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

Aims. The aim of this study was to investigate whether the use of antibiotic-loaded bone cement influenced the risk of revision surgery after primary total hip arthroplasty (THA) for osteoarthritis. Methods. The study involved data collected by the National Joint Registry (NJR) for England and Wales, Northern Ireland and the Isle of Man between 1 September 2005 and 31 August 2017. Cox proportional hazards were used to investigate the association between use of antibiotic-loaded bone cement and the risk of revision due to prosthetic joint infection (PJI), with adjustments made for the year of the initial procedure, age at the time of surgery, sex, American Society of Anesthesiologists (ASA) grade, head size, and body mass index (BMI). We looked also at the association between use of antibiotic-loaded bone cement and the risk of revision due to aseptic loosening or osteolysis. Results. The cohort included 418,857 THAs of whom 397,896 had received antibiotic-loaded bone cement and 20,961 plain cement. After adjusting for putative confounding factors, the risk of revision for PJI was lower in those in whom antibiotic-loaded bone cement was used (hazard ration (HR) 0.79; 95% confidence interval (CI) 0.64 to 0.98). There was also a protective effect on the risk of revision due to aseptic loosening or osteolysis, in the period of > 4.1 years after primary THA, HR 0.57, 95% CI 0.45, 0.72. Conclusion. Within the limits of registry analysis, this study showed an association between the use of antibiotic-loaded bone cement and lower rates of revision due to PJI. The findings support the continued use of antibiotic-loaded bone cement in cemented THA. Cite this article: Bone Joint J 2020;102-B(8):997–1002

Aims. This study aimed to compare the effect of antibiotic-loaded bone cement (ALBC) versus plain bone cement (PBC) on revision rates for periprosthetic joint infection (PJI) and all-cause revisions following primary elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods. MEDLINE, Embase, Web of Science, and Cochrane databases were systematically searched for studies comparing ALBC versus PBC, reporting on revision rates for PJI or all-cause revision following primary elective THA or TKA. A random-effects meta-analysis was performed. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42018107691). Results. Nine studies and one registry report were identified, enabling the inclusion of 371,977 THA and 671,246 TKA. Pooled analysis for THA demonstrated ALBC was protective against revision for PJI compared with PBC (relative risk (RR) 0.66, 95% confidence interval (CI) 0.56 to 0.77; p < 0.001), however, no differences were seen for all-cause revision rate (RR 0.62, 95% CI 0.35 to 1.09; p = 0.100). For TKA, there were no significant differences in revision rates for PJI or all causes between ALBC and PBC (RR 0.92, 95% CI 0.59 to 1.45; p = 0.730, and RR 0.73, 95% CI 0.53 to 1.02; p = 0.060, respectively). Conclusion. ALBC demonstrated a protective effect against revision for PJI compared with PBC in THA with no difference in all-cause revisions. No differences in revision rates for PJI and all-cause revision between ALBC and PBC for TKA were observed. Cite this article: Bone Joint J 2021;103-B(1):7–15

Bone cements produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement, which may not be apparent to surgeons, can also affect these properties. The supplier of Palacos bone cement with added gentamicin changed in 2005. We carried out a study to examine the mechanical characteristics and antibiotic elution of Schering-Plough Palacos, Heraeus Palacos and Depuy CMW Smartset bone cements. Both Heraeus Palacos and Smartset bone cements performed significantly better than Schering-Plough Palacos in terms of mechanical characteristics, with and without additional vancomycin (p < 0.001). All cements show a deterioration in flexural strength with increasing addition of vancomycin, albeit staying above ISO minimum levels. Both Heraeus Palacos and Smartset elute significantly more gentamicin cumulatively than Schering-Plough Palacos. Smartset elutes significantly more vancomycin cumulatively than Heraeus Palacos. The improved antibiotic elution characteristics of Smartset and Heraeus Palacos are not associated with a deterioration in mechanical properties. Although marketed as the ‘original’ Palacos, Heraeus Palacos has significantly altered mechanical and antibiotic elution characteristics compared with the most commonly-used previous version

