Aims. To compare the cost-effectiveness of high-dose, dual-antibiotic cement versus single-antibiotic cement for the treatment of displaced intracapsular hip fractures in older adults. Methods. Using data from a multicentre randomized controlled trial (World Hip Trauma Evaluation 8 (WHiTE-8)) in the UK, a within-trial economic evaluation was conducted. Resource usage was measured over 120 days post randomization, and cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY), gained from the UK NHS and personal social services (PSS) perspective in the base-case analysis. Methodological uncertainty was addressed using sensitivity analysis, while decision uncertainty was handled using confidence ellipses and cost-effectiveness acceptability curves. Results. The base-case analysis showed that high-dose, dual-antibiotic cement had a significantly higher mean cost (£224 (95% confidence interval (CI) -408 to 855)) and almost the same QALYs (0.001 (95% CI -0.002 to 0.003)) relative to single-antibiotic cement from the UK NHS and PSS perspective. The probability of the high-dose, dual-antibiotic cement being cost-effective was less than 0.3 at alternative cost-effectiveness thresholds, and its net monetary benefit was negative. This finding remained robust in the sensitivity analyses. Conclusion. This study shows that high-dose, dual-antibiotic cement is unlikely to be cost-effective compared to single-antibiotic cement for the treatment of displaced intracapsular hip fractures in older adults. Cite this article: Bone Joint J 2023;105-B(10):1070–1077

Aims. The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems. Methods. In this case-control study, 25 patients (22 female) at mean age of 78 years (70 to 89) received cemented Exeter short stem (case group). Cases were selected based on Dorr type A femora and matched first by Dorr type A and then age to a control cohort of 21 patients (11 female) at mean age of 74 years (70 to 89) who received with cemented Exeter standard stems (control group). Preoperatively, all patients had primary hip osteoarthritis and no osteoporosis as confirmed by dual X-ray absorptiometry scanning. Patients were followed with radiostereometry for evaluation of stem migration (primary endpoint), evaluation of cement quality, and Oxford Hip Score. Measurements were taken preoperatively, and at three, 12, and 24 months and a minimum five-year follow-up. Results. At three months, subsidence of the short stem -0.87 mm (95% confidence interval (CI) -1.07 to -0.67) was lower compared to the standard stem -1.59 mm (95% CI -1.82 to -1.36; p < 0.001). Both stems continued a similar pattern of subsidence until five-year follow-up. At five-year follow-up, the short stem had subsided mean -1.67 mm (95% CI -1.98 to -1.36) compared to mean -2.67 mm (95% CI -3.03 to -2.32) for the standard stem (p < 0.001). Subsidence was not influenced by preoperative bone quality (osteopenia vs normal) or cement mantle thickness. Conclusion. The standard Exeter stem had more early subsidence compared with the short Exeter stem in patients with Dorr type A femora, but thereafter a similar migration pattern of subsidence until minimum five years follow-up. Both the standard and the short Exeter stems subside. The standard stem subsides more compared to the short stem in Dorr type A femurs. Subsidence of the Exeter stems was not affected by cement mantle thickness. Cite this article: Bone Jt Open 2023;4(7):507–515

Aims. Highly polished stems with force-closed design have shown satisfactory clinical results despite being related to relatively high early migration. It has been suggested that the minimal thickness of cement mantles surrounding the femoral stem should be 2 mm to 4 mm to avoid aseptic loosening. The line-to-line cementing technique of the femoral stem, designed to achieve stem press-fit, challenges this opinion. We compared the migration of a highly polished stem with force-closed design by standard and line-to-line cementing to investigate whether differences in early migration of the stems occur in a clinical study. Methods. In this single-blind, randomized controlled, clinical radiostereometric analysis (RSA) study, the migration pattern of the cemented Corail hip stem was compared between line-to-line and standard cementing in 48 arthroplasties. The primary outcome measure was femoral stem migration in terms of rotation and translation around and along with the X-, Y-, and Z- axes measured using model-based RSA at three, 12, and 24 months. A linear mixed-effects model was used for statistical analysis. Results. Results from mixed model analyses revealed a lower mean retroversion for line-to-line (0.72° (95% confidence interval (CI) 0.38° to 1.07°; p < 0.001), but no significant differences in subsidence between the techniques (-0.15 mm (95% CI -0.53 to 0.227; p = 0.429) at 24 months. Radiolucent lines measuring < 2 mm wide were found in three and five arthroplasties cemented by the standard and line-to-line method, respectively. Conclusion. The cemented Corail stem with a force-closed design seems to settle earlier and better with the line-to-line cementing method, although for subsidence the difference was not significant. However, the lower rate of migration into retroversion may reduce the wear and cement deformation, contributing to good long-term fixation and implant survival. Cite this article: Bone Joint J 2022;104-B(1):19–26

Aims. The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system. Methods. We retrospectively analyzed a multicentre, international clinical database of a single platform shoulder system to compare the short-, mid-, and long-term clinical outcomes associated with three designs of aTSA glenoid components: 294 cemented keel, 527 cemented peg, and 981 hybrid cage glenoids. Outcomes were evaluated at 4,746 postoperative timepoints for 1,802 primary aTSA, with a mean follow-up of 65 months (24 to 217). Results. Relative to their preoperative condition, each glenoid cohort had significant improvements in clinical outcomes from two years to ten years after surgery. Patients with cage glenoids had significantly better clinical outcomes, with higher patient-reported outcome scores and significantly increased active range of motion, compared with those with keel and peg glenoids. Those with cage glenoids also had significantly fewer complications (keel: 13.3%, peg: 13.1%, cage: 7.4%), revisions (keel: 7.1%, peg 9.7%, cage 3.5%), and aseptic glenoid loosening and failure (keel: 4.7%, peg: 5.8%, cage: 2.5%). Regarding radiological outcomes, 70 patients (11.2%) with cage glenoids had glenoid radiolucent lines (RLLs). The cage glenoid RLL rate was 3.3-times (p < 0.001) less than those with keel glenoids (37.3%) and 4.6-times (p < 0.001) less than those with peg glenoids (51.2%). Conclusion. These findings show that good long-term clinical and radiological outcomes can be achieved with each of the three aTSA designs of glenoid component analyzed in this study. However, there were some differences in clinical and radiological outcomes: generally, cage glenoids performed best, followed by cemented keel glenoids, and finally cemented peg glenoids. Cite this article: Bone Joint J 2023;105-B(6):668–678

Aims. To date, there is insufficient evidence available to compare the outcome of cemented and uncemented fixation of the humeral stem in reverse shoulder arthroplasty (RSA). . Methods. A systemic review comprising 41 clinical studies was performed to compare the functional outcome and rate of complications of cemented and uncemented stems in RSA. These included 1455 cemented and 329 uncemented shoulders. The clinical characteristics of the two groups were similar. Variables were compared using pooled frequency-weighted means and relative risk ratios (RR). Results. Uncemented stems had a significantly higher incidence of early humeral stem migration (p < 0.001, RR 18.1, 95% confidence interval (CI) 5.0 to 65.2) and non-progressive radiolucent lines (p < 0.001, RR 2.4, 95% CI 1.7 to 3.4), but a significantly lower incidence of post-operative fractures of the acromion compared with cemented stems (p = 0.004, RR 14.3, 95% CI 0.9 to 232.8). There was no difference in the risk of stem loosening or revision between the groups. The cemented stems had a greater relative risk of infection (RR 3.3, 95% CI 0.8 to 13.7), nerve injury (RR 5.7, 95% CI 0.7 to 41.5) and thromboembolism (RR 3.9, 95% CI 0.2 to 66.6). The functional outcome and range of movement were equivalent in the two groups. . Discussion. RSA performed with an uncemented stem gives them equivalent functional outcome and a better complication profile than with a cemented stem. The natural history and clinical relevance of early stem migration and radiolucent lines found with uncemented stems requires further long-term study. Take home message: This study demonstrates that uncemented stems have at least equivalent clinical and radiographic outcomes compared with cemented stems when used for reverse total shoulder arthroplasty. . Cite this article: Bone Joint J 2016;98-B:65–74

Aims. The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA. Methods. A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis. Results. RLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7). Conclusion. This study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL. Cite this article: Bone Joint Open 2021;2(5):278–292

Aims. Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients. Materials and Methods. Data from the National Joint Registry (NJR) of England and Wales were obtained for all primary cemented TKAs between March 2003 and July 2016. Patient, implant, and surgical variables were analyzed. Cox proportional hazards models were used to assess the influence of ALBC on risk of revision. Body mass index (BMI) data were available in a subset of patients. Results. Of 731 214 TKAs, 15 295 (2.1%) were implanted with plain cement and 715 919 (97.9%) with ALBC. There were 13 391 revisions; 2391 were performed for infection. After adjusting for other variables, ALBC had a significantly lower risk of revision for any cause (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77 to 0.93; p < 0.001). ALBC was associated with a lower risk of revision for all aseptic causes (HR 0.85, 95% CI 0.77 to 0.95; p < 0.001) and revisions for infection (HR 0.84, 95% CI 0.67 to 1.01; p = 0.06). The results were similar when BMI was added into the model, and in a subanalysis where surgeons using only ALBC over the entire study period were excluded. Prosthesis survival at ten years for TKAs implanted with ALBC was 96.3% (95% CI 96.3 to 96.4) compared with 95.5% (95% CI 95.0 to 95.9) in those implanted with plain cement. On a population level, where 100 000 TKAs are performed annually, this difference represents 870 fewer revisions at ten years in the ALBC group. Conclusion. After adjusting for a range of variables, ALBC was associated with a significantly lower risk of revision in this registry-based study of an entire nation of primary cemented knee arthroplasties. Using ALBC does not appear to increase midterm implant failure rates. Cite this article: Bone Joint J 2019;101-B:1331–1347

