Acrylic Cement Research Articles

Two-stage treatment of infected total knee arthroplasty: two to thirteen year experience using an articulating preformed spacer

Infection following knee replacement is an important cause of failure despite rigorous prophylaxis antibiotic protocols. The two-stage reimplantation procedure is considered the gold standard for treatment of subacute and chronic deep periprosthetic infections. The purpose of this study was to determine whether or not a preformed articulated spacer would allow comparable eradication of infection equal to rates reported in published studies and to see whether there is a resulting improvement in postoperative function with an acceptable quality of life, reducing postoperative pain and limiting surgical complications, thus simplifying the second stage of the procedure. We retrospectively reviewed 50 patients with infected TKA who underwent a two-stage exchange arthroplasty using an articulating preformed spacer. The device, designed like an ultracongruent condylar knee prosthesis, is composed of acrylic cement impregnated with antibiotic, with tested and standardised mechanical properties and antibiotic content and release mechanism. The median follow-up period was seven (two to 13) years. Two-stage exchange arthroplasty was successful in controlling the infection in 92% of patients; 64% of patients where women, and median patient age was 68 (54-80) years. Median implantation time of the preformed spacer was 16 (four to 60) weeks; 4% of infections were delayed, and 96% were late. Forty-six percent were caused by coagulase-negative Staphylococcus (CoNS). Mean Knee Society Score (KSS) was 35.38 (clinical) and 37.96 (function) on presentation; it improved to a mean of 72.92 (clinical) and 76.04 (function) after the first stage and to a mean of 75.38 (clinical) and 80.58 (function) at the final review. Bone loss was unchanged between stages, and range of motion remained unchanged or improved after definitive reimplantation. The use of preformed articulated knee spacer during a two stage technique for infected TKA improves patient QOL between stages and increases patient compliance and cooperation, reducing social costs.

Bone cement and cementation technique, antibiotics and bone cement spacers: what should you know?

Analyzed cementing technique and implant design . It is shown that scientific and technological progress in the industry enables us to obtain 97% survival rate of implants 10 years after surgery. According to recent reports , infectious complications in 20% of cases the cause of revision cases . Using acrylic cement saturated antibiotics reduces the risk of infectious complications. Cement spacers allow to obtain a positive result in the case of chronic infection.

Intramedullary nailing for treatment of pathologic femoral fractures due to metastases

Pathologic fractures of the femur because of bone metastases seriously affect the quality of life of cancer patients. Different surgical options are indicated to achieve a durable and solid fixation, depending on several clinical, prognostic and mechanical factors. Locked intramedullary nailing is currently used to treat pathologic femoral fractures in patients with multiple metastases when the trochanteric region or shaft is mainly involved. This study evaluates intramedullary nailing for treatment of patients with pathologic femoral fractures, focussing on complications, clinical and functional outcomes and survival rates. The series included 80 pathologic fractures treated with a titanium alloy Proximal Nail (Standard or Antirotation) or Lateral Anterograde Femoral Nail (PFN, PFNA or LAFN, Synthes) inserted in a locked static mode. Acrylic cement was used to fill the bone cavity after nail insertion in eight patients; percutaneous cementoplasty was simultaneously performed in 11 cases of severe ipsilateral acetabular osteolysis. Postoperative outcomes focussed on pain relief, postoperative mobility and quality of life and they were analysed retrospectively using QOL-ACD and ECOG. Eleven patients (13.75%) suffered from non-fatal DVT post-surgery, with no pulmonary embolism. Six patients (7.5%) developed superficial wound infections and two patients (2.5%) developed pnaeumonia. There was no loss of reduction, breakage, screw pull out, or hardware or implant failure that required component substitution or revision. Lung histotype and the contemporary presence of cerebral and visceral metastases appeared to be predisposing factors in reducing survival time. All patients attained satisfactory pain relief, early deambulation and a marked clinical improvement during the first 6–10 postoperative months, with gradual worsening thereafter from deterioration of their general condition due to cancer progression. The patients’ survival rate was 40% at 1 year, 25% at 2 years and 15% at 3 years. Results confirm that multiple factors related to patients and primary cancer may affect survival rate after femoral fracture. Intramedullary nailing should be indicated for pathologic fractures at femoral diaphysis and metaphysis when cancer is in an advanced stage. This procedure offers good and durable stability, and enables pain relief, early postoperative mobilisation and weight-bearing, thus improving the quality of life of cancer patients.