We prospectively investigated a consecutive series of ten patients undergoing a cemented primary total hip replacement (THR) for osteoarthritis in order to establish the elution characteristics of Simplex-tobramycin bone cement (Howmedica, Limerick, Ireland). Specimens of blood, urine and drainage fluid were collected for 72 hours postoperatively. Very high concentrations of tobramycin were found in the drainage fluid, with mean levels at one hour of 103 mg/l, which steadily declined to 15.1 mg/l after 48 hours. The mean serum tobramycin levels reached a peak of 0.94 mg/l at three hours and declined rapidly to 0.2 mg/l by 48 hours. The mean urinary tobramycin levels peaked at 57.8 mg/l at 12 hours with a rapid decline to 12.6 mg/l by 24 hours. There was a direct correlation between the amount of tobramycin bone cement which was implanted and the amount of tobramycin systemically absorbed. Excellent local delivery was achieved with minimal systemic concentrations. Simplex-tobramycin bone cement is an efficient and safe method for the delivery of antibiotics after THR

Aims. Refobacin Bone Cement R and Palacos R + G bone cement were introduced to replace the original cement Refobacin Palacos R in 2005. Both cements were assumed to behave in a biomechanically similar fashion to the original cement. The primary aim of this study was to compare the migration of a polished triple-tapered femoral stem fixed with either Refobacin Bone Cement R or Palacos R + G bone cement. Repeated radiostereometric analysis was used to measure migration of the femoral head centre. The secondary aims were evaluation of cement mantle, stem positioning, and patient-reported outcome measures. Methods. Overall, 75 patients were included in the study and 71 were available at two years postoperatively. Prior to surgery, they were randomized to one of the three combinations studied: Palacos cement with use of the Optivac mixing system, Refobacin with use of the Optivac system, and Refobacin with use of the Optipac system. Cemented MS30 stems and cemented Exceed acetabular components were used in all hips. Postoperative radiographs were used to assess the quality of the cement mantle according to Barrack et al, and the position and migration of the femoral stem. Harris Hip Score, Oxford Hip Score, Forgotten Joint Score, and University of California, Los Angeles Activity Scale were collected. Results. Median distal migration (y-axis) at two years for the Refobacin-Optivac system was -0.79 mm (-2.01 to -0.09), for the Refobacin-Optipac system was -0.75 mm (-2.16 to 0.20), and for the Palacos-Optivac system was -1.01 mm (-4.31 to -0.29). No statistically significant differences were found between the groups. Secondary outcomes did not differ statistically between the groups at the two-year follow-up. Conclusion. At two years, we found no significant differences in distal migration or clinical outcomes between the three groups. Our data indicate that Refobacin Bone Cement R and Palacos R + G are comparable in terms of stable fixation and early clinical outcomes. Cite this article: Bone Joint J 2024;106-B(5):435–441

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

We used a rat model in vivo to study the effects of particulate bone cements at the bone-implant interface. A ceramic pin was implanted into the tibiae of 48 rats. Three types of particle of clinically relevant size were produced from one bone-cement base without radio-opacifier, with zirconium dioxide (ZrO. 2. ) and with barium sulphate (BaSO. 4. ). The rats were randomly assigned to four groups to receive one of the three bone cements or normal saline with 2% v/v Sprague-Dawley serum as the control. A total of 10. 9. particles was injected into the knee at 8, 10 and 12 weeks after the original surgery. The animals were killed at 14 weeks and the tibiae processed for histomorphometry. The area of fibrous tissue and the gap between the implant and bone were measured using image analysis. All three types of particle were associated with a larger area of bone resorption than the control. Only in the case of the BaSO. 4. -containing cement did this reach statistical significance (p = 0.01). Particles of bone cement appear to promote osteolysis at the bone-implant interface and this effect is most marked when BaSO. 4. is used as the radiopaque agent