Objectives. The objective of this study was to characterize the effect of rifampin incorporation into poly(methyl methacrylate) (PMMA) bone cement. While incompatibilities between the two materials have been previously noted, we sought to identify and quantify the cause of rifampin’s effects, including alterations in curing properties, mechanical strength, and residual monomer content. Methods. Four cement groups were prepared using commercial PMMA bone cement: a control; one with 1 g of rifampin; and one each with equimolar amounts of ascorbic acid or hydroquinone relative to the amount of rifampin added. The handling properties, setting time, exothermic output, and monomer loss were measured throughout curing. The mechanical strength of each group was tested over 14 days. A radical scavenging assay was used to assess the scavenging abilities of rifampin and its individual moieties. Results. Compared with control, the rifampin-incorporated cement had a prolonged setting time and a reduction in exothermic output during polymerization. The rifampin cement showed significantly reduced strength and was below the orthopaedic weight-bearing threshold of 70 MPa. Based on the radical scavenging assay and strength tests, the hydroquinone structure within rifampin was identified as the polymerization inhibitor. Conclusion. The incorporation of rifampin into PMMA bone cement interferes with the cement’s radical polymerization. This interference is due to the hydroquinone moiety within rifampin. This combination alters the cement’s handling and curing properties, and lowers the strength below the threshold for weight-bearing applications. Additionally, the incomplete polymerization leads to increased toxic monomer output, which discourages its use even in non-weight-bearing applications. Cite this article: G. A. Funk, E. M. Menuey, K. A. Cole, T. P. Schuman, K. V. Kilway, T. E. McIff. Radical scavenging of poly(methyl methacrylate) bone cement by rifampin and clinically relevant properties of the rifampin-loaded cement. Bone Joint Res 2019;8:81–89. DOI: 10.1302/2046-3758.82.BJR-2018-0170.R2

Aims. Cementing in arthroplasty for hip fracture is associated with improved postoperative function, but may have an increased risk of early mortality compared to uncemented fixation. Quantifying this mortality risk is important in providing safe patient care. This study investigated the association between cement use in arthroplasty and mortality at 30 days and one year in patients aged 50 years and over with hip fracture. Methods. This retrospective cohort study used linked data from the Australian Hip Fracture Registry and the National Death Index. Descriptive analysis and Kaplan-Meier survival curves tested the unadjusted association of mortality between cemented and uncemented procedures. Multilevel logistic regression, adjusted for covariates, tested the association between cement use and 30-day mortality following arthroplasty. Given the known institutional variation in preference for cemented fixation, an instrumental variable analysis was also performed to minimize the effect of unknown confounders. Adjusted Cox modelling analyzed the association between cement use and mortality at 30 days and one year following surgery. Results. The 30-day mortality was 6.9% for cemented and 4.9% for uncemented groups (p = 0.003). Cement use was significantly associated with 30-day mortality in the Kaplan-Meier survival curve (p = 0.003). After adjusting for covariates, no significant association between cement use and 30-day mortality was shown in the adjusted multilevel logistic regression (odd rati0 (OR) 1.1, 95% confidence interval (CI) 0.9 to 1.5; p = 0.366), or in the instrumental variable analysis (OR 1.0, 95% CI 0.9 to 1.0, p=0.524). There was no significant between-group difference in mortality within 30days (hazard ratio (HR) 0.9, 95% CI 0.7to 1.1; p = 0.355) or one year (HR 0.9 95% CI 0.8 to 1.1; p = 0.328) in the Cox modelling. Conclusion. No statistically significant difference in patient mortality with cement use in arthroplasty was demonstrated in this population, once adjusted for covariates. This study concludes that cementing in arthroplasty for hip fracture is a safe means of surgical fixation. Cite this article: Bone Jt Open 2023;4(3):198–204

Objectives. Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep. Methods. We cemented six collarless polished tapered (CPT) stems (two stems each of small, medium and large sizes) into composite femurs that had been reamed with a large CPT rasp to achieve various thicknesses of the cement mantle. Two or three tantalum balls were implanted in the proximal cement in each femur. A cyclic loading test was then performed for each stem. The migration of the balls was measured three-dimensionally, using a micro-computed tomography (CT) scanner, before and after loading. A digital displacement gauge was positioned at the stem shoulder, and stem subsidence was measured continuously by the gauge. Final stem subsidence was measured at the balls at the end of each stem. Results. A strong positive correlation was observed between mean cement thickness and stem subsidence in the CT slices on the balls. In the small stems, the balls moved downward to almost the same extent as the stem. There was a significant negative correlation between cement thickness and the horizontal:downward ratio of ball movement. Conclusion. Collarless polished tapered stems with thicker cement mantles resulted in greater subsidence of both stem and cement. This suggests that excessive thickness of the cement mantle may interfere with effective radial cement creep. Cite this article: E. Takahashi, A. Kaneuji, R. Tsuda, Y. Numata, T. Ichiseki, K. Fukui, N. Kawahara. The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem: When are thick cement mantles detrimental? Bone Joint Res 2017;6:–357. DOI: 10.1302/2046-3758.65.BJR-2017-0028.R1

Aims. The main objective of this study is to analyze the penetration of bone cement in four different full cementation techniques of the tibial tray. Methods. In order to determine the best tibial tray cementation technique, we applied cement to 40 cryopreserved donor tibiae by four different techniques: 1) double-layer cementation of the tibial component and tibial bone with bone restrictor; 2) metallic cementation of the tibial component without bone restrictor; 3) bone cementation of the tibia with bone restrictor; and 4) superficial bone cementation of the tibia and metallic keel cementation of the tibial component without bone restrictor. We performed CT exams of all 40 subjects, and measured cement layer thickness at both levels of the resected surface of the epiphysis and the endomedular metaphyseal level. Results. At the epiphyseal level, Technique 2 gave the greatest depth compared to the other investigated techniques. At the endomedular metaphyseal level, Technique 1 showed greater cement penetration than the other techniques. Conclusion. The best metaphyseal cementation technique of the tibial component is bone cementation with cement restrictor. Additionally, if full tibial component cementation is to be done, the cement volume used should be about 40 g of cement, and not the usual 20 g. Cite this article: Bone Joint Res 2021;10(8):467–473

Standard practice in revision total hip replacement (THR) for periprosthetic fracture (PPF) is to remove all cement from the femoral canal prior to implantation of a new component. This can make the procedure time consuming and complex. Since 1991 it has been our practice to preserve the old femoral cement where it remains well fixed to bone, even if the cement mantle is fractured, and to cement a new component into the old mantle. We have reviewed the data of 48 consecutive patients, treated at our unit between 1991 and 2009, with a first PPF around a cemented primary THR stem where a cement in cement revision was performed. 8 hips were revised to a standard length stem, 39 hips to a long stem & 1 patient had the same stem reinserted. All fractures were reduced and held with cerclage wires or cables and four had supplementary plate fixation. Full clinical and radiographic follow up was available in 38 patients & clinical or radiographic follow up in a further 6 patients. The other 4 patients. without follow up but whose outcome is known, have suffered no complications and are pain free. Of the remaining 44 patients, forty-two went on to union of the fracture and two have required further surgery for non-union. One patient has ongoing undiagnosed hip pain. Our long term experience with cement in cement revision for periprosthetic femoral fractures shows that this is a viable technique with a low complication rate and high rate of union (95%) in what is generally regarded as a very difficult condition to treat

Aims. The aim of this study was to report the long-term follow-up of cemented short Exeter femoral components when used in primary total hip arthroplasty (THA). Methods. We included all primary 394 THAs with a cemented short Exeter femoral component (≤ 125 mm) used in our tertiary referral centre between October 1993 and December 2021. A total of 83 patients (21%) were male. The median age of the patients at the time of surgery was 42 years (interquartile range (IQR) 30 to 55). The main indication for THA was a childhood hip disease (202; 51%). The median follow-up was 6.7 years (IQR 3.1 to 11.0). Kaplan-Meier survival analyses were performed to determine the rates of survival with femoral revision for any indication, for septic loosening, for fracture of the femoral component and for aseptic loosening as endpoints. The indications for revision were evaluated. Fractures of the femoral component were described in detail. Results. The 20-year rate of survival was 85.4% (95% confidence interval (CI) 73.9 to 92.0) with revision for any indication, 96.2% (95% CI 90.5 to 98.5) with revision for septic loosening and 92.7% (95% CI 78.5 to 97.6) with revision for fracture of the femoral component. No femoral components were revised for aseptic loosening. There were 21 revisions of the femoral component; most (seven) as part of a two-stage management of infection. Fracture of the femoral component occurred in four THAs (1.0%) at 6.6, 11.6, 16.5, and 18.2 years of follow-up, respectively. Three of these were transverse fractures and occurred at the level of the lesser trochanter. In one THA, there was a fracture of the neck of the component. Conclusion. THAs using cemented short Exeter femoral components showed acceptable rates of survival of the femoral component at long-term follow-up, in this young cohort of patients. Although fracture is a rare complication of these components, surgeons should be aware of their incidence and possible risk factors. Cite this article: Bone Joint J 2024;106-B(3 Supple A):137–142

