The Wear on a Novel Motion Mode Hinged Knee Prosthesis: A Finite Element Analysis / 医用生物力学

Objective To perform finite element analysis on a novel motion mode hinged knee prosthesis, and investigate the method of wear simulation on hinged prosthesis and the influence of motion mode on wear of the prosthesis. Methods Based on the finite element model of contact stress on spherical axis prosthesis, the finite element model of wear was established according to Archard wear theory. The kinematics data during different motions were input as loading condition to simulate mechanical environment of the knee arthroplasty in physiological activities. The wear results of spherical axis prosthesis were studied. Results For tibial insert, the average and maximum contact stresses during upstairs and downstairs climbing were higher than those during walking, and the cumulative wear volume during upstairs climbing was larger than that during downstairs climbing and walking. The wear mainly occurred on lower surface of tibial insert during all 3 motions. For rotating bushing, there was only a short period of contact and wear during walking, and the cumulative wear was 0. 19 mm3. Conclusions The spherical axis motion of hinged knee prosthesis can improve the mechanical environment of knee, reduce the wear of rotating bushing, and prolong the prosthesis survival. The finite element simulation can predict the wear of hinged prosthesis effectively, and provide the theoretical basis for design and improvement of the prosthesis.

Prosthetic maintenance assessment for implant fixed complete dentures and implant overdentures: a randomized clinical trial / Avaliação da manutenção protética para próteses totais fixas suportadas por implantes e Overdentures: um ensaio clínico randomizado

Objective: The rehabilitation choice for the edentulous patients usually lies between the fixed and removable prosthetic options. The treatment decisions are affected by many factors where complications and maintenance needs are both considered crucial factors, in addition to the cost effectiveness of the chosen treatment. Material and Methods: This study was applied on 44 edentulous patients, where 22 patient for each group were enrolled in the outpatient clinic of prosthodontics, Cairo University as per a set of eligibility criteria. Four inter-foraminal implants were installed for all eligible participants. Three months later, healing abutments were used for soft tissue preparation prior to the fabrication of the final prosthesis. A prosthetic treatment option was then randomly allocated to obtain two equal groups via computer generated randomization program; Group. A received telescopic implant overdentures, and Group. B received screw retained dentures. All Complications (Screw loosening or fracture, tooth or denture base fracture and mucositis) were reported after overdenture insertion along the follow up period (1, 6, 9 and 12 months respectively). Results: The frequency of the screw loosening for hybrid overdentures where (59.1%) compared to (27.3%) of telescopic prosthesis at 12 months follow up period (p=0.035), mucositis reporting at 6m interval had shown the highest frequency in both groups (Group A (54.5%), Group B (81.8%), (p=0.045), all other reported complications that lack statistical significance either within the same group or between both groups at different time intervals. Conclusion: Both treatment modalities; telescopic implant overdenture and hybrid fixed screw-retained are reliable for restoring the completely edentulous arches, the decision whether to make a fixed or removable implant denture shall be guided with the patient preference together with the dentist assessment in relation (AU)

Objetivo: A escolha da reabilitação para pacientes edêntulos geralmente recai entre próteses fixas e removíveis. As decisões de tratamento são afetadas por muitos fatores onde as complicações e as necessidades de manutenção são consideradas critérios cruciais, além do custo-efetividade do tratamento escolhido. Material e Métodos: Este estudo foi aplicado em 44 pacientes edêntulos, onde 22 pacientes para cada grupo foram matriculados no ambulatório de prótese dentária da Universidade do Cairo de acordo com um conjunto de critérios de elegibilidade. Quatro implantes interforaminais foram instalados para todos os participantes elegíveis. Três meses depois, pilares de cicatrização foram utilizados para preparação dos tecidos moles antes da fabricação da prótese final. Uma opção de tratamento protético foi então alocada aleatoriamente para obter dois grupos iguais por meio de andomização gerada através programa de computador. O Grupo A recebeu overdentures de implantes telescópicos e o Grupo B recebeu dentaduras fixas parafusadas sobre os implantes. Todas as complicações (afrouxamento ou fratura do parafuso, fratura da base do dente ou da prótese e mucosite) foram relatadas após a inserção da overdentures ao longo do período de acompanhamento (1, 6, 9 e 12 meses, respectivamente). Resultados: A frequência do afrouxamento do parafuso para Overdentures híbridas (59,1%) em comparação com (27,3%) da prótese telescópica no período de acompanhamento de 12 meses (p=0,035), o relato de mucosite no intervalo de 6 meses mostrou a maior frequência em ambos os grupos (Grupo A (54,5%), Grupo B (81,8%), p=0,045, todas as outras complicações relatadas foram sem significância estatística dentro do mesmo grupo ou entre os dois grupos em intervalos de tempo diferentes. Conclusão: Ambas as modalidades de tratamento; overdentures sobre implantes telescópicos e próteses híbridas fixas parafusadas são confiáveis para reabilitar as arcadas completamente edêntulas. A decisão de fazer uma prótese fixa ou removível sobre implantes deve ser guiada pela preferência do paciente juntamente com a avaliação do dentista em relação ao estado geral do paciente e sua saúde bucal. (AU)

Safety, Effectiveness, and Hemodynamic Performance of the Bovine Pericardium Organic Valvular Bioprosthesis

ABSTRACT Objective: To assess actual data on the safety, effectiveness, and hemodynamic performance of Bovine Pericardium Organic Valvular Bioprosthesis (BVP). Methods: The BIOPRO Trial is an observational, retrospective, non-comparative, non-randomized, and multicenter study. We collected data from 903 patients with symptomatic, moderate, or severe valve disease who underwent BVP implants in the timeframe from 2013 to 2020 at three Brazilian institutions. Death, valve-related adverse events (AEs), functional recovery, and hemodynamic performance were evaluated at the hospital, at discharge, and six months and one year later. Primary analysis compared late (> 30 days after implant) linearized rates of valve-related AEs, such as thromboembolism, valve thrombosis, major hemorrhage, major paravalvular leak, and endocarditis, following objective performance criteria (OPC). Analysis was performed to include at least 400 valve-years for each valve position (aortic and mitral) for complete comparisons to OPC. Kaplan-Meier survival and major adverse cardiovascular and cerebrovascular event analyses were also performed. Results: This retrospective study analyzed follow-up data collected from 903 patients (834.2 late patient-years) who have undergone surgery for 455 isolated aortic valve replacement (50.4%), 382 isolated mitral valve replacement (42.3%), and 66 combined valve replacement or other intervention (7.3%). The linearized rates of valve-related AEs were < 2 × OPC. One-year survival rates were 95.1% and 92.7% for aortic and mitral valve replacement, respectively. This study demonstrated an improvement in the New York Heart Association classification from baseline and hemodynamic performance within an expected range. Conclusion: According to this analysis, BVP meets world standards for safety and clinical efficacy.