The fatigue failure of bone cement, leading to loosening of the stem, is likely to be one mode of failure of cemented total hip replacements. There is strong evidence that cracks in the cement are initiated at voids which act as stress risers, particularly at the cement-stem interface. The preferential formation of voids at this site results from shrinkage during polymerisation and the initiation of this process at the warmer cement-bone interface, which causes bone cement to shrink away from the stem. A reversal of the direction of polymerisation would shrink the cement on to the stem and reduce or eliminate the formation of voids at this interface. We have investigated this by implanting hip prostheses, at room temperature or preheated to 44°C, into human cadaver femora kept at 37°C. Two types of bone cement were either hand-mixed or vacuum-mixed before implantation. We found that the area of porosity at the cement-stem interface was dramatically reduced by preheating the stem and that the preheating temperature of 44°C determined by computer analysis of transient heat transfer was the minimum required to induce initial polymerisation at the cement-stem interface. Temperature measurements taken during these experiments in vitro showed that preheating of the stem caused a negligible increase in the temperature of the bone. Reduction of porosity at the cement-stem interface could significantly increase the life of hip arthroplasties

A heavy infiltrate of foreign-body macrophages is commonly seen in the fibrous membrane which surrounds an aseptically loose cemented implant. This is in response to particles of polymethylmethacrylate (PMMA) bone cement and other biomaterials. We have previously shown that monocytes and macrophages responding to particles of bone cement are capable of differentiating into osteoclastic cells which resorb bone. To determine whether the radio-opaque additives barium sulphate (BaSO. 4. ) and zirconium dioxide (ZrO. 2. ) influence this process, particles of PMMA with and without these agents were added to mouse monocytes and cocultured with osteoblast-like cells on bone slices. Osteoclast differentiation, as shown by the presence of the osteoclast-associated enzyme tartrate-resistant acid phosphatase (TRAP) and lacunar bone resorption, was observed in all cocultures. The addition of PMMA alone to these cocultures caused no increase in TRAP expression or bone resorption relative to control cocultures. Adding PMMA particles containing BaSO. 4. or ZrO. 2. , however, caused an increase in TRAP expression and a highly significant increase in bone resorption. Particles containing BaSO. 4. were associated with 50% more bone resorption than those containing ZrO. 2. . Our results suggest that radio-opaque agents in bone cement may contribute to the bone resorption of aseptic loosening by enhancing macrophage-osteoclast differentiation, and that PMMA containing is BaSO. 4. likely to be associated with more osteolysis than that containing ZrO. 2.

Coloured bone cements have been introduced to make the removal of cement debris easier at the time of primary and revision joint replacement. We evaluated the physical, mechanical and pharmacological effects of adding methylene blue to bone cement with or without antibiotics (gentamicin, vancomycin or both). The addition of methylene blue to plain cement significantly decreased its mean setting time (570 seconds (. sd. 4) vs 775 seconds (. sd. 11), p = 0.01), mean compression strength (95.4 MPa (. sd. 3) vs 100.1 MPa (. sd.  6), p = 0.03), and mean bending strength (65.2 MPa (. sd. 5) vs 76.6 MPa (. sd. 4), p < 0.001) as well as its mean elastic modulus (2744 MPa (. sd. 97) vs 3281 MPa (. sd. 110), p < 0.001). The supplementation of the coloured cement with vancomycin and gentamicin decreased its mean bending resistance (55.7 MPa (. sd. 4) vs 65.2 MPa (. sd . 5), p < 0.001).The methylene blue significantly decreased the mean release of gentamicin alone (228.2 µg (. sd. 24) vs 385.5 µg (. sd . 26), p < 0.001) or in combination with vancomycin (498.5 µg (. sd. 70) vs 613 µg (. sd. 25), p = 0.018) from the bone cement. This study demonstrates several theoretical disadvantages of the antibiotic-loaded bone cement coloured with methylene blue