Osteosarcoma and other types of bone cancers often require bone resection, and backfill with cement. A novel silorane-based cement without PMMA's drawbacks, previously developed for dental applications, has been reformulated for orthopedic use. The aim of this study is to assess each cement's ability to elute doxorubicin, maintain its potency, and maintain suitable weight-bearing strength. The silorane-based epoxy cement was synthesized using a platinum-based Lamoreaux's catalyst. Four groups of cement were prepared. Two PMMA groups, one without any additives, one with 200 mg of doxorubicin. Two silorane groups: one without any additive, one with doxorubicin, added so that the w% of drug into both cements were equal. Pellets 6 × 12 mm were used for testing (ASTM F451). n=10. Ten pellets from each group were kept dry. All others were placed into tubes containing 2.5 mL of PBS and stored at 37 °C. Elution from doxorubicin-containing groups were collected every day for 7 days, with daily PBS changeout. Antibiotic concentrations were determined via HPLC. Compressive strength and compressive modulus of all groups were determined for unsoaked specimens, and those soaked for 7 and 14 days. MTT assays were done using an MG63 osteosarcoma cell line. Both cements were able to elute doxorubicin over 7 days in clinically-favorable quantities. For PMMA samples, the incorporation of doxorubicin was shown to significantly affect the compressive strength and modulus of the samples (p<0.01). Incorporation of doxorubicin into silorane had no significant effect on either (p>.05). MTT assays indicated that doxorubicin incorporated into the silorane cement maintained its effectiveness whereas that into PMMA did not. At the dosing used, both cements remained above the 70 MPa. Both PMMA and silorane-based cements can deliver doxorubicin. Doxorubicin, however, interacts chemically with PMMA, inhibiting polymerization and lowering the chemotherapeutic's effectiveness

Aims. Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening. Methods. A systematic search was undertaken using the Cochrane methodology in three online databases: MEDLINE, Embase, and CINAHL. Studies were screened against predetermined criteria, and data were extracted. Available National Joint Registries in the Network of Orthopaedic Registries of Europe were also screened. A random effects model meta-analysis was undertaken. Results. Of 263 studies, 12 were included with a total of 3,861 TKAs. Meta-analysis of ten studies showed high rates of overall tibial or femoral RLLs for the cemented original design of the ATTUNE TKA. The overall rate was 21.4% (95% confidence interval (CI) 12.7% to 33.7%) for all types of design but was higher for certain subgroups: 27.4% (95% CI 13.4% to 47.9%) for the cruciate-retaining type, and 29.9% (95% CI 15.6% to 49.6%) for the fixed-bearing type. Meta-analysis of five studies comparing the ATTUNE TKA with other implants showed a significantly higher risk of overall tibial or femoral RLLs (odds ratio (OR) 2.841 (95% CI 1.219 to 6.623); p = 0.016) for the ATTUNE. The rates of loosening or revision for loosening were lower, at 1.2% and 0.9% respectively, but the rates varied from 0% to 16.3%. The registry data did not report specifically on the original ATTUNE TKA or on revision due to loosening, but ‘all-cause’ five-year revision rates for the cemented ATTUNE varied from 2.6% to 5.9%. Conclusion. The original cemented ATTUNE TKA has high rates of RLLs, but their clinical significance is uncertain given the overall low associated rates of loosening and revision. However, in view of the high rates of RLLs and the variation in the rates of loosening and revision between studies and registries, close surveillance of patients who have undergone TKA with the original ATTUNE system is recommended. Cite this article: Bone Joint J 2023;105-B(6):610–621

Introduction: The failure rate of cemented hip replacements is about 1% per year, mainly due to aseptic loosening. PMMA acts as a grout, therefore high pressure is needed to ensure fixation. Various plug designs are used to increase pressure. No data is available on their ability to occlude the canal. Factors including canal size, canal shape and cement viscosity may affect performance. The two aims of this study are (I) to determine the effect of cement viscosity, canal shape and canal size on the ability of cement restrictors to withstand cementation pressures, and (II) to determine which of the currently commercially available designs of cement restrictor is able to withstand cementation pressures, regardless of values of other potentially influential factors. Methods: Artificial femoral canals were drilled in oak blocks. Circular canals had diameters of 12 or 17.5 mm. Oval canals had short axes equal to the diameter of the circular canals and long axes 1.3 times longer. This ellipticity of 1.3 is average for human femoral canals. One of four types of cement plugs (Hardinge, DePuy, UK; Exeter, Stryker, UK; Amber Flex, Summit Medical, UK; and OptiPlug, Scandimed, Sweden) was inserted. A pressure transducer was fitted in the canal just proximal to the plug. Bone cement (Palacos LV-40 low viscosity or Palacos R-20 high viscosity, both Schering Plough, UK) was prepared in a mixing device for 1 min at 21°C, and inserted in the artificial canal after 4 minutes. A materials testing machine was used to generate pressure in the cement. Cement pressure and plug position were measured. All combinations of canal size and shape, plug design and cement viscosity were pre-selected according to a D-optimal experimental design which was optimised to perform a four-way ANOVA to analyse the four main factors plus the interactions between plugs and the other three factors. A total of 23 experiments was performed. Results: Average cement pressures achieved differed between implants (OptiPlug 448±66 kPa, Hardinge 142±66, Exeter 705±66, Amber Flex 475±72; p=0.002, all mean±SEM). They also differed between canal sizes (12 mm 529±49, 18 mm 356±47; p=0.03), canal shapes (Round 631±45, Oval 254±51; p=0.004) and cement viscosity (High 535±54, Low 350±43; p=0.03). No significant interaction between factors was found. Discussion and Conclusion: All plugs resisted lower pressures in large canals, oval canals or with low viscosity cement. When comparing plugs, these different circumstances should therefore be taken into account. Of the four tested, the Exeter plug performed best in all adverse circumstances. The OptiPlug and AmberFlex, which are both resorbable, had an intermediate performance. The Hardinge plug performed worse

Aims. Both the femoral and tibial component are usually cemented at revision total knee arthroplasty (rTKA), while stems can be added with either cemented or press-fit (hybrid) fixation. The aim of this study was to compare the long-term stability of rTKA with cemented and press-fitted stems, using radiostereometric analysis (RSA). Methods. This is a follow-up of a randomized controlled trial, initially involving 32 patients, of whom 19 (nine cemented, ten hybrid) were available for follow-up ten years postoperatively, when further RSA measurements were made. Micromotion of the femoral and tibial components was assessed using model-based RSA software (RSAcore). The clinical outcome was evaluated using the Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (pain and satisfaction). Results. The median total femoral translation and rotation at ten years were 0.39 mm (interquartile range (IQR) 0.20 to 0.54) and 0.59° (IQR 0.46° to 0.73°) for the cemented group and 0.70 mm (IQR 0.15 to 0.77) and 0.78° (IQR 0.47° to 1.43°) for the hybrid group. For the tibial components this was 0.38 mm (IQR 0.33 to 0.85) and 0.98° (IQR 0.38° to 1.34°) for the cemented group and 0.42 mm (IQR 0.30 to 0.52) and 0.72° (IQR 0.62° to 0.82°) for the hybrid group. None of these values were significantly different between the two groups and there were no significant differences between the clinical scores in the two groups at this time. There was only one re-revision, in the hybrid group, for infection and not for aseptic loosening. Conclusion. These results show good long-term fixation with no difference in micromotion and clinical outcome between fully cemented and hybrid fixation in rTKA, which builds on earlier short- to mid-term results. The patients all had type I or II osseous defects, which may in part explain the good results. Cite this article: Bone Joint J 2022;104-B(7):875–883

Multiple studies have established an inverse relationship between ambient theatre temperatures and polymethyl methacrylate (PMMA) cement setting times. It is also known that allowing cement to equilibrate to ambient theatre temperatures restores expected setting characteristics. One overlooked entity is the transport and storage conditions of cement. This is important in tropical regions, where extreme temperature and humidity may cause rapid cement setting times, resulting in potentially significant intra-operative complications. This study investigated the relationship between extreme transport and storage conditions of Antibiotic Simplex cement (Stryker), and the effect on setting times at Cairns Hospital, Far North Queensland, Australia. Fifty units of cement were divided evenly into a control arm and four experimental arms. The experimental arms were designed to mimic potential transport and storage conditions. They included seven days of storage in a medication fridge, on the hospital loading dock, in a cane shed, and in a Toyota Landcruiser parked outdoors during January 2022. Humidity and temperature readings were recorded. The samples in each group were evenly distributed to equilibrate to theatre conditions for 1 hour and 24 hours. Setting time was recorded when a no. 15 scalpel blade was unable to mark the surface. All three ‘hot’ exposures setting times were significantly faster for both 1 hour (ρ=0.001) and 24 hours (ρ=0.024) equilibration times. The difference in setting times for the ‘cold’ exposure was not significant for either equilibration times (ρ=1). To our knowledge, this is the first study investigating cement setting times in tropical climates. Further studies are required to address the effect of these conditions on biomechanical strength of PMMA cement. We conclude that extreme heat and humidity during transport and storage have a statistically significant effect on cement setting times

Aims. In recent years, the use of a collared cementless femoral prosthesis has risen in popularity. The design intention of collared components is to transfer some load to the resected femoral calcar and prevent implant subsidence within the cancellous bone of the metaphysis. Conversely, the load transfer for a cemented femoral prosthesis depends on the cement-component and cement-bone interface interaction. The aim of our study was to compare the three most commonly used collared cementless components and the three most commonly used tapered polished cemented components in patients aged ≥ 75 years who have undergone a primary total hip arthroplasty (THA) for osteoarthritis (OA). Methods. Data from the Australian Orthopaedic Association National Joint Replacement Registry from 1 September 1999 to 31 December 2022 were analyzed. Collared cementless femoral components and cemented components were identified, and the three most commonly used components in each group were analyzed. We identified a total of 11,278 collared cementless components and 47,835 cemented components. Hazard ratios (HRs) from Cox proportional hazards models, adjusting for age and sex, were obtained to compare the revision rates between the groups. Results. From six months postoperatively onwards, patients aged ≥ 75 years undergoing primary THA with primary diagnosis of OA have a lower risk of all-cause revision with collared cementless components than with a polished tapered cemented component (HR 0.78 (95% confidence interval 0.64 to 0.96); p = 0.018). There is no difference in revision rate prior to six months. Conclusion. Patients aged ≥ 75 years with a primary diagnosis of OA have a significantly lower rate of revision with the most common collared cementless femoral component, compared with the most common polished tapered cemented components from six months postoperatively onwards. The lower revision rate is largely due to a reduction in revisions for fracture and infection. Cite this article: Bone Joint J 2024;106-B(3 Supple A):121–129

