Percutaneous Vertebroplasty: A History of Procedure, Technology, Culture, Specialty, and Economics.

Percutaneous vertebroplasty (VP) progressed from a virtually unknown procedure to one performed on hundreds of thousands of patients annually. The development of VP provides a historically exciting case study into a rapidly adopted procedure. VP was the synthesis of information gained from spinal biopsy developments, the inception of biomaterials used in medicine, and the unique health care climate in France during the 1980s. It was designed as a revolutionary technique to treat vertebral body fractures with minimal side effects and was rapidly adopted and marketed in the United States. The impact of percutaneous vertebroplasty on spine surgery was profound.

Cost-Effective Technique of Fabrication of Polymethyl Methacrylate Based Cranial Implant Using Three-Dimensional Printed Moulds and Wax Elimination Technique.

OBJECTIVE: Cranioplasty is one of the oldest known neurosurgical procedure performed. Many materials have been used for cranioplasty since ages. Polymethyl methacrylate (PMMA) has become the workhorse for fabrication of cranial implants since World War II in cases where autologous bone is not available or cannot be harvested. The aim of the present study is to present author's experience in the management of cranioplasty using acrylic implants fabricated using 2 different techniques. METHODS: The author conducted a retrospective analysis of patients with extensive skull defects undergoing acrylic cranioplasties between October 2016 and January 2018. The surgical results were classified based on surgical time, blood loss, and the 3 scales of patient satisfaction, improvement of facial symmetry, and need for additional surgery along with the rate of wound complications. RESULTS: Thirty patients underwent cranioplasty with PMMA-based implants, whether fabricated using alginate impression technique (56.67%) or fabricated using 3-dimensional (3D) printed patient-specific moulds (43.33%). Complications included infection (13.3%). The authors considered the craniofacial aesthetics based on patient satisfaction excellent (69%) with the degree of improvement of craniofacial symmetry satisfactory (92.3%), and 1 patient requiring resurgery in alginate impression technique fabricated implants. CONCLUSION: The author recommends a unique technique for fabrication of PMMA-based implants using 3D printed moulds to achieve a better fitting implant and highly cosmetic outcome for cranioplasty at affordable cost.

Polymethylmethacrylate cranioplasty using low-cost customised 3D printed moulds for cranial defects - a single Centre experience: technical note.

We report our experience with 3D customised cranioplasties for large cranial defects. They were made by casting bone cement in custom made moulds at the time of surgery. Between October 2015 and January 2018, 29 patients underwent the procedure; 25 underwent elective cranioplasties for large cranial defects and four were bone tumour resection and reconstruction cases. The majority of patients (96.5%) reported a satisfactory aesthetic outcome. No infections related to the surgical procedure were observed in the follow-up period. The method proved to be effective and affordable.

Polymethyl Methacrylate in Patient-Specific Implants: Description of a New Three-Dimension Technique.

Polymethyl methacrylate (PMMA), an easily moldable and economical synthetic resin, has been used since the 1940s. In addition, PMMA has good mechanical properties and is one of the most biocompatible alloplastic materials currently available. The PMMA can serve as a spacer and as a delivery vehicle for antibiotics. Prior studies have indicated that no significant differences in infection rates exist between autologous and acrylic cranioplasty. Although inexpensive, the free-hand cranioplasty technique often yields unsatisfactory cosmetic results. In the present study, the application of a recently developed, economic modality for the perioperative application, and molding of PMMA to ensure a precise fit in 16 patients using computer-aided design, computer-aided manufacturing, and rapid prototyping was described.The mean defect size was 102.0 ±â€Š26.4 cm. The mean volume of PMMA required to perform the cranioplasty procedure was 51 mL. The cost of PMMA was approximately 6 Euro (&OV0556;) per mL. The costs of fabricating the implants varied from 119.8 &OV0556; to 1632.0 &OV0556; with a mean of 326.4 &OV0556; ±â€Š371.6. None of the implants required removal during the follow-up period.

Antibiotic-laden Bone Cement in Primary and Revision Hip and Knee Arthroplasty.

Antibiotic-laden bone cement (ALBC) has a number of different uses in primary and revision total joint arthroplasty. However, considerable controversy remains regarding how and when it is best used. The prophylactic use of low-dose ALBC in primary cemented total hip arthroplasty is well supported by the literature, conferring both clinical and economic benefits. In contrast, conclusive evidence on the clinical efficacy or economic benefit of the routine use of ALBC in primary total knee arthroplasty remains elusive. Given the currently available evidence, we cannot determine definitively whether the routine use of ALBC in primary total knee arthroplasty is justified, although selective use in patients with a high risk of infection seems warranted. The routine use of ALBC in revision total joint arthroplasty is well accepted, with good supporting evidence in studies of both aseptic and first-stage revision procedures. Although limited clinical evidence exists on the use of ALBC at the time of definitive component reimplantation after septic revision, the rationale for its use is strong.

