Comparison of Surgical Procedures in the Treatment of Hip Periprosthetic Infection / Comparação entre procedimentos cirúrgicos no tratamento da infecção de prótese do quadril

Abstract Objective The present study aimed to compare the cure rate recovery time and Merle d'Aubigné-Postel functional (MAPF) score after single-stage surgery (C1T) or two-stage surgery (C2T) to treat prosthetic infections of the hip considering sociodemographic and clinical features of the patients. Materials and Methods The present retrospective study occurred in a single center from 2011 to 2014 with 37 studied cases including 26 treated with C1T and 11 with C2T. We compared the cure rate recovery time and MAPF score in the two groups as well as the sociodemographic and clinical features of the patients. We also considered surgical complications and the most common infectious agents. Results The C1T group had a faster functional recovery than the C2T group but there were no significant differences in the cure rate surgical complications or MAPF score. However C1T group patients were significantly younger which may have influenced the outcomes. Staphylococcus spp. was the most common infectious agent (62%). Conclusion Although C2T appears superior regarding infection cure C1T may be preferable for faster functional recovery. However it is critical to consider individual patient characteristics when choosing treatment. Further research with a larger sample size is required to confirm these results.

Resumo Objetivo Comparar a taxa de cura, o tempo de recuperação e a pontuação na escala funcional de Merle d'Aubigné-Postel (EFMA) entre a cirurgia em tempo único (C1T) e a cirurgia em dois tempos (C2T) no tratamento de infecções protéticas do quadril, considerando as características sociodemográficas e clínicas dos pacientes. Materiais e Métodos Foi realizado um estudo retrospectivo num único centro, entre 2011 e 2014, com um total de 37 casos estudados, sendo 26 tratados com C1T e 11 com C2T. Foram comparadas a taxa de cura, o tempo de recuperação e a pontuação EFMA entre os dois grupos, bem como as características sociodemográficas e clínicas dos pacientes. Foram também consideradas as complicações cirúrgicas e o agente infeccioso mais comum. Resultados O grupo C1T teve uma recuperação funcional mais rápida do que o grupo C2T, mas não houve diferenças significativas na taxa de cura, nas complicações cirúrgicas ou na pontuação EFMA. No entanto, o grupo C1T era significativamente mais jovem, o que pode ter influenciado os resultados. Staphylococcus spp. foi o agente infeccioso mais comum (62%). Conclusão Embora a C2T pareça ser superior em termos de cura de infecção, a C1T pode ser preferível para uma recuperação funcional mais rápida. No entanto, as características individuais dos pacientes devem ser consideradas na escolha do tratamento. São necessárias mais pesquisas com um tamanho de amostra maior para confirmar estes resultados.

Reproducibility of Digital Planning in Cementless Total Hip Arthroplasty Among Experienced and Novice Surgeons / Reprodutibilidade do planejamento digital na artroplastia total do quadril sem cimento entre cirurgiões experientes e iniciantes

Abstract Objective The present study aims to assess the reproducibility of digital planning for cementless total hip arthroplasty (THA) among surgeons with different levels of experience. In addition, it attempts to determine the degree of planning reliability based on a contralateral THA or on a spherical marker positioned at the greater trochanter for calibration. Methods Two evaluators with different experience levels (A1 and A2) performed independently the retrospective digital surgical planning of 64 cementless THAs. Next, we compared the planning with the implants used in the surgery. The reproducibility was excellent when planning and implants were identical; proper in case of a single-unit variation; and inappropriate if there was variation in two or more units. The present analysis also determined the calibration accuracy between the contralateral THA and the spherical marker at the greater trochanter level. Results The present study demonstrated greater success when the most experienced evaluator performed the planning and greater accuracy for the contralateral THA. When splitting the analysis per parameter (contralateral THA or spherical marker), there was a statistical difference only for the planning of A1 and the implants used in the surgery. This difference occurred in the excellent category, with 67.3% for contralateral THA compared with 30.6% for a spherical marker (p < 0.001), and in the inappropriate category, with 7.1% for contralateral THA compared with 30.6% for a spherical marker (p < 0.001). Conclusions Digital planning is more accurate when performed by an experienced evaluator. The contralateral prosthesis head was a better reference than a marker on the greater trochanter.

Resumo Objetivo Avaliar a reprodutibilidade do planejamento digital da artroplastia total de quadril (ATQ) sem cimento entre cirurgiões com diferentes níveis de experiência e o grau de confiabilidade no planejamento baseado na ATQ contralateral com o método de marcador esférico posicionado ao nível do trocanter maior. Método Dois avaliadores com níveis de experiência diferentes (A1 e A2) realizaram de forma independente o planejamento digital operatório retrospectivo de 64 ATQs sem cimento. O planejamento foi comparado com os implantes utilizados na cirurgia, sendo classificados como: excelentes, quando idênticos; adequados, quando houve variação de uma unidade; e inadequados, quando ocorreu variação de duas ou mais unidades. Na presente análise, também foi avaliada a acurácia do parâmetro de calibragem entre a ATQ contralateral comparada com o marcador esférico ao nível do trocanter maior. Resultados O estudo demonstrou maior êxito no planejamento quando realizado pelo avaliador mais experiente, com maior acurácia na ATQ contralateral. Ao fragmentar a análise de acordo com o parâmetro utilizado (ATQ contralateral ou marcador esférico), houve diferença estatística apenas na comparação do planejamento do avaliador A1 com os implantes utilizados na cirurgia. Esta diferença ocorreu na classificação excelente com 67,3% em ATQ contralateral como parâmetro contra 30,6% com marcador esférico (p < 0,001) e inadequado de 7,1% contra 30,6%, respectivamente (p < 0,001). Conclusões A acurácia do planejamento digital é mais precisa quando realizada por um avaliador experiente e a utilização da cabeça de prótese contralateral como referência se mostrou superior à utilização de um marcador no trocanter maior.