Aim. Galleria mellonella larvae is a well-known insect infection model that has been used to test the virulence of bacterial and fungal strains as well as for the high throughput screening of antimicrobial compounds against infections. Recently, we have developed insect infection model G. mellonella larvae to study implant associated biofilm infections using small K-wire as implant material. Here, we aimed to further expand the use of G. mellonella to test other materials such as bone cement with combination of gentamicin to treat implant-associated infections. Method. The poly methyl methacrylate (PMMA) with and without gentamicin and liquid methyl methacrylate (MMA) were kindly provided by Heraeus Medical GmbH, Wehrheim. To make the bone cement implants as cubes, Teflon plate (Karl Lettenbauer, Erlangen) with specified well size was used. The Radiopaque polymer and monomer were mixed well in a bowl, applied over on to the Teflon plate and pressed with spatula to form fine and uniform cubes. After polymerization, the bone cement implants were taken out of the Teflon well plate with the help of pin. For the infection process, bone cement cubes were pre-incubated with S. aureus EDCC 5055 culture at 5×10. 6. CFU/ml for 30 min at 150 rpm shaking conditions. Later, these implants were washed with 10ml PBS and implanted in the larvae as mentioned. Survival of the larvae were observed at 37°C in an incubator. To analyze the susceptibility of the bacterial infections towards gentamicin, survival of the larvae compared with control group implanted only with bone cement. The effect of gentamicin was also measured in terms of S. aureus load in larvae on 2. nd. day. SEM analysis was performed to see the effect of gentamicin on biofilm formation on bone cement. Results. Our experiments established the G. mellonella as an excellent model to screen bone cement with antimicrobial compounds against bacterial infections. The gentamicin bone cement samples showed excellent S. aureus bacterial load reduction after the implantation in G. mellonella model. The bone cement with gentamicin showed better survival of larvae infected with S. aureus compared to control. Finally, the gentamicin also affected the biofilm formation on the bone cement surface with S. aureus. Conclusions. Thus, our work showed G. mellonella is a rapid, cheap economical pre-clinical model to study the bone cement associate bacterial infections as well as screening of the various antimicrobial compounds

Aim: Cementation of tibial implants in total knee arthroplasty is a gold-standard considering the high loosening rates of cementless implants. In contrast, only sparse data exist regarding unicondylar arthroplasty due to limited use. In this study, we compare cemented with cementless unicondylar knee arthroplasty and aim to define both clinical and radiological differences in treatment outcome. Materials and Methods: In a retrospective study, 106 patients who had undergone a medial unicondylar replacement were examined after a mean postoperative period of 8 years. Of these, 42 patients (median age 81±7 years) had received a cemented and 64 (median age 73±7 years) a cementless knee arthroplasty by the same surgeon while 7 patients were deceased or could not be reached. Well-established clinical (VAS, HSS, KSS, UCLA, WOMAC) and quality of life (SF-36) scores were used to evaluate treatment outcome. X-rays were performed to evaluate periprosthetic loosening zones, according to Ewald’s criteria. Results: The cementless patient group presented significantly better clinical scores (HSS, KSS, UCLA, WOMAC), except in the Visual Analogue Scale (VAS) for pain assessment. The quality of life was significantly better in the cementless group except in the subgroups concerning physical function, vitality and social role, which resembled normal population. Moreover, radiographic analysis using antero-posterior X-rays revealed significantly more and larger periprosthetic loosening areas in tibial zone 2 in the cementless group. Conclusion: The inferior clinical results characterising the cemented group could be attributed to the higher mean age. Regarding the radiological loosening zones, we did not detect any differences in the techniques of fixation, although physical activity and mechanical stresses were higher in the cementless group

Aims. The aim of this study was to assess the association of mortality and reoperation when comparing cemented and uncemented hemiarthroplasty (HA) in hip fracture patients aged over 65 years. Methods. This was a population-based cohort study on hip fracture patients using prospectively gathered data from several national registries in Denmark from 2004 to 2015 with up to five years follow-up. The primary outcome was mortality and the secondary outcome was reoperation. Hazard ratios (HRs) for mortality and subdistributional hazard ratios (sHRs) for reoperations are shown with 95% confidence intervals (CIs). Results. A total of 17,671 patients with primary HA were identified (9,484 uncemented and 8,187 cemented HAs). Compared to uncemented HA, surgery with cemented HA was associated with an absolute risk difference of 0.4% for mortality within the period zero to one day after surgery and an adjusted HR of 1.70 (95% CI 1.22 to 2.38). After seven days, there was no longer any association, with an adjusted HR of 1.07 (95% CI 0.90 to 1.28). This continued until five years after surgery with a HR of 1.01 (95% CI 0.96 to 1.06). There was a higher proportion of reoperations due to any reason after five years in the uncemented group with 10.2% compared to the cemented group with 6.1%. This yielded an adjusted sHR of 0.65 (95% CI 0.57 to 0.75) and difference continued up until five years after the surgery, demonstrating a sHR of 0.70 (95% CI 0.59 to 0.83). Conclusion. In a non-selected cohort of hip fracture patients, surgery with cemented HA was associated with a higher relative mortality during the first postoperative day compared to surgery with uncemented HA, but there was no difference after seven days up until five years after. In contrast, surgery with cemented HA was associated with lower risk of reoperation up to five years postoperatively compared with surgery with uncemented HA. There was a higher relative mortality on the first postoperative day for cemented HA versus uncemented HA. There was no difference in mortality after seven days up until five years after surgery. There were 6.1% reoperations for cemented HA compared to 10.2% for uncemented HA after five years. Cite this article: Bone Joint J 2022;104-B(1):127–133

Aims. The aim of this study was to compare the cost-effectiveness of cemented hemiarthroplasty (HA) versus hydroxyapatite-coated uncemented HA for the treatment of displaced intracapsular hip fractures in older adults. Methods. A within-trial economic evaluation was conducted based on data collected from the World Hip Trauma Evaluation 5 (WHiTE 5) multicentre randomized controlled trial in the UK. Resource use was measured over 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from the NHS and personal social service perspective. Methodological uncertainty was addressed using sensitivity analysis, while decision uncertainty was represented graphically using confidence ellipses and cost-effectiveness acceptability curves. Results. The base-case analysis showed that cemented implants were cost-saving (mean cost difference -£961 (95% confidence interval (CI) -£2,292 to £370)) and increased QALYs (mean QALY difference 0.010 (95% CI 0.002 to 0.017)) when compared to uncemented implants. The probability of the cemented implant being cost-effective approximated between 95% and 97% at alternative cost-effectiveness thresholds held by decision-makers, and its net monetary benefit was positive. The findings remained robust against all the pre-planned sensitivity analyses. Conclusion. This study shows that cemented HA is cost-effective compared with hydroxyapatite-coated uncemented HA in older adults with displaced intracapsular hip fractures. Cite this article: Bone Joint J 2022;104-B(8):922–928

Aims. A novel enhanced cement fixation (EF) tibial implant with deeper cement pockets and a more roughened bonding surface was released to market for an existing total knee arthroplasty (TKA) system.This randomized controlled trial assessed fixation of the both the EF (ATTUNE S+) and standard (Std; ATTUNE S) using radiostereometric analysis. Methods. Overall, 50 subjects were randomized (21 EF-TKA and 23 Std-TKA in the final analysis), and had follow-up visits at six weeks, and six, 12, and 24 months to assess migration of the tibial component. Low viscosity bone cement with tobramycin was used in a standardized fashion for all subjects. Patient-reported outcome measure data was captured at preoperative and all postoperative visits. Results. The patient cohort mean age was 66 years (SD seven years), 59% were female, and the mean BMI was 32 kg/m. 2. (SD 6 kg/m. 2. ). Mean two-year subsidence of the EF-TKA was 0.056 mm (95% confidence interval (CI) 0.025 to 0.086) versus 0.006 mm (95% CI -0.029 to 0.040) for the Std-TKA, and the two-year maximum total point motion (MTPM) was 0.285 mm (95% upper confidence limit (UCL) ≤ 0.363) versus 0.346 mm (95% UCL ≤ 0.432), respectively, for a mean difference of -0.061 mm (95% CI -0.196 to 0.074). Inducible displacement also did not differ between groups. The MTPMs between 12 and 24 months for each group was below the published threshold of 0.2 mm for predicting early aseptic loosening (p < 0.001 and p = 0.001, respectively). Conclusion. Both the enhanced fixation and the standard tibial implant design showed fixation with a predicted low risk of long-term aseptic loosening. Cite this article: Bone Jt Open 2024;5(1):20–27

Aims. The aim of this investigation was to compare risk of infection in both cemented and uncemented hemiarthroplasty (HA) as well as in total hip arthroplasty (THA) following femoral neck fracture. Methods. Data collection was performed using the German Arthroplasty Registry (EPRD). In HA and THA following femoral neck fracture, fixation method was divided into cemented and uncemented prostheses and paired according to age, sex, BMI, and the Elixhauser Comorbidity Index using Mahalanobis distance matching. Results. Overall in 13,612 cases of intracapsular femoral neck fracture, 9,110 (66.9%) HAs and 4,502 (33.1%) THAs were analyzed. Infection rate in HA was significantly reduced in cases with use of antibiotic-loaded cement compared with uncemented fixated prosthesis (p = 0.013). In patients with THA no statistical difference between cemented and uncemented prosthesis was registered, however after one year 2.4% of infections were detected in uncemented and 2.1% in cemented THA. In the subpopulation of HA after one year, 1.9% of infections were registered in cemented and 2.8% in uncemented HA. BMI (p = 0.001) and Elixhauser Comorbidity Index (p < 0.003) were identified as risk factors of periprosthetic joint infection (PJI), while in THA cemented prosthesis also demonstrated an increased risk within the first 30 days (hazard ratio (HR) = 2.73; p = 0.010). Conclusion. The rate of infection after intracapsular femoral neck fracture was statistically significantly reduced in patients treated by antibiotic-loaded cemented HA. Particularly for patients with multiple risk factors for the development of a PJI, the usage of antibiotic-loaded bone cement seems to be a reasonable procedure for prevention of infection. Cite this article: Bone Joint Res 2023;12(5):331–338