Acrylic bone cement: current concept review

Acrylic bone cement has had for years an important role in orthopedic surgery. Polymethylmethacrylate (PMMA) has been extended from the ophthalmological and dental fields to orthopedics, as acrylic cement used for fixation of prosthetic implants, for remodeling osteoporotic, neoplastic and vertebral fractures repair. The PMMA bone cement is a good carrier for sustained antibiotic release in the site of infection. Joint prostheses chronic infection requires surgical removal of the implant, in order to eradicate the infection process. This can be performed in the same surgical time (one-stage procedure) or in two separate steps (two-stage procedure, which involves the use of an antibiotic-loaded cement spacer). The mechanical and functional characteristics of the spacers allow a good joint range of motion, weight-bearing in selected cases and a sustained release of antibiotic at the site of infection. The improvement of fixation devices in recent years was not accompanied by the improvement of elderly bone quality. Some studies have tested the use of PMMA bone cement or calcium phosphate as augmentation support of internal fixation of these fractures. Over the past 20 years, experimental study of acrylic biomaterials (bone cement, bioglass ceramic, cement additives, absorbable cement, antibiotic spacers) has been of particular importance, offering numerous models and projects.

Management of Operative Complications Related to Occipitocervical Instrumentation

The continued evolution of instrumentation techniques for fusions at the craniovertebral junction has enabled surgical treatment of a wide range of developmental, neoplastic, traumatic, and degenerative conditions. There has been an increased recognition of the morbidity associated with the complications secondary to occipitocervical instrumentation. To present representative complications secondary to occipitocervical instrumentation in patients who presented to our institution and to emphasize underlying principles in diagnosis and management of craniovertebral disease conditions through illustrative examples of their presentation, management, and follow-up. Clinical records for patients referred to the senior author (A.H.M.) between 2005 and 2010 for evaluation and management of their symptoms arising as a consequence of surgical intervention by a different primary neurosurgeon were reviewed. Eight patients were identified with representative complications secondary to occipitocervical instrumentation. These complications included incorrect surgical technique, persistent instability, hardware misplacement with potential for vascular injury, associated neural injury, and secondary complications of wound healing resulting from methyl methacrylate use. Surgical revision was required in 2 patients. The remaining patients improved with removal of the offending hardware and acrylic cement. All patients reported symptom resolution, and dynamic imaging studies on follow-up indicated stable alignment and bony fusion. These cases serve as illustrative examples of the spectrum of neural, vascular, biomechanical, and instrument-related complications associated with occipitocervical arthrodesis. Basic principles of occipitocervical instrumentation that enable safe and successful treatment of craniovertebral junction disease conditions have been highlighted. Potential complications and management strategies are discussed.

Asymptomatic Bone Cement Pulmonary Embolism after Vertebroplasty: Case Report and Literature Review

Introduction. Acrylic cement pulmonary embolism is a potentially serious complication following vertebroplasty. Case Report. A 70-year-old male patient was treated with percutaneous vertebroplasty for osteoporotic nontraumatic vertebral collapse of L5-S1. Asymptomatic pulmonary cement embolism was detected on routine postoperative chest radiogram and the patient was treated with enoxaparin, amoxicillin, and dexamethasone. At the followup CT scan no further migration of any cement material was reported; and the course was uneventful. Discussion. The frequency of local leakage of bone cement is relatively high (about 80–90%), moreover, the rate of cement leakage into the perivertebral veins (seen in up to 24% of vertebral bodies treated) with consequent pulmonary cement embolism varies from 4.6 to 6.8% (up to 26% in radiologic studies); the risk of embolism is increased with the liquid consistency of the cement and with the treatment of some malignant lesions. Patients may remain asymptomatic and develop no known long-term sequelae. Conclusions. Our ancedotal case illustrates the need for close monitoring of patients undergoing percutaneous vertebroplasty and emphasizes the importance of prompt and correct diagnosis and treatment, even if actually there is no agreement regarding the therapeutic strategy.