Digital design and 3D-printed customized flanged cups in hip revision with severe acetabular bone defects / 中华骨科杂志

Objective:To investigate the effect of 3D-printed customized flanged cup in hip revision with severe acetabular bone defects.Methods:Since February 2017, 10 cases of 3D-printed customized flanged cups were used in hip revision with severe acetabular bone defects, including 2 cases of Paprosky type IIIA and 8 cases of Paprosky type IIIB. There were 5 males and 5 females, mean age 73.6±8.1 yrs (range, 62-87 yrs), 5 left and 5 right cases. The preoperative thin-layer CT scan was preformed to reverse reconstruct digital pelvis. Five cases of one-piece flanged cups and 5 cases of decomposed flanged cups, including 3 cases of composite one-piece cups were designed by computer. The surgery was performed strictly according to the plan.Postoperative follow-up was performed to evaluate the Harris score. Operation time,intraoperative bleeding and other complications such as vascular and nerve injury, postoperative infection, and dislocation were counted. Pelvic X-ray was used to assess the height and horizontal position of the center of rotation and the stability of the prosthesis.Results:The surgical procedure was successful, with an average operative time of 147.9±48.3 min (range, 96-212 min) and an average intraoperative bleeding of 730.4±262.6 ml (range, 500-1 300 ml). The mean time of final follow-up was 40.8±18.7 months (range, 16-70 months) after surgery. At the last follow-up, the average Harris score was 83.80±6.73, with 4 cases excellent, 5 cases good, and 1 case fair. The excellent and good rate was 90%. The last Harris score was significantly higher than that before operation 28.60±8.40 ( t=16.84, P<0.001). The height of affected hip joint rotation center decreased from 46.24±7.74 mm before operation to 15.54±2.54 mm after operation with significant difference ( t=14.61, P<0.001). It was slightly higher than the opposite side (13.81±1.48 mm), which had no significant difference ( t=1.83, P=0.100). The horizontal distance of affected hip joint rotation center increased from 33.79±5.27 mm before operation to 40.53±4.50 mm after operation with significant difference ( t=3.62, P=0.006). It had no significant difference ( t=1.28, P=0.232) compared with the opposite side (38.54±3.46 mm). All incisions were healed in one stage without infection, vascular or nerve injury. During the following-up, all prostheses were in satisfied position without loosening, dislocation or screw breaks. Conclusion:Digitally assisted 3D-printed flanged cups can be used in hip revision with severe acetabular bone defect. It can not only improve hip joint function, but also restore the acetabular rotation center and the prosthesis stability, which can achieve good early and mid-term effect.

Comparison of clinical effects of minimally invasive femoral head replacement and proximal femoral nail antirotation in the treatment of comminuted intertrochanteric fracture in the elderly / 中国骨伤

OBJECTIVE@#To analyze the clinical effect of minimally invasive femoral head replacement and proximal femoral nail antirotation(PFNA) internal fixation at the same time in the treatment of elderly patients with comminuted intertrochanteric fracture.@*METHODS@#From April 2020 to October 2020, 76 elderly patients with comminuted intertrochanteric fracture treated by minimally invasive femoral head replacement and PFNA were analyzed retrospectively. There were 35 patients in the prosthetic group, including 24 females and 11 males with an average age of (86.2±6.1) years old. There were 41 patients in PFNA group including 28 females and 13 males with an average age of (84.6±5.3) years old. The operation time, intraoperative blood loss, postoperative ambulation time, hospitalization time and complications were observed and compared between two groups. Harris hip score was performed at 1, 6 and 12 months after operation.@*RESULTS@#All patients were followed up for 13 to 17 months with an average of (14.3±1.4) months. The operation time of the prosthesis group was longer than that of the PFNA group (P<0.05);the amount of bleeding in PFNA group was less than that in prosthesis group (P>0.05);the time of ambulation in prosthetic group was earlier than that in PFNA group(P<0.05);the number of complications in the prosthesis group was less than that in the PFNA group(P<0.05); the Harris score of prosthesis group was significantly higher than that of PFNA group at 1 and 6 months after operation (P<0.05), but there was no significant difference in Harris score between two groups at 12 months after operation(P>0.05);the number of complications in the prosthesis group was less than that in the PFNA group (P<0.05).@*CONCLUSION@#Minimally invasive femoral head replacement is a good choice for the elderly patients with commuited intertrochanteric fracture. It can improve the quality of life and reduce the burden of family members and society.

Strain Analysis in Cementless Hip Femoral Prosthesis using the Finite Element Method - Influence of the Variability of the Angular Positioning of the Implant / Análise da deformação na prótese femoral não cimentada do quadril pelo método de elementos finitos - Influência da variabilidade do posicionamento angular do implante

Abstract Objective The present study aims to evaluate the influence of different positioning of the hip femoral prosthesis on the stress and strain over this implant. Methods A femoral prosthesis (Taper - Víncula, Rio Claro, SP, Brazil) was submitted to a stress and strain analysis using the finite element method (FEM) according to the International Organization for Standardization (ISO) 7206-6 Implants for surgery - Partial and total hip joint prostheses - Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral components standard. The analysis proposed a branch of the physical test with a +/− 5° angle variation on the standard proposed for α and β variables. Results The isolated +/− 5° variation on the α angle, as well as the association of +/− 5° variation on the α and β angles, presented significant statistical differences compared with the control strain (p= 0.027 and 0.021, respectively). Variation on angle β alone did not result in a significant change in the strain of the prosthesis (p= 0.128). The stem positioning with greatest implant strain was α = 5° and β = 14° (p= 0.032). Conclusion A variation on the positioning of the prosthetic femoral stem by +/− 5° in the coronal plane and/or the association of a +/− 5° angle in coronal and sagittal planes significantly influenced implant strain.

Resumo Objetivo Avaliar a influência da variação do posicionamento da prótese femoral do quadril na tensão e na deformação produzidas neste implante. Métodos Utilizou-se a análise de tensão e de deformação da prótese femoral (Taper, Víncula, Rio Claro, SP, Brasil) pelo método de elementos finitos (MEF) de acordo com a norma ISO 7206-6 Implants for surgery - Partial and total hip joint prostheses-Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral components. A análise propôs uma ramificação do ensaio físico, com variação da angulação de +/− 5° sobre a proposta normativa das variáveis α e β. Resultados Ao comparar com a deformação controle, houve significância estatística com a angulação isolada de +/− 5° do ângulo α, bem como com a associação de +/− 5° nas angulações α e β (p= 0,027 e 0,021, respectivamente). Já com a variação apenas do ângulo β, não houve variação significativa na deformação da prótese (p= 0,128). A posição da haste com maior deformação no implante foi com α = 5° e β = 14° (p= 0,032). Conclusão A variabilidade de posicionamento da haste femoral protética de +/− 5° no plano coronal e/ou a associação da angulação de +/− 5° nos planos coronal e sagital interferiu de forma significativa na deformação do implante.