The serum liver enzyme levels of 40 consecutive patients before and after cemented hip replacement were compared with a control group having operation without use of cement. Serum gammaglutamyl transferase (SGGT) was abnormally raised, for more than four days, in 12 of the 40 patients (32%) in whom bone cement was used, compared with one of the 36 control patients. The changes in SGGT levels after operation correlated with the weight of cement used (r = 0.66, p less than 0.001), but there was return to normal levels in all patients. A temporary dose-related effect of bone cement on liver function is demonstrated

Aims. In the 1990s, a bioactive bone cement (BABC) containing apatite-wollastonite glass-ceramic (AW-GC) powder and bisphenol-a-glycidyl methacrylate resin was developed at our hospital. In 1996, we used BABC to fix the acetabular component in primary total hip arthroplasty (THA) in 20 patients as part of a clinical trial. The purpose of this study was to investigate the long-term results of primary THA using BABC. Patients and Methods. A total of 20 patients (three men and 17 women) with a mean age of 57.4 years (40 to 71), a mean body weight of 52.3 kg (39 to 64), and a mean body mass index (BMI) of 23.0 kg/m. 2. (19.8 to 28.6) were evaluated clinically and radiologically. Survival analyses were undertaken, and wear analyses were carried out using a computer-aided method. Results. The mean follow-up was 17.6 years (1.5 to 21.1). Radiological loosening occurred in four sockets with aseptic loosening at a mean of 7.8 years (1.5 to 20.7). Kaplan–Meier survival analyses using revision of the acetabular component, radiological loosening of the acetabular component, and the worst-case scenario with revision of the acetabular component to include the two patients lost to follow-up as endpoints yielded survival rates of 94.7%, 84.4%, and 85.0% at ten years, and 70.0%, 84.4%, and 62.8% at 20 years, respectively. Wear analysis revealed a mean linear wear rate of 0.068 mm per year. Conclusion. The long-term results of primary THAs using BABC were unsatisfactory. Its brittle nature and poor handling properties need to be improved before it becomes an alternative method of fixing the acetabular component in cemented THA. Cite this article: Bone Joint J 2019;101-B:787–792

Polymethylmethacrylate remains one of the most enduring materials in orthopaedic surgery. It has a central role in the success of total joint replacement and is also used in newer techniques such as percutaneous vertebroplasty and kyphoplasty. This article describes the current uses and limitations of polymethylmethacrylate in orthopaedic surgery. It focuses on its mechanical and chemical properties and links these to its clinical performance. The behaviour of antibiotic-loaded bone cement are discussed, together with areas of research that are now shedding light upon the behaviour of this unique biomaterial

We performed a prospective, randomised study on 110 patients more than 50 years old with fractures of the distal radius to compare the outcome of conservative treatment with that using remodellable bone cement (Norian skeletal repair system, SRS) and immobilisation in a cast for two weeks. Patients treated with SRS had less pain and earlier restoration of movement and grip strength. The results at one year were satisfactory in 81.54% of the SRS patients and 55.55% of the control group. The rates of malunion were 18.2% and 41.8%, respectively. There was a significant relationship between the functional and radiological results. Soft-tissue extrusion was present initially in 69.1% of the SRS patients; most deposits disappeared progressively, but persisted in 32.73% at one year. We conclude that the injection of a remodellable bone cement into the trabecular defect of fractures of the distal radius provides a better clinical and radiological result than conventional treatment

We have tested the porosity and fatigue life of five commonly used bone cements: Simplex P, LVC, Zimmer regular, CMW and Palacos R. Tests were conducted with and without centrifugation and with the monomer at room temperature and, except for LVC, at 0 degrees C. We found that the fatigue life of different specimens varied by a factor of nearly 100. It did not depend on porosity alone, but was more influenced by the basic composition of the cement. Simplex P when mixed with monomer at 0 degrees C and centrifuged for 60 seconds had the highest fatigue life and was still sufficiently liquid to use easily