Acrylic formulations containing bioactive and biodegradable fillers to be used as bone cements: Properties and biocompatibility assessment

The solid phase of bioactive self-curing acrylic cements was modified by different biodegradable fillers such as poly(3-hydroxybutyrate) (PHB) and its copolymer with hydroxyvalerate (PHBV). The addition of the biodegradable fillers made the cement partially degradable, which is important to allow new bone replacement and ingrowth. The thermal analysis, crystallinity, curing parameters, mechanical properties, degradation and cellular tests were studied in order to characterize the cement performance. Within this context it was verified that the incorporation of the PHBV polymer made the cement more resistant, reaching values within the range reported for typical PMMA bone cements. The results also showed that the cement filled with PHBV took up more water than the cement with PHB after 60days, for all studied formulations. Regarding the osteoblastic cytocompatibility assessment, the inclusion of the PHBV greatly improved the biological response in both cements filled with the silicate or the borate glass, compared to the inclusion of the PHB. The importance of this novel approach resides on the combination of the properties of the cements components and the possibility of allowing bone regeneration, improving the interfaces with both the prosthesis and the bone, and leading to a new material with suitable performance for application as bone cement.

Nuove prospettive sperimentali e cliniche per il cemento osseo acrilico: “review” delle moderne potenzialità di un materiale caro ai chirurghi ortopedici, veicolo di farmaci e sostituto dell’osso

Acrylic bone cement has had for years an important role in orthopedic surgery. Polymethylmethacrylate (PMMA) has been extended from the ophthalmologic and dental fields to orthopedics, as acrylic cement used for fixation of prosthetic implants, for remodeling osteoporotic, neoplastic or metastatic areas and for vertebral fractures repair. The PMMA bone cement is a good carrier for sustained release of antibiotic in the site of infection. Joint prostheses chronic infection requires surgical removal of the implant, in order to eradicate the infection process. This can be performed in the same surgical time (one-stage procedure) or in two separate steps (twostage procedure, which involves the use of an antibiotic-loaded cement spacer). The mechanical and functional characteristics of the spacers allow a good joint range of motion, weight-bearing in selected cases, and a sustained release of antibiotic in the site of infection. The improvement of fixation devices in recent years was not accompanied by the improvement of elderly bone quality. Some studies have tested the use of PMMA bone cement or calcium-phosphate as augmentation-support of internal fixation of these fractures. Over the past 20 years, experimental study of acrylic biomaterials (bone cement, bioglass ceramic, cement additives, absorbable cement, antibiotic spacers) has been of particular importance, offering numerous models and projects:

Decompressed percutaneous vertebroplasty: A secured bone cement delivery procedure for vertebral augmentation in osteoporotic compression fractures

The purpose of this study was to assess the efficacy of a new assistive procedure for injecting cement in percutaneous vertebroplasty (PV). Percutaneous vertebroplasty is frequently used for treating patients with osteoporotic vertebral compression fractures. However, the leakage of bone cement during PV may lead to serious complications, such as spinal cord compression or pulmonary embolism. Herein we present a secure procedure designed to safely and effectively deliver the bone cement into the vertebral column. Materials and methodsThirty-five patients with a total of 50 levels of osteoporotic compression fracture were consecutively recruited for the study. During a routine PV operation, acrylic cement was injected with a simultaneous application of a continuous negative pressure to the contralateral side of the vertebral body. This negative pressure exerts a pulling force that attracts the bone cement to flow within the vertebral body. ResultsWith the proposed decompressed PV procedure, cross-filling of the vertebrographys was achieved for all 50 fracture levels, with no paravertebral venous plexus leakage. Three of the 50 levels (6%) exhibited contrast-medium leakage into the intradisc or cortical defect regions. After decompressed cement injection, excellent cross-filling of bone cement deposition was achieved in 38 of the 50 levels (76%; cement cross-filling region >75%), good cross-filling deposition was achieved in 7 levels (14%; cement cross-filling region >50%), deposition was poor in 3 levels (6%; cement cross-filling region <50%), and deposition failed in 2 levels (4%; fixed cement with no sign of cross-filling). Routine postoperative reviews revealed that six fracture levels (12%) had minimal cement leakage, with two leaking into the disc and four into paravertebral cortical defect regions. ConclusionsCompared to the reported 20–88% cement leakage rate for the conventional PV procedure, the proposed decompressed PV procedure offers a more secure and effective way to perform cement injection, and reduces the likelihood of cement leakage.