Copa de doble movilidad: aciertos, riesgos y enseñanzas / Dual mobility cup: successes, risks and lessons learned

Resumen: Se hace una revisión narrativa del desarrollo y evolución hasta el momento de las copas de doble movilidad enfocada en sus aciertos, fallas y enseñanzas. Se mencionan las herramientas con las cuales contamos para prevenir y en su caso, tratar la luxación protésica de cadera y los principales problemas que presentan. El principal objetivo de esta publicación es hacer reflexiones y comentarios en cuanto a lo que debemos estar atentos ante un mundo de diseños que actualmente existen en el mercado con una diversidad de diseños, materiales, aleaciones, tipos de polietileno, etc. Se analizan los problemas que enfrentan algunos modelos para obtener una fijación estable a largo plazo, el problema que posiblemente representan los diferentes modelos contemporáneos de doble movilidad y sus resultados clínicos. Se discuten y comentan los puntos anteriores y se establecen conclusiones y recomendaciones.

Abstract: A narrative review of the development and evolution to date of the double mobility cups is made, focusing on their successes, failures and teachings. The tools with which we have to prevent and treat prosthetic hip dislocation and the main problems are mentioned. The main objective of this publication is to make reflections and comments about what we should be attentive to in a world of designs that currently exist in the market with a diversity of designs, materials, alloys, types of polyethylene, etc. Some models are found to obtain a stable long-term fixation, the problem that potentially represents the different contemporary models of double mobility and their clinical results. The previous points are discussed and commented and conclusions and recommendations were reached.

Is There Any Difference Between a Spherical Marker and a Simple Coin for Hip Replacement Digital Planning? / Existe alguma diferença entre um marcador esférico e uma moeda simples para planejamento digital de substituição de quadril?

Abstract Objective To evaluate the accuracy and differences between 2 types of metallic markers, sphere, and coin, for radiographic calibration in the preoperative planning of hip arthroplasty. Methods Four spherical metallic markers and four coins, both 25 mm in diameter, were placed on the greater trochanter, pubic symphysis, between the thighs, and on the table of the exam, for radiographic examination of the hip in 33 patients with hip prosthesis. The prosthesis head was used for calibration and two examiners measured the markers' image diameters, and the results were analyzed statistically. Results In the greater trochanter, the sphere and the coin were not visualized in 19 radiographs (57.6%). Between the thighs, the coin marker was not visualized in 13 radiographs (39.4%). In the greater trochanter, the 25-mm accuracy of the coin and the sphere was, respectively, between 57.1 and 63.3% and between 64.3 and 92.9%. The coin between the thighs reached 25-mm accuracy in between 50 and 60% of cases. Over the exam table, the coin and sphere markers reached, respectively, the mean diameters of 22.91 mm and 23 mm, the lowest coefficient of variation, the lowest confidence interval, and the easiest positioning. There was statistical difference between the evaluations of the markers (coin vs. sphere) in all positions (p< 0.032), except for the exam table position (p= 0.083). Conclusions The coin between the thighs is the best marker for radiographic calibration in the preoperative planning of hip arthroplasty, and we suggest the use of another coin on the exam table for comparison, considering the 8% reduction in relation to its real size.

Resumo Objetivo Avaliar a precisão e as diferenças entre 2 tipos de marcadores metálicos, esfera e moeda, para calibração radiográfica no planejamento pré-operatório da artroplastia de quadril. Métodos Quatro marcadores metálicos esféricos e quatro moedas, ambas de 25 mm de diâmetro, foram colocadas em trocânter maior, sínfise púbica, entre as coxas e a mesa do exame, para exame radiográfico do quadril em 33 pacientes com prótese de quadril. A cabeça da prótese foi utilizada para calibração e dois examinadores mediram os diâmetros da imagem dos marcadores, e os resultados foram analisados estatisticamente. Resultados No trocânter maior, a esfera e a moeda não foram visualizadas em 19 radiografias (57,6%). Entre as coxas, o marcador de moeda não foi visualizado em 13 radiografias (39,4%). No trocânter maior, a precisão de 25 mm da moeda e da esfera foi, respectivamente, entre 57,1 e 63,3% e entre 64,3 e 92,9%. A moeda entre as coxas atingiu 25 mm de precisão entre 50 e 60%. Sobre a mesa de exame, os marcadores de moeda e esfera atingiram, respectivamente, diâmetros médios de 22,91 mm e 23 mm, o menor coeficiente de variação, o menor intervalo de confiança e o posicionamento mais fácil. Houve diferença estatística entre as avaliações dos marcadores (moeda vs. esfera) em todas as posições (p< 0,032), com exceção da posição na mesa de exame (p= 0,083). Conclusões A moeda entre as coxas é o melhor marcador para calibração radiográfica no planejamento pré-operatório da artroplastia de quadril, e sugerimos o uso de outra moeda na mesa de exame para comparação, considerando os 8% de redução em relação ao seu tamanho real.

Cemented Calcar Replacement versus Long Stem Cemented Hemiarthroplasty in Unstable Intertrochanteric Fractures in Octogenarians / Substituição do calcar cimentado versus hemiartroplastia de haste longa cimentada em fraturas intertrocantéricas instáveis em octogenários

Abstract Objective The aim of the present study was to compare functional results after Cemented Calcar replacement vis-a-vis Long stem Cemented hemiarthroplasty in patients aged more than 80 years with unstable intertrochanteric fractures. Methods The present prospective, randomized trial included 140 patients with AO/OTA type 31-A2, A3 intertrochanteric femur fracture, randomized into 2 treatment groups and followed-up for a minimum of 2 years. Sixty-seven patients in group A were treated with a cemented calcar replacing prosthesis, and 65 patients in group B were treated with a cemented long stem femoral stem prosthesis. The primary end points were hip functions at 2 years. The secondary end points were the complications encountered, mortality, surgical time, reoperation, blood loss, and activities of daily living. Results There were no major differences between the groups in terms of hip function, quality of life (health related), reoperation, mortality, and blood loss. However, the function in hip joint and activities of daily living deteriorated in both groups in comparison with prefracture levels. Conclusion In octogenarians with an unstable intertrochanteric fracture, cemented calcar replacing prosthesis has similar clinical results in comparison with long stem cemented hemiarthroplasty. Hemiarthroplasty with either implant is a good option in this subset of patients. Level of evidence: I

