Application of 3D printed model in clinical teaching of hip revision / 中华医学教育探索杂志

Objective:To evaluate the effect of 3D printed models assisted teaching method on clinical teaching of hip revision and improve the teaching quality.Methods:Fifty students who were in the standardized training for surgical specialty from Peking University Third Hospital were divided into a control group and an experimental group, with 25 students in each group. The control group was taught by traditional methods, while the experimental group was taught by 3D printed models. After the training, professional theory test and teaching evaluation questionnaire survey were conducted among the members of the two groups, and statistical analysis was made on the students' professional theory test scores, learning interests and teaching satisfaction. SPSS 18.0 was used for t test. Results:The theoretical scores of the experimental group [(84.60±5.76) points] were higher than those of the control group [(78.20±6.90) points], and the difference was statistically significant ( P<0.05). The teaching satisfaction and learning interest of the experimental group were both better than those of the control group [(4.72±0.46) vs. (4.28±0.61), (4.76±0.44) vs. (4.28±0.54)], with statistically significant differences ( P<0.05). Conclusion:The 3D printed model assisted teaching can effectively deepen students' understanding of hip joint structure, improve the teaching quality, and enhance their enthusiasm and initiative in learning.

Prótesis total de fémur en pacientes no oncológicos / Total femur prosthesis in non-oncological patients

Resumen: Introducción: Las prótesis totales de fémur (PTF) son un procedimiento muy excepcional y más aún en pacientes no oncológicos. El objetivo es analizar una serie de casos de prótesis total de fémur, su seguimiento y resultados a largo plazo. Material y métodos: Estudio retrospectivo en el que se incluyeron siete pacientes, intervenidos desde 2011 hasta 2014. Tras aplicar los criterios de exclusión (seguimiento y pacientes oncológicos), se analizaron cuatro pacientes. Se utilizó la clasificación de Paprosky para medir el defecto óseo y se valoraron diferentes parámetros: número de cirugías previas, duración de la cirugía, complicaciones, cirugías de revisión, escala de valoración funcional y seguimiento clínico radiológico. Resultados: Edad media de 78.5 años al implante de la prótesis total de fémur (PTF). El defecto óseo en el fémur (1-IIIA, 2-IIIB y 1-IV) fue más importante que en el acetábulo (2-I, 1-IIA y 1-IIB). El tiempo medio de la cirugía fue de 110 minutos. El motivo de la cirugía de revisión más frecuente fue el recambio del componente acetabular en tres pacientes debido a inestabilidad. La complicación más frecuente fue la infección. Flexión media de cadera de 85 grados y extensión de 0. La diferencia entre la valoración funcional Harris Hip Score pre- y post- es de 54.9 puntos, en la escala de Enneking fue de 14.25 puntos de media y la escala de dolor (VAS) medio es inferior a 2. El seguimiento promedio es de aproximadamente siete años y medio. Conclusiones: La PTF es una cirugía sin protocolo estandarizado al día de hoy. La infección en nuestra serie está siempre presente y el componente acetabular constreñido evitaría inestabilidades. Por lo que el implante de PTF debe ser a pacientes muy bien seleccionados.

Abstract: Introduction: Total femoral replacement (TFR), it is an uncommon surgery in non-oncological patients. Our main objective is to review our total femur replacement surgeries and analyze functional and clinical outcomes. Material and methods: We retrospectively review our series of seven non-oncological patients treated at our center with a TFR from 2011 to 2014. After excluding patients (Oncological patients or non-follow up) we revised four patients. Paprosky bone loos classification and different values were studied: number and time of surgeries, complications, revision surgeries, functional scales, and follow-up. Results: Mean age of 78.5 years. According to Paprosky classification of femur bone loss: 1 IIIA, 2 were IIIB, 1 IV. On the other side acetabular loss: 2 I, 1 IIA, 1 IIB. Surgical time for TFR was 110 minutes on average. Three patients were need revision surgery due to instability. And every single patient suffered from chronic infection. Mean range of motion was 85 flexion, 0o extension. Comparing preoperative and postoperative Harris Hip Score for hip function was 54.9 points and Enneking score was an average of 14.25 points better in our patients with TFR. Visual analogue pain score was on average less than two points. Mean follow-up is almost seven and a half years. Conclusions: TFP has not a standardized surgical protocol yet. Infection is always present in our series and acetabular constrained components in TFR avoid instability complications. TFP should be implanted only in selected patients.

A retrospective study on the application of cemented polyethylene liner technique in hip revision / 中国修复重建外科杂志

Objective: To evaluate the effectiveness of cemented polyethylene liner technique in hip revision. Methods: Based on inclusion criteria, the clinical data of 26 patients who were undergone hip revision between January 2011 and December 2013, were retrospectively reviewed. Among them, 14 cases were treated with isolated liner exchange (group A) and 12 cases were treated with cemented polyethylene liner technique (group B). There was no significant difference in gender, age, the time from primary total hip arthroplasty to revision, and the preoperative Harris score between 2 groups ( P>0.05). The post-operative Harris score and complications were compared between 2 groups, and X-ray findings of the hip joint were recorded to review the position of hip components. Results: All patients were followed up 4.4-6.4 years (mean, 5.4 years). Except for two femoral fractures during the revision (1 in each group), there was no other complication in 2 groups. The hip pain relieved and the lame gait corrected in 2 groups. The hip's function of 2 groups improved gradually after operation, with a better Harris score at 3 months and the best at the last follow-up, compared with preoperative scores ( P0.05). X-ray films showed no dislocation, aseptic loosening, and other interface related complication. Conclusion: For the cases without the chance to do change liner, cemented polyethylene liner technique has a good effectiveness. But restrict patient selection should be considered before hip revision.