Application of newly designed modular hinged ankle prosthesis in the reconstruction of defect after surgical treatment of malignant tumor at the distal tibia / 中华骨科杂志

Objective:To investigate the outcome of surgical treatment of malignant tumor at the distal tibial after reconstruction with modular hinged ankle prosthesis.Methods:The data of 9 patients with malignant tumor at the distal tibia at Musculoskeletal Tumor Center of PKUPH from June 2020 to November 2021 were analyzed retrospectively. They were male patients with age of 17 (14, 24) years (range 11-56 years). There were five tumors at the left sides and four at the right sides. There were eight patients with osteosarcoma who received the neo-chemotherapy. Among eight osteosarcomas, one was Enneking IIA and seven Enneking IIB. Furthermore, there was only one patient with renal carcinama and with solitary metastatic lesion at the distal tibia. After the resection of tumor at the distal tibia, talus cartilage was removed and talus component was fixed by lag screws. The proper tibia component was used to restore the defect of tibia and the reduction of tibia and talus components were performed. The following clinical data were collected: baseline demographic features, surgical and follow-up data. The baseline demographic features included gender, age, side, lung or/and other metastasis at initial diagnosis, Enneking stage or systematic progression for renal carcinama, histological type. The surgical data included: surgery time, blood loss, length of bone involved by the tumor, prosthesis type. Monitoring data was also recorded: complications (ankle pain when loading, talar collapse, component loosing, infection and wound dehiscence), local recurrence, pulmonary and systematic metastasis, radiological image and the function at the last follow-up (MSTS and VAS evaluation).Results:Among these nine patients, the average blood loss was 245.6±103.9 ml (range 100-400 ml) and the mean surgery time was 178.9±56.9 mins (range 120-300 min). No patient was lost during the follow-up period and the average follow-up was 21.4±5.6 months (range 12.5-27.2 months). The excision length of tibia was 14 (11, 17) cm (range 11-28 cm). There were one case with 2# prosthetic base, three cases with 3# and five cases with 4#. Five had cement fixation of prosthetic stem and four had the pressing fixation. No pulmonary and other organ metastasis occurred among eight patients with osteosarcoma and one patient with distal tibia matastasis of renal carcinama. One patient with OShad the local recurrence and received the resection. One sustained the deep infection after four months and received the removal of prosthesis and spacer implant. At the final follow-up, except one with deep infection and receiving the removal of prosthesis and spacer implant, eight patients were assessed for the function. The average MSTS was 97.1%±3.3% (range 93%-100%). The VAS of all patients was 0. One patient with prosthesis removal had no functional evaluation. At the final follow-up, all patients walked without crutch. No breakage and loosening of prosthetic stem, talar collapse, prosthetic sinking and ankle pain occurred at the final follow-up.Conclusion:The early satisfactory outcome can be obtained for patients with segmental defect after resection of malignant tumor at the distal tibia, who received the newly designed modular hinged ankle prosthesis. Meanwhile, it's worth promoting in the reconstruction of large segmental defect at the distal tibia.

Design and clinical application of the distal femur spherical motion axis hinge knee prosthesis / 中华骨科杂志

Objective:To investigate the feasibility and early clinical efficacy of spherical motion axis hinge knee prosthesis to reconstruct distal femoral bone defects.Methods:A retrospective analysis was performed on 16 patients admitted to PLA 960th Hospital and Tianjin Hospital from October 2019 to November 2021, including 8 males and 8 females, with an average age of 43.3±17.8 years (range, 15-71 years). There were 13 patients of primary tumors of the distal femur and 3 patients of postoperative revision of knee joint prostheses. Among the 13 patients with distal femur tumors, there were 6 cases of osteosarcoma, 5 cases of giant cell tumor of bone, 1 case of leiomyosarcoma and 1 case of chondrosarcoma. The reasons for revision after prosthesis replacement in 3 cases were: 2 cases of aseptic loosening after tumor-type prosthesis and 1 case of periphery fracture of surface artificial knee prosthesis. A spherical shaft rotary hinged knee prosthesis was designed and fabricated to reconstruct postoperative femoral defects in 16 patients. Follow up regularly after the operation, recheck the X-ray film to evaluate the lower limb force line, evaluate the quality of life after the operation with the Chinese version of 36-item short-form (SF-36), and evaluate the postoperative limb function with the Musculoskeletal Tumor Society (MSTS) 93 evaluation system.Results:All 16 patients were successfully placed with prostheses, and except for 2 patients undergoing total femoral replacement, the length of bone defects was 18.2±11.7 cm (range, 8.6-47.1 cm) in other 14 patients, and the operation time was 138±19 min (range, 110-170 min), the intraoperative blood loss was 211±118 ml (range, 100-500 ml). The postoperative full length orthostatic X-ray film of the lower limbs showed that the distance between the mechanical axis of the lower limb and the center of the knee joint was 0.1 (0, 0.7) cm in 16 patients, and the hip-knee ankle angle was 179.0°±2.3°(range, 173.3°-182.2°). The patients were followed up for 12-36 months. No prosthesis complications were found in 16 patients. The SF-36 score was 56.7±7.0 (range, 42.7-67.4) for physiological function and 54.1±7.6 (range, 40.5-66.3) for psychological function. The maximum knee flexion angle was 120.0°±15.6° (range, 95°-130°). The MSTS 93 score of 15 patients with tumor was 25.0±1.7 (range, 22-28), including 7 excellent and 8 good. One patient developed liver and lung metastases 10 months after surgery and died 18 months after surgery. The remaining patients, as of the last follow-up, were alive and had no local recurrence or distant metastases. Tumor-free survival time was 25.8±8.4 months (range, 12-36 months).Conclusion:The spherical motion axis hinge knee prosthesis reconstruction for distal femoral bone defects is simple and fast in intraoperative prosthesis installation, and there are no prosthetic related complications during short-term follow-up. The clinical efficacy is satisfactory.