Resumo Objetivo O objetivo do presente estudo foi comparar os resultados funcionais após a substituição do Calcar cimentado em comparação com a hemiartroplastia cimentada de haste longa em pacientes com mais de 80 anos com fratura intertrocantérica instável. Métodos O presente estudo prospectivo e randomizado incluiu 140 pacientes com fratura de fêmur intertrocantérica, conforme classificação AO/OTA tipo 31-A2, A3, randomizados em 2 grupos de tratamento e acompanhados por um período mínimo de 2 anos. Sessenta e sete pacientes do grupo A foram tratados com uma prótese de substituição do calcar cimentada e 65 pacientes do grupo B foram tratados com uma prótese femoral de haste longa cimentada. Os desfechos primários foram as funções do quadril em 2 anos. Os eventos secundários foram as complicações encontradas, a mortalidade, o tempo cirúrgico, segunda cirurgia, perda de sangue e as atividades do cotidiano. Resultados Não houve grandes diferenças entre os grupos em termos de função do quadril, qualidade de vida (relacionada à saúde), segunda cirurgia, mortalidade e perda de sangue. No entanto, a função da articulação do quadril e as atividades da vida diária se deterioraram em ambos os grupos em comparação com os níveis pré-fratura. Conclusão Nos octogenários com fratura intertrocantérica instável, a prótese de substituição do calcar cimentada apresentou resultados clínicos semelhantes em comparação com a hemiartroplastia de haste longa cimentada. A hemiartroplastia comqualquer umdos implantes é uma boa opção nesse subgrupo de pacientes. Nível de evidência: I

Osteonecrosis of the Femoral Head: Update Article / Osteonecrose da cabeça femoral: Artigo de atualização

Abstract Among the pathologies that affect the hip joint, osteonecrosis of the femoral head (ONFH) is probably the most intriguing and challenging. It consists of a multifactorial disease with a highly-variable spectrum in its clinical presentation. It has a devastating effect, due to disabling painful conditions, both for usual activities and sports. Given the huge range of risk factors, such as prolonged use of corticosteroids (especially in cases of rheumatologic diseases), trauma sequelae, sickle cell anemia, HIV, alcoholism, smoking, blood dyscrasias, and several other diseases that compromise the blood supply to the femoral head, ONFH has a varied clinical presentation and prognosis, which makes it difficult to determine a specific treatment, especially in cases in which chondral involvement has not yet occurred and the hip joint is still preserved. These are the main factors found in the literature that determine the classifications of this pathology. The range of treatments includes several options for cases in which an attempt is made to save the joint: conservative treatment, traditional decompression and/or combined with some type of adjuvant treatment (homologous grafting, synthetic grafting, vascularized grafts, tantalum screws, and bone marrow aspirate injection), and, for cases in which there is already a subchondral fracture and/or collapse of the femoral head and/or a reduction in the joint space, femoral osteotomies or total hip arthroplasty are commonly performed.

Resumo Entre as patologias que acometem a articulação coxofemoral, a osteonecrose da cabeça femoral (ONCF) é provavelmente a mais intrigante e desafiadora. Consiste em uma doença multifatorial, com um espectro muito variável em sua apresentação clínica. Tem efeito devastador, devido a quadros dolorosos incapacitantes tanto para atividades habituais quanto esportivas. Dada a gama enorme de fatores de risco, tais como uso prolongado de corticoides (principalmente em casos de doenças reumatológicas), sequelas de trauma, anemia falciforme, HIV, etilismo, tabagismo, discrasias sanguíneas, e várias outras doenças que comprometem a irrigação sanguínea da cabeça femoral, a ONCF tem apresentação clínica e prognósticos bem variados, o que dificulta a determinação de um tratamento específico, especialmente em casos nos quais ainda não houve acometimento condral e a articulação do quadril ainda se mantém preservada, sendo estes os principais fatores encontrados na literatura que determinam as classificações desta patologia. No leque de tratamentos, encontramos diversas opções para os casos em que setenta salvar a articulação: tratamento conservador, descompressão simples e/ou associada a algum tipo de tratamento adjuvante (enxertia homóloga, enxertia sintética, enxertos vascularizados, parafusos de tântalo, e injeção de aspirado de medula óssea), e, para casos nos quais já há fratura subcondral e/ou colapso da cabeça femoral e/ou diminuição do espaço articular, reserva-se, comumente, a realização de osteotomias femorais ou artroplastia total do quadril.

Preliminary clinical effect of in situ preservation of tumor bone combined with hip prosthesis in the treatment of proximal femur malignancy / 中华骨科杂志