Aims. The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes. Methods. A retrospective consecutive study of all patients who underwent a rTKA using the fully cemented SMILES rotating hinge prosthesis between 2005 to 2018. Outcome measures included aseptic loosening, reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both prospectively collected local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years. Results. Overall, 69 consecutive patients (69 knees) were included with a median age of 78 years (interquartile range 69 to 84), and there were 46 females (66.7%). Indications were septic revisions in 26 (37.7%), and aseptic aetiology in the remining 43 (62.3%). The mean follow-up was 9.7 years (4 to 18), and the overall complication was rate was 7.24%, all with patellofemoral complications. Failure rate with ‘any cause revision’ was 5.8%. There was one case of aseptic loosening of the femoral component. At ten years, 17/69 patients (24.63%) had died, and implant survivorship was 92.2%. Conclusion. In our experience, the SMILES rotating hinge prosthesis achieves satisfactory long-term outcomes with ten-year implant survivorship of 92.2% and a patellofemoral complication rate of 7.24%. Cite this article: Bone Jt Open 2023;4(10):776–781

Primary hip and knee joint replacements in Canada have been estimated to cost over $1.4 billion dollars annually, with revision surgery costing $177 million. The most common cause of revision arthroplasty surgery in Canada is infection. Periprosthetic joint infections (PJIs) are a devastating though preventable complication following arthroplasty. Though variably used, antibiotic laden bone cement (ALBC) has been demonstrated to decrease PJIs following primary total knee arthroplasty (TKA). Unfortunately, ALBC is costlier than regular bone cement (RBC). Therefore, the aim of this study was to determine if the routine use of ALBC in primary TKA surgery is a cost-effective practice from the perspective of the Canadian healthcare system. A decision tree was constructed using a decision analysis software (TreeAge Software, Williamstown, Massachusetts) to a two-year time horizon comparing primary TKA with either ALBC or RBC from the perspective of a single-payer healthcare system. All costs were in 2020 Canadian dollars. Health utilities were in the form of quality adjusted life years (QALYs). Model inputs for cost were derived from regional and national databases. Health utilities and probability parameters were derived from the latest literature. One-way deterministic sensitivity analysis was performed on all model parameters. The primary outcome of this analysis was an incremental cost-effectiveness ratio (ICER) with a willingness-to-pay (WTP) threshold of $50,000 per QALY. Primary TKA with ALBC (TKA-ALBC) was found to be more cost-effective compared to primary TKA with RBC (TKA-RBC). More specifically, TKA-ALBC dominated TKA-RBC as it was less costly on the long term ($11,160 vs. $11,118), while providing the same QALY (1.66). The ICER of this cost-utility analysis (CUA) was $-11,049.72 per QALY, much less than the WTP threshold of $50,000 per QALY. The model was sensitive to costs of ALBC-TKA as well as the probability of PJI following ALBC-TKA and RBC-TKA. ALBC ceased to be cost effective once the cost of ALBC was greater than $223.08 CAD per bag of cement. The routine use of ALBC in primary TKA is a cost-effective practice in the context of the Canadian healthcare system as long as the cost of ALBC is maintained at a reasonable price and the published studies to-date keep supporting the efficacy of ALBC in decreasing PJI following primary TKA. Further, this analysis is very conservative, and ALBC is likely much more cost-effective than presented. This is due to this model's revision surgery cost parameter being based on the average cost of all revision TKA surgery in Canada, regardless of etiology. Considering many PJIs require two-stage revisions, the cost parameter used in this analysis for revision surgery is an underestimate of true cost. Ultimately, this is the first cost-effectiveness study evaluating this topic from the perspective of the Canadian healthcare system and can inform future national guidelines on the subject matter

Aims. Poly(methyl methacrylate) (PMMA)-based bone cements are the industry standard in orthopaedics. PMMA cement has inherent disadvantages, which has led to the development and evaluation of a novel silorane-based biomaterial (SBB) for use as an orthopaedic cement. In this study we test both elution and mechanical properties of both PMMA and SBB, with and without antibiotic loading. Methods. For each cement (PMMA or SBB), three formulations were prepared (rifampin-added, vancomycin-added, and control) and made into pellets (6 mm × 12 mm) for testing. Antibiotic elution into phosphate-buffered saline was measured over 14 days. Compressive strength and modulus of all cement pellets were tested over 14 days. Results. The SBB cement was able to deliver rifampin over 14 days, while PMMA was unable to do so. SBB released more vancomycin overall than did PMMA. The mechanical properties of PMMA were significantly reduced upon rifampin incorporation, while there was no effect to the SBB cement. Vancomycin incorporation had no effect on the strength of either cement. Conclusion. SBB was found to be superior in terms of rifampin and vancomycin elution. Additionally, the incorporation of these antibiotics into SBB did not reduce the strength of the resultant SBB cement composite whereas rifampin substantially attenuates the strength of PMMA. Thus, SBB emerges as a potential weight-bearing alternative to PMMA for the local delivery of antibiotics. Cite this article: Bone Joint Res 2021;10(4):277–284

Aims. Stemmed tibial components are frequently used in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate patient satisfaction, overall pain, and diaphyseal tibial pain in patients who underwent revision TKA with cemented or uncemented stemmed tibial components. Methods. This is a retrospective cohort study involving 110 patients with revision TKA with cemented versus uncemented stemmed tibial components. Patients who underwent revision TKA with stemmed tibial components over a 15-year period at a single institution with at least two-year follow-up were assessed. Pain was evaluated through postal surveys. There were 63 patients with cemented tibial stems and 47 with uncemented stems. Radiographs and Knee Society Scores were used to evaluate for objective findings associated with pain or patient dissatisfaction. Postal surveys were analyzed using Fisher’s exact test and the independent-samples t-test. Logistic regression was used to adjust for age, sex, and preoperative bone loss. Results. No statistically significant differences in stem length, operative side, or indications for revision were found between the two cohorts. Tibial pain at the end of the stem was present in 25.3% (16/63) of cemented stems and 25.5% (12/47) of uncemented stems (p = 1.000); 74.6% (47/63) of cemented patients and 78.7% (37/47) of uncemented patients were satisfied following revision TKA (p = 0.657). Conclusion. There were no differences in patient satisfaction, overall pain, and diaphyseal tibial pain in cemented and uncemented stemmed tibial components in revision TKA. Patient factors, rather than implant selection and surgical technique, likely play a large role in the presence of postoperative pain. Stemmed tibial components have been shown to be a possible source of pain in revision TKA. There is no difference in patient satisfaction or postoperative pain with cemented or uncemented stemmed tibial components in revision TKA. Cite this article: Bone Joint J 2021;103-B(6 Supple A):165–170

This study aimed to analyze the effect of two different techniques of cement application: cement on bone surface (CoB) versus cement on bone surface and implant surface (CoBaI) on the short-term effect of radiolucent lines (RLL) in primary fully cemented total knee arthroplasties (TKA) with patella resurfacing. 379 fully cemented TKAs (318 patients) were included in this monocentric study. Preoperative and postoperative at week 4 and 12 month after surgery all patients had a clinical and radiological examination and were administered the Oxford Knee Score (OKS). Cement was applied in two different ways among the two study groups: cement on bone surface (CoB group) or cement on bone surface and implant surface (CoBaI group). The evaluation of the presence of RLL or osteolysis was done as previously described using the updated Knee Society Radiographic Evaluation System. The mean OKS and range of motion improved significantly in both groups at the 4-week and 12-month follow-up, with no significant difference between the groups (CoB vs. CoBaI). RLL were present in 4.7% in the whole study population and were significantly higher in the CoBaI group (10.5%) at the 4-week follow-up. At the 12-month follow-up RLL were seen in 29.8% of the TKAs in the CoBaI group, whereas the incidence was lower in the CoB group (24.0% (n.s.)). There were two revisions in each group. None of these due to aseptic loosening. Our study indicated that the application of bone cement on bone surface only might be more beneficial than onto the bone surface and onto the implant surface as well in respect to the short-term presence of RLL in fully cemented primary TKA. The long-term results will be of interest, especially in respect to aseptic loosening and might guide future directions of bone cement applications in TKA

According to the latest report from the German Arthroplasty Registry, aseptic loosening is the primary cause of implant failure following primary hip arthroplasty. Osteolysis of the proximal femur due to the stress-shielding of the bone by the implant causes loss of fixation of the proximal femoral stem, while the distal stem remains fixed. Removing a fixed stem is a challenging process. Current removal methods rely on manual tools such as chisels, burrs, osteotomes, drills and mills, which pose the risk of bone fracture and cortical perforation. Others such as ultrasound and laser, generate temperatures that could cause thermal injury to the surrounding tissues and bone. It is crucial to develop techniques that preserve the host bone, as its quality after implant removal affects the outcome of a revision surgery. A gentler removal method based on the transcutaneous heating of the implant by induction is proposed. By reaching the glass transition temperature (T. G. ) of the periprosthetic cement, the cement is expected to soften, enabling the implant to be gently pulled out. The in-vivo environment comprises body fluids and elevated temperatures, which deteriorate the inherent mechanical properties of bone cement, including its T. G. We aimed to investigate the effect of fluid absorption on the T. G. (ASTM E2716-09) and Vicat softening temperature (VST) (ISO 306) of Palacos R cement (Heraeus Medical GmbH) when dry and after storage in Ringer's solution for up to 8 weeks. Samples stored in Ringer's solution exhibited lower T. G. and VST than those stored in air. After 8 weeks, the T. G. decreased from 95.2°C to 81.5°C in the Ringer's group, while the VST decreased from 104.4°C to 91.9°C. These findings will be useful in the ultimate goal of this project which is to design an induction-based system for implant removal. Acknowledgements: Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB/TRR-298-SIIRI – Project-ID 426335750