Properties and osteoblast cytocompatibility of self-curing acrylic cements modified by glass fillers

Materials filled with a silicate glass (MSi) and a borate glass (MB) were developed and compared in terms of their in vitro behavior. The effect of filler composition and concentration (0, 30, 40 and 50 wt%) on the curing parameters, residual monomer, water uptake, weight loss, bioactivity, mechanical properties (bending and compression) and osteoblast cytocompatibility was evaluated. The addition of bioactive glass filler significantly improved the cements curing parameters and the mechanical properties. The most relevant results were obtained for the lower filler concentration (30 t%) a maximum flexural strength of 40.4 Pa for MB3 and a maximum compressive strength of 95.7 MPa for MSi3. In vitro bioactivity in acellular media was enhanced by the higher glass contents in the cements. Regarding the biological assessment, the incorporation of the silicate glass significantly improved osteoblast cytocompatibility, whereas the presence of the borate glass resulted in a poor cell response. Nevertheless it was shown that the surviving cells on the MB surface were in a more differentiated stage compared to those growing over non-filled poly(methyl methacrylate). Results suggest that the developed formulations offer a high range of properties that might be interesting for their use as self-curing cements.

Intra-arterial injection of acrylic cement as a complication of percutaneous vertebroplasty

Percutaneous vertebroplasty (PVP) with polymethylmethacrylate (PMMA) is a minimally invasive procedure that provides significant pain relief in a high percentage of patients with osteoporotic fractures. The complication rate of PVP is reported to be below 6%. This case illustrates, for the first time, an arterial PMMA embolus to the aorta and its branches as a complication of PVP.

Micromechanical characterisation of failure in acrylic bone cement: The effect of barium sulphate agglomerates

Acrylic bone cement has been established as a method of fixation of load-bearing orthopaedic implants for nearly five decades, and has produced excellent long term clinical results. However, increasing patient BMI values and longer life expectancies are placing ever greater demands on joint replacements, so there is a need to further improve the performance of cemented fixation. Damage accumulation in the in vivo cement mantle due to initiation and coalescence of fatigue micro-cracks has been implicated in the aseptic loosening and failure of implants. While the effect of porosity on crack initiation processes has been widely reported, the relative influence of different radiopacifying agents is less well studied. In particular, barium sulphate radiopacifier particles have been reported to form large agglomerates within the cement that have been linked to initiation of fatigue cracks in vitro. However, there appears to be little understanding of the micromechanical aspects of cement failure due to barium sulphate agglomeration.The present study utilised micro-computed tomography (μCT) and field emission gun scanning electron microscopy (FEG-SEM), alongside mechanical testing, to provide a systematic, quantitative assessment of the effect of barium sulphate agglomeration on crack initiation processes in a conventional, vacuum-mixed acrylic cement. Three-dimensional characterisation of defect populations was performed, with agglomerates of barium sulphate particles found to be large (up to 0.37mm equivalent spherical diameter), present at spatial densities up to 22permm3, and evenly distributed through each cement specimen. Fatigue cracks consistently initiated at the largest agglomerates; furthermore, fatigue life was found to scale consistently with largest defect size. As such, the tendency of barium sulphate particles to agglomerate is clearly evidenced to be detrimental to the fatigue performance of this cement in vitro. Optimisation of mixing techniques and/or cement formulations containing barium sulphate may therefore be advantageous to reduce the formation of agglomerates and their potential effects in vivo.

Treatment of symptomatic para-articular intraosseous cysts by percutaneous injection of bone cement

To describe the technique and clinical outcome of percutaneous injection of bone cement in the treatment of symptomatic para-articular intraosseous cysts. Five patients (three men, two women; mean age 35years) with painful para-articular intraosseous cysts were treated by percutaneous injection of bone cement under combined fluoroscopic and computed tomography (CT) guidance. The lesions were all located in weight-bearing bones, involving the acetabulum, proximal tibia, distal tibia, talus, and calcaneus, respectively. The average amount of bone cement injected was 2.1ml (range, 0.6-3.5ml). Calcium phosphate cement was used in four cases and acrylic cement in one case. There were no immediate or delayed complications. Full pain relief was obtained between 1 and 4weeks after treatment. All patients made a complete recovery and were pain-free at their last visit. Percutaneous injection of bone cement was a safe and efficient technique in the management of symptomatic para-articular intraosseous cysts in our population.