Objective:To summarize the technical points of microwave ablation for inactivating the preserved bone in situ combined with hip prosthesis for proximal femoral malignancy and analyze its clinical efficacy.Methods:A total of 28 patients with proximal femoral malignancy who were treated in Tianjin Hospital from January 2018 to December 2021 were included in the study. There were 12 males and 16 females, aged 65.3±10.9 years (range 39-85 years); 26 metastatic bone tumors and 2 patients with proximal femoral primary tumors accompanying marrow cavity jumping focus in the study. According to whether the tumor bone mass was preserved in situ during microwave ablation, the patients were divided into the bone mass preservation group (18 cases) and conventional surgery group (10 cases). In the bone mass preservation group, according to the evaluation of preoperative CT and MRI, part of the tumor bone was preserved in situ and hip arthroplasty was performed after microwave inactivation. In the conventional surgery group, total resection of the tumor and microwave inactivation were performed firstly, and then hip prosthesis replacement was performed. Clinical efficacy was evaluated by comparing the length of osteotomy, the postoperative prosthesis stability and Musculoskeletal Tumor Society (MSTS) score.Results:The follow-up time of 28 patients was 11.9±5.9 months (range 4 to 24 months). The intraoperative length of osteotomy was 9.2±2.5 cm in the bone mass preservation group and the intraoperative length of osteotomy was 15.4±3.6 cm in the conventional surgery group, and the difference between the two groups was statistically significant ( t=5.40, P=0.002). There were 5 common hip prosthesises and 13 modular hip prosthesises in the bone mass preservation group. In 2 patients with common prosthesis, X-ray showed partial bone resorption at the osteotomy interface 3 and 8 months after operation, no loosening or fracture at the prosthesis-bone interface, and no pain or limitation of walking. There were 10 modular hip prosthesises in the conventional surgery group, with one patient suffered pain while walking at 19 months after surgery, and the X-ray suggested loosening between the prosthesis-bone interface. MSTS score of bone mass preservation group at 3 months post-operation was 16.6±1.9 points, including good 6 cases and moderate 12 case, and the excellent and good rate was 33%, meanwhile MSTS score of conventional surgery group was 15.5±3.6 points, including good 3 cases, moderate 5 cases and poor 2 cases, and the excellent and good rate was 30% at 3 months post-operation, and the difference between the two groups was not statistically significant ( t=0.94, P=0.366). MSTS score of bone mass preservation group at 6 months post-operation was 21.7±3.2 points, including excellent 3 cases, good 9 cases, moderate 1 case and poor 1 case, and the excellent and good rate was 86% (12/14), meanwhile MSTS score of conventional surgery group at 6 months post-operation was 16.5±4.9 points, including excellent 1 case, good 3 cases, moderate 3 cases and poor 2 cases, and the excellent and good rate was 44% at 6 months post-operation, and the difference between the two groups was statistically significant ( t=3.03, P=0.006). MSTS score of bone mass preservation group at 12 months post-operation was 22.3±7.6 points, including excellent 8 cases, good 2 cases, moderate 1 case and poor 1 case, and the excellent and good rate was 83% (10/12), meanwhile conventional surgery group at 12 months post-operation was 22.1±6.6 points, including excellent 3 case, good 3 cases, moderate 1 cases and poor 1 cases, and the excellent and good rate was 75%(6/8), and the difference was not statistically significant ( t=0.06, P=0.957). The MSTS scores of 6 months after operation, including movement function, acceptance degree, brace assistance and walking ability, were significantly improved in the bone mass preservation group compared with the conventional surgery group, and the differences were statistically significant ( t=2.33, P=0.030; t=2.74, P=0.012; t=2.80, P=0.011; t=2.59, P=0.026). Conclusion:Preserved bone mass in situ inactivated by microwave ablation combined with tumor hip prosthesis is an alternative surgical method for the treatment of proximal femoral malignancy, which can increase the stability of the prosthesis, facilitate the biological reconstruction of soft tissues and early functional recovery.

Application of porous tantalum Jumbo cup in revision of hip arthroplasty / 中国骨伤

OBJECTIVE@#To investigate the clinical effect of porous tantalum Jumbo cup on acetabular reconstruction in revision of total hip arthroplasty.@*METHODS@#From September 2014 to December 2017, 18 patients(18 hips) with acetabular defect were reconstructed by porous tantalum Jumbo cup technology, including 6 males and 12 females;the age ranged from 54 to 76 years old with an average of(63.8±15.3) years. There were 6 cases of paprosky typeⅡA, 8 cases of typeⅡB, 2 cases of typeⅡC and 2 cases of type Ⅲ a. Harris score and visual analogue scale (VAS) were performed before and after operation. Imaging examination was performed to evaluate the position of hip rotation center and prosthesis, and to judge whether acetabular loosening, displacement and complications existed.@*RESULTS@#All cases were followed up for 13 to 49 months, with an average of 20.6 months. Harris score increased from 54.6±4.7 to 86.5±3.2 one year after operation(P<0.01), and VAS score decreased from 6.8±0.7 to 0.8±0.6 one year after operation (P<0.01). The transverse coordinate of hip rotation center was (3.52±0.72) cm before operation and (3.47±0.54) cm after operation (P>0.05). The longitudinal coordinate of hip rotation center was improved from (3.02±0.84) cm before operation to (2.35±0.53) cm after operation (P<0.01). During the follow-up period, the Jumbo cup was well fixed without loosening and displacement, the acetabular cup had bone ingrowth in varying degrees, and no light transmission line and osteolysis around the acetabular cup were found. No complications such as infection and nerve injury occurred.@*CONCLUSION@#The method of reconstructing acetabular bone defect with porous tantalum Jumbo cup is simple and easy, the early stability of acetabulum is good, and the short-term follow-up effect is good.

Prevalencia de fracturas periprotésicas de fémur en una serie determinada de pacientes con reemplazo de cadera / Prevalence of periprosthetic femoral fractures in a selected series of hip replacement patients

Objetivo Determinar la prevalencia de fracturas periprotésicas en pacientes con antecedente de reemplazo de cadera que ingresaron a un servicio de ortopedia entre el 2010 al 2018. Materiales y métodos 709 pacientes fueron atendidos, pero solo 15 pacientes presentaron fracturas periprotésicas. Resultados La prevalencia de fracturas periprotésicas fue del 2.1% (IC 95%: 1.05; 3.17). La mayor parte de los casos se presentaron en el sexo femenino con un porcentaje de 53,3%, con edad promedio de 74.2 año. Las principales causas de fractura periprotésica fueron el trauma en la cadera por caída desde su propia altura. Solo el 12.12% presentaron alguna complicación local o sistémica. Conclusiones La prevalencia de fracturas periprotésicas fue menor del 3%; esta patología depende de distintos factores que se deben tener en cuenta al momento de realizar los procedimientos quirúrgicos.

Objective To determine the prevalence of periprosthetic fractures in patients with a history of hip replacement admitted to an orthopedic service between 2010 and 2018. Materials and methods 709 patients were seen, but only 15 patients had periprosthetic fractures. Results The prevalence of periprotic fractures was 2.1% (95% CI: 1.05; 3.17). The majority of cases occurred in females with a percentage of 53.3%, with an average age of 74.2 years. The main causes of periprotic fracture were hip trauma from falling from its own height. Only 12.12% presented some local or systemic complication. Conclusions The prevalence of periprosthetic fractures was less than 3%; this pathology depends on different factors that must be taken into account when performing surgical procedures.