Three-dimensional printing technology in reverse shoulder arthroplasty after resection of proximal humeral tumors / 中华骨科杂志

Objective:To analyze the efficacy of the reconstruction of the proximal humerus by reverse shoulder arthroplasty with three-dimensional (3D) printing technology after tumor rescetion.Methods:A retrospective analysis was conducted on the data of eight patients undergoing semi-constrained reverse shoulder arthroplasty with 3D printing technology after the resection of bone tumors in proximal humeri at the Affiliated Wuxi People's Hospital of Nanjing Medical University from December 2017 to January 2021. There were four males and four females with an average age of 55.1 (range, 31-73) years, all of whom had unilateral onset, 2 on the left and 6 on the right. There was one case of leiomyosarcoma (Enneking IIB), two cases of chondrosarcomas (one Enneking IA and one Enneking IB), four cases of Campanacci grade 3 giant cell tumor of bone, and one case of bone metastasis of lung adenocarcinoma. Individualized prosthesis and implantation protocol were completed preoperatively in all patients. The glenoid baseplate was manufactured using 3D printing technology. During the surgery, Malawer type I tumor resection and semi-constrained reverse shoulder arthroplasty were performed, with 6 cases simultaneously using allograft-prosthetic composite reconstruction. The follow-up was scheduled, and the patient received X-ray examination of the shoulder. The range of motion of the shoulder was measured, the Constant-Murley score and musculoskeletal tumor society (MSTS) score were recorded.Results:All 8 patients successfully completed the surgery, with a surgical time of 173.8±46.7 min (range, 130-260 min), intraoperative blood loss of 487.5±334.6 ml (range 200-1,200 ml), and proximal humeral resection of 9.9±4.6 cm (range, 4.5-19.0 cm). All patients were followed up for a period of 45.6±12.5 months (range, 24-60 months). At the last follow-up, the abduction ranges of motion of the affected shoulders increased from 27.5°±14.4° pre-operatively to 106.3°±21.8° post-operatively, with a statistically significant difference ( t=11.37, P<0.001). The forward flexion ranges increased from 28.1°±12.8° pre-operatively to 115.6°±24.0° post-operatively, with a statistically significant difference ( t=11.49, P<0.001). The Constant-Murley score was improved from 40.5±14.3 pre-operatively to 79.3±11.2 post-operatively, with a statistically significant difference ( t=9.58, P<0.001). The MSTS score was 25.6±2.2 (range, 23-28), including 6 excellent cases and 2 good cases. At 2 weeks after surgery, one patient experienced joint dislocation that was successfully reduced manually. Up to the final follow-up, all patients had survived without local tumor recurrence, metastasis, prosthesis infection and loosening. Conclusion:3D printing technology assisted shoulder arthroplasty is helpful for effective reconstruction and shoulder joint function recovery after resection of proximal humeral tumors, with satisfactory outcomes in the early and middle stages.

Correlation Between Implant Positioning and Functional Outcomes in Partial Shoulder Resurfacing / Correlação entre posicionamento do implante das artroplastias parciais de recobrimento do ombro e os resultados funcionais

Abstract Objective The present study aimed to correlate functional outcomes and implant positioning in a case series of partial shoulder resurfacing arthroplasties. Methods A total of 25 patients were assessed for range of motion, functional outcome per the University of California at Los Angeles (UCLA) score and radiographic findings. Preand postoperative data were compared. In addition, patients were grouped according to the cervical-diaphyseal angle (CDA) determined by an anteroposterior radiography and to the retroversion angle (RVA) determined by an axillary radiography. A CDA from 130° to 140° and a RVA from 20° to 40° consisted in ideal positioning (anatomical standard). Data were analyzed using the Wilcoxon signed-rank test, analysis of variance (ANOVA) followed by the Kruskal-Wallis test or the Mann-Whitney test as appropriate. Results The mean follow-up time was 48.3 months (12 to 67 months). The postoperative functional score (31.5) was higher than the preoperative score (15.5) (p < 0.001). In 6 patients, the implant was in anatomical positioning, while implant positioning was considered "nonstandard" in 19 subjects. Seven patients had a CDA < 130°, and 14 patients had a CDA ranging from 130° to 140°; in addition, the CDA was > 140° in 4 subjects. The RVA was up to 20° in 15 patients and ranged from 20° to 40° in 10 subjects. Using these criteria to group patients, the postoperative clinical-functional parameters were not statistically different from the preoperative findings (p > 0.05). Conclusion Partial shoulder resurfacing results in significant postoperative functional recovery in patients with degenerative joint diseases. However, implant positioning assessed by CDA and RVA does not correlate with clinical-functional outcomes and, therefore, it is an inaccurate indicator of surgical success. Level of Evidence IV; Case Series.

Resumo Objetivo O objetivo do presente estudo é correlacionar os resultados funcionais de uma série de casos de artroplastias parciais de recobrimento do ombro com o posicionamento do implante. Métodos Um total de 25 pacientes foram avaliados em relação à amplitude de movimentos, à avaliação funcional pelo escore de Universidade da Califórnia Los Angeles (UCLA) e por análise radiográfica. Os dados pré- e pós-operatórios foram comparados. Adicionalmente, os pacientes foram agrupados quanto ao ângulo cérvico-diafisário (ACD) avaliado na radiografia em anteroposterior e quanto ao ângulo de retroversão (ARV) avaliado na radiografia em posição axilar. Foi considerado como posicionamento ideal (padrão anatômico) um ACD entre 130° e 140° e um ARV entre 20° e 40°. Os dados foram analisados pelo teste pareado de Wilcoxon, pela análise de variância (ANOVA, na sigla em inglês) seguida pelo pós-teste de Kruskal-Wallis ou pelo teste de Mann-Whitney, quando apropriado. Resultados O seguimento médio foi de 48,3 meses (12 a 67 meses). A avaliação funcional pós-operatória (31,5) foi melhor do que a pré-operatória (15,5) (p < 0,001). Seis pacientes apresentaram posicionamento anatômico do implante, enquanto 19 pacientes foram considerados "fora do padrão." Sete pacientes apresentaram um ACD < 130°, quatorze apresentaram um ACD entre 130° e 140°, e quatro apresentaram um ACD >140°. Quinze pacientes apresentaram um ARV ≤ 20°, e 10 entre 20° e 40°. Utilizando esses critérios para agrupar os pacientes, a comparação dos parâmetros da avaliação clínico-funcional pós-operatória não foi estatisticamente diferente (p > 0,05). Conclusão A artroplastia parcial de recobrimento do ombro oferece significativa recuperação funcional pós-operatória em pacientes com doenças degenerativas articulares. Entretanto, o posicionamento do implante avaliado pelos ACD e ARV não se correlaciona com o resultado clínico-funcional, sendo, portanto, uma medida imprecisa de sucesso da cirurgia. Nível de Evidência IV, Série de Casos.

