Assessment of in vivo bone activity patterns in medial mobile-bearing unicompartmental knee arthroplasty : a prospective SPECT/CT study.

AIMS: Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs. METHODS: In total, 34 patients (13 female, 21 male; mean age 62 years (41 to 79); BMI 29.7 kg/m2 (23.6 to 42.1)) with 38 medial Oxford partial UKAs (20 left, 18 right; 19 cementless, 14 cemented, and five hybrid) were prospectively followed with sequential 99mTc-hydroxymethane diphosphonate single photon emission CT (SPECT)/CT preoperatively, and at one and two years postoperatively. Changes in mean osteoblastic activity were investigated using a tracer localization scheme with volumes of interest (VOIs), reported by normalized mean tracer values. A SPECT/CT registration platform additionally explored cortical tracer evolution in zones of interest identified by previous experimental research. RESULTS: Significant reduction of tracer activity from the preoperative situation was found in femoral and anteromedial tibial VOIs adjacent to the UKA components. Temporarily increased osteoblastic bone activity was observed in VOIs comprising the UKA keel structure at one year postoperatively compared to the preoperative activity. Persistent higher tracer uptake was found in the posterior tibial cortex at final follow-up. Multivariate analysis showed no statistical difference in osteoblastic bone activity underneath cemented or cementless components. CONCLUSION: Well-functioning medial mobile-bearing UKAs showed distinct changes in patterns of normalized bone tracer activity in the different VOIs adjacent to the prosthetic components, regardless of their type of fixation. Compared to the preoperative situation, persistent high bone activity was found underneath the keel and the posterior tibial cortex at final follow-up, with significant reduced activity only being identified in femoral and anteromedial tibial VOIs. Cite this article: Bone Joint J 2022;104-B(1):34-44.

Should all patients with a culture-negative periprosthetic joint infection be treated with antibiotics? : a multicentre observational study.

AIMS: The aim of this study was to analyze the prevalence of culture-negative periprosthetic joint infections (PJIs) when adequate methods of culture are used, and to evaluate the outcome in patients who were treated with antibiotics for a culture-negative PJI compared with those in whom antibiotics were withheld. METHODS: A multicentre observational study was undertaken: 1,553 acute and 1,556 chronic PJIs, diagnosed between 2013 and 2018, were retrospectively analyzed. Culture-negative PJIs were diagnosed according to the Muskuloskeletal Infection Society (MSIS), International Consensus Meeting (ICM), and European Bone and Joint Society (EBJIS) definitions. The primary outcome was recurrent infection, and the secondary outcome was removal of the prosthetic components for any indication, both during a follow-up period of two years. RESULTS: None of the acute PJIs and 70 of the chronic PJIs (4.7%) were culture-negative; a total of 36 culture-negative PJIs (51%) were treated with antibiotics, particularly those with histological signs of infection. After two years of follow-up, no recurrent infections occurred in patients in whom antibiotics were withheld. The requirement for removal of the components for any indication during follow-up was not significantly different in those who received antibiotics compared with those in whom antibiotics were withheld (7.1% vs 2.9%; p = 0.431). CONCLUSION: When adequate methods of culture are used, the incidence of culture-negative PJIs is low. In patients with culture-negative PJI, antibiotic treatment can probably be withheld if there are no histological signs of infection. In all other patients, diagnostic efforts should be made to identify the causative microorganism by means of serology or molecular techniques. Cite this article: Bone Joint J 2022;104-B(1):183-188.

Componentes protésicos más usados en la artroplastia total de cadera en las provincias centrales / Most Used Prosthetic Components in Total Hip Arthroplasty in Central Provinces