Standardization of Acrylic Bone Cement Mixing Protocols for Total Knee Arthroplasty Results in Cost Savings.

Cost reduction is important in total joint replacement surgery. Bone cement is used to fixate implants in most knee replacement procedures. The authors instituted a 4-pronged approach to reduce the cost of cement. Their approach included reducing the cost of the cement powder, changing the type of mixing method, using less antibiotic cement, and decreasing the amount of cement required for smaller implants. The authors evaluated the implementation of this program and measured the overall costs of cementation during knee replacement. A retrospective review of total knee replacement cementation technique and cost was performed before and after the cost-reduction program was implemented. The type of cement and cement mixing equipment used, the amount of cement used, and the cost of cement and cement mixing equipment were examined. The authors also reported the short-term complication rate including 90-day readmission rate and 30-day revision rate. The program resulted in an overall decrease in cement-related costs from approximately $310 to $105 per case. Reductions in the amount of cement used and the use of antibiotic cement were shown. Among the 3 surgeons, adoption of the program varied. Bone cement is an expense of modern total knee replacement. Implementing a cost-reduction program can reduce cement costs without changing quality of cementation. [Orthopedics. 2018; 41(5):e671-e675.].

Gold fiducials are a unique marker for localization in the thoracic spine: a cost comparison with percutaneous vertebroplasty.

We present a unique application of the gold fiducial as a preoperative, radiographic marker placed in the thoracic spine and used for intraoperative localization. In comparison to percutaneous vertebroplasty marking of thoracic spinal levels with polymethyl methacrylate (PMMA) cement, implantation of the gold fiducial is technically facile with a minimal learning curve. The fiducial markers are also associated with significantly less financial resources. Following 2013 Current Procedural Terminology (CPT) coding, the cost of vertebroplasty under fluoroscopic guidance, $3195·43, or under computed tomography (CT) guidance, $3232·54, is more than double the cost of the gold fiducial implantation - $1237·55 and $1267·03, under similar imaging techniques, respectively. In the first description of gold fiducials in the thoracic spine, we conclude that the marker is a safe and cost-effective method for preoperative localization of the thoracic levels.

Influencia del medio fisiológico sobre las propiedades mecánicas del cemento óseo. ¿Son los estudios actuales extrapolables? / Influence of the physiological medium on the mechanical properties of bone cement: can current studies be extrapolated?

Objetivo. El uso del cemento óseo esta muy extendido en COT, existiendo multitud de estudios experimentales que lo avalan. La mayoría de los ensayos mecánicos están realizados en seco, lo que cuestiona la extrapolación de los resultados a la clínica. El objetivo de este estudio es evaluar si las propiedades mecánicas del polimetilmetacrilato (PMMA) obtenidas en series previas en seco, se mantienen en un medio fisiológico. Material y método. Se ha diseñado un estudio experimental para evaluar este aspecto, utilizando PMMA con antibiótico (vancomicina). Cuatro grupos fueron definidos en función del medio estudiado (seco o líquido) y de la realización de un acondicionamiento previo en suero fisiológico (una semana o un mes). Se hicieron estudios de desgaste y resistencia a flexión según las normativas ISO y ASTM, valorando el desgaste, el coeficiente de fricción, la resistencia a la rotura y el modulo de Young. Las muestras fueron analizadas mediante microscopía electrónica. Resultados. Las muestras ensayadas en medio líquido presentaron menores valores de desgaste, así como menor resistencia a flexión, obteniéndose significación en el desgaste. El tipo de desgaste se modificó de un desgaste abrasivo a uno adhesivo en aquellas muestras estudiadas en medio líquido. El tiempo de acondicionamiento proporcionó menores valores de desgaste (p < 0,05). Conclusiones. Se recomienda precaución a la hora de extrapolar los resultados de los estudios sobre PMMA en seco dado el diferente comportamiento mecánico del cemento en un medio líquido mucho más cercano a la situación clínica real, como es el suero fisiológico (AU)