Aims. Vancomycin is commonly added to acrylic bone cement during revision arthroplasty surgery. Proprietary cement preparations containing vancomycin are available, but are significantly more expensive. We investigated whether the elution of antibiotic from ‘home-made’ cement containing vancomycin was comparable with more expensive commercially available vancomycin impregnated cement. Materials and Methods. A total of 18 cement discs containing either proprietary CopalG+V; or ‘home-made’ CopalR+G with vancomycin added by hand, were made. Each disc contained the same amount of antibiotic (0.5 g gentamycin, 2 g vancomycin) and was immersed in ammonium acetate buffer in a sealed container. Fluid from each container was sampled at eight time points over a two-week period. The concentrations of gentamicin and vancomycin in the fluid were analysed using high performance liquid chromatography mass spectrometry. Results. The highest peak concentrations of antibiotic were observed from the ‘home-made’ cements containing vancomycin, added as in the operating theatre. The overall elution of antibiotic was, fivefold (vancomycin) and twofold (gentamicin) greater from the ‘home-made’ mix compared with the commercially mixed cement. The use of a vacuum during mixing had no significant effect on antibiotic elution in any of the samples. Conclusion. These findings suggest that the addition of 2 g vancomycin powder to gentamicin-impregnated bone cement by hand significantly increases the elution of both antibiotics compared with commercially prepared cements containing vancomycin. We found no significant advantages of using expensive commercially produced vancomycin-impregnated cement and recommend the addition of vancomycin powder by hand in the operating theatre. Cite this article: Bone Joint J 2017;99-B:73–7

We used 99 strains of organisms representative of orthopaedic infections to examine the effectiveness of a bone cement containing tobramycin, employing a modified in vitro Kirby-Bauer susceptibility model. The spectrum was broad, including Gram-positive and Gram-negative aerobic organisms, anaerobes and mycobacteria. Simplex P with added tobramycin was effective against most of the strains, including those which are resistant to typical systemic levels of tobramycin. Although direct correlation between in vitro and in vivo results is difficult, the study showed that tobramycin is stable to the exothermic polymerisation of the cement, and that it is released from the surface of the cement at concentrations high enough to inhibit the growth of most organisms which may be encountered after joint arthroplasty

We have investigated whether the particle-stimulated release of inflammatory cytokines from human primary macrophages in vitro was dependent upon the type of bone cement used. Particles of clinically relevant size were produced from Palacos R without radio-opacifier, Palacos R with BaSO. 4. , Palacos R with ZrO. 2. and from CMW3 which contains BaSO. 4. All four preparations produced significantly greater release of tumour necrosis factor alpha, interleukin-6 and interleukin-1 beta than a negative control but there were no significant differences between them. The differences in the ability to stimulate bone resorption and in clinical performance between proprietary bone cements previously recorded are not explained by the release of the cytokines most commonly implicated in osteolysis

We have compared the rates of infection and resistance in an animal model of an orthopaedic procedure which was contaminated with a low-dose inoculum of Staphylococcus epidermidis. We randomised 44 Sprague-Dawley rats to have bone cement implanted subcutaneously containing either gentamicin or saline (control). The wound was inoculated with a dilute solution of gentamicin-sensitive Staphylococcus epidermidis. At two weeks the cement was retrieved and microbiologically tested. A lower overall rate of infection was seen in the gentamicin-loaded cement group, but there was a significantly higher rate of gentamicin-resistant infection in this group (Fisher’s exact test, p < 0.01). Antibiotic-impregnated cement has an optimum surface for colonisation and prolonged exposure to antibiotic allows mutational resistance to occur. Gentamicin-loaded cement may not be appropriate for revision surgery if it has been used already in previous surgery