Arthrodesis reconstruction of distal tibia by 3D-printed porous prosthesis after malignant tumor resection / 中华骨科杂志

Objective:To evaluate the safety and short-term clinical postoperative functional outcomes of a novel 3D-printed porous prosthesis of the distal tibia for the bone defect after tumorectomy.Methods:From December 2017 to December 2019, a total of eight patients diagnosed with malignant bone tumor of the distal tibia were enrolled in this study. All cases received standard preoperative chemotherapy, after which osteosarcoma resection was performed and ankle arthrodesis was reconstructed using a 3D-printed prosthesis developed by our medical center. The contact surface between the distal part of the prosthesis and the talus is a 3D-printed porous surface, which is conducive to ankle fusion. The length of the prosthesis is adjusted by the conical mounting part of the modular prosthesis. The proximal part of the prosthesis can be fixed either biologically or with bone cement. At postoperative follow-up, the function of the fused ankle was assessed by radiographs and the monthly Musculoskeletal Tumor Society (MSTS) score.Results:Of the 8 patients, 5 were male and 3 were female, aged 8-29 years (mean 16.1±7.4 years), including 7 osteoblastic osteosarcomas and 1 telangiectatic osteosarcoma. Among the procedures, the mean length of osteotomy was 16 cm (11-20 cm). The method of fixation of the proximal part of the prosthesis included one case with 3D-printing of trabecular metal bone, one case with autogenous fibular graft, and six cases with bone cement. All patients were followed up for 7-39 months (mean 15.6±10.5 months). The distal prosthesis and talus were completely fused in all cases. The mean fusion duration was 4.3±0.7 months. The mean MSTS score was 84.2%±3.0% (mean 80%-90%). No tumor recurrence, wound complications, or prosthesis loosening were observed during the follow-up period.Conclusion:The novel 3D-printed distal tibial prosthesis is a safe and effective technique for reconstruction of a massive bone defect after tumorectomy of a malignant bone tumor, with high fusion rate, few complications, and satisfactory postoperative function.

Research progress on the design of fixed implant-supported prostheses in edentulous jaws / 口腔疾病防治

@#With the aging of the population and the increase in the number of edentulous patients, implant-supported fixed restorations have become more prevalent in clinical treatment. It is necessary to assess the patient's remaining bone and occlusal situation correctly; the upper jaw usually needs 6 to 8 implants, whereas the lower jaw needs 4 to 6 implants. Patients with severe alveolar bone atrophy can adopt the "all-on-4/6" treatment plan, short implants, and zygomatic and pterygomaxillary implants to avoid complex bone grafting and remain cautious when the surgical procedures require more surgical experience. According to the repair methods, the superstructure can be divided into one-piece repair and segmental repair. One-piece repair has a lower implant number, flexible location, and reasonable stress distribution but a high maintenance cost. Sectional repair easily achieves passive placement, convenient cleaning, and maintenance in the late stages, but implants need quantity and high requirements for alveolar bone. However, the requirements for alveolar bone and implant number are high. Mutually protected occlusion with minimal or no cantilever on provisional prosthesis is recommended.

Tasa de supervivencia de prótesis fija unitaria de cerámica feldespática y feldespática reforzada / Survival rate of feldspathic and reinforced feldspathic ceramic single-unit fixed prostheses

Introducción: Gracias a su eficiencia y al uso exclusivo de cerámicas libres de metal, en rehabilitación oral se ha logrado alcanzar los estándares estéticos y mecánicos, manteniendo o, incluso, superando, la calidad de los tratamientos en comparación con las restauraciones metal cerámicas tradicionales. Actualmente los mecanismos de confeccion de cerámica libre están evolucionando cada vez mas hacia las tecnologías maquinadas CAD-CAM y disminuyendo su producción mediante la técnica de Inyeccion PRESS. Objetivo: Comparar la tasa de supervivencia de prótesis fija unitaria realizadas con cerámicas feldespáticas convencionales y reforzadas con disilicato de litio, confeccionadas con sistema CAD/CAM de CEREC® chair-side, en comparación con el método de inyección de laboratorio PRESS convencional de prensión. Métodos: Revisión sistemática realizada a través de búsqueda de evidencia científica en PubMed, PubMed Clinical Queries, Epistemónikos, Tripdatabase, Cochrane Library, recursos electrónicos de la Universidad de los Andes y bibliografía retrógrada, de artículos publicados hasta el año 2019. Se incluyeron todos aquellos estudios referentes a prótesis fija unitaria de cerámicas feldespática convencional y feldespática reforzada con disilicato de litio, confeccionadas mediante CAD/CAM y/o método convencional. Resultados: Un total de 28 artículos cumplieron los criterios de inclusión: 21 estudios observacionales de cohorte, 4 ensayos clínicos aleatorizados y 3 no aleatorizados. A corto y mediano plazo, CAD/CAM de CEREC® registró tasas de supervivencia de 98 por ciento y 91,9 por ciento, respectivamente. El sistema convencional registró tasas de supervivencia de 97,5 por ciento a corto plazo y 93 por ciento a mediano. Conclusiones: A corto plazo se describe en la literatura que CAD/CAM de CEREC® tuvo una tasa de supervivencia ligeramente superior al sistema convencional. Por otro lado, a mediano plazo CAD/CAM de CEREC® presentó una leve disminución respecto al sistema convencional. Aún no hay estudios disponibles para determinar la supervivencia clínica de los tratamientos a largo plazo(AU)