The role of vacuum mixing on the reduction of porosity and on the clinical performance of cemented total hip replacements remains uncertain. We have used paired femoral constructs prepared with either hand-mixed or vacuum-mixed cement in a cadaver model which simulated intra-operative conditions during cementing of the femoral component. After the cement had cured, the distribution of its porosity was determined, as was the strength of the cement-stem and cement-bone interfaces. The overall fraction of the pore area was similar for both hand-mixed and vacuum-mixed cement (hand 6%; vacuum 5.7%; paired t-test, p = 0.187). The linear pore fractions at the interfaces were also similar for the two techniques. The pore number-density was much higher for the hand-mixed cement (paired t-test, p = 0.0013). The strength of the cement-stem interface was greater with the hand-mixed cement (paired t-test, p = 0.0005), while the strength of the cement-bone interface was not affected by the conditions of mixing (paired t-test, p = 0.275). The reduction in porosity with vacuum mixing did not affect the porosity of the mantle, but the distribution of the porosity can be affected by the technique of mixing used

Retention of well fixed bone cement at the time of a revision THA is an attractive proposition, as its removal can be difficult, time consuming and may result in extensive bone stock loss or fracture. Previously reported poor results of cemented revision THA, however, have tended to discourage Surgeons from performing “cement in cement” revisions, and this technique is not in widespread use. Since 1989, we have performed a cement within cement femoral stem revision on 354 occasions. The indications for in cement revision included facilitating acetabular revision, replacement of a monoblock stem with a damaged or incompatible head, revision of hemiarthroplasty to THA, component malposition and broken stem. Cement in cement revision was only performed in the presence of well fixed cement with an intact bone-cement interface. An Exeter polished tapered stem was cemented into the existing cement mantle on each occasion. Follow up of 5 years or longer is available for 175 cases, and over 8 years in 41. On no occasion has a cement in cement femoral stem had to be re-revised during this time for subsequent aseptic loosening. Advantages include preservation of bone stock, reduced operating time, improved acetabular exposure and early post operative full weight bearing mobilisation. This technique has not been used for 1 stage revision of infection. This experience has encouraged the refinement of this technique, including the development of a new short stem designed specifically for cement within cement revisions. This stem is designed to fit into an existing well fixed cement mantle of most designs of cemented femoral component or hemi-arthroplasty, with only limited preparation of the proximal mantle required. The new stem greatly simplifies cement in cement revision and minimises the risk of distal shaft perforation or fracture, which is otherwise a potential hazard when reaming out distal cement to accommodate a longer prosthesis

Aims. Giant cell tumours (GCTs) of the proximal femur are rare, and there is no consensus about the best method of filling the defect left by curettage. In this study, we compared the outcome of using a fibular strut allograft and bone cement to reconstruct the bone defect after extended curettage of a GCT of the proximal femur. Methods. In a retrospective study, we reviewed 26 patients with a GCT of the proximal femur in whom the bone defect had been filled with either a fibular strut allograft (n = 12) or bone cement (n = 14). Their demographic details and oncological and nononcological complications were retrieved from their medical records. Limb function was assessed using the Musculoskeletal Tumor Society (MSTS) score. Results. Mean follow-up was 116 months (SD 59.2; 48 to 240) for the fibular strut allograft group and 113 months (SD 43.7; 60 to 192) for the bone cement group (p = 0.391). The rate of recurrence was not significantly different between the two groups (25% vs 21.4%). The rate of nononcological complications was 16.7% in the strut allograft group and 42.8% in the bone cement group. Degenerative joint disease was the most frequent nononcological complication in the cement group. The mean MSTS score of the patients was 92.4% (SD 11.5%; 73.3% to 100.0%) in the fibular strut allograft group and 74.2% (SD 10.5%; 66.7% to 96.7%) in the bone cement group (p < 0.001). Conclusion. Given the similar rate of recurrence and a lower rate of nononcological complications, fibular strut grafting could be recommended as a method of reconstructing the bone defect left by curettage of a GCT of the proximal femur. Cite this article: Bone Joint J 2022;104-B(2):297–301

Retention of well fixed bone cement at the time of a revision THA is an attractive proposition, as its removal can be difficult, time consuming and may result in extensive bone stock loss or fracture. Previously reported poor results of cemented revision THA, however, have tended to discourage Surgeons from performing ‘cement in cement’ revisions, and this technique is not in widespread use. Since 1989 in Exeter, we have performed a ‘cement within cement’ femoral stem revision on 354 occasions. An Exeter polished tapered stem has been cemented into the existing cement mantle on each occasion. Clinical and radiological follow up of 5 years or longer is available for 156 cases. On no occasion has a cement in cement femoral stem had to be re-revised during this time for subsequent aseptic loosening. This has encouraged the refinement of this technique, including the development of a new short stem designed specifically for cement within cement revisions. This stem is designed to fit into an existing well fixed cement mantle of most designs of cemented femoral components or hemi-arthroplasties, with only limited preparation of the proximal mantle required. The new stem greatly simplifies cement in cement revision and minimises the risk of distal shaft perforation or fracture, which is otherwise a potential hazard when reaming out distal cement to accommodate a longer prosthesis

Aims. The aim of this retrospective study was to assess the incidence of early periprosthetic femoral fracture (PFF) associated with Charnley-Kerboull (CK) femoral components cemented according to the ‘French paradox’ principles through the Hueter anterior approach (HAA) in patients older than 70 years. Methods. From a prospectively collected database, all short CK femoral components implanted consecutively from January 2018 to May 2022 through the HAA in patients older than 70 years were included. Exclusion criteria were age below 70 years, use of cementless femoral component, and approaches other than the HAA. A total of 416 short CK prostheses used by 25 surgeons with various levels of experience were included. All patients had a minimum of one-year follow-up, with a mean of 2.6 years (SD 1.1). The mean age was 77.4 years (70 to 95) and the mean BMI was 25.3 kg/m. 2. (18.4 to 43). Femoral anatomy was classified according to Dorr. The measured parameters included canal flare index, morphological cortical index, canal-calcar ratio, ilium-ischial ratio, and anterior superior iliac spine to greater trochanter (GT) distance. Results. Among the 416 THAs, two PFFs (0.48% (95% confidence interval 0.13 to 1.74)) were observed, including one Vancouver type B2 fracture 24 days postoperatively and one intraoperative Vancouver type B1 fracture. Valgus malalignment and higher canal bone ratio were found to be associated with PFF. Conclusion. This study demonstrated that short CK femoral components cemented according to the French paradox were associated with a low rate of early PFF (0.48%) in patients aged over 70 years. Longer follow-up is warranted to further evaluate the rate of fracture that may occur during the bone remodelling process and with time. Cite this article: Bone Joint J 2024;106-B(3 Supple A):67–73

Introduction. Cement in cement revision with preservation of the original cement mantle has become an attractive and commonly practised technique in revision hip surgery. Since introducing this technique to our unit we have used two types of polished tapered stem. We report the clinical and radiological outcomes for cement in cement femoral revisions performed using these prostheses. Materials and Methods. All patients who underwent femoral cement in cement revision with a smooth tapered stem between 2005 –2013 were assessed. Data collected included indication for revision surgery and components used. All patients were followed up annually. Outcomes recorded were radiographic analysis, clinical outcome scores (Oxford Hip Score, WOMAC and SF-12) and complications, including requirement for further revision surgery. Median follow-up was 5 years (range 1 – 8 years). 116 revision procedures utilising cement in cement femoral revision were performed in the 8 year study period (68 females, 48 males, and mean age of 69 years). The femoral component was a C-stem AMT (Depuy) in 59 cases and Exeter stem (Stryker) in 57 cases. Results. Radiographic analysis demonstrated no progressive radiolucencies around the femoral component in any patient and no evidence of stem loosening at most recent review. Median Oxford Hip Score increased from 15 to 32, WOMAC from 22 to 38, and SF-12 from 25 to 32. Two patients had a further revision procedure for recurrent dislocation and 1 patient for infection. Two patients had a peri-prosthetic fracture at 4 years following initial revision surgery. There were 2 femoral stem fractures (occurring at 3 and 4 years post revision, both occurring in Exeter stems). Conclusion. Our results report cement in cement revision of the femoral component provides promising mid-term radiographic and clinical results. No femoral stems required revision for aseptic loosening. Stem fracture however occurred in 2 cases suggesting stem design is crucial for this technique

The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone. Cite this article: Bone Joint J 2023;105-B(5):481–486

In revision hip surgery, a solidly cemented femoral component may obstruct access to the acetabulum, may be poorly orientated, or may have inadequate offset and head diameter. These problems can be addressed by revising the femoral component. The object of this study was to determine the outcome of cementing a polished, tapered, modular implant into the retained cement mantle. Benefits of cement within cement revision of a femoral stem include simplicity, reduced theatre time, and potentially reduced complication rates. A consecutive series of 36 patients (11 men, 25 women) age range 35 to 90 years (mean age 70) underwent c stem cement in cement revision hip arthroplasty between June 2000 and April 2006. Indications for revision arthroplasty included 20 patients with aseptic acetabular loosening and 13 patients with recurrent instability. Follow up (12–84 months, mean 48 months) was annual and the outcome for every implant was known. Outcome measures included the shortened WOMAC score, Orthowave patient satisfaction survey, radiographic analysis, and assessment of the records for perioperative complications. No patients were lost to follow up, 2 patients died with their hip in situ. The mean post operative WOMAC score at latest follow up was 10.89 (median 11, range 0 to 29). There has been no clinical or radiological signs of prosthesis loosening or failure on follow up. Complications included: one sacral plexus palsy which had a partial recovery, and one intra-operative periprosthetic fracture identified and treated at the time of the revision procedure. One patient underwent a further cup revision for recurrent dislocation. Cement within cement revision hip arthroplasty using a highly polished tapered stem in the short to medium term provides satisfactory functional outcomes and is associated with low complication rates and good survivorship. Longer term results are awaited