Concentración preoperatoria de fibrinógeno plasmático como predictor de sangrado en artroplastía total de cadera / Preoperative concentration of plasma fibrinogen as a predictor of bleeding in total hip arthroplasty

Resumen: Introducción: La artroplastía total de cadera tiene popularidad debido al éxito en el tratamiento de coxartrosis; son procedimientos asociados a la pérdida de sangre. Un sangrado importante provoca complicaciones como aumento en días de estancia intrahospitalaria, mayor costo de la enfermedad, exponiendo al paciente a complicaciones asociadas a transfusión sanguínea. El objetivo del estudio es investigar asociación entre concentración de fibrinógeno plasmático preoperatorio con sagrado transquirúrgico y determinar el nivel de corte de fibrinógeno para presentar mayor sangrado transquirúrgico. Material y métodos: Estudio retrospectivo, observacional, analítico, de Junio a Diciembre de 2020, incluyendo 227 pacientes con coxartrosis IV de la escala de Kellgren y Lawrence sometidos a artroplastía total primaria de cadera, derechohabientes, mayores de 18 años, en ausencia de enfermedades hepáticas o hematológicas y antecedente de sangrado quirúrgico importante. Resultados: El valor promedio de hemoglobina preoperatoria fue 14.6 ± 1.3 g/dl, posterior a cirugía (48 horas) 10.5 ± 1.4 g/dl; observando descenso de 4.1 ± 1.2 g/dl (p ≤ 0.0001). Valor promedio del hematocrito prequirúrgico 43% [41-45], posterior al procedimiento 32% [29-35]; se observó descenso de 11% [8-14] (p ≤ 0.0001); 98 pacientes presentaron sangrado transquirúrgico ≥ 300 ml; 129 tuvieron sangrado ≤ 300 ml; 61.2% de pacientes con sangrado mayor de 300 ml mostraron valores de fibrinógeno debajo del punto de corte (388 mg/dl). Conclusión: En pacientes postoperados los niveles preoperatorios de fibrinógeno ≤ 388 mg/dl y edad ≥ 58 años se asociaron al aumento en el riesgo del OR = 0.18 (IC 95% 0.10-0.32) de presentar sangrado transquirúrgico ≥ 300 ml, con descenso de la Hb de 4.1 ± 1.2 g/dl (p = 0.0001) y Hto de 11% [8-14] (p = 0.0001) entre el preoperatorio y el postoperatorio en 48 horas.

Abstract: Introduction: Total hip arthroplasty is popular for its success in treating coxarthrosis, its associated with substantial blood loss. Significant bleeding causes complications such as increase in hospitalization days, higher costs, exposing the patient to complications associated with blood transfusion. The aim of the study is to investigate the association between preoperative plasma fibrinogen concentration and trans-surgical bleeding and determine fibrinogen level cut-off to present greater trans-surgical bleeding. Material and methods: Retrospective, observational, analytical study, from June to December 2020, including 227 patients with Kellgren and Lawrence scale IV coxarthrosis undergoing primary total hip arthroplasty, beneficiaries, older than 18 years, without liver or hematological diseases, and history of significant surgical bleeding. Results: Mean preoperative hemoglobin value was 14.6 ± 1.3 g/dl, after surgery (48 hours) 10.5 ± 1.4 g/dl; decrease of 4.1 ± 1.2 g/dl (p ≤ 0.0001). Mean preoperative hematocrit value 43% [41-45], after the procedure; 32% [29-35]; decrease of 11% [8-14] (p ≤ 0.0001). 98 patients had intraoperative bleeding ≥ 300 ml, 129 had ≤ 300 ml; 61.2% of patients with bleeding greater than 300 ml had fibrinogen values below the cut-off point (388 mg/dl). Conclusion: In postoperative patients, preoperative fibrinogen levels ≤ 388 mg/dl and age ≥ 58 years were associated with an increased risk of OR = 0.18 (95% CI 0.10-0.32) of presenting trans-surgical bleeding ≥ 300 ml, with a decrease in Hb of 4.1 ± 1.2 g/dl (p = 0.0001) and Hto of 11% [8-14] (p = 0.0001) between the pre and postoperative period in 48 hours.

Intervalos de tempo para processamento de materiais consignados de prótese total de quadril / Processing time of loaner items for total hip replacement / Intervalos de tiempo para el procesamiento de materiales consignados para prótesis total de cadera

Objetivo: Estimar os intervalos de tempo envolvidos no reprocessamento de materiais consignados temporários de prótese total de quadril em um centro de material e esterilização de um hospital privado de São Paulo (SP). Método: Estudo exploratório-descritivo, de campo, com abordagem quantitativa. A amostra foi composta de 41 processamentos de materiais consignados. Os intervalos de tempo foram registrados com auxílio de cronômetro digital, hora inicial e final de cada atividade. O cálculo amostral foi estimado com intervalo de confiança de 95%. Resultados: O tempo total do processamento teve mediana de 10 horas, o tempo efe-tivo total foi de 4,9 horas e o intervalo de tempo entre o fim do reprocessamento e o horário da cirurgia foi de 4,7 horas de antecedência. Houve cancelamento de uma cirurgia em virtude do atraso na entrega do material. Conclusão: Nesta pesquisa foram mensurados os tempos de reprocessamento de materiais consignados, sendo mantido o rigor metodológico em todas as etapas, com estimativas que respeitaram o intervalo de confiança, o que faz deste estudo passível de reprodução. Sugere-se que profissionais de outras instituições realizem tais mensurações, de modo que permitam a construção de indicadores, auxiliando enfermeiros na tomada de decisão.

Objective: To estimate the time intervals necessary to reprocess loaner items for total hip replacement in a sterile processing department of a private hospital in São Paulo (SP). Method: This is an exploratory, descriptive field study with a quantitative approach. The sample consisted of 41 processing cycles for loaner items. Intervals were recorded using a digital stopwatch, including the start and end times of each activity. Sample calculation was estimated with a 95% confidence interval. Results: Median total processing time was 10 hours, total effective time was 4.9 hours, and the interval between the end of reprocessing and the time of surgery was 4.7 hours in advance. One surgery was canceled due to delayed delivery of the item. Conclusions: This study measured the reprocessing times of loaner items, maintaining the methodological rigor at all stages, with estimates that respected the confidence interval, making this investigation reproduci-ble. We suggest that professionals from other facilities perform these measurements to allow the construction of indicators that can help nurses in decision-making.