Introducción: La cirugía de la artroplastia y el recambio de una prótesis de cadera es una cirugía compleja y costosa. La estrategia quirúrgica y componentes protésicos son completamente diferentes en función de las deformidades óseas existentes y características anatómicas personales de cada paciente, por tanto, la planificación de suministros de los diferentes componentes es básica para cubrir las demandas de la población necesitada y la adecuada eficiencia económica para evitar gastos innecesarios por sobreestimación o infraestimación de las demandas. Objetivos: Determinar las necesidades por medidas de los diferentes tipos de componentes protésicos utilizados en la artroplastia total de cadera en las provincias centrales y de este modo optimizar las inversiones, con las ventajas económicas que supone. Métodos: Estudio longitudinal descriptivo retrospectivo de los casos operados de artroplastia total de cadera en el Hospital Arnaldo Milián Castro de Villa Clara, desde diciembre de 1998 hasta la fecha. Se analizan las variables edad, sexo, procedencia y componentes protésicos. Se recoge la información en la base de datos creada en SPSS, donde se realizan los análisis estadísticos. Resultados: La edad media fue 62,36 años. El grupo de 61 - 80 años fue el de mayor incidencia con 215 pacientes. Predominó el sexo masculino 51,8 por ciento. La mayor incidencia, correspondió a Villa Clara con 692 pacientes. Los componentes cementados 46 - 50 fueron los más usados y en los no cementados los más usados fueron 48-56. Vástagos Tipo Müller 7.5 - 12.5. RALCA Cementadas T0-T4, no cementados T1-T3. En las SLA, 11.5 y 13. Los cuellos estándar fueron los de mayor incidencia con 390 pacientes. Conclusiones: Con las incidencias de las diferentes medidas utilizadas por cada uno de los componentes expresados, se puede determinar con bastante exactitud la demanda de cada medida por cada 100 casos pendientes de operación. Esto permite satisfacer las demandas de las medidas más usadas y hacer una distribución apropiada a la hora del suministro, lo que redundaría en un beneficio económico vital en las actuales condiciones del país(AU)

Introduction: The arthroplasty surgery and the replacement of a hip replacement is a complex and expensive surgery. The surgical strategy and prosthetic components are completely different depending on the existing bone deformities and personal anatomical characteristics of each patient, therefore, the planning of supplies of the different components is essential to meet the demands of the needy population and adequate economic efficiency to avoid unnecessary expenses due to overestimation or underestimation of claims. Objective: To determine the needs by measurements of the different types of prosthetic components used in total hip arthroplasty in the central provinces and thus optimize investments, with the economic advantages that it entails. Methods: A retrospective descriptive longitudinal study was carried out of the total hip arthroplasty operated cases at Arnaldo Milián Castro Hospital in Villa Clara, from December 1998 to date. Age, sex, origin and prosthetic components are the variables examined. The information is collected in the database created in SPSS, statistical analyzes was performed. Results: The mean age was 62.36 years. The group of 61-80 years was the one with the highest incidence (215 patients). Male sex predominated (51.8 percent). The highest incidence corresponded to Villa Clara (692 patients). The cemented components 46-50 were the most used and in the uncemented components the most used were 48-56. Müller Stems 7.5 - 12.5. RALCA Cemented T0-T4, uncemented T1-T3. In the SLA the most used were 11.5 and 13 respectively. Standard necks were those with the highest incidence (390 patients). Conclusions: The demand for each measure can be determined quite accurately for every 100 cases pending operation with the incidents of the different measures used by each of the components expressed, allowing to meet the demands of the most used measures and appropriate distribution at supplying, which would result in vital economic benefit in the current conditions of the country(AU)

Use of polyethylene terephthalate as a prosthetic component in the prosthesis on an overdenture implant.