Background. Antibiotic loaded bone cement (ALBC) is commonly used in cemented total hip arthroplasty (THA) in an attempt to reduce the risk of prosthetic joint infection (PJI). However, its role versus plain cement remains controversial due to the potential risk of developing resistant organisms and potential excess costs incurred from its usage. We investigated the relationship of ALBC and plain cement in affecting outcome of revision surgery after primary THA. Methodology. We conducted a retrospective study of data collected from National Joint Registry for England and Wales, Northern Ireland and the Isle of Man between 1. st. September 2005 until 31. st. August 2017. A logistic regression analysis model was used to investigate the association between ALBC versus plain cement and the odds ratio (OR) for revision, adjusting for age, ASA grade, bearing surfaces, head size and cup and stem fixation. Indications for revision recorded in NJR were considered in separate models. Results. We identified 418,925 THAs where bone cements were used (22,037 plain cement; 396,888 ALBC). After adjusting for confounding factors, the risk of revision for infection was lower with ALBC (OR 0.77, 95% CI 0.62–0.95). There was also lower risk of revision for aseptic loosening of stem (OR 0.53, 95% CI 0.39–0.72), aseptic loosening of socket (OR 0.46, 95% CI 0.37– 0.58). When breaking down hips into fully cemented or hybrid fixation, the protective effect of ALBC against infection was only apparent in fully cemented (OR 0.65, 95% CI 0.48–0.87) when compared against hybrid fixation (OR 0.90, 95% CI 0.66–1.23). Discussion. Within the limits of registry analysis, this study has demonstrated an association between the use of ALBC and lower rates of revision for infection and aseptic loosening. Conclusion. This finding supports the current use of ABLC in cemented THAs

Aims. The aim of this study was to investigate whether wear and backside deformation of polyethylene (PE) tibial inserts may influence the cement cover of tibial trays of explanted total knee arthroplasties (TKAs). Methods. At our retrieval centre, we measured changes in the wear and deformation of PE inserts using coordinate measuring machines and light microscopy. The amount of cement cover on the backside of tibial trays was quantified as a percentage of the total surface. The study involved data from the explanted fixed-bearing components of four widely used contemporary designs of TKA (Attune, NexGen, Press Fit Condylar (PFC), and Triathlon), revised for any indication, and we compared them with components that used previous generations of PE. Regression modelling was used to identify variables related to the amount of cement cover on the retrieved trays. Results. A total of 114 explanted fixed-bearing TKAs were examined. This included 76 used with contemporary PE inserts which were compared with 15 used with older generation PEs. The Attune and NexGen (central locking) trays were found to have significantly less cement cover than Triathlon and PFC trays (peripheral locking group) (p = 0.001). The median planicity values of the PE inserts used with central locking trays were significantly greater than of those with peripheral locking inserts (205 vs 85 microns; p < 0.001). Attune and NexGen inserts had a characteristic pattern of backside deformation, with the outer edges of the PE deviating inferiorly, leaving the PE margins as the primary areas of articulation. Conclusion. Explanted TKAs with central locking mechanisms were significantly more likely to debond from the cement mantle. The PE inserts of these designs showed characteristic patterns of deformation, which appeared to relate to the manufacturing process and may be exacerbated in vivo. This pattern of deformation was associated with PE wear occurring at the outer edges of the articulation, potentially increasing the frictional torque generated at this interface. Cite this article: Bone Joint J 2021;103-B(12):1791–1801

Introduction and Objective. The continued effectiveness of antibiotic loaded bone cements is threatened by antibiotic resistance. The common antiseptic, chlorhexidine (CHX), is a potential alternative to antibiotics in bone cements, but conventional salts are highly soluble, causing burst release and rapid decline to subinhibitory local CHX concentrations. Here, chlorhexidine triphosphate (CHX-TP), a low solubility CHX salt, is investigated as an alternative antimicrobial in PMMA bone cements. The aim was to assess duration of antimicrobial release and antimicrobial efficacy, along with handling, setting and mechanical properties of CHX-TP loaded cements, compared with an existing cement formulation containing gentamicin. Materials and Methods. Palacos R (Heraeus Medical, Newbury, UK) with 0, 1, 4, 7 and 12% CHX-TP (w/w) cements were prepared by combining solid CHX-TP with Palacos R components, and compared with Palacos R+G. All cements were prepared without vacuum and under ISO 5833:2002 conditions. Cements were tested under ISO 5833:2002 for compressive and bending properties, setting time, maximum temperature and doughing time. Antimicrobial release from the cements into deionised water was studied and antimicrobial efficacy of unaged and aged cements against Staphylococcus aureus (ATCC 29213) was assessed using a disc diffusion assay. Results. Compressive strength of CHX-TP loaded cements was not significantly different to Palacos R or Palacos R+G (p > 0.05, all exceeding ISO 5833:2002 minimum of 70 MPa). Mean bending strength was significantly lower with CHX-TP loading (p < 0.05) than bending strength of Palacos R and Palacos R+G, though all bending moduli exceeded the ISO 5833:2002 minimum (1800 MPa). All cements studied were within the ISO 5833:2002 limits for setting time (3 to 15 min), doughing time (≤ 5 min) and maximum temperature (90 . o. C). Mean doughing time for Palacos R, Palacos R+G and Palacos R + 12 % CHX-TP respectively: 52.5 s, 45 s and 45 s. Mean setting time and mean maximum temperature for Palacos R, Palacos R+G and Palacos R + 1, 4, 7 and 12% CHX-TP respectively: 11.00 min (73 . o. C), 11.25 min (72 . o. C), 12.25 min (66 . o. C), 10.50 min (70 . o. C), 10.00 min (70 . o. C), 10.75 min (62 . o. C). Sustained CHX release into deionised water was observed from all Palacos R + CHX-TP cements. Duration varied according to CHX-TP dosing and diminished over time, although to an extent that itself varied with dosing. 1 % CHX-TP ceased releasing CHX at 6.9 weeks; 4 % CHX-TP ceased at 67.7 weeks; 7 % and 12 % CHX-TP were ongoing at 75.5 weeks. Palacos R+G cements ceased releasing detectable levels of gentamicin after 14.4 weeks. Palacos R+G and Palacos R + CHX-TP cement discs showed efficacy against S. aureus (ATCC 29213) when applied as prepared (unaged) to S. aureus bacterial lawns in disc diffusion assays, with CHX-TP cements showing dose dependency. Zone of inhibition (ZOI) size was significantly reduced for Palacos R+G cements and Palacos R + 1% CHX-TP cements after 1 week and 6 weeks aging, compared to ZOI from unaged cements (p < 0.05). ZOI size produced by Palacos R + 4, 7, and 12 % CHX-TP cements did not decline significantly after 6 weeks aging (p > 0.05). Conclusions. CHX-TP can be incorporated into the Palacos R cement matrix up to 12% w/w without deterioration of compressive strength, bending modulus, doughing time, setting time or maximum temperature. Bending strength was significantly reduced at all CHX-TP loadings studied. Palacos R + 4, 7 and 12% CHX-TP cements provided sustained CHX release, exceeding the duration of gentamicin release from Palacos R+G, and showed sustained efficacy against S. Aureus after 6 weeks aging, which was not achieved by Palacos R+G cements

Aims. The aim of this study was to determine both the incidence of, and the reoperation rate for, postoperative periprosthetic femoral fracture (POPFF) after total hip arthroplasty (THA) with either a collared cementless (CC) femoral component or a cemented polished taper-slip (PTS) femoral component. Methods. We performed a retrospective review of a consecutive series of 11,018 THAs over a ten-year period. All POPFFs were identified using regional radiograph archiving and electronic care systems. Results. A total of 11,018 THAs were implanted: 4,952 CC femoral components and 6,066 cemented PTS femoral components. Between groups, age, sex, and BMI did not differ. Overall, 91 patients (0.8%) sustained a POPFF. For all patients with a POPFF, 16.5% (15/91) were managed conservatively, 67.0% (61/91) underwent open reduction and internal fixation (ORIF), and 16.5% (15/91) underwent revision. The CC group had a lower POPFF rate compared to the PTS group (0.7% (36/4,952) vs 0.9% (55/6,066); p = 0.345). Fewer POPFFs in the CC group required surgery (0.4% (22/4,952) vs 0.9% (54/6,066); p = 0.005). Fewer POPFFs required surgery in males with a CC than males with a PTS (0.3% (7/2,121) vs 1.3% (36/2,674); p < 0.001). Conclusion. Male patients with a PTS femoral component were five times more likely to have a reoperation for POPFF. Female patients had the same incidence of reoperation with either component type. Of those having a reoperation, 80.3% (61/76) had an ORIF, which could greatly mask the size of this problem in many registries. Cite this article: Bone Joint J 2024;106-B(2):144–150

The cement in cement technique for revision total hip arthroplasty (THA) has shown good results in selected cases. However, results of its use in the revision of hemiarthroplasty to THA has not been previously reported. Between May 1994 and May 2007 28 (20 Thompson's and 8 Exeter bipolar) hip hemiarthroplasties were revised to THA in 28 patients using the cement in cement technique. All had an Exeter stem inserted at the time of revision. Clinical and operative data were collected prospectively. Clinical evaluation was by the Charnley, Harris and Oxford. Hip scores and radiographs were analysed post-operatively and at latest follow up. The mean age at time of hemiarthroplasty revision was 80 (35 to 93) years. The reason for revision was acetabular erosion in 12 (43%), recurrent dislocation in eight (29%), aseptic stem loosening in four (14%), periprosthetic fracture in two (7%) and infection in a further two (7%) patients. No patient has been lost to follow up. Three patients died within three months of surgery. The mean follow up of the remainder was 50 (16 to 119) months. Survivorship with revision of the femoral stem for aseptic loosening as the endpoint was 100%. Three cases (11%) have since undergone further revision, one for recurrent dislocation, one for infection, and one for periprosthetic fracture. The cement in cement technique can be successfully applied to revision of hip hemiarthroplasty to THA. It has a number of advantages in this elderly population including minimising bone loss, blood loss and operative time