Objetivo: Estimar los intervalos de tiempo involucrados en el reprocesamiento de materiales consignados temporalmente para reemplazo total de cadera en un Centro de Material y Esterilización de un hospital privado de São Paulo. Método: Estudio de campo exploratorio-descriptivo con enfoque cuantita-tivo. La muestra consistió en 41 procesamientos de materiales consignados. Los intervalos de tiempo se registraron con la ayuda de un cronómetro digital, hora de inicio y finalización de cada actividad. El cálculo del tamaño de la muestra se estimó con un intervalo de confianza del 95%. Resultados: El tiempo total de procesamiento tuvo una mediana de 10 horas; el tiempo efectivo total fue de 4,9 horas y el intervalo de tiempo entre el final del reprocesamiento y el momento de la cirugía fue de 4,7 horas antes. Se canceló una cirugía debido al retraso en la entrega del material. Conclusión: En esta investigación se midieron los tiem-pos de reprocesamiento de los materiales consignados, manteniendo el rigor metodológico en todas las etapas, con estimaciones que respetaron el intervalo de confianza, haciendo este estudio susceptible de reproducción. Se sugiere que profesionales de otras instituciones realicen dichas mediciones, de manera que per-mitan la construcción de indicadores, ayudando a las enfermeras en la toma de decisiones.

Evaluation of the range of motion of a hip arthroplasty system: a computer simulation study / Avaliação da amplitude de movimento de um sistema artroplástico do quadril: estudo por simulação computacional

ABSTRACT Objective: To date, the literature lacks consensus on the most efficient method to measure the range of motion of an in vitro prosthetic system. In this study, we propose the use of a relatively low-cost online software to measure the range of motion of hip prosthetic implants manufactured in Brazil and compare its results with the current technical standards for hip arthroplasty. Methods: Three different diameters of femoral heads were evaluated (28 mm, 32 mm, and 36 mm). The mean values of the angular displacement of the prosthesis in each motion axis were obtained by computer simulations. Results: The range of motion with each femoral head was 28mm (extension/flexion: 148°, internal/external rotation: 179°, adduction/abduction: 107°), 32 mm (152°/185°/114°), and 36 mm (158°/193°/120°). Conclusion: The computational method showed that the larger the femoral head, the greater the range of motion of the hip joint prosthetic system. Additional clinical studies are necessary to compare the physical results obtained with the values found in this study by computational modeling. Level of evidence V, Experimental study.

RESUMO Objetivo: A maneira mais eficiente de se aferir a amplitude de movimento de um sistema protético in vitro ainda não é bem estabelecido na literatura. Assim, o presente estudo propõe a utilização de um software online de custo relativamente baixo para mensuração da amplitude de movimento de um conjunto protético nacional de quadril e comparar os resultados obtidos com a norma técnica vigente para as artroplastias de quadril. Métodos: A avaliação foi realizada com três diferentes diâmetros de cabeças femorais (28 mm, 32 mm e 36 mm); os valores médios do deslocamento angular da prótese em cada eixo de movimento foram obtidos por meio de simulações computacionais no programa Autodesk Inventor. Resultados: as amplitudes de movimento obtidas foram: cabeça 28mm (extensão/flexão: 148°, rotação interna/externa: 179°, adução/abdução: 107°), cabeça 32° (152°/185°/114°), cabeça 36° (158°/193°/120°). Conclusão: O método computacional utilizado no presente estudo possibilitou concluir que quanto maior a cabeça femoral, maior será a amplitude de movimento do sistema protético para articulação de quadril. Novos estudos clínicos, tanto pré quanto pós-operatórios, devem ser realizados para comparar os resultados físicos obtidos com os valores encontrados nesta avaliação por meio de modelo computacional. Nível de Evidência V, Estudo experimental.

Concordancia interobservador en la clasificación de Paprosky en un hospital de un país de una economía emergente / Inter-observer agreement in the Paprosky classification in a hospital in a country of an emerging economy

Resumen: Introducción: La evaluación y manejo de la pérdida ósea acetabular en la artroplastía total de cadera es un desafío para los cirujanos ortopédicos, deseamos en este estudio determinar la concordancia interobservador en la clasificación de Paprosky para defectos acetabulares. Material y métodos: Estudio observacional, descriptivo, longitudinal, prospectivo. Se realizó utilizando las radiografías anteroposteriores de cadera de pacientes programados para artroplastía total de cadera primaria o de revisión con defecto óseo acetabular, sistema de rayos X local Sinapse, se valoraron 20 radiografías por observador tomadas de manera aleatoria (médicos adscritos al servicio de reemplazos articulares con experiencia mínima de cinco años) utilizando la clasificación de Paprosky de manera espontánea (sin clases previas) de defectos acetabulares, se evaluó la concordancia interobservador mediante el coeficiente de kappa de Cohen. Resultados: Se obtuvo una concordancia interobservador en promedio para la clasificación de Paprosky de defectos acetabulares utilizando el coeficiente de kappa de Cohen, el análisis de concordancia se hizo empleando el programa estadístico Statistical Package for the Social Sciences de 0.237. Conclusiones: Tanto la hipótesis nula (kappa mayor de 0.80 valor considerado óptimo) como la hipótesis alternativa (kappa de 0.41 a 0.80 valor igual a moderada a buena) no concordaron con nuestro estudio (kappa igual a 0.237) valor igual a leve, además se demostró que a mayor defecto acetabular menor es la concordancia interobservador en cirujanos en nuestra institución.

Abstract: Introduction: The evaluation and management of acetabular bone loss in total hip arthroplasty is a challenge for orthopedic surgeons, we wish in this study to determine the inter-observer concordance in the Paprosky classification for acetabular defects. Material and methods: Observational, descriptive, longitudinal, prospective study. It was performed using anteroposterior hip radiographs of patients scheduled for primary total hip arthroplasty or revision with acetabular bone defect, Sinapse local X-ray system, 20 X-rays were assessed per observer taken randomly (doctors assigned to the joint replacement service with minimum experience of five years) using the Paprosky classification spontaneously, (without previous classes) for acetabular defects, inter-observer concordance was assessed using Cohen's Kappa coefficient. Results: An interobserver agreement was obtained on average for the Paprosky classification of acetabular defects using the Cohen's Kappa coefficient, the concordance analysis was done using the statistical program statistical package for the social sciences of 0.237. Conclusions: Both the null hypothesis (Kappa greater than 0.80 value considered optimal) and the alternative hypothesis (Kappa from 0.41 to 0.80 value equal to moderate to good) did not agree with our study (Kappa equal to 0.237) value equal to mild, in addition , it was shown that the greater the acetabular defect, the lower the interobserver agreement in surgeons in our institution.