The aim of this study was to evaluate the physical-mechanical and morphological properties of polyethylene terephthalate (PET), for a new application as a prosthetic component for overdentures implant-retained, compared with different polymers. Were prepared 20 specimens for each material: Polyethylene terephthalate (PET), Polyacetal, Polytetrafluoroethylene (PTFE) and Polyethylene, for analysis of roughness and hardness surface, compressive strength and pull out test. For fatigue strength test, a total of 200 capsules (n = 40) were captured in pairs with acrylic resin and subjected to 2900 insertion/removal cycles, simulating 24 months of overdenture use. In this test, a group was added (o-ring Intra-Lock System) as a standard of comparison. The morphological and structural analysis were realized by stereomicroscopy, scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD). All specimens in this study were analyzed before and after thermocycling (5-55 °C, for 10,000 cycles). Two-way ANOVA with repeated measurements and Tukey test were used (α = 0.05). For roughness, difference was observed only between the materials, with lowest averages for Polyacetal and PET (p < 0.001). For the hardness there was no statistically significant difference between the materials (p > 0.001). For compressive strength, Polyacetal, followed by PET (p < 0.001) presented the highest values independent of thermocycling. In the pullout test, PET and polyacetal presented, the highest values (p = 0.033). In the fatigue test, for 24 months analysis, difference was observed before and after thermocycling for O-ring group (p = 0.010) and polyacetal (p = 0.002), PET also presented higher values of resistance in relation to the o-ring (p < 0.001). The thermocycling did not alter the polyethylene surface through SEM images as well as the structure of all the materials analyzed by FTIR and DRX. In this study, the PET presented results compatible with those expected, which suggests its application for making retention capsules for implant-retained overdentures.

Restauração estética implantossuportada de dente anterior utilizando pilar protético com interface de titânio e zircônia / Anterior tooth implantsupported esthetic restoration using a titanium-zirconia interface prosthetic abutment

Os componentes protéticos em restaurações implantossuportadas atuam como intermediários entre a prótese e o implante, evitando que a prótese seja parafusada diretamente sobre o implante. O titânio ainda é o material mais utilizado para fabricação destes componentes, mas pode levar à coloração acinzentada do tecido gengival, prejudicando o resultado final estético. Com isso, a zircônia tem sido cada vez mais utilizada, principalmente em restaurações anteriores. Este artigo relatou um caso clínico com a confecção de restauração implantossuportada de dente localizado em região anterior (incisivo central superior direito) utilizando um intermediário protético fabricado em zircônia associado a um componente metálico parafusado sobre o implante. A paciente compareceu à clínica odontológica com um implante dentário instalado na região do incisivo central superior direito (dente #11). Foi fabricado um componente em titânio (pilar interface) para ser parafusado diretamente sobre o implante, e que seria associado a um pilar customizado de zircônia, preso por fricção ao componente de titânio e com o auxílio de parafuso. Tanto o pilar customizado quanto a restauração final foram fabricados com tecnologia CAD/CAM (computer-aided design/computer-aided manufacturing). A restauração foi fabricada em dissilicato de lítio e cimentada adesivamente com cimento resinoso. A restauração implantossuportada de dente localizado em região anterior, com o uso de pilar híbrido fabricado em zircônia associado a componente metálico parafusado sobre o implante, apresentou resultados clínicos satisfatórios e estética otimizada, sendo uma opção bastante viável para a restauração de dentes anteriores. (AU)

The prosthetic components in implant-supported restorations are intermediary between the prosthesis and the implant, thus avoiding direct prosthetics screwing. Titanium remains the most used material but the its coronal gray area compromises esthetics. Zirconia has therefore been increasingly used to improve the final esthetic outcome. This article will describe the implantsupported restoration of an anterior tooth (right upper central incisor) by using a titanium-zirconia interface prosthetic abutment. The patient arrived at the dental office with an implant already placed at the right upper central incisor region. Both the titanium-zirconia interface prosthetic abutment and the final restoration were fabricated by using CAD/CAM (computer-aided design/computer-aided manufacturing) technology. The final restoration was fabricated in lithium disilicate and luted using resin cement. The implant-supported restoration of an anterior tooth using a titanium-zirconia interface prosthetic abutment screwed to the implant showed a satisfactory clinical outcome and optimized esthetics, thus being a reliable option to restore anterior teeth. (AU)

Analysis and management of implant-prosthetic complications: Description of a diagnostic and therapeutic algorithm with a clinical case.

