Planificación pre-operatoria digital en artroplastia total de cadera / Digital templating in total hip arthroplasty

Introducción: La planificación preoperatoria favorece la realización de un acto quirúrgico sin complicaciones. Actualmente existe escasa información a nivel nacional sobre la eficacia de la planificación pre-operatoria digital por lo que el objetivo del presente estudio es el analizar los resultados de la implementación de esta estrategia en una población de pacientes con indicación de artroplastia total de cadera. Materiales y métodos: Estudio observacional, prospectivo, analítico. Se realizó un muestreo no probabilístico de casos consecutivos atendidos en la Cátedra de Ortopedia y Traumatología de la Facultad de Ciencias Médicas (U.N.A). Fueron captados pacientes >18 años con indicación de ATC, entre diciembre 2018 ­ octubre 2019, previo consentimiento informado. Se relevaron datos cuya caracterización fue posible mediante un instrumento establecido previamente, ingresado en base Excel. Se utilizó el software TraumaCad® versión 2.5 de Brainlab y marcadores radiológicos King Mark®. Fueron comparados ambos tipos de planificación ejecutando análisis estadísticos con el software R.v3.4.2., siendo un valor p ˂0.05, considerado estadísticamente significativa. Resultados: 57 pacientes fueron evaluados con el método digital y los resultados fueron comparados con los de 42 pacientes en los que se utilizó una planificación manual. La relación masculino-femenino fue 1/1, siendo los del grupo de 50 a 60 años, los más afectados. La coxartrosis primaria y la necrosis ósea aséptica fueron los diagnósticos más frecuentes. El tiempo quirúrgico, la correlación entre planificación y resultados para componentes acetabular, femoral, presentaron mejores resultados en el grupo de pacientes con planificación digital. Conclusión: La planificación digital comparada con la manual presentó mayor eficacia.

Introduction: Preoperative planning allows a surgical act without complications. It can be manual or digital. Its usefulness in total hip arthroplasty (ATC) is important, being digital seemingly more beneficial since it reduces surgical time and complications. The present study analyzed the effectiveness of the digital modality. Materials and methods: Observational, prospective, analytical study. Non-probabilistic sampling of consecutive cases attended in Department of Orthopedics and Traumatology of the Medicine Scholl (Universidad Nacional de Asunción). Patients> 18 years of age were indicated with ATC indication, between december 2018 to october 2019, with prior informed consent. Data whose characterization was made possible by means of a previously established instrument, entered in Excel basis, were released. Each patient had both types of planning: manual and digital. For TraumaCad® version 2.5 Brainlab software and King Mark® radiological markers were used for the digital. Both types of planning were compared by executing statistical analyzes with the software R.v3.4.2., being a value p <0.05, considered statistically significant. Results: 57 patients were evaluated with the digital method and 42 with the manual. The male-female ratio was 1/1, with those in the 50-60 age group being the most affected. The most frequent reason for consultation was hip pain, with primary coxarthrosis and aseptic bone necrosis being their cause. The consultation time 1 and surgery was 12.5 days. The surgical time, the correlation between planning and results for acetabular, femoral components, were more effective with digital planning. Conclusion: Digital planning compared to the manual is more effective.

Dimensional Accuracy of 3D-printed Models of the Right First Metacarpal Bones of Cadavers

Background@#The use of 3D printing in medical education, prosthetics, and preoperative planning requires dimensional accuracy of the models compared to the replicated tissues or organs. Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from cadavers. @*Methods@#Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA), digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width, base height, head width, and head height. Mean measurements were compared using non-inferiority testing and multidimensional scaling.@*Results@#Mean measurements of the 3D-printed models were slightly larger than their control bones (standard deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width, 99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling, DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899).@*Conclusion@#The 3D-printed models are dimensionally accurate when compared to bones.

Useful Method for Neutral Positioning of the Femoral Stem in Cementless Total Hip Arthroplasty / 대한고관절학회지

PURPOSE: The aim of this study was to evaluate the usefulness of a method for positioning the femoral stem in neutral position refer to the measured value of "lateral distance" in pre-operative templating and the femoral stem position post-operatively. MATERIALS AND METHODS: A total of 81 hips in 76 patients underwent cementless total hip arthroplasty between March 2008 and April 2012 using the C2 stem (Lima Corporate S.P.A, Udine, Italy). We measured the perpendicular distance from the lateral outermost part of the greater trochanter to the lateral outermost part of the femoral stem (lateral distance, LD) in pre-operative templating. We aimed to insert the femoral stem in neutral position by comparing LD measured intra-operatively. We evaluated the position of the femoral stem on post-operative plain radiography. We compared the result of post-operative re-measurement of the LD with that of pre-operative measurement. RESULTS: In all of the 81 cases, the femoral stem was inserted in neutral position, defined as the femoral stem position within 3degreesvalgus or varus. The average angle of the inserted femoral stem was 1.20degrees(0.003-2.85degrees). LD measured in preoperative templating was 15.6 mm(10-21.5 mm), and it showed no correlation ratio with LD; LD re-measured post-operatively was 15.9 mm(10.3-23.5 mm) (P=0.781). CONCLUSION: Measuring LD pre-operatively and using the value intra-operatively is an effective method for insertion of the femoral stem in neutral position.