Fractura periprotésica acetabular intraoperatoria / Intraoperative acetabular periprotesic fracture

Resumen: Las fracturas intraoperatorias acetabulares (FIA) son una complicación rara con incidencia de 2 a 5%. Presentamos la revisión de una serie de 13 casos, que aborda diagnóstico, tratamiento y resultados. Material y métodos: entre 2006 y 2018 realizamos 4,800 artroplastías primarias de cadera (ATC). En nuestro hospital identificamos 13 casos con FIA con un seguimiento de 38.3 meses. Resultados: Dos casos fueron estables con manejo conservador; 11 casos inestables: en siete casos colocamos trabecular metal, en un caso aumentamos diámetro acetabular, en un caso recambio de cotilo, en un caso revisión con anillo tipo Ganz y un caso no aceptó tratamiento. El uso de trabecular metal es un implante que ayuda eficazmente y con buenos resultados en FIA. Conclusión: Estas fracturas son raras, conocer el implante a utilizar es imperativo, ya que si los implantes están sobredimensionados, con mayor rigidez o hemisféricos, los pacientes tienen mayor riesgo de sufrir esta complicación.

Abstract: Intraoperative acetabular fractures (IAF) is a rare complication with an incidence 2% - 5%. We present the review of a series of 13 cases, discussing diagnosis, treatment and results. Material and methods: Between 2006 and 2018, we performed 4800 primary hip arthroplasties (THA) In our hospital, we identified 13 cases with FIA with a follow-up of 38.3 months. Results: Two cases were stable with conservative management; 11 unstable cases: seven cases we placed trabecular metal, one case we increased acetabular diameter, one case acetabular replacement, one case revision with Ganz type ring and one case do not accept treatment. The use of trabecular metal is an implant that helps effectively and with good results in FIA. Conclusion: These fractures are rare, knowing the implant to use is mandatory because if the implants are oversized, with greater rigidity or hemispheric, patients have increased risk of suffering from this complication.

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

ABSTRACT Purpose To evaluate the biomechanical properties of a novel total hip replacement femoral stem. Methods Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. Results Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. Conclusions The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

Effects of 3D-printed porous metal cup with hip dual-mobility revision system for reconstruction of severe acetabular ring defects in revision total hip arthroplasty / 中华骨科杂志

Objective:To prospectively analyze the early clinical effects of 3D-printed porous metal cup with hip dual-mobility revision (HDR) system in treating severe acetabular bone defects.Methods:A total of 17 patients with severe acetabular defects (15 patients in Allan-Gross type 4 and 2 patients in type 5; 2 patients in Paprosky type 2B, 4 patients in type 3A and 11 patients in type 3B) who underwent revision hip arthroplasty between July 2019 and May 2020 were analyzed. There were 7 males and 10 females (mean age 67.3±9.3 years; range 42-80 years). The average body mass index was 22.2±3.8 kg/m 2 (range 17.7-33.3 kg/m 2). The preoperative mean leg length discrepancy (LLD) was 42.9±31.1 mm (range 10-160 mm) . One patient presented positive Trendelenburg sign. The follow-up duration was 12.1±3.0 months (range 6-16 months). The clinical and radiographic hip scores in all patients were evaluated. Results:The mean Harris Hip Score (HHS) was 31.2±11.3 points at preoperatively, 63.5±10.0, 68.7±10.4 and 70.2±10.1 points at 3 days, 7 days and 1 month postoperatively. At the latest follow-up, HHS was increased to 81.6±7.0 points. The outer cup mean abduction angle was 48.1°±10.6° and the mean inclination angle was 10.8°±6.0° postoperatively. The inner cup mean abduction angle was 45.0°±6.2° and the mean inclination angle was 10.8°±3.7°. The mean LLD decreased to 11.1±3.8 mm (range: 0-15 mm) after surgery. At the latest follow-up, all acetabular components were radiologically stable without displacement. No osteolysis or absorption was observed. There was no infection, loosening or nerve injury in all cases.Conclusion:During short-term follow-up, the 3D-printed porous metal HDR system can effectively enhance the stability of implants with satisfied quality of life. It can provide a good result for the revision of total hip arthroplasty with severe acetabular defects.

Comparison of prosthesis locations and postoperative hip functions between supercapsular percutaneously-assisted total hip (SuperPATH) and posterolateral approaches in total hip arthroplasty / 中华创伤骨科杂志

Objective:To compare the prosthesis locations and postoperative hip functions between supercapsular percutaneously-assisted total hip (SuperPATH) approach and traditional posterolateral approach (PLA) in total hip arthroplasty.Methods:A retrospective analysis was conducted of the 107 patients who had undergone unilateral total hip arthroplasty at Department of Orthopedic Surgery, The First Affiliated Hospital to Soochow University from August 2016 to February 2019. They were divided into 2 groups according to their surgical approaches. In the SuperPATH group of 54 cases, there were 20 males and 34 females with an age of (64.3±9.1) years; in the PLA group of 53 cases, there were 20 males and 33 females with an age of (62.2±10.6) years. The 2 groups were compared in terms of abduction angle, ratio of abduction angle to safety zone, anteversion angle, ratio of anteversion angle to safety zone, retroversion angle, incidence of retroversion, and differences in eccentricity and lower limb length on the first day after operation, and Harris hip scores at 1 week, 3 months and the last follow-up postoperatively. Their complications were also recorded as well.Results:There were no statistically significant differences in the preoperative general data between the 2 groups, showing comparability ( P>0.05). The postoperative imaging data were complete for the 107 patients who had been followed up satisfactorily for 14 to 36 months (average, 25 months). The SuperPATH group had significantly larger retroversion angle (13.6°±9.6°) and incidence of retroversion (18.5%, 10/54), significantly smaller difference in eccentricity [0.26 (0.13,0.49) cm], and significantly higher Harris hip score [(74.8±7.8) points] at one week after surgery than those in the PLA group [3.0°±1.0°; 5.7%, 3/53; 0.38 (0.13,0.70) cm; (72.0±6.7) points] ( P<0.05). There were no statistically significant differences between the 2 groups in abduction angle, ratio of abduction angle to safety zone, anteversion angle, ratio of anteversion angle to safety zone, difference in lower limb length, or Harris hip scores at 3 months or the last follow-up postoperatively (all P>0.05). Follow-ups in both groups observed no more than one case of dislocation which responded to manual reduction. Conclusion:The minimally invasive SuperPATH approach may obtain better femoral eccentricity and higher early hip function scores than the traditional posterolateral approach, but may lead to a higher incidence of retroversion after prosthesis placement.