PATIENT: A 65-year-old non-smoker man with stabilized chronic periodontitis and in good general health conditions presented to our observation. The patient reported crown mobility, gingival inflammation and localized pain, corresponding to the mandibular right first molar rehabilitated with a cement-retained implant crown. This clinical situation suspected a fracture of an implant-prosthetic component. Through the described diagnostic algorithm, an abutment hexagon fracture was revealed. Thus, a minimally invasive treatment was carried out in order to use the residual implant-prosthetic components for a new implant-prosthetic rehabilitation. DISCUSSION: Fractures of implant-prosthetic components are clinical occurrences that may result in irreversible failures. The main causes of a possible fracture are dependent on biomechanical considerations and production processes of implant-prosthetic components. The respect of the rigorous planning and the employment of the implant-prosthetic devices of the same manufacturer are recommended. CONCLUSIONS: Specific employments and protocols have to be offered in order to manage the fractures of implant-prosthetic components. This work showed that through the described diagnostic and therapeutic algorithm, the clinician can be guided towards a proper diagnosis and a correct management of the cases where a fracture of implant-prosthetic components may occur.

Axial bone-socket displacement for persons with a traumatic transtibial amputation: The effect of elevated vacuum suspension at progressive body-weight loads.

BACKGROUND: Elevated vacuum suspension systems use a pump to draw air from the socket with the intent of reducing bone-socket motion as compared to passive suction systems. However, it remains unknown if elevated vacuum suspension systems decrease limb displacement uniformly during transitions from unloaded to full-body-weight support. OBJECTIVES: To compare limb-socket motion between elevated vacuum and passive suction suspension sockets using a controlled loading paradigm. STUDY DESIGN: Comparative analysis. METHODS: Persons with transtibial amputation were assessed while wearing either an elevated vacuum or passive suction suspension socket. Digital video fluoroscopy was used to measure axial bone-socket motion while the limb was loaded in 20% body-weight increments. An analysis of variance model was used to compare between suspension types. RESULTS: Total axial displacement (0%-100% body weight) was significantly lower using the elevated vacuum (vacuum: 1.3 cm, passive suction: 1.8 cm; p < 0.0001). Total displacement decreased primarily due to decreased motion during initial loading (0%-20%; p < 0.0001). Other body-weight intervals were not significantly different between systems. CONCLUSION: Elevated vacuum suspension reduced axial limb-socket motion by maintaining position of the limb within the socket during unloaded conditions. Elevated vacuum provided no meaningful improvement in limb-socket motion past initial loading. CLINICAL RELEVANCE: Excessive bone-socket motion contributes to poor residual limb health. Our results suggest elevated vacuum suspensions can reduce this axial displacement. Visual assessment of the images suggests that this occurs through the reduction or elimination of the air pocket between the liner and socket wall while the limb is unloaded.

Implante cone morse ultra rosqueante de torque interno: parte II: componentes cirúrgicos e protéticos / Implant cone morse ultra self tapping of internal torque: part II: surgical and prosthetic components

Este trabalho apresenta características e resultados de ensaios realizados em componentes protéticos utilizados em implantes com conexão cônica interna. Nele estão descritas as características principais dos componentes protéticos e o sistema de fresagem para inserção do implante de acordo com a classificação óssea.

This work shows characteristics and tests results of implant prosthetics components used with internal taper connection. There are described the main characteristics of the prosthetics components and milling system for insertion of the implant according to the bone classification.

Relaltionship Between The Depth Access Hole And Prosthetic Components In Screw Retained Implants / 대한치과보철학회지

A total of 605 implant fixture prosthesis delivered by 3 clinics and 2 laboratories were examined in this study. The object of this study was to determine the proper length of screw head. The depth of access hole were measured and compared to the type of fixture, abutment, gold screw and prosthesis. The results were as follows: 1. The average number of fixtures per patient were 2.97. 2. The number of fixture installed in the lower posterior area are 327(55.56 %), the upper posterior area 171(28.25%). 3. The depth of access hole is 4.23 mm in shallow area, and 5.46 mm in deep area and the differences were 1.23 mm. 4. The average depth of the aceess hole of the UCLA abutment were 5.02 mm. 5. The number of 4-5 mm access hole depth were 60(22.39%)in abutment screw level and the number of 4-5 mm depth in fixture level were 101(29.19%). 6. In the shape of screw head, hexed type were 576(95.21%), slotted type were 29(4.79%).