Introduction: Thanks to its efficiency and the exclusive use of metal-free ceramics, in oral rehabilitation it has been possible to achieve aesthetic and mechanical standards, maintaining or even exceeding the quality of the treatments compared to traditional metal-ceramic restorations. Currently, free ceramic manufacturing mechanisms are increasingly evolving towards CAD-CAM machined technologies and decreasing their conventional production through the PRESS Injection technique. Objective: Compare the survival rate of single-unit fixed prostheses made with conventional feldspathic ceramics and reinforced with lithium disilicate by the CEREC® CAD/CAM chairside system, with the conventional PRESS laboratory injection method. Methods: A systematic review was conducted of scientific evidence included in papers published until the year 2019 in PubMed, PubMed Clinical Queries, Epistemonikos, Tripdatabase, Cochrane Library, electronic resources of Los Andes Peruvian University, and retrograde bibliography. The papers selected dealt with conventional and lithium-disilicate reinforced feldspathic ceramic single-unit prostheses made by CAD/CAM and/or the conventional method. Results: A total 28 papers met the inclusion criteria. Of these, 21 were observational cohort studies, four were randomized clinical assays and three were non-randomized assays. Short- and mid-term, CEREC® CAD/CAM achieved survival rates of 98 percent and 91.9 percent, respectively. The conventional system achieved survival rates of 97.5 percent short-term and 93 percent mid-term. Conclusions: As described in the literature, CEREC® CAD/CAM had a slightly higher survival rate than the conventional system in the short term. In the medium term, however, CEREC® CAD/CAM displayed a slight reduction in comparison with the conventional system. No studies are available to determine the clinical survival of the treatments in the long term(AU)

Evaluation of Polyethylene Wear in a Brazilian Ultracongruent Knee Prosthesis with a Rotating Platform / Avaliação do desgaste do polietileno de uma prótese de joelho nacional ultracongruente de base rotatória

Abstract Objective To evaluate the wear of polyethylene in a Brazilian ultracongruent knee prosthesis with a rotating platform (Rotaflex, Víncula, Rio Claro, SP, Brasil). Methods We used the test method with the loading and preparation parameters mentioned in the standards regulation ISO 14243-1:2009, and the measurement methods mentioned in the standards regulation ISO 14243-2:2009, for the evaluation of the wear behavior of a Brazilian prosthesis with a rotating platform. The equipment used for the wear test was the ISO 14243-1 gait simulator (EndoLab, Riedering, Germany). Results After 10 million cycles, the evaluation of the polyethylene wear showed a regular appearance of surface wear at a mean rate of 2.56 mg per million cycles. Conclusion The wear of the polyethylene of the evaluated prosthesis was minimal after the tests performed and with safety limits higher than those recommended by biomechanical engineering.

Resumo Objetivo Avaliar o desgaste do polietileno de uma prótese de joelho brasileira ultracongruente de base rotatória (Rotaflex, Víncula, Rio Claro, SP, Brasil). Métodos Utilizou-se o método de ensaio com os parâmetros de carregamento e preparação citados na norma ISO 14243-1:2009, e os métodos de medição citados na norma ISO 14243-2:2009, para a avaliação do comportamento de desgaste de uma prótese nacional com base rotatória. O equipamento utilizado para o teste de desgaste foi o simulador de marcha ISO 14243-1 (EndoLab, Riedering, Alemanha). Resultados Após 10 milhões de ciclos, a avaliação do desgaste do polietileno mostrou uma aparência regular do desgaste da superfície com taxa média de 2,56 mg por milhão de ciclos. Conclusão O desgaste do polietileno da prótese avaliada foi mínimo após os ensaios realizados e com os limites de segurança superiores aos preconizados pela engenharia biomecânica.

Screwed and cement implant prosthesis: current clinical considerations / Prótese sobre implante cimentada e parafusada: considerações clínicas atuais

ABSTRACT Introduction: There is no consensus as to which cemented or screwed retention system is best to avoid bone loss around the implant from a fixed implant-supported restoration. Objective: To evaluate the prosthesis retention systems on screw and cemented implants, regarding: bone loss, survival and failure rate, biological complications and microbiological analysis. Methods: A search was made for scientific articles that contemplated the subject through the databases Pubmed and SciELO, without period restriction. The titles, abstracts and then access to the full text has been verified. Results: It was found that excess cement may play an important role in the development of peri-implant disease. Technical failures are most seen in prosthesis retained by screws, and biological complications in cemented crowns. The success rate for both restraint systems is high, and retention-independent implant prosthesis treatment provides predictability. Conclusion: The appropriate retention system for the patient depends on several factors, including indication, advantages and disadvantages, retention provided, aesthetics and clinical performance.

RESUMO Introdução: Não há consenso sobre qual sistema de retenção, cimentado ou parafusado, é o melhor para evitar perda óssea ao redor do implante de uma restauração fixa implanto-suportada. Objetivo: Avaliar os sistemas de retenção de próteses sobre implantes parafusadas e cimentadas, quanto aos fatores: perda óssea, taxa de sobrevivência e de falhas, complicações biológicas e análises microbiológicas. Métodos: Foi realizada uma busca por artigos científicos que contemplassem o tema através das bases de dados Pubmed e SciELO, sem restrição de período. Os títulos, resumos e em seguida o acesso ao texto completo foi verificado. Resultados: Foi observado que o excesso de cimento pode desempenhar um papel importante no desenvolvimento da doença peri-implantar. Falhas técnicas são mais observadas em próteses retidas por parafusos e complicações biológicas em coroas cimentadas. A taxa de sucesso para os dois sistemas de retenção é alta e o tratamento com próteses sobre implantes independente da retenção oferece previsibilidade ao caso. Conclusão: O sistema de retenção apropriado para o paciente depende de diversos fatores, incluindo a indicação, vantagens e desvantagens, retenção fornecida, estética e desempenho clínico.

Comparative Biomechanical Study of Crosslinked Polyethylene Wear with 36-mm Ceramic Femoral Heads and with 32-mm Metal Femoral Heads / Estudo biomecânico comparativo do desgaste do polietileno reticulado com cabeças femorais cerâmicas de 36 mm e com cabeças metálicas de 32 mm

Abstract Objective This study aims to compare the in vitro wear rate of crosslinked, high molecular weight polyethylene coupled to 36-mm diameter ceramic heads and 32-mm diameter metal heads. Methods Ceramic-on-polyethylene (36 mm) and metal-on-polyethylene (32 mm) tribological pairs were submitted to biomechanical tests in a simulator to determine the wear rate after 15 × 106 cycles. Results A statistically significant difference (p= 0.0005) was detected when comparing the wear rate of assemblies with metallic heads (average wear: 14.12 mg/MC) and ceramic heads (average wear: 7.46 mg/MC). Conclusion The present study demonstrated the lower wear rate in prosthetic assemblies using 36-mm crosslinked ceramic-on-polyethylene tribological pairs compared to 32-mm crosslinked metal-on-polyethylene assemblies. This finding demonstrates the effectiveness of ceramic-on-polyethylene tribological pairs, even with large diameter heads.