Revisión femoral con tallo cónico de fijación distal / Femoral revision surgery with conical stem of distal fixation

Introducción: La pérdida de hueso proximal en la cirugía de revisión del vástago femoral es el principal desafío que enfrenta el cirujano al efectuar una revisión. El objetivo es obtener una fijación estable de los componentes, así como la restauración de la cinemática de la articulación. Materiales y Métodos: Evaluamos a 37 pacientes (39 revisiones femorales), entre 2010 y 2014, a quienes se les colocaron tallos cónicos no cementados de fijación distal (28 modulares y 11 no modulares). La edad promedio fue 63.5 años. Se incluyó a 18 (48,64%) mujeres y 19 (51,35%) hombres. Se intervinieron 14 (35,89%) casos de aflojamiento aséptico, 14 (35,89%) infecciones, 7 (17,94%) fracturas periprotésicas, 3 (7,69%) fracturas de vástago y una (2,56%) por inestabilidad. El seguimiento medio fue de 42 meses (rango 24-74). Resultados: El puntaje medio de Harris mejoró de 37 (rango 10-77) antes de la operación a 81 (rango 33-96) en el último seguimiento. Cuatro pacientes (10,2%) presentaron luxación, uno (2,5%) tuvo una infección profunda; otro (2,5%), una fractura intraoperatoria; en tres (7,6%) pacientes, se produjo un hundimiento y fue necesario revisar 2 (5,1%) implantes femorales. Conclusiones: Con el vástago cónico se han logrado resultados satisfactorios en 2-6 años de seguimiento, en varias condiciones de revisión femoral. Requiere de una técnica simple y reproducible, con una mejoría clínica ampliamente publicada. Nivel de Evidencia: IV

Introduction: Proximal bone loss at the femoral stem is the main challenge facing surgeons at the time of revision total hip arthroplasty. The aim of revision surgeries is to obtain a stable placement of components and to restore joint kinematics. Methods: Between 2010 and 2014, we evaluated 37 patients (39 hips) in whom non-cemented femoral stems were used (28 modular and 11 non-modular).The average age was 63.5 years. Study patients included 18 (48.64%) women and 19 (51.35%) men. Causes of reoperation included 14 (35.89%) cases of aseptic loosening, 14 (35.89%) infections, 7 (17.94%) periprosthetic fractures, 3 (7.69%) stem fractures and one (2.56%) for instability. Mean follow-up was 42 months (range 24-74). Results: The average Harris score improved from 37 (range 10-77) points before surgery to 81 points (range 33-96) at the last follow-up. Four patients (10.2%) presented dislocation, one (2.5%) suffered a deep infection, one (2.5%) had an intra-operative fracture; 3 (7.6%) patients presented subsidence and it was necessary to revise 2 (5.1%) femoral implants. Conclusions: Satisfactory results were obtained with the femoral stem in 2 to 6 years of follow-up in several conditions of femoral revision surgeries. It requires a simple and reproducible technique with clinical improvement that has been widely published in the literature. Level of Evidence: IV

Utilización de tallos femorales porosos extendidos en revisiones de cadera / Use of extensively porous femoral stem in revision hip arthroplasty

Introducción: Ante el difícil y cada vez más frecuente escenario de una revisión de cadera, existen diferentes alternativas para conseguir una fijación estable y duradera del componente femoral. El objetivo de este estudio fue evaluar la evolución clínica y radiográfica de los pacientes sometidos a una revisión del componente femoral con tallo cilíndrico de superficie rugosa extendida. Materiales y Métodos: Se llevó a cabo un estudio multicéntrico y retrospectivo de 148 pacientes, operados entre marzo de 1997 y marzo de 2010, a quienes se les realizó una cirugía de revisión femoral con un tallo cilíndrico con recubrimiento poroso. La edad promedio era de 63.1 años. Resultados: El seguimiento promedio fue de 7.7 años. En 134 (89,9%) pacientes, se observó una fijación ósea estable; en 12 (8%), una fijación fibrosa estable y, en 3 (2%), una fijación fibrosa inestable. El puntaje de Harris se modificó de 41 en el preoperatorio a 92 después de la cirugía. Las complicaciones fueron infección profunda (2 casos, 1,3%), fractura de fémur intraoperatoria (12,8%) y luxación protésica (3 casos, 2%). Conclusión: Los tallos cilíndricos con recubrimiento poroso han demostrado ser un eficaz recurso para solucionar la mayoría de las revisiones femorales por la posibilidad de obtener fijación estable a corto y largo plazo. Nivel de Evidencia: IV