Preformed Articulating Knee Spacers in 2-Stage Total Knee Revision Arthroplasty: Minimum 2-Year Follow-Up

Two-stage revision arthroplasty using articulating spacers for the treatment of infected total knee arthroplasty (TKA) is a successful management technique. Our purpose was to report our results using preformed, commercially available articulating spacers made of gentamicin-impregnated cement. Thirty-three patients with infected primary or revision TKAs were treated with these spacers using a 2-stage revision technique. In most cases, the spacers were modified intraoperatively by adding a stem of reinforced antibiotic-impregnated acrylic cement. Successful eradication was achieved in 30 of 33 cases at a minimum 2-year follow-up interval. Two patients required a second spacer before successful revision TKA. No spacer fractures or dislocations occurred in this series. No adverse soft tissue effects were noted from the use of this type of articulating spacer.

Modified acrylic cranioplasty for large cranial defects

ObjectiveTo describe a novel technique for constructing polymethylmethacrylate (acrylic) cranioplasty to repair large cranial defects. MethodsA rim of bone is cut from the edge of the skull defect using a craniotome. This bony rim provides a scaffold to fashion the acrylic cement away from the patient thus avoiding thermal injury to the brain. The inner edge of the bony rim is drilled circumferencially to form a groove. Acrylic is then used to fill the defect in the bony rim with continuous manipulation of the paste from both sides to form a dome in the shape of the skull. The groove allows the edge of the acrylic dome to fit snugly with the bony rim thus avoiding sinking. The final cranioplasty, comprised of the hardened acrylic dome with the surrounding bone rim, is firmly attached to the skull with bioplates. ResultsWe used the modified acrylic cranioplasty technique in three patients. Modified acrylic cranioplasty is cheaper and immediately available, compared with ten cases of titanium cranioplasty, with similar cosmetic outcome, intraoperative blood loss and operating theatre time. ConclusionOur technique is quick and easy to perform, avoids thermal injury to the brain and produces a strong implant with excellent cosmesis even with large bony defects.

Chondrogenic Potential and Homogeneity of Cell Populations of Donor and Recipient Cells in a Fresh Osteochondral Allograft

Fresh osteochondral allografts have been widely used to treat cartilage lesions for more than 100 years1. Transplantation of cartilage and bone in the form of an allograft allows osseous healing while maintaining the articular cartilage architecture. This composite tissue transplant remains intact in vivo for extensive periods of time with a favorable mechanical and biological environment. The chondrocytes of the graft are thought to actively remodel the extracellular matrix environment, and thus contribute to the tissue integrity. We recently reported that allograft cells could survive up to twenty-nine years after transplantation without the need for systemic immunosuppression2. Although mosaic cell populations have been demonstrated in other forms of transplantation, these have always been under the umbrella of long-term systemic immunosuppression3,4. In a classic study, Langer and Gross5 showed that intact articular cartilage surfaces obtained by removing the subchondral bone of rat femoral heads and filling of the osseous segments with acrylic cement exhibited essentially no humoral immune response in contrast to that seen with minced cartilage or isolated chondrocyte transplants. This finding has been attributed to the so-called “immunoprivileged” status of articular cartilage, which protects the chondrocytes from the immune system of the host. The extent to which allograft chondrocytes retain their gene expression profiles and chondrogenic capacities remains unknown. Our goal was to compare gene expression, proliferation rate, and chondrogenic potential between host and allograft chondrocytes isolated three years after an unsuccessful fresh osteochondral allograft transplant in the knee. The patient was informed that data concerning her case would be submitted for publication, and she provided consent. The study was performed in full compliance with our institutional review board (IRB). Our IRB at University of California Davis Medical Center does not consider case reports to be research and does not …

Antibiotic Addition to Cement - is it Beneficial?

Antibiotic loaded acrylic cement (ALAC) is widely employed in primary as well as revision hip arthroplasties. There are prerequisites in relation to antibiotic choice and mixing techniques. The 2007 French Consensus Conference delivered recommendations for ALAC in primary arthroplasty. Decisions need to be more patient-specific in revision surgery. Appropriate use of ALAC (and associated antibiotics) and awareness of alternative possibilities such as collagen or bone graft impregnated with antibiotics may guide future practice.