Resumo Objetivo: O objetivo do presente estudo foi comparar, in vitro, a taxa de desgaste do polietileno de alto peso molecular reticulado acoplado a cabeças cerâmicas de 36 mm de diâmetro e acoplado a cabeças metálicas de 32 mm de diâmetro. Métodos: Foram realizados ensaios biomecânicos em simulador de desgaste para os pares tribológicos cerâmica-poli (36 mm) e metal-poli (32 mm) a fim de verificar a taxa de desgaste após em 15 × 106 ciclos. Resultados: Na comparação entre as medidas de taxa de desgaste dos conjuntos com cabeças metálicas (média:14,12 mg/MC) e cerâmicas (média:7,46 mg/MC) houve diferença estatitsticamente significativa (p= 0,0005). Conclusão: O presente estudo demonstrou menor taxa de desgaste em conjuntos protéticos que utilizaram o par tribológico cerâmica-polietileno reticulado de 36 mm em comparação aos conjuntos com metal-polietileno reticulado de 32 mm. Tal achado demonstra a eficácia do par tribológico cerâmica-poli, mesmo com a utilização de cabeças de grande diâmetro.

Three-dimensional morphological measurement of proximal radius and its guiding significance for prosthesis design / 吉林大学学报(医学版)

Objective: To measure the morphological parameters of the radial head of the Chinese and compare with those of the Western population, and to provide the references for the design of the radial head prosthesis of the Chinese. Methods: The CT scan data of normal elbow from 130 Chinese cases were selected. All the data were scanned by using a 64-slice spiral CT scanner and reconstructed and measured on AW 4. 5 workstations. The angle between neck and shaft (

CT anatomical features of the distal humerus in healthy adults / 中华骨科杂志

Objective@#To study the anatomical features of the distal humerus in Chinese healthy adults.@*Methods@#A total of 121 cases of normal elbow joint CT images were selected from the picture archiving and communication system (PACS), and reconstructed and measured on the AW4.5 workstation. Coronal plane and horizontal plane were determined by flexion-extension (FE) axis and humeral shaft, while the sagittal plane was perpendicular to the FE axis. The angle between the axis of humerus medullary cavity and the FE axis of elbow (H-FE angle) was measured on the coronal plane. The capitellar height (CH), lateral trochlear height (LTH), trochlear height (TH) and medial trochlear height (MTH) were measured on four different sagittal planes. The capitellar width (CW), capitellar depth (CD), anterior lateral trochlear width (ALTW), posterior lateral trochlear width (PLTW), trochlear width (TW), anterior medial trochlear width (AMTW), posterior medial trochlear width (PMTW), trochlear depth (TD), anterior lateral trochlear depth (ALTD), posterior lateral trochlear depth (PLTD), anterior medial trochlear depth (AMTD), posterior medial trochlear depth (PMTD), and distal humeral width (W) were measured on the horizontal plane. The gender differences in measured parameters, correlations between data, and differences in H-FE angle from 90° were analyzed.@*Results@#In male, CH was 21.5± 1.3 mm, CW 17.5±1.1 mm, CD 10.8±0.9 mm, TW 25.1±2.2 mm, TH 17.3±1.5 mm, TD 17.5±1.4 mm, ALTW 7.7±1.2 mm, PLTW 12.5±1.6 mm, AMTW 12.4±1.6 mm, PMTW 9.8±2.0 mm, ALTD 10.0±0.8 mm, PLTD 16.3±1.4 mm, AMTD 12.9±1.4 mm, PMTD 13.2±1.4 mm, LTH 20.6±1.3 mm, MTH 25.0±2.4 mm, W 42.6±2.5 mm. The above parameters in female was 18.7±1.1 mm, 15.3±1.1 mm, 9.5±0.6 mm, 21.7±1.5 mm, 15.4±1.7 mm, 15.6±1.5 mm, 6.8±1.3 mm, 10.7±1.4 mm, 10.6±1.4 mm, 8.5±1.4 mm, 8.9±0.8 mm, 14.5±1.1 mm, 11.4±1.1 mm, 11.5±1.0 mm, 18.1±1.4 mm, 21.6±1.4 mm and 37.0±1.8 mm, respectively. All the above anatomical parameters in men were larger than those in women with statistically significant difference (P<0.05). However, the H-FE angle (male: 87.4°±3.5°, female 87.8°±3.3°), CW/CH (male: 0.8±0.1, female: 0.8±0.1), TW/CW (male: 1.4±0.2, female: 1.4±0.1), MTH/LTH (male: 1.2±0.1, female: 1.2±0.1), AMTW/TW (male: 0.5±0.1, female: 0.5±0.1), PMTW/TW (male: 0.4±0.1, female: 0.4±0.1), ALTW/TW (male: 0.3±0.0, female: 0.3±0.1), PLTW/TW (male: 0.5±0.1, female: 0.5±0.1) were not statistically different between male and female groups (P>0.05). All measurements except for the H-FE angle had a positive correlation with the articular width (0.335≤r≤0.928, P<0.05). The difference between the angle of the H-FE axis (87.6°±3.4°) and 90° was statistically significant (t=-7.287, P<0.05).@*Conclusion@#The size of the distal humerus in male is larger than that in female without difference in shape. Distal humerus width can be used as an indicator to measure the size of the distal humerus. The humeral shaft is more biased toward the radial side.