Useful Method for Minimizing Leg Length Discrepancies in Hip Arthroplasty: Use of an Intraoperative X-ray

PURPOSE: There are numerous opinions about the methods and usefulness of minimizing leg length discrepancies after hip arthroplasty. In this study, we tried to evaluate the usefulness of an intraoperative x-ray in addition to preoperative templating for minimizing leg length discrepancy. MATERIALS AND METHODS: We reviewed pre- and post-operative pelvis AP x-rays of 46 patients who underwent hip arthroplasty due to a traumatic femoral neck fracture or intertrochanteric fracture between May 2008 and February 2009. A leg length discrepancy is the difference in vertical distance between a horizontal line drawn along the bottom of the ischial tuberosities and the most inferior points of the lesser trochanter. It was measured in a pelvis AP x-ray. In each case, pre-operative templating was performed and an intraoperative pelvis AP x-ray was taken again to assess the accuracy of preoperative planning. Implant positions were readjusted when necessary. RESULTS: The mean post-operative leg-length discrepancy was 0.3 mm (SD, 3.1 mm). The range was from -5.8 mm to +5.9 mm. CONCLUSION: Combining preoperative templating and intraoperative x-rays is a useful method of minimizing leg length discrepancy during hip arthroplasty.

Preoperative Templating in PACS for Total Hip Replacement / 대한정형외과학회잡지

PURPOSE: The objective of our study was to compare preoperative "Monitor Templating" with postoperative results for total hip replacement and to investigate the accuracy of "Monitor Templating" that was carried out by monitoring with picture archiving communication system (PACS). MATERIALS AND METHODS: Forty five patients underwent primary cementless total hip replacements. For setting parameters, we located the 10cm rod placed in the medial thigh on anteroposterior view of both hips and in the anterior thigh on Lowenstein lateral view. We measured implant sizes and the predictive value of corrective change in leg length and horizontal offset, by using radiographs magnified 120% of the anteroposterior views of both hips and Lowenstein lateral view of PACS on 27 inch monitor. We examined the correlation between preoperative monitor templating and the actual implant size, postoperative leg length and horizontal offset difference. RESULTS: The preoperative monitor templating showed a high rate of coincidence with the actual implant size, the postoperative leg length, and the horizontal offset difference. The averages in accurate prediction were 98% in the acetabular cup, 98% in the femoral stem, 97% in the postoperative actual difference of leg length, and 97% in the horizontal offset. With regard to leg length discrepancy, the sick limb was on average 4.7 mm shorter and 0.5 mm longer postoperatively than the contralateral limb. The average ratio of horizontal offset of the sick limb to the contralateral limb was 94.6% preoperatively and increased to 97.8% postoperatively. CONCLUSION: Preoperative "Monitor Templating" using PACS images on 26 inch monitor is an easy and effective method for predicting implant size, correcting leg length discrepancy and restoring horizontal offset.

Comparison of Conventional and Digital Templating Technique in Total Hip Arthroplasty

PURPOSE: To examine the effectiveness of digital templating in patients who underwent primary total hip arthroplasty by comparing and analyzing the accuracy of acetate and digital templating. MATERIALS AND METHODS: One hundred and nine patients who underwent primary total hip arthroplasty between November 2002 and May 2006 were assigned to the acetate templating group (group I), and 113 patients between June 2006 and April 2009 were assigned to the digital templating group (group II). The sizes of the acetebular cup and femoral stem were examined to determine the accuracy of each method. RESULTS: In group I, acetabular cup accuracy was found in 46.8% of cases, and 94.5% showed a mismatch less than +/- 1 sizes. In the case of the femoral stem, accuracy was found in 53.2% and 92.7% showed a mismatch. In group II, acetebular cup accuracy was observed in 43.4% of cases, and 92.9% showed a mismatch below +/- 1 size. In femoral stem cases, 46.9% were accurate and 93.8% showed a mismatch. CONCLUSION: The accuracy of the digital templating method is equivalent to that of acetate templating, and should replace acetate templating before the operation.

Comparison of Digital Templating with Manual Templating for Total hip Replacement / 대한정형외과학회잡지

PURPOSE: The objectives of this study are to compare digital with manual templating in preoperative planning for total hip arthroplasty and to assess the usability of digital templating. MATERIALS AND METHODS: Conventional and digital radiographs performed prior to hip arthroplasty in forty one patients. Preoperative templating was performed by four independent observers with manual and digital templates on a Picture Archiving and Communication System (PACS) workstation. In all cases, acetabular cup, femoral stem sizes and length of femoral neck were measured. Intra- and interobserver agreement and predictability of real component size were calculated with weighted kappa analysis and Mann-Whitney test. RESULTS: For acetabular cup and femoral stem size, inter- and intraobserver agreement was substantial, nevertheless, for length of femoral neck, it was poor in both methods. Comparing with the real size, digital templating method showed statistically significant predictability for acetabular cup size (p=0.001). However, there was no significant difference in femoral stem size and the length of femoral neck by both methods (p=0.074, p=0.140). CONCLUSION: Both inter- and intraobserver agreement was similar. However, considering advantage of PACS system and superior predictability of digital templating technique, we recommend the preoperative digital templating in hospital with PACS system.

Relationship between femoral isthmus and selection of femoral prosthesis in total hip arthroplasty / 第三军医大学学报

0.05). Conclusion Isthmus is an essential structure to determine the size of femoral component. The dimension of isthmus correlates fairly well with the size of femoral stem. As a measurement to choose the appropriate femoral implant in total hip arthroplasty, the isthmus-method has the similar accuracy as the common templating.