Introduction: In the set of hip revision surgery there are different options to achieve a stable fixation of the femoral component. The objective of this study was to evaluate the clinical and radiographic outcomes of patients who underwent hip revision with cylindrical extensively porous stem. Methods: Between March 1997 and March 2010 a multicenter retrospective study was performed in 148 patients who underwent hip revision with cylindrical extensively porous stem. The mean age was 63.1 years. Results: The follow-up was 7.7 years. One hundred thirty-four (89.9%) patients achieved a stable bone ingrowth fixation; 12 (8%) a stable fibrous fixation and 3 (2%) a non-stable fixation. The Harris Hip Score improved from 41 points before surgery to 92 points in the postoperative period. Complications included: two deep infections (1.3%), 12 intra-operative femoral fractures (8%) and three hip dislocations (2%). Conclusion: The cylindrical extensively porous femoral stem seems to be a reliable technique for femoral hip revision surgery, as it is possible to obtain a short- and long-term stable fixation. Level of Evidence: IV

Impaction bone grafting with morselized bone in total hip revision for acetabular deficiency / 中国组织工程研究

BACKGROUND:Bone graft for acetabular reconstruction includes morselized bone graft, structural bone graft and hybrid bone graft, and the morselized bone has been widely used because of the advantages of simple production and short healing time. OBJECTIVE:To explore the key technologies and clinical effect of impaction bone grafting with morselized bone in total hip revision for AAOS Ⅲ acetabular deficiency. METHODS:Sixteen cases of AAOS Ⅲ acetabular deficiency were treated with impaction bone grafting with morselized bone combined with metal devicesor constructive bone grafting. The hip Harris scores and radiographic data were compared before and after treatment. The effect of impaction bone grafting with morselized bone on acetabular deficiency was assessed. RESULTS AND CONCLUSION:Al the patients were fol owed-up at 3, 6, 12 months after surgery and every half a year successively. The pain of hip joints after operation was relieved significantly and the walking function was restored. The hip Harris score was improved from 48.00 points before surgery to 84.94 points after surgery (Pacetabular cup prosthesis did not displaced, and no displacement and breakage happened to the metal devices. Impaction bone grafting with morselized bone in total hip revision for AAOS Ⅲ acetabular deficiency can effectively reconstruct the acetabular bone structure, retain and restore the acetabular bone mass, and it has good technical advantages and good clinical effects.

Risk Factors Related to Modular Femoral Stem Failures in Revision Hip Arthroplasty / 대한고관절학회지

PURPOSE: The purpose of this study was to analyze failure rates and causes of hip arthroplasty revisions associated with the use of cementless modular femoral stems. MATERIALS AND METHODS: This study comprised 93 patients(100 hips) that were followed up for more than two years after revision involving modular femoral stem arthroplasty. The clinical results were evaluated using the Harris Hip Score and the radiologic results were evaluated using leg length discrepancy, subsidence and bone formation assessments. We analyzed the relationship between the number of hip surgeries performed and the bone deficiencies and failures observed. Preoperative femoral bone deficiencies were described by Paprosky Grade; Grade I or II were identified in 24 hips, IIIa in 4 hips, IIIb in 28 hips and IV in 3 hips. RESULTS: We observed 80 hips with aseptic loosening, 10 hips with infection after previous revision, 8 hips with periprosthetic fractures and 2 hips with dislocations. Clinical results improved from a preoperative score of 42 (HHS) to a postoperative mean score of 81.5. The cause of early failure in 4 hips was identified as femoral stem subsidence, and the cause of late failure in 3 hips was due to infection. According to the comparison analysis, there was no statistical significance between femoral bone deficiency (P=0.727) and application of cement (P=0.087), but hips with previous revision surgery showed a higher rate of failure (P=0.024). CONCLUSION: Cementless modular stems produced satisfactory results. The main cause of failure was subsidence. A significant risk factor for failure was hips which had undergone previous revision surgery.

Revision of total Hip Arthroplasty Using Allogenic Bone Graft in Acetabular Deficiency / 대한정형외과학회잡지

Patients with severe acetabular bony deficiency in total hip revision arthroplasties need the use of autogenous or allogenic bone grafts. The Authors performed 28 cases of total hip revision arthroplasties between June 1991 and January 1995 with femoral head allograft for acetabular bony deficiencies and evaluated the clinical and radiological results according to AAOS classification. The clinical result was evaluated by D'Aubigne and Postel score. The mean score was improved from 3.9 points to 5.1 points at follow-up. In radiological evaluation, osseous union of graft was achieved within 12 month and rerevision were performed in two cases (92.8% survival rates) but radiological radiolucent line in at least one zone was seen in five hips in two year follow up. In conclusion, the results of hemispherical microporocoat cup with allogenic bone in segmental or cavitary defect using with acetabular reinforcement ring in combined deficiency were encouraging to date. Success rate of allograft reconsruction of the acetabulum results from a variety of acetabular defect. In our studies, only 40% showed stable bony fixation over short period.