CT anatomical features of the distal humerus in healthy adults / 中华骨科杂志

Objective To study the anatomical features of the distal humerus in Chinese healthy adults.Methods A total of 121 cases of normal elbow joint CT images were selected from the picture archiving and communication system (PACS),and reconstructed and measured on the AW4.5 workstation.Coronal plane and horizontal plane were determined by flexion-extension (FE) axis and humeral shaft,while the sagittal plane was perpendicular to the FE axis.The angle between the axis of humerus medullary cavity and the FE axis of elbow (H-FE angle) was measured on the coronal plane.The capitellar height (CH),lateral trochlear height (LTH),trochlear height (TH) and medial trochlear height (MTH) were measured on four different sagittal planes.The capitellar width (CW),capitellar depth (CD),anterior lateral trochlear width (ALTW),posterior lateral trochlear width (PLTW),trochlear width (TW),anterior medial trochlear width (AMTW),posterior medial trochlear width (PMTW),trochlear depth (TD),anterior lateral trochlear depth (ALTD),posterior lateral trochlear depth (PLTD),anterior medial trochlear depth (AMTD),posterior medial trochlear depth (PMTD),and distal humeral width (W) were measured on the horizontal plane.The gender differences in measured parameters,correlations between data,and differences in H-FE angle from 90° were analyzed.Results In male,CH was 21.5± 1.3 mm,CW 17.5±1.1 mm,CD 10.8±0.9 mm,TW 25.1±2.2 mm,TH 17.3±1.5 mm,TD 17.5±1.4 mm,ALTW 7.7±1.2 mm,PLTW 12.5±1.6 mm,AMTW 12.4±1.6 mm,PMTW 9.8±2.0 mm,ALTD 10.0±0.8 mm,PLTD 16.3±1.4 mm,AMTD 12.9±1.4 mm,PMTD 13.2±1.4 mm,LTH 20.6±1.3 mm,MTH 25.0±2.4 mm,W 42.6±2.5 mm.The above parameters in female was 18.7±1.1 mm,15.3± 1.1 mm,9.5±0.6 mm,21.7±1.5 mm,15.4±1.7 mm,15.6±1.5 mm,6.8±1.3 mm,10.7±1.4 mm,10.6±1.4 mm,8.5±1.4 mm,8.9±0.8 mm,14.5±1.1 mm,11.4±1.1 mm,11.5±1.0 mm,18.1±1.4 mm,21.6±1.4 mm and 37.0±1.8 mm,respectively.All the above anatomical parameters in men were larger than those in women with statistically significant difference (P＜0.05).However,the H-FE angle (male:87.4°±3.5°,female 87.8°±3.3°),CW/CH (male:0.8±0.1,female:0.8±0.1),TW/CW (male:1.4±0.2,female:1.4±0.1),MTH/LTH (male:1.2±0.1,female:1.2±0.1),AMTW/TW (male:0.5±0.1,female:0.5±0.1),PMTW/TW (male:0.4±0.1,female:0.4± 0.1),ALTW/TW (male:0.3±0.0,female:0.3±0.1),PLTW/TW (male:0.5±0.1,female:0.5±0.1) were not statistically different between male and female groups (P＞0.05).All measurements except for the H-FE angle had a positive correlation with the articular width (0.335≤r≤0.928,P＜0.05).The difference between the angle of the H-FE axis (87.6°±3.4°) and 90° was statistically significant (t=-7.287,P＜0.05).Conclusion The size of the distal humerus in male is larger than that in female without difference in shape.Distal humerus width can be used as an indicator to measure the size of the distal humerus.The humeral shaft is more biased toward the radial side.

Desarrollo mecánico y experimental de un implante discal cervical flexible / Mechanical and experimental development of a flexible cervical disc implant

Introducción: La artroplastía cervical es una cirugía que implica el uso de implantes discales con la capacidad de conservar el movimiento del segmento. Constituye un reto para paises como el nuestro desarrollar alternativas a los altos costos de los mencionados implantes, con diseños patentado, elaborado viables de manufacturar, con biocompatibilidad, seguridad, y que simule lo máximo posible los movimientos cervicales fisiológicos. Objetivo: Desarrollar la geometría y mecánica de un diseño discal patentado, elaborado, sea por manufactura aditiva de titanio ELI, así como verificar su compatibilidad con la fisiología de los movimientos cervicales. Métodos: El diseño del estudio tuvo tres etapas iterativas: la primera, el desarrollo de la geometría del implante y el estudio de elementos finitos utilizando como referencia normas internacionales; en segundo lugar, se desarrollaron estudios de metalografía, caracterización del material incluyendo pruebas de fatiga del implante; finalmente, se utilizó un modelo animal cadavérico para confirmar la compatibilidad del implante con los movimientos cervicales. Resultados: Se demostró que el implante elaborado sea por manufactura aditiva o por forja, fue compatible con las normas internacionales. Se realizaron 84 estudios de rayos X en 18 cuellos de porcino. En el 100% de las columnas cervicales de los porcinos, el rango en flexión fue menor que el de extensión. Existió mayor rango de movimiento cuando se utilizaron dos implantes y cuando el implante fue más grande. Conclusiones: El implante cervical flexible elaborado por forja o por manufactura aditiva de titanio ELI presentó resultados prometedores, por lo que podría postularse su uso experimental en pacientes tributarios de artroplastía cervical.

Introduction: Cervical arthroplasty is a surgical procedure that involves the use of disc implants with the capacity of preserving segmental movement. It is a challenge for countries like ours to develop alternatives to the high costs of the aforementioned implants, with patented designs, feasible to manufacture, with biocompatibility, safety, and that simulates as much as possible the physiological cervical movements. Objectives: To develop the geometry and mechanics of a patented disc design elaborated with titanium ELI by additive manufacturing, as well as, to verify its compatibility with the physiology of cervical movements. Methods: The study design had three iterative stages: the first one was the development of the implant geometry and the finite-element study using international standards as a reference. In second place, studies of metallography, characterization of the material and fatigue tests of the implant were developed. Finally, a cadaverous animal model was used to confirm the compatibility of the implant with cervical movements. Results: The implants manufactured by forging or by additive manufacturing are compatible with international standards. 84 x-ray studies were performed on 18 pig necks. In 100% of the cervical columns of the pigs, the range in flexion was smaller than that of extension. There was a greater range of motion when two implants were used and when the implant was larger. Conclusions: The flexible cervical implant made by forging or a titanium-ELI additive manufacturing have promising results, because of that, an experimental use in patients, who needs cervical arthroplasty, could be considered.

Is The Size of the Currently Available Implants for Total Hip Arthroplasty Adequate for Our Population? / O tamanho dos implantes atualmente disponíveis para a artroplastia total do quadril está adequado à nossa população?