Purpose. The use of bone cement is widespread in orthopaedic surgery. Most of the mechanical tests are performed in dry medium, making it difficult to extrapolate the results. The objective of this study is to assess if the mechanical properties of polymethylmethacrylate (PMMA), obtained in previous reports, are still present in a liquid medium. Material and method. An experimental study was designed with antibiotic (vancomycin) loaded PMMA. Four groups were defined according to the medium (dry or liquid) and the pre-conditioning in liquid medium (one week or one month). Wear and flexural strength tests were performed according to ASTM and ISO standards. Volumetric wear, friction coefficient, tensile strength, and Young's modulus were analyzed. All samples were examined by scanning electron microscopy. Results. The samples tested in liquid medium showed lower wear and flexural strength values (P<.05). The kind of wear was modified from abrasive to adhesive in those samples studied in liquid medium. The samples with a pre-conditioning time showed lower values of wear (P<.05). Conclusions. Caution is recommended when extrapolating the results of previous PMMA results. The different mechanical strength of the cement in a liquid medium, observed in saline medium, is much closer to the clinical situation (AU)

The economics of using prophylactic antibiotic-loaded bone cement in total knee replacement.

The rate of peri-prosthetic infection following total joint replacement continues to rise, and attempts to curb this trend have included the use of antibiotic-loaded bone cement at the time of primary surgery. We have investigated the clinical- and cost-effectiveness of the use of antibiotic-loaded cement for primary total knee replacement (TKR) by comparing the rate of infection in 3048 TKRs performed without loaded cement over a three-year period versus the incidence of infection after 4830 TKRs performed with tobramycin-loaded cement over a later period of time of a similar duration. In order to adjust for confounding factors, the rate of infection in 3347 and 4702 uncemented total hip replacements (THR) performed during the same time periods, respectively, was also examined. There were no significant differences in the characteristics of the patients in the different cohorts. The absolute rate of infection increased when antibiotic-loaded cement was used in TKR. However, this rate of increase was less than the rate of increase in infection following uncemented THR during the same period. If the rise in the rate of infection observed in THR were extrapolated to the TKR cohort, 18 additional cases of infection would have been expected to occur in the cohort receiving antibiotic-loaded cement, compared with the number observed. Depending on the type of antibiotic-loaded cement that is used, its cost in all primary TKRs ranges between USD $2112.72 and USD $112 606.67 per case of infection that is prevented.

Low cost polymer intramedullary nails for fracture fixation: a biomechanical study in a porcine femur model.

INTRODUCTION: Whilst intramedullary nailing is a commonly accepted technique for lower limb fracture fixation, the cost of nails can be prohibitive in hospitals in developing nations. In these institutions bone cement has found many off label applications, that whilst are effective do not meet manufacturers guidelines. The aim of this study was to examine the biomechanics of one such application, fracture fixation using a bone cement intramedullary nail. MATERIALS AND METHODS: Five porcine femurs underwent a mid-shaft osteotomy and were fixed using a nail made from antibiotic simplex bone cement. The torsional and flexural stiffness and shear modulus of these constructs were compared to five intact porcine femurs. RESULTS: The bone cement intramedullary nail was able to achieve relative stability in both torsion, with a mean shear modulus of 0.17 GPa and in flexion with a mean flexural stiffness of 358 N/mm. This corresponds to 47 and 22% of the respective measurements in the intact femurs. The mean ultimate flexural strength of fracture/nail constructs was 936 +/- 350 N, which is 20% of the ultimate flexural strength of an intact porcine femur (4,820 +/- 698 N). CONCLUSION: Intramedullary nails made from bone cement were able to provide sufficient promise in this situation to warrant further investigation for their applicability as a low cost alternative for use in developing countries.

Cost-effectiveness analysis of PMMA, silicone, or acrylic intra-ocular lenses in cataract surgery in four European countries.

PURPOSE: To compare the cost-effectiveness of different intra-ocular lens (IOL) materials (Hydrophobic acrylic, Polymethylmethacrylate (PMMA), Hydrophilic acrylic and Silicone) implanted after cataract surgery with reference to Nd:YAG laser capsulotomy and Nd:YAG-related complications in four European countries (France, Italy, Germany and Spain). SETTING: A retrospective review of 1,525 patients (eyes), aged 50 to 80 years, operated with phacoemulsification for cataract in 1996 or 1997 in 16 surgical centres (4 per country). METHODS: The study was conducted using a cost-effectiveness approach. Medical charts were reviewed to collect retrospective information during the 3-year period following cataract surgery in order to identify patients who underwent Nd:YAG laser capsulotomy post-operatively. Clinical data were combined with unit costs assessed by experts for Nd:YAG laser capsulotomy and their complications. A cost-effectiveness ratio (cost per patient without Nd:YAG laser capsulotomy intervention) was estimated in relation to each IOL material used in each of the four European countries. RESULTS: Hydrophobic acrylic, specifically Acrysof, was the most cost-effective IOL material in all the countries except Germany where it was second. PMMA had the best ratio in Germany, was second in Spain and only third in Italy and France. Silicone was second in France and ranked third in the other countries, while hydrophilic acrylic had the worst ratio overall in all countries. CONCLUSIONS: Cost-effectiveness ratios of hydrophobic acrylic (Acrysof) were better than those of other types of IOL materials used in most of the countries. Sensitivity analyses were performed to vary the base case analysis to demonstrate the economic importance of the assumptions. In all cases, hydrophobic acrylic IOL material was shown to be a highly cost-effective option.