Assessment of Mechanical Parameters of PMMA Used in Human Body

Commercially available acrylic cement which has been popular in orthopaedics in the nineties of the recent century (SIMPLEX P, manufactured by HOWMEDICA LIMERICK) was used in the study. The choice of this material was caused by the fact that the average period of operation of cement prostheses in human body amounts to ca. 12 years and large percentage of prostheses implanted in this period is destabilized in the bone. The investigations focused on assessment of changes in strength parameters of PMMA used in human body over a period of 10 years and their effect on prosthesis loosening. In order to determine differences in strength parameters of the cement, directly after polymerization and after a particular period of use in human body, a series of tests were carried out, aimed at determination of the effect of aggressive environment inside human body and fatigue load which results from human motor activity on changes in strength parameters in PMMA. PMMA samples (30 days after polymerization, stored in saline solution) and the samples removed from human body due to aseptic loosening were used for comparison of strength. Due to a very complex character of operation and specific load, were tested in order to determine the dynamic properties by means of DMTA method, thus to determine the storage modulus E’ and the mechanical loss factor tgδ, responsible for dispersion of mechanical energy.

Prosthesis of Antibiotic-Loaded Acrylic Cement (PROSTALAC) Use for the Treatment of Infection After Shoulder Arthroplasty

There are limited data on Prosthesis of Antibiotic-Loaded Acrylic Cement (PROSTALAC) use for the treatment of infection following shoulder arthroplasty. We performed a retrospective review of our experience with the PROSTALAC in terms of infection eradication, complications, and outcomes. Twenty-eight patients with an infection at the site of a shoulder arthroplasty who were managed with the PROSTALAC were followed until eradication of the infection and maximum functional improvement. The average duration of follow-up was 27.6 months (range, twelve to sixty-nine months). In twenty-five of the twenty-eight patients, the PROSTALAC was created with antibiotic-impregnated cement, a standard humeral head mold, and a scaffold with either a one-third tubular plate or a 3.5-mm reconstruction plate. Three PROSTALAC implants had no scaffold. Although all patients benefited from the use of the PROSTALAC, there were nine complications in eight patients (29%), with six additional unplanned surgical procedures being performed in this group. One patient had a dislocation, three had a fracture of the PROSTALAC, and five had recurrent infections requiring debridement and revision PROSTALAC placement. All fractures were associated with use of the semitubular plate. Twelve patients (43%), including two with revision PROSTALAC implants, were satisfied with pain relief and function and declined a second-stage procedure. With the exclusion of two patients who had a revision PROSTALAC implant, sixteen patients (57%) had a second-stage procedure; the procedures included ten reverse shoulder arthroplasties, three hemiarthroplasties, two total shoulder arthroplasties, and one resection arthroplasty. At the time of the latest follow-up, the average forward elevation of the shoulder was 77° (range, 30° to 130°). Fifteen patients had no or mild pain, eight patients had moderate pain, and five had severe pain. Patients with reverse total shoulder arthroplasties did not have improved function compared with the other cohorts. The use of the PROSTALAC for the treatment of infection following shoulder arthroplasty is beneficial. Infection was initially eradicated in twenty-three (82%) of twenty-eight patients, more than half of our patients had mild or no pain, and 43% of patients declined a second-stage procedure because of acceptable function and pain relief. Conversely, five of twenty-eight patients had severe pain and five patients had persistent infection requiring additional surgery. The use of the reverse total shoulder arthroplasty did not appear to improve outcomes.

Improving the Bioactivity and Biocompatibility of Acrylic Cements by Collagen Coating

Polymer-ceramic composites based on polymethyl methacrylate are widely used in orthopaedics as suture materials and fixation devices due to their biocompatibility and ability to support bony growth (osteoconductive) and also bone bioactive (to form a calcium phosphate layer on its surface). The aim of this study is to compare the microstructure, bioactivity and biocompatibility of new acrylic cement containing silver and collagen coated, with a comercial one, by in vitro study in simulated body fluid. In order to evaluate the properties of the surface layer, SEM microscopy and ATR-FTIR spectroscopy are used. The results indicates that both silver content and the presence of collagen layer favourise the mineralisation process at the surface.