Introduction. In cemented total hip arthroplasty (THA), proper cement mantle thickness in the femoral canal is still controversial subject. It is widely accepted that the cement mantle around a femoral stem should be at least 2 mm in thickness. But articles from France reported good long-term result with thin cement mantle. It is so called “The French paradox”. We have already reported that the greater compressive force at the cement-bone interface was seen in collarless polished tapered (CPT, Zimmer, USA) stem with thick cement mantle than that with thin cement mantle. However, the stem with thick cement mantle subsided more than with thin mantle. It may have a possibility to cause an early mechanical failure of cemented THA. We compared to stem and cement subsidence in various cement mantles using tantalum ball into cement in this study. Methods. A cemented stem model was used for this study with a CPT stem into composite femur. Three sizes of CPT stems (No. 1, No. 2 and No. 3) and one size composite femur were prepared for this study. We inserted two stems for each size, for a total of six stems. Composite femurs were reamed with a No. 3 rasp, and various size of stem was fixed with cement in each composite femur to make a various thicknesses of cement mantle. Two to three tantalum marker balls were injected into the cement in each femur before cement was hardened. 1-Hz dynamic load applied to the stems for half a-million cycles. Each 16 hours of loading was followed by 8 hours without loading. We used micro-CT before and after loading to measure the movement of the tantalum balls in three dimensions. And we analyzed occupation ratio of stem in the femoral canal by computed reconstructed three dimensional model of bone cement and stem. Results. We were able to detect a total of 13 balls in the cement for the 6 stems. The range of cement thickness in the CT slice on balls was 1.52 to 5.32 mm. Stem subsidence showed a significantly positive correlation to the thickness of cement mantle. In the horizontal plane, 8 of these 13 balls moved in an outside direction and five moved in an inside direction. The horizontal/perpendicular ratio for the tantalum balls showed a significant negative correlation to the thickness of the cement mantle. The subsidence rate (ratio of stem subsidence to ball subsistence) showed a significant negative correlation to the stem occupation ratio. The effective radial cement creep was also detected when the cement mantle was less than 2.5 mm thick and more than 60% in the occupation ratio. Conclusions. Stem subsistence was more commonly associated with cement subsidence in the thicker cement mantles and with a low stem occupation rate in CPT stems

Aims. To determine if primary cemented acetabular component geometry (long posterior wall (LPW), hooded, or offset reorientating) influences the risk of revision total hip arthroplasty (THA) for instability or loosening. Methods. The National Joint Registry (NJR) dataset was analyzed for primary THAs performed between 2003 and 2017. A cohort of 224,874 cemented acetabular components were included. The effect of acetabular component geometry on the risk of revision for instability or for loosening was investigated using log-binomial regression adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, operating surgeon grade, surgical approach, polyethylene crosslinking, and prosthetic head size. A competing risk survival analysis was performed with the competing risks being revision for other indications or death. Results. The distribution of acetabular component geometries was: LPW 81.2%; hooded 18.7%; and offset reorientating 0.1%. There were 3,313 (1.5%) revision THAs performed, of which 815 (0.4%) were for instability and 838 (0.4%) were for loosening. Compared to the LPW group, the adjusted subhazard ratio of revision for instability in the hooded group was 2.31 (p < 0.001) and 4.12 (p = 0.047) in the offset reorientating group. Likewise, the subhazard ratio of revision for loosening was 2.65 (p < 0.001) in the hooded group and 13.61 (p < 0.001) in the offset reorientating group. A time-varying subhazard ratio of revision for instability (hooded vs LPW) was found, being greatest within the first three months. Conclusion. This registry-based study confirms a significantly higher risk of revision after cemented THA for instability and for loosening when a hooded or offset reorientating acetabular component is used, compared to a LPW component. Further research is required to clarify if certain patients benefit from the use of hooded or offset reorientating components, but we recommend caution when using such components in routine clinical practice. Cite this article: Bone Joint J 2021;103-B(11):1669–1677

Aim: To study the influence of cement restrictors on the thickness and quality of femoral cement mantle. Methods: In this prospective study, there are 49 cases of Hardinge restrictor and 33 cases bone block restrictor were used for Charnley hip replacement. The operation was carried out by one surgeon on 78 patients between 1 March 2003 and 30th April 2004. Each preoperative X-rays were templated for the placement of restrictor. Intraoperatively, a calibrated holder for the cement restrictor was used aiming at keeping the distal cement height within 2-3 cm of the tip of the femoral prosthesis. Postoperative X-rays were checked for cement mantle thickness and quality. Results: The preoperative target of having a distal cement height of 2-3 cm was achieved as seen on postoperative X-ray in only 60.6% of the bone block group and 30.6% of the Hardinge group. Distal migration of the restrictors was associated with non-homogenous cement mantle in zones 3, 4 and 5 but did nor affect zone 2, 6, or7. As the restrictor remained within 20-30 mm, the thickness of mantle is maintained between 9mm and 21mm in zone 4. This finding is statistically significant with the p value of 0.001. Conclusion: Though the bone block was marginally better than Hardinge restrictor, we conclude that the current available cement restrictors are not sufficiently good enough to offer a good cavity for cement intrusion in to the bone; further restrictors need to be developed and tested before clinical use

Introduction. While fixation on the acetabular side in resurfacing implants has been uncemented, the femoral component is usually cemented. The most common causes for early revision in hip resurfacing are femoral head and or neck fractures and aseptic loosening of the femoral component. Later failures appear to be more related to adverse soft-tissue reactions due to metal wear. Little is known about the effect of cementing techniques on the clinical outcome in hip resurfacing, since retrieval analysis of failed hip resurfacing show large variations. Two cementing techniques have dominated. The indirect low viscosity (LV) technique as for the Birmingham Hip resurfacing (BHR) system and the direct high viscosity (HV) technique as for the Articular Surface replacement (ASR) system. The ASR was withdrawn from the market in 2010 due to inferior short and midterm clinical outcome. This study presents an in vitro experiment on the cement mantle parameters and penetration into ASR resurfaced femoral heads comparing both techniques. Methods. Five sets of paried frozen cadavar femura (3 male, 2 female) were used in the study. The study was approved by ethics committee. Plastic ASR replicas (DePuy, Leeds, UK), femoral head size 47Ø were used. The LV technique was used for the right femora (Group A, fig. 1 and 3) while the HV technigue was used for the left femora (Group B. Fig 2 and 4). The speciments were cut into quadrants. An initiial visual, qualitative evaluation was followed by CT analysis of cement mantle thickness and cement penetration into bone. Results. No significant differences were seen between the four quadrants within each group. The LV technigue resulted in greater cement penetration and increased cement mantle under the top proximally. The HV technique showed less penetration and lower cement mantle. See figures 1–4. Discussion. The aim was to analyze the effect of the cementing techniques used in hip resurfacing practice. The ASR implant was chosen to improve understanding of whether the implant may have been sensitive to cementing techniques and whether an analysis of cementing with the recommended HV technique may assist in explaning the high incidence of short-term ASR revisions due to fractures. Findings for the HV technigue would indicate a superior technique according to consensus in conventional arthropalsty However, this contradicts clinical evidence on resurfacing, where LV cementation has been shown tho be superior. The superficial intergration in the HV technigue may result in only a superficial integration and subsequently suboptimal fixation to bone. To view tables/figures, please contact authors directly

Aims. Despite multiple trials and case series on hip hemiarthroplasty designs, guidance is still lacking on which implant to use. One particularly deficient area is long-term outcomes. We present over 1,000 consecutive cemented Thompson’s hemiarthroplasties over a ten-year period, recording all accessible patient and implant outcomes. Methods. Patient identifiers for a consecutive cohort treated between 1 January 2003 and 31 December 2011 were linked to radiographs, surgical notes, clinic letters, and mortality data from a national dataset. This allowed charting of their postoperative course, complications, readmissions, returns to theatre, revisions, and deaths. We also identified all postoperative attendances at the Emergency and Outpatient Departments, and recorded any subsequent skeletal injuries. Results. In total, 1,312 Thompson’s hemiarthroplasties were analyzed (mean age at surgery 82.8 years); 125 complications were recorded, necessitating 82 returns to theatre. These included 14 patients undergoing aspiration or manipulation under anaesthesia, 68 reoperations (5.2%) for debridement and implant retention (n = 12), haematoma evacuation (n = 2), open reduction for dislocation (n = 1), fixation of periprosthetic fracture (n = 5), and 48 revised stems (3.7%), for infection (n = 13), dislocation (n = 12), aseptic loosening (n = 9), persistent pain (n = 6), periprosthetic fracture (n = 4), acetabular erosion (n = 3), and metastatic bone disease (n = 1). Their status at ten years is summarized as follows: 1,180 (89.9%) dead without revision, 34 (2.6%) dead having had revision, 84 (6.6%) alive with the stem unrevised, and 14 (1.1%) alive having had revision. Cumulative implant survivorship was 90.3% at ten years; patient survivorship was 7.4%. Conclusion. The Thompson’s stem demonstrates very low rates of complications requiring reoperation and revision, up to ten years after the index procedure. Fewer than one in ten patients live for ten years after fracture. This study supports the use of a cemented Thompson’s implant as a cost-effective option for frail hip fracture patients. Cite this article: Bone Jt Open 2022;3(9):710–715