Liquid gentamicin in bone cement: a laboratory study of a potentially more cost-effective cement spacer.

BACKGROUND: Liquid gentamicin is approved by the Food and Drug Administration, is readily available, and is much less costly than tobramycin, the more commonly used antibiotic in cement spacers. The purpose of the present study was to test the mechanical properties, elution characteristics, and antibacterial activity of liquid gentamicin in an acrylic bone cement spacer. METHODS: Standardized specimens consisting of Palacos cement combined with liquid gentamicin, powdered tobramycin, or no antibiotic were fashioned, and the three groups were tested with regard to compressive and tensile strength, elution characteristics (with use of radioimmunoassays), and antibacterial activity (with use of bioassays). RESULTS: The ultimate compression strength decreased by 49% (from 64.65 +/- 3.89 MPa to 32.96 +/- 3.33 MPa) and the ultimate tension strength decreased by 46% (from 35.85 +/- 2.97 MPa to 19.20 +/- 0.36 MPa) when the specimens containing 480 mg of liquid gentamicin were compared with the controls. The addition of tobramycin had no significant effect compared with the controls. The majority of gentamicin was released from the cement during the initial twenty-four hours (mean concentration, 26.4 mcg/mL). The mean concentrations at three and six weeks were 4.15 and 0.65 mcg/mL, respectively. The bioassays confirmed the bactericidal activity of the gentamicin released from the cement. CONCLUSIONS: Liquid gentamicin in bone cement is potent and bactericidal. Although the mechanical properties of the cement are significantly diminished by the addition of liquid gentamicin, the temporary nature of the cement spacer makes its use potentially worthwhile given the substantial cost savings to the hospital and the patient.

Acrylic bone cement: its clinical development and current status in Japan.

This article describes the transition of annual total sales figures of bone cement in Japan during the last 12 years, bone cement-related complications, the present status of bone cement application in Japan as surveyed by the Implant Committee of the Japanese Orthopaedic Association, and its proposed precautions to be taken for the prevention of bone cement complications.

Low-cost antibiotic loaded systems for developing countries.

Treatment of osteomyelitis with local antibiotic delivery systems has become a common practice in orthopaedic surgery. This study attempted to show that locally produced pure or bioglass reinforced plaster of Paris, hydroxyapatite and sodium alginate are promising biomaterials and mainly because of economical reasons and availability, may be an alternative in clinical practice, especially for developing countries. A total of 32 rabbits were divided into four groups (n:8). In group A, sodium alginate + cephazoline; in group B, plaster of Paris + bioglass + cephazoline; in group C, plaster of Paris + hydroxyapatite + cephazoline and in group D, plaster of Paris + cephazoline were used. The blood serum cephazoline concentrations were analyzed by high performance liquid chromatography on days 1 to 10 everyday and then at days 13, 17, 18, 24, 25 and 30. The mean values +/- standard deviations and median values of blood serum antibiotic concentrations for groups A, B, C and D were 1.45 +/- 0.40 (1.42) mcg/ml, 1.53 +/- 0.64 (1.31) mcg/ml, 1.92 +/- 0.39 mcg/ml (1.90) and 1.41 +/- 0.65 (1.25) mcg/ml, respectively. The detected antibiotic level was constantly over the minimum inhibitory concentration for Staphylococcus aureus. In conclusion, it can be stated that these materials are promising as a antibiotic delivery system even with simple production methods.

[Toward a more resistant resin, more economical and better suited to conditions in developing countries]. / Pour une resine plus resistante, plus economique et adaptee aux contextes des pays du sud.

The breakage of prosthesis constructed in polymethacrylate resin is a reality in daily practice. Several solutions have been proposed to overcome this problem. Thus, the reinforcement of resin with carbon fibre improved greatly the mechanical properties, notably the fatigue strength. The technique of elaboration of such prosthesis proposed in this study has little impact on aesthetic as well as on the final cost. This proposition could be a relevant solution for third world countries opposite to economical and technological problems generated by cast metallic framework.