Abstract Objective To determine if the dimensions of selected national and imported implants used in total hip arthroplasty surgeries are adequate regarding the anthropometric profile of the Brazilian population. Methods A retrospective study of patients submitted to primary total hip arthroplasty. Patients with femoral or acetabular morphological deformities that could influence the choice of implant size, including dysplasia and previous fractures, were excluded from the study. Two national implants and six imported implants were included in the study. Every patient was treated by the same group, with one of the four senior authors or under their strict supervision, following the same surgical technique. The datawere analyzed regarding gender, age, fixation type and implant model. Results The analysis of 682 hips submitted to total hip arthroplasty demonstrated that 2 models of cemented femoral stems and 1 of non-cemented stem did not seem to be perfectly adequate for the femoral morphology of the studied population, since these 3 implants were mostly used in the smallest size available, resulting in a non-Gaussian curve. The mean diameter of the native acetabulum was 54mm in men and 52mm in women. Conclusion Out of the eight models studied, five were deemed adequate for the studied population. The other three models available in our market (two national models and one imported model) apparently require more appropriate sizing. We emphasize that anthropometric studies of the Brazilian hip are necessary to give scientific subsidies to the ideal implant design for our market.

Resumo Objetivo Definir se as dimensões de alguns implantes de fabricação nacional e estrangeira utilizados nas cirurgias de artroplastia do quadril estão adequadas ao perfil antropométrico da população brasileira. Métodos Estudo retrospectivo de pacientes submetidos a cirurgia primária de substituição artroplástica total do quadril. Foram excluídos deste estudo pacientes comalterações morfológicas femorais ou acetabulares que pudessem influenciar na escolha do tamanho dos implantes, tais comosequelas de displasia, trauma, entre outras. Foramincluídos neste estudo dois implantes de fabricação nacional e seis modelos importados. Todos os pacientes foram operados pela mesma equipe, por um dos quatro autores seniores ou sob sua supervisão direta, seguindo a mesma técnica cirúrgica. Os dados foram estatisticamente analisados em relação a gênero, idade, tipo de fixação e modelo dos implantes. Resultados A análise estatística de 682 quadris submetidos a artroplastia total demonstrou que 2 modelos de hastes femorais cimentadas e 1 de haste não cimentada não estão perfeitamente adequados à morfologia femoral da população estudada, pois, na maioria dos casos, nestes 3 implantes, foi utilizado o menor tamanho disponível, resultando em uma curva não gaussiana. O diâmetro médio do acetábulo nativo foi de 54mm nos homens e de 52mm nas mulheres. Conclusão Dos oitomodelos estudados, cinco semostraram adequados à população estudada. Outros três modelos disponíveis em nosso mercado (dois nacionais e um importado) parecem necessitar de um escalonamento mais adequado. Destacamos que são necessários estudos antropométricos do quadril da população brasileira para dar subsídios científicos ao desenho ideal dos implantes para o nosso mercado.

Comparison of Wear Rate between Ceramic-on- Ceramic, Metal on Highly Cross-linked Polyethylene, and Metal-on-Metal Bearings / Comparação da taxa de desgaste entre componentes de cerâmica sobre cerâmica, de metal sobre polietileno de alta ligação cruzada e de metal sobre metal

Abstract Objective Currently, there is a lack of evidence on the medium-term follow-up of cementless total hip arthroplasty (THA) using metal on highly cross-linked polyethylene (MoP), ceramic-on-ceramic (CoC), and metal-on-metal (MoM) bearings. Our aim was to calculate the 5- to 10-year wear rate and the incidence rate of osteolysis for 3 types of bearings. Methods A total of 77 patients underwent MoP, 105 underwent ceramic CoC, and 55 underwent MoM THAs. The average patient age at the time of surgery was 64.7, 55.9, and 59.9 years old in the MoP, CoC, and MoM bearings, respectively. Clinical and radiologic measurements at a mean follow-up of 7.6 years were analyzed. Results The mean postoperative Harris hip scores showed no difference among the groups. The mean annual liner wear rates were 0.0160, 0.0040 and 0.0054 mm/year in MoP, CoC bearings, and MoM bearings, with that of CoC bearings being significantly lower than the others. Osteolysis (14.5%) among MoM bearings was significantly more frequently observed compared with the others. Kaplan-Meier survival at 10 years with implant loosening, or revisionTHA as the endpoint, was 96.1% (95% confidence interval [CI]: 88.4-98.7) forMoP, 98.6% (95% CI: 90.3-98.6) for CoC bearing, and 98.2% (95% CI: 88.0-99.7) for MoM bearings (p = 0.360). Conclusion Excellent clinical and radiological outcomes were obtained for MoP and CoC bearings.

Resumo Objetivo Hoje, não há evidências sobre o acompanhamento em médio prazo da artroplastia total do quadril (ATQ) não cimentada com componentes de polietileno de alta ligação cruzada (highly cross-linked) sobre metal (MoP, na sigla em inglês), de cerâmica sobre cerâmica (CoC, na sigla em inglês), e de metal sobre metal (MoM, na sigla eminglês). Nosso objetivo foi calcular a taxa de desgaste entre 5 a 10 anos e a taxa de incidência de osteólise nos 3 tipos de componentes. Métodos Um total de 77 pacientes foram submetidos a ATQ com componentes de MoP; 105 foram submetidos ao mesmo procedimento com componentes de CoC, e 55 foram submetidos à ATQ com componentes de MoM. A média de idade dos pacientes no momento da cirurgia foi de 64,7, 55,9 e 59,9 anos nos grupos de componentes MoP, de CoC, e de MoM, respectivamente. Asmedidas clínicas e radiológicas emumperíodo médio de acompanhamento de 7,6 anos foram analisadas. Resultados As pontuações médias de Harris no período pós-operatório não mostraram diferença entre os grupos. As taxas médias anuais de desgaste do revestimento foram de 0,0160, 0,0040 e 0,0054 mm/ano em componentes de MoP, de CoC, e de MoP, respectivamente; a taxa de desgaste dos componentes de CoC foi significativamente menor do que as dos demais. A osteólise (14,5%) nos componentes de MoM foi significativamente mais frequente em comparação aos demais. A sobrevida de Kaplan- Meier aos 10 anos comafrouxamento do implante ou revisão da ATQ como desfecho foi de 96,1% (intervalo de confiança [IC] de 95%: 88,4-98,7) nos componentes de MoP, de 98,6% (IC95%: 90,3-98,6) nos componentes de CoC, e de 98,2% (IC95%: 88,0-99,7) nos componentes de MoM (p = 0,360). Conclusão Os resultados clínicos e radiológicos de componentes de MoP e de CoC foram excelentes.